CSIRO PUBLISHING
Animal Production Science, 2015, 55, 793–798 http://dx.doi.org/10.1071/AN13552
Effects of large or small furnished cages on performance, welfare and egg quality of laying hens Fanyu Meng A, Donghua Chen A, Xiang Li A, Jianhong Li B and Jun Bao A,C A
College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, PR China. College of Life Science, Northeast Agricultural University, Harbin 150030, PR China. C Corresponding author. Email:
[email protected] B
Abstract. The study investigated the effects of large or small furnished cages on laying hens. Hyline brown hens (n = 360) were placed into three treatments with six replicates: large furnished cages (LFC), small furnished cages (SFC), and conventional cages (CC). The results showed that egg production of hens in the LFC treatment was significantly lower (P < 0.05) than that in SFC and CC groups. Daily feed intake, feed : egg ratio, egg weight, and proportion of broken eggs and dirty eggs were not affected by cage types. However, Haugh unit and albumen height of the eggs from LFC and SFC hens were significantly higher (P < 0.01) than those from the CC hens. Welfare indicators (feather conditions, gait score, and fluctuating asymmetry of tibia length or wing length) in LFC and SFC hens were much better than in CC hens (P < 0.05). In conclusion, the hens in the LFC treatment had lower productivity, higher egg quality and better welfare conditions than those in the SFC and CC treatments. Additional keywords: egg quality, large furnished cage, laying hens, performance, welfare. Received 25 December 2013, accepted 9 April 2014, published online 15 September 2014
Introduction Conventional cages for laying hens are widely used around the world because they are low-cost, high-performance, easy to manage and hygienic. However, conventional cages lead to many welfare issues (Nicol 1987a; Baxter 1994); for example, laying hens in conventional cages lack the opportunity to express their natural behaviour, which can cause frustration and stress to the hen (NAWAC 2012). In addition, the narrow living space could restrain their movements and activities, and lack of exercise may lead to osteoporosis (Webster 2004). Out of respect for animal welfare, the European Union (EU) has implemented directives to ban the use of conventional cages (Anon. 1999). From 2012 onward, only non-battery systems (e.g. cage-free, free-range) or furnished cage systems are allowed to be used in the EU. Furnished cages can provide an enriched environment that allows hens to express natural behaviour, while retaining the advantages of a traditional battery system, such as high productivity and good sanitation (Appleby 1993a). Furnished cages initially were similar in size to conventional cages, and in the latest design, group size ranges from 8 to 80 birds. In the design, attention is being paid to activity-related space and the layout of devices that meet birds’ natural behaviour. Only when the space and device layout in the cages are reasonable can the laying hens express specific behaviours such as foraging, nesting, dust-bathing and perching behaviours (Lay et al. 2011). In Europe, there have been considerable research into how to design the furnished cages, considering factors such as cage Journal compilation CSIRO 2015
height and group size (Albentosa et al. 2007), device locations (Shimmura et al. 2009), nest design (Wall and Tauson 2002), and perch locations (Wall and Tauson 2007). The fundamental purpose of these studies is to provide better welfare for laying hens, and obtain high production performance and egg quality. However, little information is available on comparisons of large and small furnished cages for the welfare and performance of laying hens. In this study, we examined the effect of size of furnished cages on welfare, production and egg quality of laying hens, and aimed to provide further information for design of furnished cages. Materials and methods Experimental design The experiment was conducted at the experimental farm of Northeast Agricultural University, Harbin, China. In total, 360 Hyline brown hens at 18 week of ages were randomly divided into three treatment groups with six replicates: large furnished cages (LFC) (Fig. 1), small furnished cages (SFC) (Fig. 2) and conventional cages (CC). Each replicate consisted of 40 hens in LFC, and 8 hens in SFC and 12 hens in CC. Detailed cage parameters are given in Table 1. The experiment started at 18 weeks of age and ended at 34 weeks of age. All of the hens were housed in the same room and they received identical, standard feeding and management. Feed for layers (metabolisable energy 11.13 MJ/kg and crude protein 16.08%) were provided twice a day at 0700 hours and 1500 hours. Water www.publish.csiro.au/journals/an
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Fig. 1. Large furnished-cage design.
