milk protein concentration from dairy cows. J . M Moo&\ t, I< J I3e\.\li~11\tt,. C TIi~)rii'~\ .... potassi~ui~i ancl sodiuln b!. tlie mctliocl oi Ales~indc~r c2f 171. (lClS5) ...... appear to redi~cc tlie ad\,erse cffccts of liigl1 c~nccntr~lte ...... fats and htt!. oils.
The influence of dietary energy source and dietary protein level on milk protein concentration from dairy cows J .M
Moo&\ t, I< J I3e\.\li~11\tt, C TIi~)rii'~\ ,lnd S i\/l'lrsclen$
(;iii~~!ii~rll iiiiri iZiiiiiiiiiiii1 51 ii,ircc Zlif~iii tiiii7irt
~ ~ i ~ / l Agii~riltiiiiil i ~ ! i (-i~/!c~:.cl i i i l i i i i c i i i i ~ l i / \ I / /
k,lii 51 i11
Abstract
Keywords: allar~torrr,dn1r.y cosus, rtr~lkprndr~rt~or~, rrrrlk /~rotclrl
Introduction Recent chanees In the uses o f inilk and in the consumption of inilk products have meant thit protein has become an increasingly important component of milk. Dietary energy intake and protein level ha1.e been identified as t\vo major attributes c ~ f tlie dairy cow diet wliicl~ cxcrt an important influence 01; the concentration of prcltci~~ in milk (Emery, 1978; 'lliomas and Martin, 1988; Spiirndly, 1989; DePeters a n d Cant, 1992). 111 general, ! ~ n d L;o\ 11c' ( IOSI ), ~ n c i \\,a tc~~~-~c1luhlt~ cc~rboli\dratr5OF t l ~ c c o t i c e ~ i t r ~ ~ t h! e b tlie Luiid u r ~ n gthc .;,>me pi%rio(lat t\ze, c;,~ihcc~~ti\ c milk~ng, Sclioorl metlind (b.uropcc1n Fcononl~c C'olnrn~~nit\., , ~ n d h~~lktxcl,licorilin:; to \it,ld ,it tllc' t ~ m e ot 1971) ,111~1 ot iil,~gcl h!. Lhc Solnog! I metlloii ;,t collectio~l. I h e ) \\c'rt> t r o ~ v n a n d stoi.cd l 0 C Mc-LI~n~ilci,~ncl Hc~icic-rson (lCjh-l).C'r~iclc. protc.i~l \\itliout thi. llse ot ,l p r e ~ e r \ . , l t i \ . ~ I-hc~\c. . \ \ t w 3 1,ltt.l. (Cl') \\,as clekcr~iiinc~d h\ Kjc~ld,ihl( N X (3.35) sing cincil!s c ~ tor l CI' (h X 6.33; FiS 1741 Sc~ctio~l 15 : 2 ICjC)O sclcnil~nidio\icir, '1s a c,itclly\t, 'icid-clctergenk fibre blociifieci), cCisc~in(PI l ,-1LIf739 : lC)i34),LIre~i ( S ~ g ~ i i ~ i h! tlie ~nc~tlioclo f V;ln S o ~ s t LYilie (lC)h7), Lest kit N ~ I .(140; Sigma C h ~ ~ ~ n i cCornpan\ al ILtcl, nc~1tr~jlLdrterge11t tihrt. by thc m e t h o ~ lof \/,in Sc~clst1.1 Poole) ,lnd tot,>l non-protcsin nitrogrt, ,issesseci h!, tlie t~lectrometrictitration mc~thod(C)tftlr I'riiiiic7 iii.ri~~iitirlc',~.SpoL ~ ~ r i n e i,i~iiples ot 17f lll., 1'lC)3). ;~pproxirn.ittI! IOl) 1111 bverc, collt~cteii h! \ L I ~,l1 \ st~mulationat , i b o ~ ~ 10.30 t 11 dnd 15.30 h tor 7 cla\s at hlilk. Morning ,ind c\.rning milk samples wcrt. the encl of e,icli cxprrinleilt,~lperiocl. These \ < , c ~ c ~ collected o\,cr 4 days ;it ttict twci ot c.ach e x p e r i m e ~ ~ t ~ ~t rl o ~ c nand stored , ~ t2 0 ° C until analysed h!, Lhc pc,riod. Tliese \vcrcx prescr\red using I.;ict;th milk tiigli-kwrfor1n~i11cc~ liquid c l i r o r n a t ~ g r ~ ~method p t i ~ ~ ot presc~\,ati\,tttahlets (Tliompson and C'apper Ltci, Gc~lcells1'1 171. (1992) for crcatinine and tlie purinc liuncorn, Cheshire) ,ilicl kept retrigr,rated until d u i \ dti\.e (PD) ,ill;ulitoin sing cornt-7osittr. morning analvsrd tor protein, fat and lactose c o ~ t c e i i t r ~ ~ t i o ~ iand s a f t e r n o o ~samples. ~ A d d i t i o ~ w l,lndlysis oi the four most complete sets of incli\,idual s c ~ m p l e ns , a s c x r i c d out to obtain inform,1tion '1bo~1ttlic h e t ~ v e c ~ i a n d within-dcly \,ariatioi~i11 PD excretion. Table 2 ( ' I I I I I ~ I I ~ ~ ~ I OI I II 1111~ ~ c~i111~.1~1itr17/~~ / I I I ~ ~ I I I I I >I (:;/liy iiry iriiitti3iiiiilc'si ot/icr~~i.r~ bii7lnl)t B1 I
RL
SH
t111,1f11,Ib
I ~
SL
1'C
Dry ~m~itter (LIM) (g/kg) H7(1 Organic matter (OM) 943 Crudc protcin 181 Efft.cti\.e rumen degr,ldahlr protein$ 120 1)igestible ~~ndcigr,ide~l protc.int 82 Mci'iboliz,lble enc%r,qy (ME)(MJ/kg DM) 13-2 Frrmentablc M E 5 (MJ/l\g DM) 12.2 Neutlal-detcrgrnt tibw 128 Acid-detel-gcwt tihrta OH St'll-c.ll 477 W'iter-wluble c,i rbohydr,l tcs 20 Acid liydrol! sis ct1ic.r c'\tr,ict 1') 111 i1iti.o O M digcstihility (::/kg onu 89'3 I'ota\\ium 8.3 c'alciulu 8.2 Pho\phoru~ 5.h Magnesium .>.-I Sodium 2.4 q
r
t K = harle), S iu:;,ir-beet pulp, H = his11 protein, L - Io\v protein, I'C = parlour conct~ntl.atc~. Estimattd (Aldcmnan n ~ p e ) s ~ tctid ~ o n n o t c h ~ n g c ,grc~atl! c)\ c.r t h e iiulation (it the, exper-imclnl, rz,itli, lor e ~ a r n p l e , ,182, 174, 17(>,incl l89 g C'I' t7csr k g LILT ;uncI I 1 . I , 11.?, 1 1-3 m i l I l .4L1 l ME p e r k g DM tol- period:, I t o 4 re5pciti\,el!
!.)L
111in c, .im~nii-.i~ 1'1 111t1-i>gc.n (g I,g trcili L \ c.~.;llt) lot~ilwl~il>lt. nitrogen ig!kg hca\I>~vt'lfilit) :4niino-,lild n~tri>gt.n/iot,II ic>ll~hlr nitrogtw L ~ ~l~lic~rg! ~( M r ) ( \~I [ D ~ ~ I J~ Fc>rnic.~~t~~L>lc l l F t (All! kg Llhl) L J C ~ ~-C t01.1111~ X I C I ~ tg/kg i1-~,~11 ~\,~)ig~lt) T o t ~ \l c)lcitilct,itt\ 'it iii. ( g / k,,e trc5li \ \ cizlit) Zcid l i \ clrol! sis ether. r\tl-,ict LYatc1--5olublc.c,irholil dr'i tes I1l\m t , ktls ~ of d r \ 111~ittc.r(IIMI) (>tsil,igc' ancl concc,ntr;lte, c r ~ ~ i i protein cs (CPl) a n d n~et;tholi/,lble enrrg!. (MET), \vitli the contributions of M E From silage ,incl coi1centrcltc>s < l s s ~ ~ n t~oe he d ;~diliti\,c,,Ire givcn i l l T , ~ h l c4. There \\. 0.05).
