animal reproduction

4 downloads 209 Views 38MB Size Report
Margaret J. Evans - CDHB, New Zealand. Martha C. Gomez .... Paulo Bayard Dias Gonçalves ...... species (Giles et al., 1993; Smith et al., 2003). Different.
ANIMAL REPRODUCTION Official journal of the Brazilian College of Animal Reproduction v.9, n.3

July/September

2012

Contents Proceedings of the 26th Annual Meeting of the Brazilian Embryo Technology Society (SBTE), August 30th to September 2nd, 2012, Foz do Iguaçu, PR, Brazil.

From the SBTE President

129

From the Scientific Committee Chair

130

Conference papers Impact of using artificial insemination on the multiplication of high genetic merit beef cattle in Brazil J.B.S. Ferraz, J.P. Eler, F.M. Rezende

133

History, evolution and perspectives of timed artificial insemination programs in Brazil P.S. Baruselli, J.N.S. Sales, R.V. Sala, L.M. Vieira, M.F. Sá Filho

139

Bovine semen quality control in artificial insemination centers P. Vincent, S.L. Underwood, C. Dolbec, N. Bouchard, T. Kroetsch, P. Blondin

153

Developmental aspects of early pregnancy in mares C. Meira, J.C. Ferreira, E.S.M. Silva, F.S. Ignácio

166

Monitoring of the last third of gestation and peripartum disorders C.B. Fernandes

173

Newborn adaptations and healthcare throughout the first age of the foal B.R. Curcio, C.E.W. Nogueira

182

Practical aspects for implementing in vitro embryo production and cloning programs in sheep and goats H. Baldassarre

188

From cattle to sheep: a view of the difficulties and success of commercial in vitro production of sheep embryos J.C.B. Silva, W.K. Okabe, A.S. Traldi

195

Preservation of wild feline semen by freeze-drying: experimental model L.C.O. Magalhães, C.M. Melo-Oña, M.J. Sudano, D.M. Paschoal, L.F. Crocomo, C.L. Ackermann, F.C. Landim-Alvarenga, M.D. Lopes

201

Oocyte maturation in bitches L.M.C. Pereira, S.D. Bicudo, M.D. Lopes

205 Support: Fundação de Amparo à Pesquisa do Estado de Minas Gerais

IETS statement on worldwide ET statistics for 2010 B. Stroud, H. Callesen

210

Research in animal reproduction: Quo vadimus? B.D. Murphy

217

Equine chorionic gonadotropin: an enigmatic but essential tool B.D. Murphy

223

Positive and negative effects of progesterone during timed AI protocols in lactating dairy cattle M.C. Wiltbank, A.H. Souza, J.O. Giordano, A.B. Nascimento, J.M. Vasconcelos, M.H.C. Pereira, P.M. Fricke, R.S. Surjus, F.C.S. Zinsly, P.D. Carvalho, R.W. Bender, R. Sartori

231

Comparison of endocrine and cellular mechanisms regulating the corpus luteum of primates and ruminants M.C. Wiltbank, S.M. Salih, M.O. Atli, W. Luo, C.L. Bormann, J.S. Ottobre, C.M. Vezina, V. Mehta, F.J. Diaz, S.J. Tsai, R. Sartori

242

Influences of nutrition and metabolism on fertility of dairy cows R.S. Bisinotto, L.F. Greco, E.S. Ribeiro, N. Martinez, F.S. Lima, C.R. Staples, W.W. Thatcher, J.E.P. Santos

260

Angiogenic and steroidogenic responses of the corpus luteum after superovulatory and stimulatory treatments using eCG and FSH L.A. Fátima, M. Binelli, P.S. Baruselli, A.P. Bonfim Neto, P.C. Papa

273

Improving oocyte quality in cows and heifers - What have we learned so far? P. Blondin, C. Vigneault, A.L. Nivet, M.A. Sirard

281

Postpartum uterine diseases in dairy cows K.N. Galvão

290

Uterine environment and conceptus development in ruminant F.W. Bazer, J. Kim, G. Song, M.C. Satterfield, G.A. Johnson, R.C. Burgardt, G. Wu

297

Modulation of uterine function by endocrine and paracrine factors in ruminants F.W. Bazer, M.C. Satterfield, G. Song

305

Increasing pregnancies following synchronization of bovine recipients G.A. Bó, P.S. Baruselli, R.J. Mapletoft

312

Association between immune function and development of uterine disease in dairy cows K.N. Galvão

318

Large-scale programs for recipients of in vitro-produced embryos L.S.R. Marinho, R.M. Untura, F. Morotti, L.L. Moino, A.G. Rigo, B.V. Sanches, J.H.F. Pontes, M.M. Seneda

323

Several insights on evaluation of semen G.E. Seidel, Jr.

329

Origins and effects of oocyte quality in cattle R. Boni

333

Challenges in work with bovine gametes and embryos H. Callesen

341

Aspects related to the technique and the utilization of sexed semen in vivo and in vitro R.P. Arruda, E.C.C. Celeghini, M.A. Alonso, H.F. Carvalho, K.M. Lemes, D.F. Silva, S.A.F. Rodriguez, F.J. Affonso

345

Control of ovulation in mammals P.B.D. Gonçalves, B.G. Gasperin, R. Ferreira, J.T. Santos

354

Ovum pick-up in cattle: a 25 yr retrospective analysis R. Boni

362

Economic aspects of applying reproductive technologies to dairy herds E.S. Ribeiro, K.N. Galvão, W.W. Thatcher, J.E.P. Santos

370

New applications for bovine IVP technology: from ‘single oocyte culture’ to toxicity screening P.E.J. Bols, I.G.F. Goovaerts, E.P.A. Jorssen, E.M.L. Petro, A. Langbeen, J.L.M.R. Leroy

388

Heat stress induced alteration in bovine oocytes: functional and cellular aspects F.F. Paula-Lopes, R.S. Lima, P.H.B. Risolia, J. Ispada, M.E.O.A. Assumpção, J.A. Visintin

395

Novel bovine embryo transfer technologies in the United States C.R. Looney, J.H. Pryor

404

Paracrine and autocrine factors in the differentiation of the cumulus-oocyte complex J. Buratini, E.S. Caixeta

414

High throughput non-invasive oocyte quality assessment: the search continues P.E.J. Bols, E.P.A. Jorssen, I.G.F. Goovaerts, A. Langbeen, J.L.M.R. Leroy

420

Conference abstracts

426

Abstracts Male Reproductive Physiology and Semen Technology (Abstracts A001 to A020)

436

Folliculogenesis, Oogenesis and Superovulation (Abstracts A021 to A044)

456

FTAI, FTET and AI (Abstracts A045 to A106)

480

OPU-IVP and ET (Abstracts A107 to A155)

542

Embryology, Biology of Development and Physiology of Reproduction (Abstracts A156 to A201)

591

Cloning, Transgenesis and Stem Cells (Abstracts A202 to A221)

637

Supporting Biotechnologies: Cryopreservation and Cryobiology, Image Analysis and Diagnosis, Molecular Biology and “Omics” (Abstracts A222 to A251)

657

Author index to volume 9, n.3, 2012

687

ANIMAL REPRODUCTION Official journal of the Brazilian College of Animal Reproduction v.9, n.3

July/September

2012

Editors-in-Chief Eduardo L. Gastal - Southern Illinois University, Carbondale, USA Luiz Renato de França - UFMG, Brazil Co-Editors-in-Chief José Ricardo Figueiredo - UECE, Brazil Mário Binelli - USP, Brazil Editorial Board Andrzej Bartke - Southern Illinois University, USA Antônio Carlos S. Castro - UFMG, Brazil Arlindo A. Moura - UFC, Brazil Barry D. Bavister - University of New Orleans, USA Bart Gadella - Utrecht University, The Netherlands Brian Setchell - University of Adelaide, Australia Eduardo Bustos Obregón - Universidad de Chile, Chile Eduardo Paulino da Costa - UFV, Brazil Edward L. Squires - Colorado State University, USA Fernanda da Cruz Landim-Alvarenga - UNESP, Brazil George E. Seidel Jr - Colorado State University, USA Goro Yoshizaki - Tokyo University of Marine Science and Technology, Japan Heriberto Rodriguez-Martinez - SLU, Sweden Hugo P. Godinho - PUC/Minas, UFMG, Brazil João Carlos Deschamps - UFPEL, Brazil

J.A. (Lulu) Skidmore - The Camel Reproduction Centre, UAE Katrin Hinrichs - Texas A&M University, USA Keith Betteridge - University of Guelph, Canada Margaret J. Evans - CDHB, New Zealand Martha C. Gomez - Louisiana State University, USA Parvathi K. Basrur - University of Guelph, Canada Peter J. Broadbent - UK Rex A. Hess - University of Illinois, USA Ricardo S. Calandra - IMBICE, IBYME, Argentina Richard Fayrer-Hosken - University of Georgia, USA Rüdiger W. Schulz - Utrecht University, The Netherlands Stanley P. Leibo - University of New Orleans; Audubon Research Center, USA Sue M. McDonnell - University of Pennsylvania, USA Telma M.T. Zorn - USP, Brazil William R. Allen - University of Cambridge, UK Wilma de Grava Kempinas - UNESP, Brazil

Proofreader: Keith Haag, Southern Illinois University, Carbondale, IL, USA Secretaries: Maria Helena Chaves da Silva, Eunice de Faria Lopes Animal Reproduction publishes reviews, original articles, and short communications related to the basic, applied and biotechnological aspects of animal reproductive biology. Manuscripts should be submitted online to the Editor-in-Chief http://www.cbra.org.br/portal/index.htm. Instructions to Authors are available at http:// http://www.cbra.org.br/portal/index.htm. Animal Reproduction (ISSN 1806-9614 printed; 1984-3143 online) is published quarterly and wholly owned by the Brazilian College of Animal Reproduction (Colégio Brasileiro de Reprodução Animal - CBRA). Subscriptions and renewals are based on the calendar year. Printed versions of the journal are freely available to the members of the CBRA and electronic versions are available at the journal website. All the correspondence should be sent to the following address: Editor-in-Chief, Animal Reproduction Colégio Brasileiro de Reprodução Animal - CBRA Alameda das Princesas, 1275 - Bairro São José - 31275-180 Belo Horizonte, MG, Brazil. Phone: +55(31)3491-7122, Fax: +55(31)3491-7025, E-mail: [email protected], Website: http://www.cbra.org.br/portal/index.htm Animal Reproduction, v.1- , n.1- , 2004Belo Horizonte, MG, Brazil: Colégio Brasileiro de Reprodução Animal, 2004Quarterly. ISSN 1806-9614 (printed); 1984-3143 (online) 1. Animal reproduction - Periodicals. I. Colégio Brasileiro de Reprodução Animal. II. Brazilian College of Animal Reproduction. CDU - 636.082.4 (81) (05) - AGRIS L10