Fig. 2. Small furnished-cage design.
1700 hours), any egg laid was included for that cage on the next collection day. Feed intake was recorded daily for each cage (feed intake was calculated as total feed added in the morning minus feed left in the next morning) throughout the experiment and calculated weekly for daily feed intake. Then total feed intake, average egg production per hen, feed : egg ratio (feed conversion), and proportion broken eggs and dirty eggs were determined. Dead or sick hens were removed promptly and substituted by new hens to maintain a stable group size. For measurements of egg quality, egg sampling began on the Monday of 26 weeks of age. Ten eggs from the LSC treatment (60 eggs in total), two eggs from SFC (12 eggs), and three eggs from CC (18 eggs) were collected from each replicate. All collected eggs were weighed and quality was assessed in terms of eggshell strength, eggshell thickness, egg yolk, Haugh unit (HU) and albumen height. Eggshell strength was determined with an eggshell strength meter-NFN382 (Fujihira Industry Co., Tokyo, Japan), then albumen height with an egg-quality gaugeNFN381 (Fujihira Industry Co.). The HU was calculated as follows: HU = 100 log(H – 1.7W0.37 +7.6), where H is albumen height (mm) and W is egg weight (g). The albumen was weighed and eggshell thickness measured with a eggshell thickness gauge-NFN380 (Fujihira Industry Co.).
was available ad libitum from three nipple drinkers in each cage. Mechanical ventilation was used to control the dust and ammonia concentration. Ambient temperature of the testing room was maintained at 18 29C, and relative humidity was 45–60% during the day. The light schedule was 16 h light–8 h dark.
Measurements for welfare conditions Welfare parameters were measured at 32 weeks of age and included feather condition score, gait score, claw condition score, tonic immobility duration, and body fluctuating asymmetry.
Measurements for performance and egg quality The measurement of laying hens’ performance was from 20 to 34 weeks of age. All eggs from each replicate were recorded daily for total number of eggs, broken eggs and dirty eggs for each cage. Collection started at 0600 hours and ended at 1700 hours each day. Each egg collected was marked to identify the cage it came from. After the collecting period (0600 hours to
Feather condition score The feather condition score was assessed on eight parts of the body: head, neck, back, tail, wing, breast, vent and leg. The condition for each part was rated 0–3 (Wechsler and HuberEicher 1998), as follows: 0, feather perfect with no damage; 1, feather slightly damaged but skin all covered; 2, feather damaged and exposed area of skin was 1 cm by 1 cm. Scores for each part were summed; the highest (worst) possible score was 24. Gait score The test hens were put into a dark and quiet room to observe and record gait score. The gait score was defined as follows: 0, hens can walk normally and keep good balance; 1, hens have slight gait faults; 2, hens have obvious gait faults, such as lameness; 3, hens can walk only under intense stimulation (Dawkins 2004). Claw condition score The hen was held gently by one person, and another person examined the claw condition. Claw score was defined as follows: 0, claw intact, clear with no damage; 1, claw slightly contaminated; 2, claw seriously contaminated; 3, claw damaged and not intact. Fluctuating asymmetry of tibia and wing Measurements of the length and diameter of tibia, and the length of wing were conducted, and fluctuating asymmetry of tibia and wing were determined with the method given by Palmer and Strobeck (1992). Determination of tonic immobility duration The hens were placed into a quiet room and fixed into a U-groove. Hens were pressed gently for 15 s with the hands. The time taken for the hens to turn over and stand up was recorded. Statistical analyses Data were analysed using the ANOVA procedure of the SAS package (SAS 8.2; SAS Institute, Cary, NC, USA). Duncan’s test was used for multiple mean comparisons. Data are presented as means standard deviation. Probability values