Table 6
rif~~iii of ifii,tiii I/ fi.iZiiti~i~~iit oil iiiiiioi.iiiilii i i i t i ~ ~ ~ ~ i~N~)i~i o~ ~i iii.t:i t i i , ~ i i t ~
Crudr protein (g/kg) Truc protcin (g/kg) C 'isetn : (g/kg) Whey (g/kg) N o n - ~ ~ r enon-protein a N (g/kg) Ured (g/kg) C r ~ ~ protein de yield ( g l d a y ) True protein yield (g/dag-) Casein yield (g/day) Whey yield (g/day) Non-~~re,l non-protein N yield (g/ddy) Urc,l yield (g/day)
t See 'l'able2 tor diet codes. $ Significance o f results: P = protcin Icvc'l cttcict, E
-
clifrgy souric cftrct, P X E interactlot1 t,ffects were not significant
(1' > 0.05).
coupled with ~ ~ n f o r m u l ~ between ~tcd diet differences Tables 5 and h rrspecti\~ely.Milk yields were far in composition mea~it that estimatecl illtakes of lowcr than predicted by the diet f o r m u l ~ ~ t i o i ~ effective rumell degr'iclable protein (eRDP) mcl DUP software; nevertl~elessdifferences were seen betwcen (Alderman and Cottrill, 1993) were not as origii~~~llythe foul- experimental diets. Milk yield was predicted. Estimated intakes of 1)Ul' were greater sigi~ificd~itlyincrcdsed by the high protein diets with diets formulated to be relativelv hifill in DUP (lJ < 0.05), but was unaffected by sourcc of cnergy. content within concentrates containing the same Milk protein concentration, like the urinary A / C energy source; howe\rcr, estimated int,lkes of DUI' ratio, was significantly increased on the barley and were greater oil the sugar-beet-based diets t h m on high proteii~ diets (1' < 0.05). There was a trcnd the barley-based diets. Estimated intakes of eRDP (lJ = 0.082) for milk fat coi~centr~~tions to be increased followed tlie opposite trend. The combinatioil of by tlie inclusion of suclr-beet pulp. Milk caseill differences in estimated intakes of eRDP and FME concentrations werc not significantly 'iffected by resulted ill differences in eIlL)P/FMB ratios betcveen dietary treatmei~t,and differences in true protein diets. These were 11.2, 10.8, 9.0 and 7.6g elllll'/MJ concentration were brought about by c11,lnges in IME for diets RH, RL, SH and SI. rt~spcctivcly. whey protein concentration. Tlii~s, there WCIS no significant effect of diet on tlic proportion of milk A summary of the mean milk yicld and coinpositioi~ true protein that was casein. obtained by Milko-Sc;ui~c~nnlysisfrom each of the f o ~ ~diets, r and the tl-eatnient m e ~ l i ~ofs the incljor UI-inary I ' l l excretioi~was fourtd to diffcr with time nitrogenous constiti~clnts in thc nlilk 'ire gi\,en in of s'jmpling, ~ r i t htiiglier A/C ratios obtained in tlie
Moorby, Dewhurst, T h o m a s a n d Marsden
h
m o l - n i ~ l gthan In tlxe ,l ttcrnoon ( I .'l4 I .S(>; 5.c.d. 0.034). N o c,ffect ot ~111i n t t ~ r ~ l c t ihoe~t ~~v e e n timc3 01 i i ~ anci i ciiet5 \\'IS seen. F ~ ~ r t l i e r m o r c , significclnt ci~ttc,rc~ixces in the, diurn'il \ 'iriatic)~?oi t h e ; \ / C r'ltios J u t . to c~xperimclxtcxlperiod ~2.t.l-t.sc3cl1, \\.it11 diurn,il \ ari,ltion a s s e i s e d 'l:, tlic' rdtici 01 tlic a.ni. \.alue d ~~\i l e dh!, the, p.m. \ , , I ~ L Thc I ~ . ,l.n~./p.m. \.alues \yere 1.00, 1.10, 1.05 a n d 1.02 (s.e.ci. 0-047) tor periocis 1 , 2, 3 ,incl 4 rcspecti\.ely. Tht. \,,iluc tor pc,riocl 2 \'\,as sigi~ificantlyditferent (l' < 0.05) t o t h a t f o r pcrioci 1. A n ' ~ l y s i s o t \,,iri,~ixct,c o m p o n e n t s bq liEML (Table 7) s l ~ o \ v e dthat the gre,?tcst proportion o t vclriancc n';ls .-o\ c r ettccts o f c1ic.t hctxveen esperiment'll pclriods wlcsrc. identified. ;l.
I,ictose!CI), \\.hicl1 ,lri. h e main t,~ctorsinfluc~nc'ing m11k i)xmol,ll.ilq li'ltios ot the, three m 0.05). Table 9 Tfti'tt i!/ iiii,tiii-!l Iri~iilliii~iit iiii riitios
iiiiik jlroii'iii
/,I
/nl i7iid /iictosca,iiiid offilf to /ilc'lo5i' Dictt
I'rotein/ t'it Pl.otcin/l,~cto\e Fc~t/lclcto\e
Bk I
ET.
SH
SL
s.e.d.
I'
O-')I I 0.744 (1.883
0-856 0.770 O-CI1I
0.838 0.777 0.946
0.839 (1 76.3 0.')20
0-0209 0.0082 C1.0217
**
t See T,ihlt. 2 fol- dict codes. Significal~ccxot result.;: I' (1' > 0.05).
=
Signi ticnnce$
protein Ir\c-l cffcxct, E
- energq- hourer effect, P
E ss
X E intcr'lctioll ctfccts xvere not significdnt
p -
-,
Milk protein and diet Table 10
i < i ' / ~ i t i c ~/ ~i ,i . i ~ t r ~i 'i/itii ~ - i i ' i iii,. c 111 iiiil/< i i l t i - i i ; : i ~ i i i ~ i i~~ c l i i ~ t i t ~ iiiiiiI/< i ~ ~ l \~i.c~ti,iii i~ c ~ i i i ~ ! i i tI /iiiit, i 1 1 1 r]li7iiiiiitrihi,, :;//h;
- p
-.
J ~p
p
Vicl Sig111t1t J I ~
KI I Crud? pr~>tein
I rue protcin Casein /Vile! Non-ure,i non-protc'i~inilrogen U re,l
t Signifi~~lncc. ol P X E (l' > 0.115).
-
205 l Q4 l G6 38.h 1-00 I .')S
RL
SH
SI
120 208 L h8 403 1414 2.17
118 200 Ih?
JL7.l 1.1 l 2-15
226 2lh 174 42-2 O.C)h l .‘)C)
v>.~i.
f r n c ' l i i ~ ~ i -i-t'liitii~i' : 10 i l i i i i i i r ! l jiiii.iiicZ i i i ~ r ' i i ' i i t i iz\i.r.rtioii ;~~~
L L >( i~t
P
12-1 12-0 c).[)
2 51 0.005 0.
protein X encrg! ~nteractinnEltects o f protein 1c.x cl ,inJ c.ncrg\
Table 11 1 ii,/ii> o i i i i i l l c p r o t i , i i i
r) X
]I.>\
txl
\vtxre not iign~t~c,int
i ( . i ~ i i i l i iic7iit l !~ii~lii/iilliiiilc~~i~/c~i~~~~tii~iiii~~
r11et P -
Crude protc%in True prcitt,in
cCISCII~ :
Whey hTolrurc,i noii-protein nitrogen Ure,~
RH
[iI
SH
335 318 255 h7 2.8 3.1
327 309 245 h4 2.8 3.2
015 324 260 h3 2.8 7, 7, L>.L>
SI.