Indexed in: Biological Abstracts Biosis Previews CABI Abstracts Current Contents: Agric Biol Environ Sci Directory of Open Access Journals (DOAJ) CAPES/Qualis

Proceedings of the 26th Annual Meeting of the Brazilian Embryo Technology Society (SBTE), August 30th to September 2nd, 2012, Foz do Iguaçu, PR, Brazil. From the SBTE President Dear Colleagues, We are pleased to announce the Proceedings of the 26th Annual Meeting of the Brazilian Embryo Technology Society (SBTE). The aim of our meeting is to present and discuss the recent developments and ideas in biotechnology of reproduction and to promote cooperation and knowledge exchange among scientists, researchers and practitioners in animal reproduction and related sciences. In the 26th SBTE Meeting our main aspiration is to maintain the scientific quality that we have all become used to, while at the same time adapting to new demands of the society and introducing innovation. In 2012, our proceedings will be published in the international journal Animal Reproduction, considered the most relevant Latin America scientific journal in our area. We would like to thank the extraordinary support from the Editors and staff of this Journal and to the CBRA (Colégio Brasileiro de Reprodução Animal) to embrace this collaboration with SBTE. The current SBTE meeting is a joint event with the Brazilian Artificial Insemination Society (ASBIA) and the South American Research Consortium on Cloning and Transgenesis in Ruminants. We have organized two symposia with these Societies, that will be presented at this year’s SBTE meeting. We understand that promotion of combined events consists of a great opportunity for intellectual collaboration among scientists, researchers, professionals and students from Brazil and abroad. We upgraded the lecture sessions structure of our event. All plenary sessions will be followed by concurrent scientific and applied presentations related to the same theme of the session. These combined presentations will make it possible for the attendee to follow specific aspects of the theme, according to the professional interest. We would like to thank CAPES, CNPq and FAPESP, as well as to the pharmaceutical and veterinary equipment industry and the farmers to support our event. Without their generosity it would not have been possible to make our meeting come true. We will be pleased to have you at our event. We sincerely hope that all those attending will enjoy the 26th Annual Meeting of SBTE in Foz do Iguaçu, PR, Brazil. Pietro S. Baruselli President of the SBTE (2012-2013)

Anim Reprod, v.9, n.3, p.129, 2012

129

Proceedings of the 26th Annual Meeting of the Brazilian Embryo Technology Society (SBTE), August 30th to September 2nd, 2012, Foz do Iguaçu, PR, Brazil. From the Scientific Committee Chair Greetings and welcome to the 26th SBTE Annual Meeting! This year the Scientific Committee made an extra effort to put together a well-balanced and interesting program for all members of the society. This is not an easy task, especially because our society’s hallmark is its diversity. We invited world-class speakers and challenged them to deliver their most recent findings on embryo technology-related fields. The main program was divided in four sessions, one for each of the main biologic components involved in embryo technology: the ovary, the uterus, the gametes and the embryo itself. In the first half of each session, speakers were carefully picked to deliver contents of general interest to the society. In the second half, attendees will choose between two concurrent sessions, one focused on more basic aspects (“SBTE science”) and the other emphasizing the more applied aspects (“SBTE technology”) of that session’s topic. The pre-conference workshops present all new material and should repeat the success of previous meetings. In addition to the talks, the poster session this year received a lot of attention from the organizers. There will be more time for viewing and discussing posters and we selected a spacious ballroom in the hotel to house the poster session. The SBTE wants to thank all members that sent their best work to be presented at this meeting. The real value of SBTE is the scientific and technologic progress it brings to the Brazilian society. By presenting your findings at SBTE we can measure the contributions SBTE brings to our country and the world. Next, SBTE wants to acknowledge the speakers, for putting a lot of effort on the preparation of excellent manuscripts and lectures to be delivered at this year’s meeting. Undoubtedly, considering the breadth and depth of the information presented in this volume, it is due to become an international reference for years to come. Finally, there is a long list of people that made the SBTE proceedings a high priority for the last few months and that SBTE needs to thank enthusiastically. This list includes all folks from the SBTE administrative board, abstract session coordinators, abstract reviewers, manuscript reviewers and scientific editors. SBTE is deeply grateful to the editorial board of the journal Acta Scientiae Veterinariae and its Chief Editor, Dr. Laerte Ferreiro, for having published the SBTE proceedings for many years. Most specially, we need to thank the editors and staff at the Animal Reproduction journal, that, under the structure of the Colégio Brasileiro de Reprodução Animal, helped SBTE tremendously to put together this year’s meeting proceedings. We hope you find this volume informative and useful. See you in Foz do Iguaçu! Mario Binelli, PhD Chairman of the SBTE Scientific Committee (2012-2013)

130

Anim Reprod, v.9, n.3, p.130, 2012

Proceedings of the 26th Annual Meeting of the Brazilian Embryo Technology Society (SBTE), August 30th to September 2nd, 2012, Foz do Iguaçu, PR, Brazil. SBTE Executive Board (2012-2013) Pietro Sampaio Baruselli (President) Margot Alves Nunes Dode (Vice-president) Mayra Elena Ortiz D’Avila Assumpção (1st Secretary) Anneliese de Souza Traldi (2nd Secretary) Claudia Barbosa Fernandes (1st Treasurer) Eneiva Carla Carvalho Celeghini (2nd Treasurer) Ricardo José Garcia Pereira (Communications Director) Rodrigo Vitorio Alonso (Business Director) Márcio Ferreira Mendanha (Information Technology Specialist) Osnir Yoshime Watanabe (Industry Liaison) Carlos Alberto Rodrigues (Veterinary Practitioners Representative) Mario Binelli (Scientific Committee Chair) Proceedings General Editor Mario Binelli Scientific Editors Eduardo Gastal Fernando Silveira Mesquita Workshop Chairs Anneliese de Souza Traldi Cezinande Meira Flávio Vieira Meirelles James D. Murray José Luiz Rigo Rodrigues Lino Nogueira Rodrigues Filho Marcelo Bertolini Maria Denise Lopes Pietro Sampaio Baruselli Awards Committee Chairs José Buratini Jr. José Eduardo P. Santos José Luiz Moraes Vasconcelos Marcelo Fabio Gouveia Nogueira Mario Binelli Manuscript Reviewers Alfredo Antoniazzi Barry Hinton Bruce D. Murphy Claudia Lima Verde Leal Fabíola Freitas de Paula Lopes Fernanda da Cruz Landim Fernando Silveira Mesquita Flávia Lombardi Lopes Fuller W. Bazer Gabriel A. Bó George Seidel Anim Reprod, v.9, n.3, p.131-132, 2012

Gustavo Ferrer Carneiro Henrik Callesen José Buratini Jr. José Eduardo P. Santos José Fernando Garcia José Luiz Moraes Vasconcelos Lilian de Jesus Oliveira Luciano Andrade Silva Marcelo Alcindo de Barros Vaz Guimarães Marcelo Bertolini Marcelo Rezende Luz Margot Alves Nunes Dode Milo C. Wiltbank Peter Bols Peter J. Hansen Reuben J. Mapletoft Roberto Sartori Filho Valerio Portela William W. Thatcher Zvi Roth Abstract Session Coordinators Fernanda da Cruz Landim Guilherme de Paula Nogueira Luiz Renato França Marcelo Bertolini Marcelo Marcondes Seneda Maurício Machaim Franco Roberto Sartori Filho Abstract Reviewers Alexandre Floriani Ramos Alexandre Henryli de Souza Alexandre Rossetto Garcia Anibal Ballarotti do Nascimento Anthony César de Souza Castilho Antônio Carlos Santana Castro 131

Antônio de Pinho Marques Jr. Arlindo de Alencar Araripe Moura Bruna da Rosa Curcio Carlos Antônio Carvalho Fernandes Carlos Eduardo Ambrósio Carlos Frederico Martins Carlos José Hoff de Souza Cezinande Meira Christina Ramires Ferreira Claudia Barbosa Fernandes Claudia Lima Verde Leal Claudia Maria Bertan Membrive Cristiano Feltrin Daniel R. Arnold Evelyn Rabelo Andrade Fabiana Bressan Fabiana de Andrade Melo Sterza Fabiana Forell Fabíola Freitas de Paula Lopes Felipe Perecin Felipe Zandonadi Fernanda Landin Alvarenga Flávia Lombardi Lopes Flávio Vieira Meirelles Frederico Ozanam Papa Gabriel A. Bó Gabriel Ribas Pereira Gisele Zoccal Mingoti Guilherme Pugliesi Gustavo Martins Gomes dos Santos Henderson Ayres Hugo Pereira Godinho Hymerson Costa Azevedo Ian Martin Ivo Pivato Jose Luiz Moraes Vasconcelos José Antonio Dell’aqua Jr. José Buratini Jr. José Carlos Ferrugem Moraes José Eduardo P. Santos José Henrique F. Pontes José Luiz Rigo Rodrigues José Nélio S. Sales João Carlos Pinheiro Ferreira João Henrique Moreira Viana

Juliana Lopes Almeida Kaio César Simiano Tavares Klibs N. Galvao Lígia Pegoraro Lilian Tamy Iguma Lindsay Unno Gimenes Luciana Relly Bertolini Luiz Sergio Almeida Camargo Manoel Francisco de Sá Filho Mara Iolanda Batistella Rubin Marc Henry Marcella Pecora Milazzotto Marcelo Fabio Gouveia Nogueira Marcelo Marcondes Seneda Margot Alves Nunes Dode Maria Denise Lopes Marilu Constantino Max Mayra Elena Ortiz D`Avila Assumpção Nelcio Antonio Tonizza de Carvalho Nereu Carlos Prestes Paulo Bayard Dias Gonçalves Pedro Manuel Aponte Garcia Ricarda Maria dos Santos Ricardo C. Chebel Roberta Garbelini Gomes Ronaldo Luis Aoki Cerri Rui Machado Sabine Wohlres Viana Sony Dimas Bicudo Vilceu Bordignon Wilma de Grava Kempinas Staff Estela Rose Araujo Júlia Maria Baldrighi Laís Mendes Vieira Luciana Simões Rafagnin Marinho Maíra Bianchi Rodrigues Alves Milena Lopes Oliveira Moana Rodrigues França Rodrigo Vasconcellos Sala Roney dos Santos Ramos Shirley Andrea Florez Rodriguez Thais Rose dos Santos Hamilton

Sponsors Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Regional de Medicina Veterinária do Paraná (CRMV-PR) Conselho Regional de Medicina Veterinária do Estado de São Paulo (CRMV-SP) Conselho Federal de Medicina Veterinária (CFMV) Ministério da Agricultura, Pecuária e Abastecimento (MAPA) Banco do Brasil (BB)

132

Anim Reprod, v.9, n.3, p.131-132, 2012

Anim Reprod, v.9, n.3, p.133-138, Jul./Sept. 2012

Impact of using artificial insemination on the multiplication of high genetic merit beef cattle in Brazil J.B.S. Ferraz1,3, J.P. Eler1, F.M. Rezende2 1

University of São Paulo, FZEA, Department of Basic Sciences, Pirassununga, SP, Brazil. Universidade Federal de Uberlândia, Instituto de Genética e Bioquímica, Patos de Minas, MG, Brazil.