326 311 250 (30
2-4 3-0
\. 0-05), E = energy sourcc effect, P X E interaction ettc.rts \yere not significant (P > 0.05).
The A/C ratio (Table 4) gives an indication of the supply of n~icrobialprotein to the animal. I11 order to take this into account, production variables were divided by the A/C ratio. When this was done (Table ll), the effects of dietary protein level werc lost for 3' 11 variables. There was no change in mean live weights of the animals over any of the experimental pkriods, nor over the course of the whole experiment (grai-td mean 593 (s.d. 41.5) kg).
Discussion Two factors which are generally acknowledged to have ail important influence oil milk protein concei~trdtion are diet F : C ratio and MEI. In this experiment, the F : C ratio was kept constant thro~rgllout on '111 four diets. Mean silage intakes were slightly higher 011 the BH and ST, diets than o n the BL and SH diets, but not significantly so, and silage DM accounted proportionately for only 0.4 of the totdl DMI. It is assumed, therefore, that any effects observed were the results of differences in tlie composition of tlie concentrate portion of the diets,
a n d these in turn were the causes of large differences in the intake of protein and the form ill which diet'lry energy was consumed. Increasii~gdietary protein level caused increases in both milk CI' concentr,ltion and yield. An increase in dietary protein also caused sigiiificantl y higher inilk yields. The barley-based diets, as opposed to sugarbeet pulp diets, caused significantly increased milk protein concentrations, but not yields. However, yields of inilk from all animals on this experiment were low compared with the yields of the same animals which formed the basis of formulation parameters for the experi~nent~jldiets. This cliscrepancy between predicted and observecl milk yields must either have becn a function of the diet formulation software or of the productioil of cxperimental diets, or cornbinntioi~of thc two. of the diet One of the original ~pecific~~tions formulation WCIS to iilcreds~the level o f protein in the diet from a deficit of DUP to an excess ~z~liilst keeping the eRDP supply constant. A secoi~d objective was that of keeping the diets isoenergetic, '1nd whilst this was essentially '~chieveclin ternis of diet energy concentration, unpredictcd differences in
Milk protein a n d diet 111crt~~1scd ~i~t;ihc' 01 c31il>Pbut noL of FLIT; in ot1le.1\\,orci>, Lhc limiti~rg ts n ~ ~(Oltner ~ l l and Wiktorsso~l, 19%; lie1 nolds, lCF)2; Gurt,itsson < ~ n dI'cilmquist, Ic)L)?,;~ c ) i e l e i7t r , l / . , 1c)c)3).This Ictncls further supporL to tlie s ~ i g g e t i o i i that the iinport'int dittrrenzc bet\t,eeli die% in tclr~nsof the elZL>P/FM t' r'ltios \v,ls th,\t ot suppl! of IilIP r'lther than FMh. T ~ c ~ ~ t m c.ttect5 ent ; ~ p p ' ~ r t ~ an tt tl~~~ b u t a b to l e cl~et,ll\ enc,Ig\ 5 o ~ u i eh,id a m ~ r c hC I C ~ ~ I C effcct ~I on i n ~ l kCl' concenh,ition\ tli,ln dietary p r o t c ~ n , ~ ~ l t h o ~ ithe gh effects \verc3 rather s ~ i ~ , i l l . ~ ~ f ihigher g l ~ t l ~protein ~ concc~ntratioiisLverc, ai.Iiit~~ ecl o n tlie B diets than on the. S die%. l i o \ ~ ~ : . e r ,intake of C'[' \v;ls sligl~tlq higher on tlie B diets, , ~ n d eRDP intclkr \\,as substantiallq higher, a s were the A / C r'ltios. Again, this indicates a n o\~ercill greater supply of protein to tlic animal trom the r11111e11 ~ l i i c hrndy I~avcxresulted in tlic i n ~ r e ~ ~ s inilk e c l p r o t ~ i nproductiorl; howelrer, J L Ito~thc confounding of energy source ,~ndprotein intake i t is difficult to attribute the increased milk protein procluction to either 1' protein or a11 energy effect. 111 terms of gross rel'lti\,e efficiency of dietary proteiii ~ ~ t i l i z a t i ofor n milk protein p r o d u c t i o i ~(CPI 71. milk protein prucluction), there were no clifferences between dietary treatments. Since tlxe major effects attributable to both diet energy source and protein level may have bee11 a result of differences in eRDP supply, the cffect of ~nicrobidl protein synthesis o n milk protein production m,ly be examiiied in relation to rates of I'D excretion (Table 11). When this w a s done, significant differences between dietary treatments were lost. Tf thc original objectives of supplying equal quantities of CRDIJ with differing levels of DUP had bee11 met, this would not be expected since A / C is a reflcxion of microbial ~ ~ t i l i z a t i o n of nitrogen a n d not of runien undegr,~dablc nitrogen. This iillplics t11,lt dietary effects on milk protein production were brought ']bout t o a large extcnt by changes in microbi'11 protein production. Corrc~l~~.sioii Milk yield ancl milk protein concentration were significantly increased by a n increase in protein s ~ ~ p p to l y the animal. It i s suggested that tliis \ v , ~ s achic\recl largely through ,~ckno\\lcJgc~i rc~ic~iptof ,I sh~dc~ntslilp from rI;llgt7ty Agriceilt~treLtd. SAC I-cceives lin;lnci,ll iupport from tlit- Scottish Ott~cc, Agriculture ancl Fihheric.5 Dep,irtment.
References Agricultural and Food Research Council Technical Committee o n Responses to Nutrients. 19'12. AFIIC TCORN, report no. Nutrit~vcsr.cl~~irerncnts of ~.urnin,int '~nirnals:protein. Nit/~.itioiiAi~iinit~t.: iiii~iR i 7 i ~ i c ~ i iiSe,i-ii.5 '> h') 62: 788-8.35. Agricultural Research Council. IC)80. ' l / i c 7 iiirtrii~iit
r[~q~~irc~ilic.iit.; of i i , i i i i i i i i i i t iiir~stilc~k. Common\\ealth Agricultur;ll R ~ ~ rLc aI Slough. ~, Azricultural Research Council. 1'18-1. Tlii, iiiitric2iit " rc,i7riin~riit~irt.; of rioiiiiiniit liilc~stoc./\.Si,yjllt~riic'irti i i i i i i ~ ~1.~ ~ i ~ C o m r n o n ~ ~ a l tAgricultural li Bureaux, Slough. Albin, R. C. and Clanton, D. C. IC)66.F,ictors contributing to thc vari,ltion in urinary crc'itinine and ~ r e ~ ~ t i u i n e nitrogen rdtios in bcclf c,ittle. ]c~io'~riil of Aiiiiriiil ,Stc)gr~1t2liy. [(~i~i~iiiil (f c/iro~i~i~lc~,~r~i~il~~/-~~~~iiio A/~p/it-iztiorih 575: 15.7-157. Bhattacharya, A. N . and Sleiman F. T. 1971. Bc~4pulp '1s .I grain replactrnent for d'lir! cows ,inJ slrecp. loiii.iiii/ilf Lliiir.i/ Sciczric,r'54: 89-94. Box, G . E. F., Hunter, W. C. and Hunter, J. S. 1'178. Stiiti5tii-> for t~.~ju,i-iriic.iitc~r~.~, pp. 571-581. Joh~rWil(x> 'iind Son\, N~TI' York. Castle, M. E. 1'172. 14 comp,ir,ltivt~study of t11c fc*c.ding \ ,ilue o f dried sug,ir-beet pulp for milk productic>t~. {oiri.iiiiI i~fA,yi.ii.ii/tiirii/ 51 i t ' i r i i ~ ,Ciirir/~riif;;i,78: 371 -177.