2

Abstract Information about the Brazilian beef cattle industry is provided and the effects of massive use of genetically superior bulls, semen and embryos is simulated to show their important contribution to that industry, as a way to improve the low productivity levels observed in Brazil, one of the leaders in beef exports in the world. Any increase on the use of better genetics will cause a very significant economic impact in the Brazilian beef industry. Amounts as high as US$ 342 million/yr may be reached in the near future with the growing utilization of fixed time artificial insemination (FTAI), considering only the direct effects of weaning and yearling weights. These values will be even higher if reproductive traits are considered as selection criteria. The indirect effects, which are clearly underestimated in this simulation study, are much more important than the direct ones. The increase on the income of the industry could reach significant amounts, without the need of opening new areas for cattle grazing or destroying forests and devastating the environment. Keywords: beef industry, cattle, environment, FTAI reproduction. Introduction and objectives Brazil is the largest South-American country with 190.8 million inhabitants (Instituto Brasileiro de Geografia e Estatística - IBGE, 2011). It has an area of 8,514,876.6 km², equivalent to 47% of South American territory, and possess close to 12% of the fresh water reserves of the planet. It grows at 1.4% rate per year, with a gross national product (GNP) in 2011 of US$2,250 billion (RS$4,143 billion) and a per capita product of US$11,792.00 (IBGE, 2012a, b), being considered the world’s 7th economy. Close to 15.6% of the population (29.3 million people) still live in rural areas, while around 23% of the population works for the Brazilian agribusiness. Brazil has relatively low prices for land and labor and no extreme weather conditions, which helps to build the competitive edge for Brazilian agricultural and animal products. As a counterbalance, socio-economic problems, unsolved for centuries, span several dimensions and reach hazardous levels (Ferraz and Felício, 2010). Brazilian livestock and agriculture production _________________________________________ 3 Corresponding author: [email protected]; [email protected]

is meaningful. According to data from Food and Agriculture Organization and the U.S. Department of Agriculture, based on 2005 crops and 2004 exports, the country is an important producer of livestock, besides beef (Ferraz and Felício, 2010). As related to broiler, Brazil is responsible by 15.5% of world production and 40.7% of exports. In the pork business, the country accounts to close to 3% of world’s production, but is the 4th major exporter, embracing 15% of the international market. The country is the top exporter for several agricultural products like soybean (24% of world’s production and 33.4% of total trade), sugar cane (32.5% of total production and 42.4% of exports), orange juice (29.7% of total production and 57% of exports) and coffee (28.3% of total production and 23% of exports). Brazilian agribusiness was responsible for 31% of the GNP, 37% of the jobs and 42% of the total exports in 2003. More details on the Brazilian economy can be found in www.ipeadata.gov.br. More recent data indicate that the agribusiness sector of Brazilian economy is responsible for 22.74% of GNP (Centro de Estudos Avançados em Economia Aplicada - CEPEA/USP, 2012; Agência Brasil, 2012). The superavit of the Brazilian agribusiness in 2011 was close to US$77.4 billion, while the country’s superavit reached only US$29.8 billion (Agência Brasil, 2012). The most representative part of the Brazilian agribusiness in terms of net income is the beef industry, followed by the sugar cane, soybean, milk and cotton (Confederação da Agricultura e Pecuária do Brasil CNA and CEPEA/USP, 2012). Livestock production in Brazil is extremely significant. The different livestock population sizes are: beef and dairy cattle (209.5 million animals; IBGE, 2011), swine (32.39 million), and goat and sheep (9.09 million and 14.18 million, respectively; Ferraz and Felicio, 2010). Important information about the Brazilian beef and dairy business can be found in Ferraz and Felício (2010), and Fries and Ferraz (2006). Some highlights of the Brazilian beef industry: • • •

The population size is around 210 million heads of cattle; 80% of the population has influence of zebu cattle (Bos indicus), according to the Brazilian Zebu Breeders Association (ABCZ, www.abcz.com.br); Although around 80% of the Brazilian cattle population has Bos indicus contribution, only less than 7,000 purebred Zebu animals have been

Ferraz et al. Impact of use of high genetic merit animals.











• • •





134

imported from India in the last century. The importation from India was forbidden in 1962. The Brazilian Bos indicus population was, mostly, upgraded from Bos taurus cows, brought to South America by Portuguese and Spanish colonizers; The beef breed with the largest number of animals in Brazil is Nelore (standard/horned and polled), followed by Guzerat and Gir. Indubrasil, a Bos indicus Brazilian breed originated from crossbreeding among other Zebu breeds, decreased sharply in numbers while another local pooled breed, Tabapuã showed a steady increase; Purebred Bos taurus is raised in Southern Brazil, a region of temperate climate. Portion of the meat produced by these animals is exported and portion supplies special domestic market niches; Crossbreeding is moderately used in all regions of the country, but the highest the Bos taurus contribution is, the poorer is the adaptability to tropical environment, especially to ectoparasites (flies and ticks), which causes important impact in production costs; The major taruine breeds used in beef crossbreeding are Angus and Red Angus, Simmental, Charolais, Polled Hereford, Limousin and Braunvieh, among others; Synthetic breeds, like Brangus, Braford, Canchin/Charbray and Santa Gertrudis are also used. In the last decade, Bos taurus breeds, adapted to tropical environment, like the Brazilian Caracu, showed renewed interest. Breeds like Senepol and Bonsmara were introduced more recently, as well as composite programs (e.g.: Montana Tropical) which started to grow in the country; Uses 140 million hectares of land (all other crops, together, use 75 million hectares) distributed among 1,8 million farms; Generates around 7 million direct or indirect employments (Pineda, 1997), corresponding to 8.3% of the 82 million current job posts; Around 39.5 million heads were slaughter in 2011 and only 8.6% were finished in feedlots (ABIEC, 2012; Nogueira, 2012), ratifying the importance of pasture production system in the country; Brazilian beef production is the second largest in the planet. It produced 9.1 million tons of carcass weight equivalent (cwe) in 2011, while the USA produced a little over 12 million tons, EU-27 produced around 8.1 million tons, Australia and Argentina produced between 2 to 3 million tons and India, which did not appear in statistics before, produce around 2.5 million tons cwe (Associação Brasileira das Indústrias Exportadoras de Carne ABIEC, 2012); The number of beef processing plants and abattoirs is around 750, but is under fast shrinking. Some large industrial plants, processing more than 2,000 animals/day, with modern equipment are in



• • • •







operation, mainly in midwestern part of country; Regional distribution of the Brazilian herd is 19.7% in North, 13.8% in Northeast, 18.5% in the Southeast, 13.6% in South and 34.4% in the CenterWest (Midwestern region; IBGE, 2011); More than 180 million head are located in areas free of foot-and-mouth disease (FMD) and are regularly vaccinated; Roughly 170 million animals are used for beef production and 40 million for dairy and/or dualpurpose; Cattle population has around 70 million cows, 55 million of them used in beef production and the rest in dual purpose or dairy production; Artificial insemination (AI) studs sold 11.9 million doses of semen in 2011 (around 7 million doses for beef breeds and 4.9 million for dairy purpose). Close to 57% of the beef doses of semen were produced locally in Brazilian AI studs and 43% imported. Semen sales rank by breed was: Nelore (horned and polled) close to 3.3 million, Aberdeen Angus 1.8 million and Red Angus 0.57 million semen doses, followed by several other Bos indicus and Bos taurus breeds (Associação Brasileira de Inseminação Artificial - ASBIA, 2012). Statistics on Brazilian cattle population size and productivity can be found in Ferraz (1996, 1998); Velloso (1996) and Ferraz and Felicio (2010); Considering 1.5 doses/beef cow bred, on average, 4.67 million beef cows were inseminated, representing 11.8%, one of the largest proportions in the world’s beef industry; There are close to 3 million beef bulls in service, which points to the need of around 450,000 young replacement bulls/yr. All the genetic evaluation programs in the country together sell around 15,000 genetic superior bulls/yr, less than 3.5% of the needs for replacement bulls. This means that more, better and larger breeding programs are needed; The Brazilian beef industry exports over US$1.1 billion in leather and US$1 billion in shoes, produced in 4,200 shoe companies and 560 tanning plants. The Brazilian beef market

Domestic market absorbs close to 7.57 million tons/yr cwe, with a per capita consumption of 39 kg cwe/person/yr (Conselho Nacional da Pecuária de Corte - CNPC, 2011). This means that 82% of total production is absorbed by the internal market. Brazil is one of the largest beef exporters in the world (1.65 million tons cwe in 2010; CNPC, 2011; ABIEC, 2012). In the same year, cwe exports from different countries were: Australia 1.35 million tons, USA 1.4 million tons, India 1 million tons, New Zealand 478 thousand tons, Uruguay 350 thousand tons EU-27 297 thousand tons and Argentina 270 tons, Anim Reprod, v.9, n.3, p.133-138, Jul./Sept. 2012

Ferraz et al. Impact of use of high genetic merit animals.

(ABIEC, 2012). Brazilian beef business was responsible for around 22% of total beef trades in the world. The low productivity levels of Brazilian beef industry There are several reasons to explain the very low productivity rates of the Brazilian cattle industry. The first one is how the herd is fed. The large majority of Brazilian beef herds is fed under tropical pastures condition. That also happens with an important percentage of dairy cows, which are in fact beef cows bred for double purpose, being milk a by-product of calf production. Tropical pastures have a clearly limited production season which coincides with the raining season. The dry season lasts 6 to 7 months, and it is characterized by limited availability of feed, that is also poor quality and presents a low percentage of crude protein. During the dry season, cattle typically lose weight, taking the overall productivity, measured as kg of meat per hectare, to very low levels. Health status can be mentioned as a second major cause of low productivity. Bacterial, viral, protozoa and fungi diseases are distributed throughout the country. Foot and mouth disease, brucelosis and other reproductive abnormalities contribute to decrease the production in very limited areas. A third important reason is the low educational

level of farmers and ranchers, that challenges the dissemination of new technologies. Associated with this problem, a fourth reason should be emphasized: there are very few efforts of technology diffusion, due to lack of communication among Universities, Research Centers and ranchers. This is a problem that can be attributed to the local institutions, which do not have a clear and strong extension policy. Among the important reasons of low productivity, the genetic status of the herd can be suggested as the last, but not least important one. The vast majority of Brazilian cattle are Zebu based animals, which had very few selection efforts and, consequently, an average genetic merit lower than Bos taurus for beef and milk production. The Bos taurus breeds have many decades of selection. Genetic evaluation programs are rapidly becoming very important in the country, with very large efforts directed to Nelore, Dairy Gir, Angus, Hereford, Brangus, Braford and Braunvieh breeds. Table 1 presents the evolution of several productivity indexes of the Brazilian herd, extracted from Barcellos (2011). This information confirms that important changes are happening in the Brazilian beef industry, but the productivity levels are still low and need to be improved. This opens a unique opportunity for the use of genetically evaluated bulls and cows, leading to quick responses through their progenies and huge increments in efficiency.

Table 1. Evolution of productivity indexes of the Brazilian beef industry. Index 1996 Birth rate (%) 51.90 Mortality up to weaning (%) 9.60 Age at first parity (yr) 4.70 Age at slaughter (yr) 4.66 Holding capacity (A.U./ha) 0.52 % of slaughter 17.95 Source: Barcellos (2011). What is the participation of bull’s cost in the cost of a calf? The participation of a bull’s cost in the cost of a calf is highly relevant, because it should be compared with the cost of artificial insemination. If a bull is bought for US$2,000.00 and has an annual cost of maintenance of US$500.00, its total cost along six years of work life as a sire is around US$5,000.00. If that bull produces 100 progeny calves under natural mating, the cost per calf is around US$50.00 without taking into account its genetic merit or eventual risks such as diseases or reproduction problems. This is a very high cost, as compared to the sale’s price of a calf, which is nowadays around US$380.00 (13.2%) and there is little warranty about the genetics the bull is going to transmit. The hazard is even worse if one considers the genes that that bull will Anim Reprod, v.9, n.3, p.133-138, Jul./Sept. 2012

2006 67.80 6.51 3.36 3.34 0.70 23.23

Variation (%) 31 -32 -29 -28 34 29

spread in the population, which may cause years of regress in the genetic level. For instance, the use of nongenetically evaluated bulls allows their genes, which may not be favorable to productivity (as the ones related to reduced fertility or late maturity), to stay in the population, or even increase in frequency, as the vast majority of females are kept for replacement. This rational is a very strong justification for using AI or genetically evaluated replacement bulls. CEIP: a strong tool to identify genetically superior beef animals In the 90’s, the Brazilian Ministry of Agriculture (MAPA, www.agricultura.gov.br) started a very interesting program to promote the use of genetically superior animals in the cattle industry, called Special Certificate of Identification and Production 135

Ferraz et al. Impact of use of high genetic merit animals.

(CEIP). This program allowed bulls and cows to receive the same legal treatment as animals registered by Breeders Associations, without necessarily being registered. However, in order to receive the certification, the animal must have come from a program that performs controlled data recording and genetic evaluation, allowing only 20 to 30% of the best animals to be eligible to have the CEIP. Seventeen programs, from several breed groups were allowed to issue CEIPs in 2009 (http://www.agricultura.gov.br/ comunicacao/noticias/2009/10/certificacao-selecionabovinos-de-alta-produtividade) and about 15,000 animals received the certificate that year. Objectives Based on the impressive figures of Brazilian beef industry and due to the very limited number of genetically evaluated bulls to mate the 55 million cows from beef herds, the objective of this paper was to simulate the economic impact in beef production in Brazil if genetically superior bulls, identified through genetic evaluation programs could be disseminated in the herd by means of massive use of AI or natural mating. Material and Methods Massive use of AI or genetically evaluated replacement bulls A simulation process was developed to estimate the direct effects of increasing 25, 50, 75, 100, and 200% the current level of artificial insemination or the use of genetically evaluated replacement bulls. Several well-managed and very productive beef ranches in Brazil work with artificial insemination levels as high as 95%, and some of those farms have more than 10,000 cows. There are several companies and farms in Brazil that apply artificial insemination to more than 20,000 cows/yr. The total number of beef cows in Brazil is 55 million, and from those, 4.67 million are inseminated. The number of genetically superior bulls in natural

mating programs is about 50,000, and these bulls mate only around 1.0 to 1.5 million cows/yr. A total of 6 million beef cows, mated by genetically superior bulls, were considered in the simulation. A weaning rate of 80% and a post-weaning mortality of 1% were considered. All weaned animals that survived until 18 months were considered as marketed animals. Besides that, the increasing use of fixed time artificial insemination (FTAI), which reached more than 5,000,000 cows in 2010 (Ferreira, 2011) is causing a massive impact in the level of productivity of the Brazilian beef industry, as the semen used is in the vast majority from genetically evaluated bulls, usually situated among the top 20-30% superior bulls for economic relevant traits. The figures of the 2011/2012 breeding season are not yet available, but probably more than 6.5 million cows have been inseminated using FTAI protocols. To estimate the impact of using genetically superior bulls in natural mating or AI, only two traits were considered in this study: weaning weight (important for ranchers who sell calves) and yearling weight (a good predictor of weight to market), and the average genetic merit of cows were considered to be zero. The average EPD (expected progeny difference) of the bulls for weaning weight was arbitrarily set to +10.0 and for yearling weight (measured at 18 months of age) set to +19.5 kg (in both cases the average of the 30% better replacement bulls born in 2009 in an existing selection program was considered). The effect of increasing the use of AI or genetically superior replacement bulls was considered the same. In order to evaluate the economic effect of using higher genetic level animals, price of weaned calves was considered US$1.85/kg, while price of finished animals was set to US$1.50, the current prices in the Brazilian industry in June/2012. Results The quantitative and economic impact of the simulated increase in the percentage of cows inseminated is shown in Table 2.

Table 2. Increase in production of Brazilian beef industry as a function of the expansion of using artificial insemination or genetic superior replacement bulls in the Brazilian beef herd in 2012. Increase on percentage of cows mated by genetically Trait superior bulls or through AI 30 50 75 100 200 Nº of cows mated by superior bulls (x1000) 7,800 9,000 10,500 12,000 18,000 Rate of cows mated by superior bulls (%) 14.2 16.4 19.1 21.8 32.7 Nº of calves weaned (x1000) 6240 7,200 8,400 9,600 14,400 Extra weight of weaned calves sold (1000 kg) 31,200 36,000 42,000 48,000 72,000 Extra value of weaned calves (US$1000) 57,720 66,600 77,700 88,800 133,200 Nº of steers slaughtered (x1000) 3,089 3,564 4,158 4,752 7,128 Extra weight of slaughtered steers (1000 kg) 60,232 69,468 81,081 92,664 138,996 Extra value of slaughtered steers (US$1000) 90,347 104,247 121,622 138,996 208,494 Extra value of progeny from superior bulls (US$1000) 148,067 170,847 199,322 227,796 341,694 136

Anim Reprod, v.9, n.3, p.133-138, Jul./Sept. 2012

Ferraz et al. Impact of use of high genetic merit animals.

The use of genetic superior material in the current cows in the Brazilian herd, by means of AI or natural mating, if increased, would cause an increase in revenues between US$148 to 342 million, considering only direct revenues of 50% from weaned calves or marketed animals. Reproductive traits and other economically relevant characteristics were not included in the simulation. Several other direct benefits could be added to these results, such as better quality products leading to better prices, benefits from other products or traits not considered here (like leather for instance) etc. However this simple simulation process provides a clear illustration of the impact of using better genetics in beef herds. Massive use of AI or genetically evaluated replacement bulls - The most important indirect effects Despite of the direct effects, it is very important to emphasize that the main profits that come out from the use of AI or genetic superior replacement bulls in medium to low management level herds, like the average herd in Brazil, does not come from the direct impact of using genetically proved animals, which certainly increases the production level of the population. The indirect effects are much more important. To be able to use AI, or to decide to use genetically superior bulls in their herds, ranchers have to reach several pre-established standards in nutrition, health, organization and information, besides the training of human resources. To reach those levels, which are much higher than the current situation in average Brazilian farms, an increase in production should occur, resulting in very important economic effects.

It is not easy to measure gains due to the decrease of losses caused by poor feeding systems, subclinic diseases, and lack of organization, information, administration and management. However, it is clearly possible to reach good standards by international conditions. The simulation pointed in Table 2 considered the quantitative and economic impact verified after reaching the goals established for each trait. The criteria to define the goals were arbitrary, but considered as an intermediate level between the average Brazilian farm and the level of ranches from developed countries. Table 3 presents productivity levels and goals for improving the system in the short term. It is very important to consider that the goals proposed are perfectly reachable. The levels suggested for cows pregnant/cows exposed, mortality, animals slaughtered/total herd, mortality and average carcass weight are being effectively achieved by a significant percentage of ranchers in the country. It is necessary to disseminate knowledge and technology to the small ranchers, through a comprehensive extension service, which should be pushed forward by efforts to increase AI levels and to better choose replacement bulls and heifers. Several other indirect effects could be proposed and simulated, with very important effects. Leather and shoes industries are only two examples. It is important to point out that the values of the additional production obtained through the increase of levels of nutrition, health, technology, organization and extension, although hard to measure, are expressed in billions of dollars, as the amount of animals involved are very large in Brazil. Other indirect effects, as meat quality and others related with the consumers, as described by Pineda (1997), would cause substantial changes and add value to the cattle industry. The organization of the industry by integrating all the chain is another effect (Camargo, 1997).