l0
Moorby, D e w l ~ u r s t T, h o r n a s and M a r s d e n
Castle, M. F., Gill, M. S. and Watson, 1. N. ICIXl.Sil,~gc..111ci Reynolds, C'. K. lW7 A ~ I c ~ L I L > o I I ~ I ~ I(11 I ~ I ~ ~ O ~ L , I ~ O ill~lkp r ~ ~ i i ~ i t i oil i co1iipd1.11011 l />1>l\\c'c'11 1hlrlt>\ dlid ~ i r i ~ ~ ~i~ l ) l l l ~ > < l L i i l ' i \l>! 1 ~illlill'lllt l!\ / O l l i ! l , ? / i0J ,\ !l11 11!01! 122: i~~g,~r-hcact p ~ i l p.I\ i~l,igc iupplt>mt>nt5 (;I!?.- t i i i i i fili-ii;;~, S5(l-S7.l. 5 11,iit 1, 36: 7 l '!-724. Reynolds, C . K., Iluntington, C. B., Tyrrell, H. F. ,111d DePeters, b. 1. a n d Cant, J. P. 11)'!2. ' d u t r ~ t ~ ~ rlaiti~i-5 n~l IZeyr~olds, l'. J. l [)SS. Net ~ > o ~ - i , i l - c i ~ ~ ~ i ~ iC,I-'II i ~ , c i'111ci i n l l i i c ~ l ~ c ~the ~ i g nil[-ogtw 0\ 1 1 1 ~illill, ~ ii Ilepgcw ancl inilk nonprottlin niil-ogcv in (i,impli~ig,~ild,inal\ >is) rt~:;iil,it!oni. t 1.C Dii-t>cti\t . 71 !250/ l lt>lhtci~i cox\-i. /i~iii.i~(~/ cif Di/iri! S~.II>III I , 76: 525-534, t E C . Oftii iiii /r)iii.iiiilNo. L l . i i , 12.7 71 Sloan, B. K., Rowlinson, P. and Annstrong, D. G. 111S7. .l Groot, T. H. d e and Aafjes, J. H. lC)(iO. On tilt. const~i~ic!of natt' o n ~ o n c c ~ n t r d energv tc~ I O L I ~ C to1~ cidii-h 10\\5 111 i l l i ~ i c r ~ ~ , > t i n ~t.\c~-t>tion ile 111 the ~ ~ r i nol t j tliv ii,iir! ci>\\. Bi-itiili Iactnticrti. ~liiii~iiil Pi.oiiiii-/ic~ii 45: 331-333. l'c71c7i.iiiiii.~~ /i~iiririi/116: 40'1-4 l S. Sloan, B. K., Rowlinson, P. and Armstrong, D. G. 1'188. Grummer, R. R., Jacob, A. L. a n d Woodford, J. A. IOSi. Milk production in e,irly lactation cl,lirv c-o\\,s gI\.i,n gr.155 F,lctors ,?ssociatt.(i \\,it11 v,iri,ition in ~ n i l kt'it dcyresiicin sil'ige ,id Iibit~iin:intluence of ccrr~c'~ltr,~tt~ txnt'rg! source, resultins troln I l ~ g hglain J i t . 1 ~fed to d,iii-\ co1t.5. roiiriiiil ,I/ i r ~ ~ protein de content ,ind I t ~ c lot concc-ntrcltca,illo~v,lnce. L)iiii!! Sc i c 7 i i i c 7 70: 0 13-(11'). Aiiiiiiiii Proiliic-lioii 46: 3 17-131. Gustafsson, A. H. a n d Palmquist, D. L. 19'13. r)~~irn,il Sporndly, E. 1989. Etfcct.; of diet o n ~ u ~ composition lh ,inci \,ii-i,~tionof rwmen a, 2nd ~ n i l kLire,i in ~ i ~ l i cows ry 'it liigli ~ 1 i c 1low ~iclcis./i~~iriii~I of Diiii-!~S1.i1>11~.17 vicld of cl,ilry cows with speci;il ernphasis on milk protein content. Siilc~di>/i /e~iiriiii/i~fA~;ricii/tiirii/ Ri'~c~iirc11 19: '1')lOh. 76: 475-481. Thomas, C., Aston, K., Daley, S. R. and Bass, J. lC)Sf>.Milk Lawes Agricultural Trust. Ic)9O. Gi'iislril V ri'/i7ri7irc-c~ iiiiiiiiiiil. production from silagc. 3. The cffcct ot the compo5ition of Clarendon PI-css,Oxford. the s u p p l e r n ~ n tAiiiiiiiil . l'roilrrctio~r42: 3 15-02',. Lees, J. A., Oldham, J. D., Haresign, W. a n d Garnsworthy, Tliomas, P. C. a n d Chamberlain, D. G. 1982. Sil,igc soc.iiilioii 01 0ffic.iiiI concentrdte and le\,el of co~icentrate teed ins on mill\ A~i~il,~/tic~iii C/iiviiist.i 50: 50-55. production. Aiiiiiii?/I'ri~diic.tioii39: 65-76, Visser, H. de, Togt, P. L. van der, Iluisert, H. and Offer, N. W., Rooke, J. A., Dewhurst, R. J. a n d Thomas, C. Tamminga, S. 1992. Str~ict~11-al'incl n o n - s t r ~ ~ c t u r , ~ l IL)93. Knpicl asst~ssmcnt of silage fcrmcnt,ltion cnrboliy~lr,ite5in concentrate supplements of silage-h,iscd charncteristiis by electrometric titr'ltion. Aiiirriiil Pi~i~ili~c~tioii d'lirv cocv r'ltions. 2. Ruti~twdrgracl,ilion, fcrrnentation 'incl 56: 420A (ahstr.) Oltner, R. a n d Wiktorsson, H. IC)83.Ure'i concentr,itici in nlilk ~ 1 1 dhlooci as influenced by fcxc-cling \ arying , ~ m o i ~ n t i Visser, H. de, Togt, P. L. van d e r a n d Tamminga, S. I')C)O. of protein and energ! to ci'iir) c o ~ v s .Liilc'sloc-l< Proiliic-lioii Structur,ll ,ind nun-str~ictur~jl cclrboliydrates in concentr'itc Sciiziic-1,10: 157-407. s ~ ~ p p l c ~ r n c noft s silage-b'ised dairy cocv 1.~1lions.1. Feecl Patterson, H. D. and Thompson, R. lC)71. Recovery ot int'ik? ; ~ n d milk production. N~~tlr~~i./iii~iis /oiiriiiii of interblock-infol-rncltion rvlien hlocl\ s i ~ c s '1rc ul~eclu,ll. A:! ic-iiltiiriil S ~ ~ i c ~38: i i ~487-498. -i~ 13ioiiic~lriliii 58: 54.5-551. Wainman, F. W., Dewey, P. J. S. a n d Boyne, A. W. IL)S1 I'enning, P. D. a n d Johnson, R. H. 1'183. The use of intern'il Tliiril rc7~xwtc$ tlii, Fc~i~iliri~;stirf/sri~~iiiiiili~ii Iliiit, lioxvctt 1ilarkcr5 to estilii,ltc hcrb,lge Jigestihilit! cllid ilitakt.. 2. l i ~ s c ~ ~ ~Illst~ r c lti~ ~ tAeherdcell. , Indirc~stihle , ~ c i d detrrzrnt fibre. loiii-iiiil lit Airi-!c-iilliii-171
L I
The effect of fine grinding or sodium hydroxide treatment of wheat, offered as part of a concentrate supplement, on the performance of lactating d airy cows C. S. h/t'i\ n e t , I ~ I J. C;. Doliel-t)
A::ric
ii/liii.ii/
Rl~c~iircli lirititiiti3o f Noi.t/rc,i.ii li.c'iiiiiii, l f i / l s l ~ ~ ~ r c l C'i1. i i ~ ~l /) ci ~, i i l i i 1;120 b L l R
Abstract A it11111/i~i7.i ~ e ~ i r i i r ~ i tto i ~ i~l ~ i r i r r i i ~tire' i ' i;$fi'~t~ t . f i i i c~~r . i r r ~ f i i01. r , ~s c ~ ~ f i ~ iIr!/di.oriii~~ iri /r.c~ilfirrrrr/o f rrilrc,iif, iiirii i i , I I L ~ ~ ~ L l I I, I L i i i l l I I L I / ~ I I ~ . L I I L I ~ 1117si'if I ~ i'itl~i'~. c111 $ ~ . ~ i / i /illl~i'tlt [i j-L50:dll-nIrc.l,~ncl,ind tlic. Queen's Uni\.eri~tyof 13eltc~it effects of method of gr;nn trentmcnt
t 11lio'1 101.