Table 3. Quantitative and economic impact in cattle industry, considering the achievement of goals related to indirect effects of AI. Trait Average Developed Growth in Value (US$ level in countries Goal production million) Brazil level (1000 t) Cows pregnant/cows exposed per yr (%) 65 85 75 3,200 4,800 Beef animals slaughtered/total beef herd (%) 23 32 30 12,400 18,600 Mortality from birth to slaughter (%) 8 3 3 360,000 666,00 Increase in average carcass weight (kg) 201 variable 230 1,200,000 1,800,00 The simulations and arguments presented herein could be extended to the other countries of Mercosul or any other country, using their statistics. The impact in any of those countries should be different, as a function of each country’s current condition. In a globally integrated economy approach, a strong regional program to increase the use of AI and superior replacement bulls should be adopted, with very important results to the cattle business. Anim Reprod, v.9, n.3, p.133-138, Jul./Sept. 2012

Implications A critical analysis of the direct and indirect impacts of increasing AI and genetically superior replacement bull’s utilization shows that the value of these actions is remarkable. Any increase in the use of genetically superior animals will cause very significant economic effects in the Brazilian beef industry, reaching values as high as US$342 million with only 200% of 137

Ferraz et al. Impact of use of high genetic merit animals.

increment which, with the fast growth of FTAI, is going to be reached in near future. This refers only to direct effects of weaning and yearling weights. These values will be largely higher if reproductive traits were considered as selection criteria. The indirect effects, which were clearly underestimated in this simulation study, are much more important than the direct ones. The increase on the income of the industry could reach immense values, without opening new agricultural frontiers, to increase areas for cattle grazing, avoiding cutting trees or devastating the environment. The use of genetic superior animals, embryos or semen is the best way to improve productivity and reduce the impact in the environment, due to the significant increment in production that can be achieved without increasing the number of animals. References Agencia Brasil. 2012. Com US$ 94,6 bilhões em exportações, agronegócio tem melhor resultado desde 1997. Available on: http://agenciabrasil.ebc.com.br/ noticia/2012-01-10/com-us-946-bilhoes-em-exportacoesagronegocio-tem-melhor-resultado-desde-1997. Accessed on: April 15, 2012. Associação Brasileira das Indústrias Exportadoras de Carne (ABIEC). 2012. Available on: http://www.abiec.com.br/download/stat_mercadomundi al.pdf. Barcellos R. 2011. Remuneration for carcass quality: special cuts, precocity and carcass finish. In: SIMPEC 2011: VII Simpósio de Pecuária de Corte; II Simpósio Internacional de Pecuária de Corte, 2011, Lavras, MG. Lavras, MG: UFLA. CD-ROM. Associação Brasileira de Inseminação Artificial (ASBIA). 2012. Available on: http://www.asbia.org.br/ novo/home/. Accessed on: July 23, 2012. Camargo P. 1997. Aliança na carne bovina. In: Anais do IV Simpósio o Nelore do Século XXI, Uberaba, MG, Brazil. Uberaba, MG: ABCZ-ACNB. p. 45. (abstract). Centro de Estudos Avançados em Economia Aplicada (CEPEA-USP). 2012. PIB Agro CEPEA-USP/CNA. Available on: http://www.cepea.esalq.usp.br/pib/Accessed on: April 15, 2012. Confederação da Agricultura e Pecuária do Brasil (CNA), Centro de Estudos Avançados em Economia Aplicada (CEPEA-USP). 2012. Análise do PIB das cadeias produtivas de algodão, cana-de-açúcar, soja, pecuária de corte e de leite no Brasil. Available on: http://www.canaldoprodutor.com.br/sites/default/files/ pib-cadeias-produtivas-web.pdf. Accessed on: April 15, 2012. Conselho Nacional de Pecuária de Corte (CNPC).

138

2011. Available on: http://www.cnpc.org.br. Accessed on: July 23, 2012. Ferraz JBS. 1996. Impacto econômico na pecuária de leite e corte do Brasil, com o aumento da utilização de inseminação artificial. Rev Bras Reprod Anim, 20:95-98. Ferraz JBS. 1998. Artificial insemination and its impact in Latin America: the Brazilian example. In: Proceedings of the IV SIPAR Follow up Seminar on Animal Reproduction and Biotechnology, 1998, Belém, PA. Belém: UFPA. pp. 80-86. Ferraz JBS, Felicio PE. 2010. Production systems: an example from Brazil. Meat Sci, 84:238-243,. Ferreira MM. 2011. O crescimento da IATF e seu impacto na cadeia produtiva da carne. Available on: http://www.beefpoint.com.br/radares-tecnicos/reproducao/ o-crescimento-da-iatf-e-seu-impacto-na-cadeia-produtivada-carne-72651. Accessed on: June 28, 2012. Food and Agriculture Organization (FAO). 2009. Available on: Accessed on: February 3, 2009. Fries LA, Ferraz JBS. 2006. Beef cattle genetic programs in Brazil. In: Proceedings of the 8th World Congress on Genetics Applied to Livestock Production. Belo Horizonte, Brazil: The Congress. CD-ROM. Instituto Brasileiro de geografia e Estatística (IBGE). 2011. PPM 2010: rebanho bovino nacional cresce 2,1% e chega a 209,5 milhões de cabeças. Available at: http://www.ibge.gov.br/home/presidencia/ noticias/noticia_visualiza.php?id_noticia=2002&id_pag ina=1. Accessed on April 15, 2012. Instituto Brasileiro de Geografia e Estatística (IBGE). 2012a. Abate de animais, produção de leite, couro e ovos. In: http://www.ibge.gov.br/home/ estatistica/indicadores/agropecuaria/producaoagropecua ria/abate-leite-couro-ovos_201104_1.shtm. Accessed on: April 15, 2012. Instituto Brasileiro de Geografia e Estatística (IBGE). 2012b. Em 2011, PIB cresce 2,7% e totaliza R$ 4,143 trilhões. In: http://www.ibge.gov.br/ home/ presidencia/noticias/noticia_visualiza.php?id_noticia=2 093. Accessed on: April 15, 2012. Nogueira MP. 2012. Perspectivas para o confinamento em 2012. Available on: http://www.beefpoint.com.br/ cadeia-produtiva/espaco-aberto/perspectivas-para-oconfinamento-em-2012/. Accessed on: April 15, 2012. Pineda N. 1997. Fatores que afetam a imagem e o marketing da carne. In: Anais do IV Simpósio o Nelore do Século XXI, Uberaba, MG, Brazil, Uberaba, MG: ABCZ-ACNB. pp. 19-35. Velloso L. 1996. Evolução e tendências da pecuária de corte no Brasil. In: Anais do IV Simpósio sobre Pecuária de Corte - Produção de Novilho Precoce, Piracicaba, SP, Brazil. Piracicaba, SP: Fealq. pp. 1-40.

Anim Reprod, v.9, n.3, p.133-138, Jul./Sept. 2012

Anim Reprod, v.9, n.3, p.139-152, Jul./Sept. 2012

History, evolution and perspectives of timed artificial insemination programs in Brazil P.S. Baruselli1,3, J.N.S. Sales1,2, R.V. Sala1, L.M. Vieira1, M.F. Sá Filho1 1

Department of Animal Reproduction, FMVZ, University of São Paulo, Brazil. 2 Center of Veterinary Science, Federal University of Paraiba, Brazil.

Abstract Currently, timed artificial insemination (TAI) can be applied routinely in the reproductive programs on farms. TAI protocols are designed to promote control of both luteal and follicular function, permitting the TAI with satisfactory pregnancy per AI (P/AI). A variety of protocols for TAI have been designed according to specific characteristics and requirements of different breeds, animal categories and types of management. The most common of these therapies use GnRH or estradiol plus progesterone/progestin (P4)-releasing devices and prostaglandin F2α. Moreover, TAI programs should be considered as an important tool of reproductive management to enhance the reproductive performance of cattle. Thus, the correct incorporation of these programs within the farm routine enhances reproductive efficiency of livestock to increase overall productivity of the farm unit. Keywords: artificial insemination, cattle, reproduction, synchronization of ovulation.

mid 1990s with the development of the Ovsynch protocol (GnRH-7 days-PGF-48h-GnRH-16h- timed AI; Pursley et al., 1995). A number of protocols were designed to control both luteal and follicular function, which permit timed AI (TAI) with satisfactory pregnancy per AI (P/AI). Currently, TAI programs are applied routinely in dairy and beef herds providing a systematic approach to the use of AI (Macmillan et al., 2003; Stevenson et al., 2003; Baruselli et al., 2004; Chebel et al., 2004; Lucy et al., 2004; Santos et al., 2004; Thatcher et al., 2006; Bó et al., 2007; Galvão and Santos, 2008; Cerri et al., 2009; Meneghetti et al., 2009; Sá Filho et al., 2009a; Santos et al., 2010; Wiltbank et al., 2011; Bisinotto and Santos, 2012). A variety of protocols have been developed to design specific treatments for different animal categories and to minimize time and labor, yielding satisfactory pregnancy outcomes. Therefore, the objective of this review is to describe the history, evolution and the main perspectives of TAI programs in cattle. History and evolution of synchronization of ovulation protocols for TAI