forage intake, partic~~larly at high Ic\.els of teeding (Ylrskov, 1976). I?~.skov1.t ill. (1978) sc~ggestedthat treatment of w~lie>lecere,ll grain with sodiurn hydroxide reduced tlie r,~teof gr,lin digestion in tlie rumell and enabled n higher for'ige int;lke comparcd with a si~nil~tr le\,el of ground cereal grntr,~tes.On a\,c.rajic, '11ii11l;~Is were 9 1.3 (k35.0) clays cal\,ed wlicw nlloc,lted to e x p ~ r i ~ n t ~ ntre~xtrnel~ts. tal Anirndls were ~ ~ O L I ~ C into three blocks of eight animals on the basis oi cal\,ing date '1nc1 were then c~llocatedto treatment seq~~eticcswithin each block. The experiment wns conducted l 0-2.7
S79 O(13 1541 5
534
.-p
~
75
7.73 10-1l
965 7634 1729 565
956 770 1726 571
902 700 l6112 555
(1.46
26.6 20.5 43.9 3-68
*
L - ->
29,
>X 4
X)*
*
+*S
*
**X
*ss
t S i g n i f i ~ ~ ~conccntr,~tc nt type (T) X concentrate lcvcl (L) inter,~ction(1' < 0.05) for lactose concentration; none of the remaining intclactio~iswcls s i g ~ ~ i t i c (I' ~i~ > i0.05). t
and blood globulii~ ( P < 0.05) concentrations. Reldtive to (;W concentrates, SW coilcentrates significantly reduced both 13-hydroxybutyrate (IJ < 0.05) n11d urea ( P < 0.001) concentrations. However, there was a significant concentrate type X concentrate level interaction for both urea ( P < 0.001) ;uiid total protein (P < 0.05) concentrations.
Concentrate type had no significant effect (P > 0.05) on silage DM intake or any of the appc~rent digestibility coefficients. Increasing concentrate inclusion level significantly ( P < 0.001) reduced silage DM intake, increased ( P < 0.003) total DM intake and reduced (P < 0.001) MADF apparent digestibility. None of the remaining apparent digestibility coefficients was affected by increasing concentrate inclusion level (P > 0.05).
Tofill i.ilfioii nppilrcwf di~c'sfil~ilif!~ Treatment effects o n total ration apparent digestibility coefficients and ~~itrogen/energy Concentrate type had no s i g n ~ f i c ~effect ~ i ~ t (I' > 0.05) utilization arc shown in Tables 5 m d h respectively. on total N ~iltake,N d~gested,N balance or thc Table 4 Trc.ii/iiic~iii c~fi)fi.if.: ~ I I Ibiooif c-oirijiosifii~r~ iriiriiol/l iciilcss ofiii~ncliscsfiifru') C'oncentrdte type Sodium hydroxide treated wheat (SW)
G r o ~ ~ nu~lie~tt d (C; W) Concentlate ICY cl (kgDM~wrday)
2-5
5.0
7.5
10.0
Me'in
2-5
5.0
7-5
10.0
Signiticanct,t Mean
s.c.
Totc~lprotein(g/l) 72.3 75.2 76-7 75.0 74.8 71.0 71.0 78-5 7'1.0 75-1 1.72 Alb~rmen(g/l) 37.7 37.8 ?'l..? 37-3 38.0 36.8 37-2 .37.5 38.2 37.4 0.83 (;lobulin ( g / l ) 37-3 34.7 37-3 37.7 36.8 31-2 35.8 41-0 38-0 1.85 40.8 ~-Ii!~droxybutyr~~te0.70 0.82 0-77 O.SO 0.77 0.60 0.67 0.69 11.062 0-75 0-72 U re,~ 5.9 6-8 7.1 67 5.4 6.8 5.5 5.7 6.2 5.7 0.32 C'I-ecltiiiine(1111101/1) 108 107 110 l06 108 105 104 99 100 l02 5.5 Calciurn 2.2 2.3 2.3 2-6 2.4 2.3 2-2 2.2 2.4 2.L1 0-12 Sodium 124 131 131 l?? 129 127 126 4.6 129 128 135
T
L *X
*
'"
t Sigl~if~c,int conrcmtrntc type (T) X concentr,lte level (L) interclction for total protein ( P < 0-05) and urea (1' .:0.001) ionccntrdtion, non? o f thr remaining interactions was significant (P > (1-(15).
Treatment of wheat for dairy cows 'Table 5 iii7riiiiii~iit i , / f ~ ' i t.
15
looif iiitiiii~.iriili fiifiil tiii.1l i / ~ i ~ , wit/ ~y ~i ~~~i i i l ~ iI ii)t7ttitii2ii/z it~i
p .
-
-
~ p p p p p
P
C'~)ri~.c.ntr,?tt~ t! pe Sodium l i \ - d ~ - i ~ \ireLiteci ~de \z l;at(SLY)
C ~ I - ~ ILC \ l Ii I < ~> ~~iCJ1') tI C oncenti-,~t~> It3\el (l\$ L)hl pcr d,i\ )
~.
2-i
50
75
10 11
bltlan
2.5
0
7-.!
10.0
blr,ln
i.e.
iign~t~c.~ri~tt (11 I
. . .
Silage O\'l ~nk~lhc. (hgicI'~\) Conccntr,i te Llbl intake (I\g,fci,i! ) Totnl DM ~nt,ikc, (hg/~L~y) Apparent digeitihili t! coefficients Dr)rnatter(DM) Organicrn,ittelModif i d x i d dt,tergc1ntfibrr Nitrogen (;ross cnersy Digestible org,lnic matter in the DM (DOM D)
11.02
8.h')
'1.82
7.00
'1.13
l004
I012
~1.3'1
(,.i1.3
2.54
5-08
7 h0
10. L?
(3.34
2.57
5.14
7.73
l l
17.1;
1-54
13.31
15.21,
17.12
13.77
l
4
~)..3.5 (150.5 6-34
I
0.084 0.712
l
l !l-XI
0.78 0.81
0.78 0.81
0-SO 0.83
0-7') (1.81
07') 0.81
0-80 0.82
0-75 0.80
0-79 O.Sl
0.79 0.81
O.0iIc) O.OOL)
0-73 0.71 0.78
0-09 O.hh 0.71 0-77
0.71 0-75
0-65 0.74 0.80
0.68 0-72 0-78
0.71 0-72 0.78
0.69 0-67 0.7')
0.(7(7 0.71 0.77
0.63 0-72 (1.78
0.h8 0-70 0.78
0.017 0-020 0.Oll
0.76
0.7(7
0.76
0.78
0.76
0.75
0.76
0.75
0-76
0-75
0.00')
+ij
*t-i
t Concentrate typc rffects w t w not significant. Non' of the concentr~jtrtypc (T) X I 0.05).