Introduction GnRH based TAI protocols High reproductive performance is an essential requirement to ensure maximum livestock production and satisfactory economic return. In this context, the incorporation of reproductive programs in the routine of the farm seems like an organized approach to optimize the reproductive outcomes and profitability of dairy and beef cattle operations. Artificial insemination (AI) promotes genetic and economic gains through the use of superior genetic bulls. Despite the technological advances of AI programs, the implementation of AI programs based on estrus detection is hampered mainly by postpartum anestrous and estrus detection (ED) failure (Bó et al., 2007). These difficulties are aggravated when working with Bos indicus breeds because they exhibit estrus of shorter duration than Bos taurus (Figueiredo et al., 1997; Bó et al., 2003) or with high producing dairy cows because milk production is inversely proportional to estrus duration and reproductive performance of dairy cows (Lopez et al., 2004; Wiltbank et al., 2006). To avoid the problems associated with AI programs utilizing ED, several research groups have developed different strategies to inseminate bovine females at an appointed time, eliminating the need for ED. The first positive results of this effort emerged in _________________________________________ 3 Corresponding author: [email protected]

The GnRH administration induces the emergence of a new follicular wave after induction of ovulation (Macmillan and Thatcher, 1991; Twagiramungu et al., 1992a, b, 1995; Wolfenson et al., 1994; Schmitt et al., 1996). When prostaglandin F2α (PGF) was given 7 days after GnRH treatment, fertility at the induced estrus was not reduced (Thatcher et al., 1989; Twagiramungu et al., 1992a). This became the basis for subsequent development of programs to control timed ovulation. The first synchronization of ovulation protocol, designated Ovsynch protocol, was assigned by Pursley et al. (1995) and consisted in a first injection of GnRH followed 7 days later with an injection of PGF, followed in 48 h by a second injection of GnRH; TAI could be performed 0 to 24 h (optimally 16 to 18 h) later. Following this first report, numerous protocols have been proposed and routinely applied in high production dairy cows (Wiltbank et al., 2011). The stage of the estrous cycle (Martinez et al., 1999; Vasconcelos et al., 1999; Moreira et al., 2000) and cyclic status (Bisinotto et al., 2010) at the time that GnRH is administered has been shown to affect Ovsynch results (Wiltbank et al., 2011). Previous experiments found that the ideal phase to initiate the

Baruselli et al. Evolution of TAI programs in Brazil.

Ovsynch protocol is from days 5 to 12 of the estrous cycle (Vasconcelos et al., 1999; Moreira et al., 2000). Further researchers developed pre-synchronization systems that attempt to increase the proportion of cows in the ideal stage of the estrous cycle on the day of the first GnRH of Ovsynch (Moreira et al., 2000; Galvão et al., 2007; Souza et al., 2008; Kasimanickam et al., 2009; Chebel and Santos, 2010). GnRH-based TAI protocols in beef cattle have been associated with inconsistent results, mainly by failures in the induction of the emergence of a new follicular wave following the first GnRH treatment of the Ovsynch protocol (Geary et al., 1998; Martinez et al., 1999; Baruselli et al., 2000; Bó et al., 2003; Colazo et al., 2009). GnRH-based protocols have also been evaluated to synchronize the ovulation in suckled Bos indicus cows (Barros et al., 2000; Fernandes et al., 2001; Baruselli et al., 2002; Williams et al., 2002; Sá Filho et al., 2009b). The overall P/AI was satisfactory only in cyclic cows (Fernandes et al., 2001) but, is still lower than the results achieved after progesterone (P4) plus estradiol (E2) based TAI protocol (Baruselli et al., 2002). Thus, collectively, these data indicate that Ovsynch protocol presents low efficiency when applied in lactating zebu cows under tropical pasture condition that are frequently associated with high incidence of postpartum anestrus (Barros et al., 2000; Fernandes et al., 2001; Baruselli et al., 2002). Estradiol plus progesterone based protocol Exogenous P4 suppresses LH release, alters ovarian function, suppresses estrus and prevents ovulation in cattle (Adams et al., 1992; Savio et al., 1993). Both P4 and progestins have been incorporated to the estrus synchronization protocols in cattle by oral sources such as melangestrol acetate (Patterson et al., 1989; Madureira et al., 1997; Hiers et al., 2003) or by insertion of intravaginal P4 device or progestin ear implants (Martinez et al., 2000a; Bó et al., 2002; Cavalieri et al., 2006). Progestins given for intervals that exceed the normal lifespan of the corpus luteum are associated with highly synchronous estrus upon withdrawal, but low fertility at the ensuing estrus (Revah and Butler, 1996). Therefore, P4 based TAI protocols have incorporated an inducer of ovarian follicular wave emergence at the beginning of the protocol with exogenous P4/progestin source which is normally removed after 7, 8 or 9 days (Bó et al., 2002; Baruselli et al., 2004; Meneghetti et al., 2009; Vasconcelos et al., 2009). Due to the emergence of a new follicular wave during the protocol and the short treatment period, the incidence of persistent follicles is reduced and fertility after TAI is close to that achieved following AI upon estrus detection (Bó et al., 2002; Santos et al., 2009; Teixeira, 2010). Similar to the effect of GnRH treatment, described previously as an inducer of new follicular 140

wave emergence, novel studies introduced the use of E2 plus P4 to control follicular wave dynamics in Bos taurus (Bó et al., 1991; Martinez et al., 2000b; Colazo et al., 2003) and Bos indicus cattle (Baruselli et al., 2006; Carvalho et al., 2008; Sá Filho et al., 2011a). The E2 and progestin/P4 combination followed by TAI has been a successful hormone therapy (Bó et al., 2002), allowing satisfactory P/AI following TAI in either Bos taurus or Bos indicus cattle (Martinez et al., 2000a; Bó et al., 2002; Macmillan et al., 2003; Baruselli et al., 2004; Cavalieri et al., 2006; Meneghetti et al., 2009; Souza et al., 2009; Teixeira, 2010). Nevertheless, the use of estrogens have been commercially limited in USA, New Zealand and in countries of the European Union, even though estrogen doses used to synchronize follicular wave emergence and ovulation only reach endogenous concentrations similar to those observed at estrus or during gestation. Several studies (reviewed by Bó et al., 2002) found that E2 plus P4 treatment suppress the growing phase of the dominant follicle. The mechanism responsible for E2-induced suppression of follicle growth appears to involve suppression of FSH (Bó et al., 1991, 1993, 1996, 2002; O'Rourke et al., 2000) and LH (Burke et al., 1996). The administration of 5 or 2.5 mg of 17β-E2 (Bó et al., 2002) or 2.5 mg of estradiol benzoate (EB; Caccia and Bó, 2008) in P4/progestin-implanted cattle at random stages of the cycle was followed by synchronization of emergence of a new follicular wave approximately 4 days later. Furthermore the effect of EB on induction of new follicular wave occurs regardless of species (Bos indicus, Bos taurus or Bos taurus indicus) or breed (Beef = Angus, Nelore or Angus x Nelore or Dairy = Holstein, Gir or Holstein x Gir) of cattle (Carvalho et al., 2008). The interval from E2 treatment to follicular wave emergence seemed to depend on FSH resurgence, which has been reported to occur after E2 concentrations decreased below a threshold level (O'Rourke et al., 2000). Estradiol valerate (EV) has a long circulating half-life which promotes a prolonged suppressing effect on FSH and ovarian follicular growth than 17β-E2 or EB (Bó et al., 1993; Martínez et al., 2005). This could be the reason for the variability and length of interval from EV treatment to follicular wave emergence. In Bos indicus cattle, the administration of EV (2.5 or 5.0 mg) with a norgestomet implant delayed the day of follicular wave emergence in comparison to treatment with 2.0 mg of EB (Sá Filho et al., 2011a). Furthermore, longer interval with higher dispersion from treatment to the emergence of a new follicular wave after EV treatment has been observed in Bos indicus heifers when compared to Bos indicus cows. Consequently, EV is not recommend to be used in zebu heifers (Sá Filho et al., 2011a). Despite pharmacological differences, the estradiol esters (i.e., EV or EB) have been applied successfully in TAI synchronization protocols for Anim Reprod, v.9, n.3, p.139-152, Jul./Sept. 2012

Baruselli et al. Evolution of TAI programs in Brazil.

synchronization of follicular wave emergence of suckled Bos taurus (Odde, 1990; Geary et al., 1998) and Bos indicus beef cows (Meneghetti et al., 2009; Sá Filho et al., 2009b, 2010, 2011a; Sales et al., 2012). After luteolysis, TAI synchronization protocols use inducers of ovulation to achieve a synchronized ovulation. In E2 plus P4 protocols, a lower dose of E2 is normally given from 0 to 24 h after progestin removal to induce a synchronous LH surge (approximately 16 to 24 h after EB treatment) and ovulation approximately 24 to 32 h after the LH peak (Hanlon et al., 1997; Lammoglia et al., 1998; Martínez et al., 2005; Sales et al., 2012). The EB has been successfully used for inducing ovulations (Hanlon et al., 1997; Sales et al., 2012). Estradiol cypionate (EC) is another ester of E2 with a low water solubility that delays its release from the site of injection. Despite pharmacodynamics differences, both esters of estradiol (EB and EC) administered either at P4 device removal (EC) or 24 h later (EB) were effective in inducing an LH surge that resulted in synchronized ovulations and similar P/AI in suckled Bos indicus beef cows submitted to TAI (EB = 57.5%; 277/482 vs. EC = 61.8%; 291/471; Sales et al., 2012). In addition, the use of EC as the ovulatory stimulus given at the time of P4 device removal in the TAI protocol reduces cow handling, without reducing fertility. As described previously, some countries have regulatory limitations to the use of estradiol on synchronization of ovulation protocols for TAI. Because of these restrictions, several studies were designed to evaluate the effect of using GnRH or different E2 esters to control the follicular growth and ovulation of beef and dairy cattle. These protocols have presented different pregnancy responses according to the animal category (dairy or beef cattle) and cyclic status. Based on the studies listed in Table 1, there was no difference between the use of GnRH or E2 ester as the ovulatory stimulus in either dairy or beef cattle. However, dairy and beef cows subjected to E2 + P4-based TAI protocol had greater P/AI than cows treated with GnRH-based TAI protocols. The greater response following E2 + P4 based TAI protocol could be associated with the better control of follicular wave emergence at the beginning of the protocol. However, it is important to mention that the majority of those studies was conducted in cattle under tropical conditions of South America. Therefore, influence of the incidence of anovular cows within herd, nutrition, management or season on pregnancy responses should be considered and requires further investigation. Use of exogenous gonadotropin to enhance the ovarian responses during TAI programs Anestrous cows have insufficient pulsatile release of LH to support the final stages of ovarian follicular development and ovulation. This condition limits the effectiveness of traditional TAI protocols (Baruselli et al., 2004). The treatment with equine chorionic gonadotropin (eCG) has been demonstrate as Anim Reprod, v.9, n.3, p.139-152, Jul./Sept. 2012