Table 6 l'ri~i7tiilc~iit i;fficls 011 i~iti.c~,yl~ri irilii c7iri,r;;!y i111lizntioi~ Concentrdte typc Sodium liy J roxidc treated cvlieat (SW)
Ground wrlieat (GW) Concrntrntc Icvel (kg DM per day)
2.5
Nitrogen (N) utili/ation (g/da);) T o t n l N i ~ ~ t n k e 338 F'lcces N 1 '7 N digested 231 Urine N 148 Milk N 78 N b~l,ince 15 Eiic.rgy utilifn tion
5.0
379 108 271 180 80 l1
7.5
498 110 355 197 117 41
10.0
Mean
2.5
528 139 389 229 104 56
43h 122 314 IS9 95 31
318 95 243 147
320 6h 58 12.3
291 6.3 56 I l .H
5.0
7.5
10-0
Signil icancrt
Mcan
11
414 135 280 190 90 0.4
4 8 114 345 206 1 '0 4')
514 141 370 267 86 17
41') 130 310 203 98 I
254 55 55 10.9
285 60 53 3 4
318 72 5.3 13.5
'311 67 48 14.5
292 h4 52 13.2
S.?.
I'
11.6 10-4 10.3 11-8 7.3 1 1-2
1-
X*+ 9
**
*re
***
(Ml/day) Total enrrgy intake Faecescne~.g>. Milk energy Urine energ!, ME of diet (MJ/kg LIM)$ ME i~it'ikr (MJ/day)$
t Nonr
25h 56 51 10.') 12-81 174
259 327 58 73 49 66 1 1.1 12.4 12.61 174
12-71 221
13-03 223
12.79 198
12-79 173
12-73 191
12.44 213
12-48 210
9-7 4.4 5-h O.h3
0.05).
$ Mc~tnboli~ahlc, vntrgy (ME) intakes c,ilcul~>teJ ,~ssurningnic,th,inc energy
' 1O.Oh
*
i*
of g r o s ciit.rgy int'ike (MAFF, 1975).
Mayne and Doherty
lh
oiitt~titot N I!] t < ~ t ~ ' c \ iirinc) \, 01. nlilk. Furtlit~rrnorc~, ionic,nlr,~tc>t! hdci n o i i g ~ l i f ~ i a nc ~t f f t , i t o n tot,ll t~iic~rg\i~it,~li-g> ili tcic~~.c,\ o r ~iiill\(l1 0.0.5). I IOLI t'\ t'r, ';\l' trc3citi~~e~it sigiiitic,intl\ ~nzre,ist~ci urine c , ~ ~ c ~O~ L . gI\ ~ ~( / 'X I 0.01 ~ ). Increasing concentl-cite,toocl It.\ i ~l incre,isc~ii i tot'il K int,~kc ( P :. 0.00 l 1, N 'i\ppc~rc~ntl\digesteci (I' < 0.00 I ), N h,ll;iiic.c~ (1'- 0 . 0 i ) and the, excrc~tioilot h 1 1 1 faeces (1' < 0.001 ), urine. (I' < 0.00I) '1nJ milk (1' c O.Oi). Inirea:,~~ig conc.c,ntr,ilt. inclusion Intr;lte thdn witli those oftcred the. C W concxsntr,ite, c\,ell t h o ~ ~ gconcrntrnte h LIM intake was also m;u-gin'llly liighcr (+0.08 kg DM per d 0.05). 'The significant (P < 0.05) i~lcreascsin milk protein concentration (Mf') with increasing concentrate food
3
C;round wlie,it
A
Soda w1iclt t
Figure 3 Thc. effect of bvhe,it trc'itrnent and conc~,ntrate food It*\el (kg, dr\r rnt. ;rnd \tit~lclcomp~irt-cl\\,it11 tli,it oht,iined \\,it11 g r o ~ ~ n\Li lli~~ciL-L7~~se~i iol\ce~itr,itc,.Increase'\ in trlilk protc~in concentr,ltion \\.it11 in~rc.~jsing i l l t'it~c-~!\. c o ~ i c t ~ n t r ~ food ? t c ~ I t s \ c.1 \I t>re grc3 i ~ c e t i t r dtt~e ~p e s Previous . stuciics li63: 155-162. M,?yne a n d G o r d o n (1985), w h o obser\,ed t h a t Lawes Agricultural Trust. IL)YO. (;i3iistiit 5 rczfi~rivii.c~ ~riiiiiiiiil. increasing tlie proportion of concentrates in the. d i c t lioth,irnstcd Experi~lient'il St'ition, Rothainsted. f r o m 100 to 600 g / k g DM lidd n o effect on blood McMurray, C. H., Logan, E. F., McParland, P. J., McRory, Llre,l c o n c t ~ n t r a t i o i ~ s . F. J. and O'Neill, D. G. 1978. Secl~~cnti,~l ch,inges in some blood components ln tlir iieon,it,~l c ~ l i .Hi.itisli lfc~ti~i-iiiiii.!l Effizci i!f iorri'cvrti.ilf~'t!lf)cl. Offering t h e SW concentrates loiiriiiil 134: 5'10-597. s i g i ~ i f i c ~ ~ n t rl e? d, u c c d both blood u r e a c ~ i ~ pd Mansbridge, R. I., Blake, J. S. and Spechter, H. H. IC)')4. h ~ ~ d r o x y b ~ t y r ; 1~t C o n c e n t r ~ ~ t i o c~ ~ i sl, t h ~ ~ total gli N T11e t.CCcct of rncre,ising st,~rcli int,lke and source in intakcs w e r e similar for t h e t w o c ~ i i c e i i t r a t e s .T h e s e supplement> fed th1.ec~tinies ,l CIA!, tc) dairy c o ~ on ~ ssil,ige rcductioiis in blood i l r e ~ concentrations l m a y indicate intake, mill\ yield ,inJ milk compositioii. Pi.oc-c~t~iiiii,y~ of llic, r e d u c t i o n s in r u m e n a m m o n i a coi~ceiitr~itiolis with 44tIi iiiiiiiiiil iiii,c,tiii:: of 1111~Eiii?~pi~iiri Ai~~iiirtiori of Aiiiiriill SW c o n ~ r n t r ~ l t e spossibly , reflecting a n e n h a n c e d ~ro~iiii-tioii, ~ C I I I ~ ~p.I II ~I(,.~ , ~ I I , u p t . ~ k eof dinrnonia b y r u m c n inicl-o-organisms. I h e Mayne, C. S. and Gordon, F. J. 1984. The ettect of type of slc>~vcrr'ite of d c g r c l d c ~ t i o nof s o d i u n i h y d r o x i d e l grains in complete J i t t s for J'iiry C70r~~-!t~.5ic~ir5 cowrs:1' cornp,irison o f rolled hrley,wheat nnd oats ,111d o f Offering 'I sodiittn h v d r o x i d e t~-tt,itcd wheat-b ~ L~ e 2 c t ,llil\L~Li I L S L ~ C ~I~ . r l t t 9 ~ - t (5) I I\ l c \ t ' l o t ~ u p p l ~ ~ l ~ r ~ ~ ni ti, ~ i t Ill(> i~ o n~i l ill l ~ i c ~ t i ot i c tlic. 111111~~11 tILllLi 111 1 ill1 ~ l ~ l l L l l ~l11l ~l ' /' 20.0
0.25
0-85 17.9"
0.72 1Y.O"
11-62 20-C)'
0.12 21.9"
0.28
(1.60 U.20 0-14 3.3
38-8" 2(r.2' 50.4" 451
27.1" 51-5" 452
38.7,"' 27.7" 51.4" 461
3h.h.' 29-l ' 51.4" 460
O.hl 0.20 0-20 3.7
38.1 27.7 51-3 459"
39.1 27-3 51.2 460"
.
+-
(1.17
4
-i
\
*
X X'
-.+A
** 9
**
Means with the same superscripts, within rows, are not significantly different (1' > 0.05).
t Feeding method (M) X concentrate level (C) inter,~ctionswere not significmt (P > 0-05). concentration (P < 0.01). Metllod of feeding had no significant effect on milk yield or coniposition (P > 0.05).
concentrate offered increased. Increasing the level of concentrate offered had no significant effect on live weight (P > 0.05). Animals offered the complete diet had significantly higher silage and total DM intakes (I' < 0.01).
Treatment effects o n milk fatty acid compositioi~are presented in Table 3. Method of feeding had n o significant effcct on any of the milk fatty acids. (P > 0.05). Increasing concentrate food level significantly increased the contents of C, ,,,C,,, ,,, C,, ,,
Increasing the level of concentrate offered significantly increased milk yield and milk protein concentration (1' < 0.001) but decreased milk fat Table 3 Mi~iiitri~irtirrc~i7t 1fftv.t~oil iiiilkfi~tt!/izcid ro~i~/)ositioii (,y/l(x) Method of feeding
Concentrate level (kg/Jay) Twice daily
Fot~rtimes daily
Complete diet
80 25 23 37 35 108 301 108 220 10
H1 26 2.3 37 36 ll4 296 Ill 212 10 9
77 23 23 38 37 114 307 116 201
5.e.
2
4
h
8
s.e.
78 21 25" 40" 38' 115'" 300 107 214.'" 8" 8
69 24 25" 43" 4 120' 310 106 191" 12' 1
8-8 2.0 (1-8 1.4 1-2 3.0 8-7 3.9 7-6 1.2 (1-5
Significance of 0-05). ",".'
'uilci C , , ,, (P < O.01), significantly decreased the contents of C,, , ( P < 0.05) and had inconsistent effects on the proportion of C,, fatty acids.
Total rntiorl nppnrrrlt digc~stil~ility ~lntiz Treatment effects on total ration apparent digestibility coefficients, N and energy utilization are presented in Tables 4 and 5. Increasing the level of concentrates offered had n o significant effect on silage DM intake (lJ>0.05), but significantly increased total DM intake (P < 0,001). The level of concentrate offered had no significant effect on DM, organic rnatter (OM), energy or N apparent digestibilities (P > 0.05). However, MADF apparent digestibility was significantly decreased with increasing concentrate l e ~ ~ e( Pl < 0.01). Method of feeding had no significant effect on DM, OM, energy, N or MADF apparent digestibilities (1' > 0.05). Total N intakc increased significantly as the le\rel of concentrate offered increased (P < O.001). Similar trends were observed for faeces N (l' < O.O5), N apparently digested (P < 0.001) and milk N output ( P < 0,001). Anim'ils offered complete diets had significantly higher tot,ul N intakes than animals offerecl concentrates in two or four fecds per day (P < 0.05). Gross mergy intake was significantly i~icre~lsed by increasing the l c ~ ~ ofl concentrate offered
(lJ 0.001). A similar trend was observed for energy apparently digested (P < 0.001) and ME intake (P < 0.001). The increased energy intakes with increasing level of concentrate wei-e reflected in significant increases in faeces energy output (P < 0.05), urine energy output (lJ 0.01) and milk energy output ( P < 0.01). Method of feeding hacl no significant effect ( P > 0.05) on total gross energy intake or the output of energy in faeces, urine or milk. However, both energy digested and ME intake were significantly higher for animals offered complete diets than for 'inimals offered concentrates twice or four times daily (P < 0.05).
li~~it~r~r~fir.irrc~i~tnfioi~ clli7rnctc7ristics Treatment effects on rumen fermentation characteristics are shown in Table 6. 1,evel of concentrate offered had no significant effect on lumen pH, with all values being relatively high (P>0.05). However, the molar proportion of propionate was reduced (P < 0.05) and butyrate increased (P < 0.01) with increasing level of concentrates. There were no significant effects of method of feeding o n rumen p H or the molar proportions of acetate and p ropionate (1' > 0.05). Animals offered complete cliets tended to have higher molar proportions of acetatc ( P = 0.07) and lower proportions of butyrate (P < 0.01) than animals offered concentrates twice or four times daily.
Agnew, Mayne and Doherty
76
l'able 5 \liir~iI i i ~ r i l i i i t ~ i i ,lt f i , i I i tioiii i i / ~ / l r i i i , i i t~/i;;t,-ir/~ilii~i ~ / i i i ioii ~ / iiitio:;i~iii \ J ,iiiil ~~iii~i-; 0.05).
t Method of feeding ( M ) X level of concentrate (C) inter,lctions cvere not significant (P > 0.05). $ ME intakcs cC~lculated ,~ss~iining ~metlianeerirrgy a s 0-06of gross energy intake (MAFF, 1975).
Discussion
LIMJ
twice daily:
Ejficts or1 1lM iritnkc7 Increasing the level o f concentrates, irrespective of feeding method, significantly decreased silage DM intake. Regression equations werc clerived with the twice daily, four times daily and complete diet feeding systems by fitting equations si~iiultaneously and these are shou~nin Figure I. The following equations were derived: Table 6 Miriii trc~iitiiic~ril c;ffi.i.tsoil
10.53 0.49773 (s.c. 0.11711)
=
-
(1
four times clc3ily:DMI = 10.53 0.398X (s.e. 0.0609)
(2)
DMI = 10.50 0,27973 (s.e.0.0588)
(3)
-
complctc diet:
-
iiiiricZii fi'ri~ii~iitiitio/~ c./iifizic'tc'ristic~s
Method of feeding
'l'wice Jaily Rurnen pki VFA proportions (mrnol/mol) Aceta te Propion,~tc Rutyra te (Acct'ltc + hutyrate)/ prc)pion,itc ,'l"
7-4
656 185 130"
4.0"
Four times Complet? l dict 7.1
657 178 102"
4 '
7-3
h74 190 109~'
4.0"
Concentrate Iel cl (kg/day) s.c. O.Oh
5.6 3.4 3.8
0-10
2
4 7.1
h(73 1 L 12,'
3.9"
7.3
662 187" 122,'
4.0'
6
SigniCic,lncet 8
7.4
h(72 187" 12W'
4 I"
7.3
(362 171'' 139"
4.5l'
Mc'l~iswith tht, s ~ ~ m superscl.ipts, e witliin row\, ' ~ r cnot signifi~~lntly different ( P > 0.05).
t ICletlioJ of tc>cdi~ig (M) X level of conc.cntr,ite (C) inttxr,1ctions\vt,re not sigliitiiant (I' > 0.05).
s.e.
M
C
0.07
(3.4 1.0 4.4
0.1 1
**
X*
ii*
Feeding o f concentrates to c o w s
27
fcedi~lg mc~tliods. This i i in lint. \\-it11 thc t\,pic 0.05) effect on silage intake or substitution rate, in accord with results of previous studies (Rohinson M >H). I'lle '3pplrcnt digestibility of diet L c1ifferc.d (I' i0.05) from thosc of dicts M ,111d H w>liich \\.ere simi1,ir. W,itctring freclllency, had n o cffect on DM appCirc.nt digestibility (I' > 0.05).
I/\intc~i. iii tiilcc, Aii~iiiul/ I L > / I ~ ~ C J I (iziitf I ~ I ~ li~~7lfli Wcltc>rintc?ke \trds differeiit alnong thc tlirecs diet,lry The animal5 settled well and n~amtamedgood henlth t h r o ~ ~ g h othe u t expelimcnt, exccpt one aiiimal w h ~ c h trea tnicn ts (P < 0.05),with the c i l m o ~ ~iilcrcc~sing i~t dled of Ilcart f;ulure related to Coi1/i1~~hi7cf~'i11iiii with dietary ro~rghdgecontent (I',~hlc3). Tht. animals w'itercd ddilv drartk more th;uli those cv,itercd e\.c,r!, /II/(;~L~IIC~ 11ifcctlo11 3 week5 nftcr the 5talt of thc expcrlnien t 72 h (12.6 r?. 10.0 kg/dciy I-espcctively, P < 0.05). Expressed per unit LIM consumed ( 7 ' ~ b l c3), ~t,?ter D~/-ir~ntfc,i. iirfnlk,, tl' ilitnlte was higher for the, group \v,?tered ' ~ t24-11 LIClily dry-n1,lttcr (LIM) intakes (Tdblt. 2) indic,itc inter\~'ils thdl~for those ~ v ~ ~ t e revery e d 72 h (1.3 kg sirnply that ,111 steers ate their allottcd dicts. pcr ~ m i tIIM J I I ~2.0 kg per l~liilUM rcspecti\c~l\~).