an alternative to increase final follicular development (follicular growth from the luteolysis induction and ovulation) and P/TAI mostly in anestrous or undernourished suckled beef cows (Bó et al., 2007; Sá Filho et al., 2009a; Sales et al., 2011) and in dairy cows in anestrous or with low body condition score at the beginning of the protocol (Souza et al., 2009; GarciaIspierto et al., 2011). Therefore, in beef and dairy cows with insufficient pulsatile release of LH to support the final stages of ovarian follicular development, treatment with eCG can improve the ovulatory response to the synchronization protocol and pregnancy outcome. It is an important concern that, because eCG is a complex glycoprotein with a high molecular weight that is produced by the pregnant mare (Murphy and Martinuk, 1991), a potential immunological reaction may occur after repeated use in cattle (Drion et al., 2001). A PhD thesis (University of Sao Paulo) evaluated the potential adverse effects of the repeated use of eCG in cattle (Mantovani, 2010). A first experiment was designed to determine anti-eCG antibody production in response to 400 or 2000 IU of eCG, given once, twice or three times at 30-day intervals in Bos taurus and Bos indicus heifers. Animals were then submitted to weekly blood sampling for 63 days, and then at 30 to 60 day intervals for a total of 300 days. Antibody production was not affected by the number of eCG treatments; however, antibody production was higher in Bos taurus than in Bos indicus heifers. Higher antibodies levels were also observed in heifers receiving 2000 than 400 IU eCG. A second experiment conducted one year later focused on the evaluation of the cellular and humoral immunological memory of the Bos taurus heifers treated previously with 400 or 2000 IU of eCG. Humoral immunological memory response was not observed in animals treated previously with 400 or 2000 IU of eCG, regardless of the number of previous treatments. However, cellular immunological memory response was observed to be higher in animals subjected to increased numbers of previous treatments; but no evidence of adverse biological effects were observed. Results suggest that eCG, as used in synchronization protocols, is unlikely to have adverse effects following subsequent treatments. Another alternative to improve the endogenous gonadotropin secretion and the ovarian responses during TAI programs is the use of calf removal. The temporary weaning increases LH pulse frequency and stimulates follicular growth and ovulation in cows >30 days postpartum (Mackey et al., 2000; Yavas and Walton, 2000). Several studies have demonstrated that the addition of temporary weaning on either GnRH-based (Geary et al., 2001; Williams et al., 2002; Sá Filho et al., 2009b) or E2 plus P4-based (Barreiros et al., 2003; Penteado et al., 2004) TAI protocols improved P/AI in suckled beef cows. Similar improvement on P/AI has been observed between calf removal and eCG treatment in suckling beef cows, and no additive effect has been found (Penteado et al., 2004). 141

Baruselli et al. Evolution of TAI programs in Brazil.

Table 1. Effect of type of TAI program (GnRH or E2) on the pregnancy per artificial insemination (P/AI) of dairy and beef cattle. Type of TAI program Ovulatory stimulus1 Base of protocol2 P-Value3 Reference (additional GnRH E2 GnRH E2 information) ---------------------------- P/AI (n) --------------------------Dairy 27.7 (314) 34.7 (366) NS Stevenson and Phatak, 2005(A) 23.9 (309) 27.9 (412) NS Kasimanickam et al., 2005(A) 25.2 (127) 25.8 (132) NS Bartolome et al., 2005 58.7 (63) 48.3 (60) 0.05 Ambrose et al., 2005(B,C) 37.4 (179) 35.4 (192) NS Pancarci et al., 2002(A,D) 28.0 (157) 29.3 (164) NS Pancarci et al., 2002(A,D) 43.4 (488) 45.3 (483) NS Hillegass et al., 2008(E) 45.5 (44) 36.7 (30) NS Iwakuma et al., 2008(B,C) 28.9 (194) 30.9 (194) NS Souza et al., 2009(B) 33.8 (198) 29.1 (196) NS Souza et al., 2009(B,F) 36.4 (228) 32.9 (252) NS Shabankareh et al., 2010 45.7 (300) 39.9 (281) 0.07 Lima et al., 2010(B) 58.7 (63) 66.1 (56) NS Ambrose et al., 2005(B,C) 30.6 (98) 44.9 (98) < 0.05 Veneranda et al., 2006(B,D) 37.8 (98) 30.0 (100) NS Veneranda et al., 2006(B,D,F) 41.0 (100) 52.0 (100) NS Veneranda et al., 2006(B,D) 24.2 (66) 30.6 (62) 0.009 Capitaine Funes et al., 2009(G) 27.4 (208) 40.8 (211) 0.03 Lima et al., 2010(A) 30.9 (97) 43.4 (99) NS Ranieri et al., 2011(E,G) Rodrigues et al; unpublished 15.5 (200) 20.4 (201) NS data Ayres and Ferreira; unpublished 10.4 (67) 25.0 (52) 0.04 data(E,G) Overall

Beef

Overall

35.2 (2,601) 35.0 (100) 38.9 (190) 50.9 (212) 48.7 (195)

35.0 (2,752) 30.8 (104) 56.2 (178) 51.8 (228) 44.8 (424)

28.7 (997) -

-

-

42.4 (92) 39.1 (92) 15.0 (100) 65.0 (103) 45.2 (166)

44.8 (697)

47.1 (934)

42.0 (553)

37.3 (979) 45.1 (91) 40.4 (99) 47.3 203) 61.5 (52) 52.9 (174)

NS 0.002 NS NS

Fernandes et al., 2001 Sá Filho et al., 2011b(B) Sá Filho et al., 2011a(B) Sá Filho et al., 2011a(B,C)

NS NS 0.01 NS NS

Williams et al., 2002(F) Williams et al., 2002(C) Baruselli et al., 2002 Martinez et al., 2002(B) Mialot et al., 2003

48.6 (619)

37.2 38.1 33.4 41.7 (3,298) (3,686) (1,500) (1,598) 1 Induction of ovulation: GnRH or an estradiol ester was used as ovulatory stimulus regardless the treatment used to induce the follicular wave emergence or the progesterone supplementation during the synchronization protocol; 2 Base of protocol: GnRH-based or E2 plus P4-based TAI protocols; 3Effect of treatment (GnRH vs. E2); A Presynchronization was used; BProgesterone supplementation was used during the synchronization protocol; C Cyclic heifers; DExperiments I and II; EThe E2 group also received GnRH at the TAI; FFemales had their calves removed during 48 h before TAI or were treated with eCG; GDouble Ovsynch protocol. NS = non-significant. Total

142

Anim Reprod, v.9, n.3, p.139-152, Jul./Sept. 2012

Baruselli et al. Evolution of TAI programs in Brazil.

Impact of TAI on reproductive performance Many studies compared the efficacy of the TAI protocol as tool of reproductive management for dairy cows (Cordoba and Fricke, 2002; Cavestany et al., 2007; Gutiérrez et al., 2009; Lima et al., 2009; Teixeira, 2010; Herlihy et al., 2011; Ribeiro et al., 2011; Bisinotto and Santos, 2012). Similar P/AI has been found of cows bred upon estrus detection or following TAI (Santos et al., 2009; Teixeira, 2010; Wiltbank et al., 2011). Furthermore, timed synchronization protocols decreased the interval from parturition to first service and increased the proportion of cows becoming pregnant sooner after the voluntary waiting period (VWP; Cavestany et al., 2007; Gutiérrez et al., 2009; Teixeira, 2010; Herlihy et al., 2011). In Brazil, we performed an experiment to evaluate the impact of TAI on the first day after the VWP on reproductive performance of high-producing dairy cows compared to the use of only AI upon ED (Teixeira, 2010). No difference (P = 0.55) was found in P/AI between dairy cows receiving the first service after ED (26.8%; 125/467) or TAI synchronization protocol (25.5%; 126/495). However, shorter interval from calving to first AI (78.3 ± 0.9 vs. 60.6 ± 0.1 days; P < 0.01 and from calving to conception (94.6 ± 1.8 vs. 87.4 ± 1.8 days; P < 0.01) were observed in cows receiving a TAI after the VWP (Teixeira, 2010). In tropical countries, it is common to use a breeding season (BS) for beef herds during spring and summer months because there is higher availability of forage. For this pasture-based system, high pregnancy rates in the beginning of the breeding season are critical for herd profitability. Cows that become pregnant earlier in the breeding season will calf earlier in the next calving season, and, consequently, will have additional time to recover before the next breeding season. This improves their chances to conceive again and reduces the risk of involuntary culling (Rhodes et al., 2003). Furthermore, calves born early in the calving season would be heavier at weaning, yielding additional income to the producer (Cutaia et al., 2003; Bó et al., 2005). We designed two experiments to compare the performance of different reproductive programs that used natural service (NS), AI upon ED and TAI within a 90-day breeding season (Penteado et al., 2005, 2008). In experiment 1, 594 suckled beef Nelore cows between 55 to 70 days postpartum were randomly allocated to one of four groups according the strategy of breeding. Cows in the TAI + NS group (n = 150) were synchronized with an E2 plus progestin-based TAI protocol. Bulls were placed with cows 10 days after the TAI and remained together until end of the BS. Cows in the TAI + ED + NS (n = 148) received TAI, then AI based on estrus detection for the next 45 days, and then NS for the last 45 days of the BS. Cows in the ED + NS (n = 147) were artificially inseminated based on twice daily estrus detections during the first 45 days of the BS and then exposed to NS for the last 45 days of the BS. Cows in the NS (n = 149) were bred by NS for the entire 90 days BS. Cows in the ED + NS or NS groups Anim Reprod, v.9, n.3, p.139-152, Jul./Sept. 2012

had decreased (P < 0.001) hazard of pregnancy compared to cows in either groups that received TAI at the onset of BS. Furthermore, cows receiving TAI had higher (P < 0.01) pregnancy rates at the end of the BS compared to cows that did not receive TAI (Table 2; Fig. 1). In experiment 2, 507 suckled beef cows (Nelore; Bos indicus; n = 303) and crossbred (Crossbred; Bos taurus x Bos indicus; n = 204) between 30 and 60 days postpartum were blocked by parity and breed, and assigned randomly to one of two groups at the onset of the BS. The NS group (n = 255) received only NS during the entire BS and TAI + NS group (n = 252) received TAI at the onset of the BS followed by NS until the end of a 90-day BS. Cows in the TAI + NS group had 63% higher hazard of pregnancy (P < 0.001) compared to cows in the NS group. This change in rate of pregnancy reduced the median days to pregnancy by 44 days (11 vs. 55 days). However, there was no difference (P = 0.31) in the proportion of pregnant cows at the end of the BS (TAI + NS = 77.0% vs. NS = 71.0%; Table 3, Fig. 2). In addition, pluriparous cows had greater (P < 0.01) P/AI, and had greater (P < 0.01) proportion of pregnant cows at 45 days and at the end of the BS than primiparous cows (Fig. 3). Cows with BCS ≥ 3.0 had greater (P < 0.01) P/AI and also greater (P < 0.01) proportion of pregnant cows at 45 days of BS than cows with BCS 320 days), but with clinical and behavioral signs similar to those observed in premature foals (Rossdale, 1976), exhibiting the syndrome known as intrauterine growth retardation (IUGR; Rossdale and Ousey, 2002). Several studies have been performed to identify factors related to the deprivation of nutrients to the developing fetus as a result of placental or uterine defects (Rossdale and Ousey, 2002). Foals originated from pregnancies with these complications present signs of immaturity, which exemplifies the importance of pre-natal evaluation to identify potential problems of newborn foals. Behavior of the equine neonate The next adaptation stage of the newborn is the activation of neuromuscular reflexes and behavior, which are essential for the foal to remain standing and gain the energy to follow the footsteps of the mare, obeying his instincts to escape from predators, which are characteristic of the prey attitude of the equine (Rossdale, 2004). The time intervals from birth to the manifestation of specific reflexes in foals are used as parameters for evaluating goals on health of the newborn. However, these values may vary according to breed (Stoneham, 2006), monitoring and degree of manipulation in foaling. For healthy foals, the following times are described: sternal recumbence, 5-10 min; 183

Curcio and Nogueira. Newborn adaptations and healthcare of the foal.

sucking reflex, 5-20 min; standing, up to 1 h; nursing from the mare, up to 2 h; and eliminating the meconium, 2 h (Koterba, 1990; Kurtz Filho et al., 1997; Vaala, 2000; Pierce, 2003; Stoneham, 2006). Table 1 describes the results obtained by our

research group over three reproductive seasons (20092011) regarding neuromuscular reflexes and behavioral signs observed in monitored foaling in Thoroughbred breeding farms in Southern Brazil (31°51’55” south; 54°10’02” west).

Table 1. Values of mean and standard deviation (SD) for neuromuscular reflexes and behavioral signs in monitored foaling in Thoroughbred breeding in the south of Brazil (31°51’55” south; 54°10’02” west). Sitting sternally Sucking reflex Time to stand Time to suck Time to eliminate (n = 273) (n = 278) (n = 278) (n = 274) meconium (n = 264) Mean ± SD 4 ± 5 min 30 ± 11 min 34 ± 14 min 51 ± 18 min 63 ± 28 Neonates with musculoskeletal (flexural or angular changes, incomplete ossification), neurological (fasciculation and reduced muscle tone) or septic (joint distension and incomplete ossification) impairment tend to remain in one position for a longer time (Morressey, 2005). When the time to achieve sternal recumbence and a standing position exceed the expected values, the reasons for those changes should be investigated. Performing feeding in the first 2 h is critical for a proper energy supply and for the absorption of immunoglobulins by the foal (Le Blanc, 1990). In general, foals with little ability to remain standing and nurse within 2 h of life are considered to be potentially abnormal (Koterba, 1990). These events are essential for the maintenance of metabolic homeostasis and for establishing the bond between the foal and mare. Most foals’ passage of the meconium starts 2 h after birth, in certain cases demonstrating mild abdominal discomfort. The complete elimination can take 12-24 h (Koterba, 1990; Morressey, 2005). Colostrum has the ability to stimulate gastrointestinal motility in foals (Le Blanc, 1990), and the passage of the meconium typically starts 30 min after the colostrum intake of the newborn (Kurts Filho et al., 1997). Therefore, a foal that achieved adequate intake of colostrum does not require the administration of laxatives or enemas for the prophylaxis of meconium retention (Kurts Filho et al., 1997). However, the routine use of a commercial sodium phosphate-based enema in all animals after delivery is described in the literature (Pierce, 2003) and widely used in horse farms in Brazil. The evaluation of parameters related to the urinary system is not routinely performed. The reduced flow of urine may be a result of low fluid intake, increased fluid losses by other mechanisms or impaired renal function (Morresey, 2005). The time for the first urination after delivery is 6 to 10 h in foals and fillies (Jeffcott, 1972). The rate of production of urine in the neonate is 6 ml/Kg/h (Brewer et al., 1990). The blockage or rupture of a portion of the urinary tract, resulting in uroperitoneum, is a common occurrence in compromised foals or in cases of trauma during delivery (Morresey, 2005). When all these steps have been completed, the 184

observation of the foal continues, with emphasis on adaptation of renal functions and a gradual increase in the demand for food. Passive transfer of immunity Macromolecules, such as immunoglobulins, that are present in the colostrum are absorbed by pinocytosis in the intestinal epithelium of the neonate without significant digestion. The uptake of immunoglobulins presents maximum absorption immediately after birth, declining to 22% of its capacity in the foal within 3 h of life (Jeffcott, 1971). For the process of transfer of passive immunity through colostrum to occur efficiently, it is necessary to ensure that the foal ingests approximately 1 liter of good quality colostrum within the first 6 h of life (Sellon, 2006). Good quality colostrum has a viscous, yellowish aspect and a specific density ≥1060 (evaluated by a densimeter), which corresponds to a minimum concentration of IgG of 3,000 mg/dl. Upon delivery, the concentration of IgG in the colostrum of mares exceeds 9,000 mg/dl (Le Blanc, 1990). In the evaluation of colostrum, a portable refractometer unit is used to determine the Brix% and follows the following interpretation: Regular, 15-20% Brix and 28-50 g/dl IgG; Adequate, 50-80 g/dl Brix and 21-30% of IgG and Very good, >30% Brix and >80 g/dl IgG (Cash, 1999). The indicated procedure during the monitoring of the delivery is to collect a sample for the evaluation of the colostrum before the foal begins the first feeding. If the mother does not have the appropriate concentration of IgG in the colostrum, colostrum from a wet stock of milk or frozen colostrum must be offered to the neonate. Foals that fail to receive the transfer of passive immunity (if the IgG is less than 400 mg/dl) may be subjected to the transfusion of plasma to increase the concentration of serum IgG. The donor plasma must have a minimum concentration of 1,200 mg/dl IgG. An increase from 200 to 300 mg/dl is observed in the foal serum IgG after the administration of 1 liter of plasma. In Brazil, horse farms often collect plasma from their own animals, which are donors with adequate sanitary control, instead of commercial equine plasma. This practice results in a lower cost and antibodies specific for the agents in the environment in which the foal lives. Anim Reprod, v.9, n.3, p.182-187, Jul./Sept. 2012

Curcio and Nogueira. Newborn adaptations and healthcare of the foal.

Clinical pathology of the foal Hematology Erythrocytes During the fetal period, the process of hematopoiesis occurs in the liver, and the bone marrow does not contribute to this process until the end of pregnancy. At birth, the foal has high levels of packed cell volume, red blood cell (RBC) and hemoglobin concentration (Harvey et al., 1984). This increase is likely due to blood transferred from the placenta via the umbilical cord at birth. The hematocrit values decrease by approximately 10% within the first 12-24 h (Axon and Palmer, 2008). The RBC and hemoglobin values decline during the first 2 weeks and then remain low in proportion to reference values of adult horses (Harvey et al., 1984). Leukocytes A significant increase in white blood cells is

observed in the first 12 h of the foal’s life. This increase is due to the large increase in circulating neutrophils. The neutrophil/lymphocyte (N/T) ratio is 2.5:1 at birth, and after 3 h of life, it increases to 3.5-4:1 in response to the peak level of cortisol in the fetal circulation that occurs in this phase (Silver et al., 1984). These events are important markers of adrenocortical activity and maturity of the newborn (Rossdale, 2004). Eosinophils are not found in the fetus and neonate, first appearing in foals at 4 months of age. Monocytes and basophils are absent or reduced in number during the neonatal period and do not show significant changes during the first year of life (Harvey, 1990). In Table 2, hematological data in Thoroughbred foals are described, accompanied by data obtained by our research group during the foaling season of 2011 (South Brazil). The means of the hematological values found in foals before suckling (the immediate postpartum period), during the first 12-24 h and in the first 7 days of life were compared by the Tukey’s test.

Table 2. Hematological data found in Thoroughbred foals before suckling (immediate postpartum period), during the first 12-24 h and at the 7th day of life, in the south of Brazil (31°51’55” south; 54°10’02” west). Trials Immediate postpartum 12-24 h 7th day N Mean SD N Mean SD N Mean SD PCV (%) 88 46.47ª 3.80 89 40.98b 4.94 78 36.30c 5.07 TPP (g/dl) 88 6.40a 0.74 89 7.53b 0.90 78 7.55b 0.78 ab b 126.68 87 275.86 131.15 77 345.45ª 130.33 FB (mg/dl) 88 312.5 2.00 86 8.84b 2.17 76 9.68b 3.45 Leucocytes (x10³/µl) 87 6.25a a,b,c Different letters in the same row indicate differences (P < 0.05). Abbreviations: PCV: Packed cell volume; TPP: Total plasma proteins; FB: fibrinogen. Blood biochemistry The values related to blood chemistry are widely varied during the first 4 weeks in the equine neonate. In this review, we discuss plasma proteins, urea, creatinine, glucose and lactate. We do not discuss changes in enzymology and electrolytes; for more information on these topics, we recommend a review published by Axon and Palmer (2008). Total plasma proteins Foals are born with a wide variety of plasma proteins, including albumin and fibrinogen. Starting in the first 12-24 h of life, there is a gradual increase in the serum protein concentration due to the absorption of globulins from adequate intake of colostrum (Axon and Palmer, 2008). Fibrinogen concentrations are low at birth (