WC> tct- intake. 24 11 \v1 72 lit \V t
0vc.rall CI ~I, Water i n t , ~ k pt.r ~ > unit ot dr! ~ n ~ i t t (I\g/kg t~l. LIM) 24 l i
t
72 11 t O\ t ~ ~ rnc>,~n l l
'1.5 S.? 8.c))
(1.5.:
3-4
0.12 Cl- 12 0-0s
7.9
;.7.1
0.5; 0.3s
12 4 ~).o l0
.X 2-4 q.(l,117
0-53 0.5; 0.78
0- 12 0.12 0.0s
l00 12.; 14.4
0 - hI
X1 2.4
0-14 0. l 2 0.0')
7.71,
(1.5:
l ?.(>l l(1.o"
t) .31
" ">'I
0.07 0.07
0.3 I
0-40
,l'" O\,el-,ill tnc,lns in the. \amex t-a\v 1 ~ 1 t h ditfcri.~ii\utpCricript\ ~11.c~ \igniiic,intl\ iiiltertwt ( l ' .- 0-05) t 72 11 \ , a l u c ~~-cter ~ to c ~ c l ~ ~ ~ i ldi triuenbk o n cl,)! 1 d i \ ~cic>d L!] :.
)-
7.(,IT
7(7
IIatendi, Mulenga, Siba~idaand Ndlovu
Illere ~v'isa trrtid to\v;lrds rc,cl~lccd\\,'iter intakc pc3r ~lnitof DM ,ISdictCiryroug11;lge content itlcre'ist~d. h ' ~ i l ~ / - i ~ l c ~ ; ;
p
\IL>~III
-..ct
- -
-.
\l ,1te1 c'onLcLnt 1 4 h \\.F 73 h \\.I C l \ , e r ~ lI~IL,AI~ l FJ t contcnl 24 h \ \ t 7 1 h \\,I O v e r a l l 111c~i1i I'rotc.in content 24 11 x\>f 72 l1 \ v t O\,er,ill mcX,in Ash i r ~ n t e n t
24 h \vt 72 h \vt O v c r , ~ l lm e a n ,'l'
h00
74
(AIC) 004
7.4 52
1 32 126 120,'
L1.2 '1.2
I SLJ
I 85 187
79 81 X0
5OU h07 hO I
74 74 5-2
(3.3 l h(I4 h17
S.4
0.2 '1.2
'13 ll0
(3-7
128 112 1 31"
(1.5
lO2',
I05 '1.2 7.0
43 4.7 .7.0
189 1 IJ' l
4..3 4-3
l Cl.? ISC) IC)l
4.8 4.3 30
5.4
84
5.4
83
3.8
H1
'7.4 3.8
S1 07 81 '
(7-2
5.4
3.0
( h c r a l l me,ins in thc same r o w w i t h ditferCnt superscripts 'ire signilic,intl!.
dittcrcnt
7.4
(>I0 (305
4.
0.05; T'ible ( 3 ) . Diet H homeorhesis. had significantly less fat th'm diets L and M in tlie three-rib joint (P < 0.05). Watering frequency affected water intake significantly, t l ~ e anim,lls watered daily drank proportionately about 0.24 morc than those ~ratcred every 3rd day. This obser\ration is similar to that of Discussion Nicholson (1Y89), who observed between 0.20 to 0.30 There is 1' positive correlation between water intake pr(~portional reduction in w'iter intake by the 3rdand DM intake (Sliirlcy, 1985; Forbes, 1986). Food d'ly watered animals, cvhile French (1956) observed a intake is 1' inajor cleterniin'mt of fluid intake and reduction o f 0.08 to 0.30. fluid intake appears to facilitate eating (Langhans 1.f ill., 1995). Significant differences were observecl Wlicn total watcr int;tke was considered in rel,ition among the dietary tre,itments where intake increased to tlic total watcr offered, the group watercd rvery as the roughage content, and consequeiitl!l amount, 72 h drank proportionately more (0656to 0.422) t1icin of the diet offered increased. Thc increase in total those watered daily. However, the group \vatercd water intake Inay be associated with the need to every 72 11 did not drink three times as ir~uchas those dissipate thc cxtra heat increment of feeding a i ~ dto watcred daily. These steers adC1ptcclto the w'1tering facilitate digestion and excretion (King, 1'183; f~.eil~~eiicy and limitations imposed by runirn volume Langhans c J f ill., 1995). on the quantity cirunk in single bout. 'l'llus, as c~bserved by Silanikovc (lC192), less frequently Silankove (1989) related water intake of goats (a wa terecl animals were ~ipparcntly ,iblc to balance species wt.11 ,~clapteclto drought) to digestible cnergy thcir water recl~~irements at a lowcr Ie\rel of intake. int,ike; and wliole-body wC1ter turn-o\.er to cncrgy t ~ ~ r n - o \ ~ e, ~r n d oxygen consumption. 111 this Maintenance rations should theoreticdlly pro\,idc experiment the lower tot'11 watcr int'lke o f t11c higher for the ,lnim'll so that there is concentratt3 diets mlris r>~~oci;lted with increds~d nutrient recl~~irements neithcr loss nor g,iin in weight. The energy intake rneasured per unit DM intake. It may bc rcq~~irt,nicnts \,dry ~vitlithe anim'il's n,~iglitcllid the erroneous to intcrprct this correlation as 1' C ~ ~ L I S J I
OS
Hatendi, Mulenga, S i b a ~ i d aa n d Ndlovu
Forbes, J. M. lL)Xh Tlii, ; , i ~ / i i i i t i ~ it i- i~i ~ , i i i i 1 , i X ~ 01 ~ /,I! iii r ~ i i i i i i i i / ~ cqlt~ility 01- c'11~'rg).c ~ ~ i ~ ~ ~ ~ ofi r the ~ i t oi ~o c~lgi\t\li i ortI15, I ~ l l l ~ l i ~ l 1 . ( l ot7t" t ~ ~ l Oli\ e i c'r, 1993) ~11c1thc 0\,e1.it!i ofZiii~bnlliclc~. 35'%more o n diet M a s compared with diet H. It may Nicholson, M. J . 1989. Dcprcssion of dry m'ittcr intake and thus be concluded that during times of water and water intake in Ror'in cattlc owing to pliysiological, trolumetric 'ind ternporal limitations. Aiiit/iiil I~ro~liie~tl~ii 49: food scarcity, a lo.cv-roughC3gediet, coupled with 3' 29-34. rcstrictecl watering regime, may be 'ippropriatc for growing steers fed a t n~aintenance. Shirley, R. L. 1985. Water r'cli~iremcnts for grafing ruminants and w7ater'1s ~isourcc ot milier,ils. In Niitritii~iiof ;L)-7(3.
-
Energy expenditure of cattle walking on a flat terrain
Abstract A stird!/ i i l i i ~~-iri.rii~i c l i i f to 1~7!i111iirf1~ fli(' o'ffi'c-1 ~ ? ~ I ~ L I I .rllillkirig ~ z o I I ~i i f~~ Io ~~CO, ii ~ ~ r o i f r i ~ l iriifiJ o i i b y tlio' c-irrlloii iii(1.x-iifi~ iiiliitiori ri~tc,li~c~lirii~liic~. Tliis :ilirs iise~iirs 1111 ir~dii-ir/or~ ; firr~i~iii~l 07iicJr x p i ~ i r d i f iT~Tr iO~ ;rkxrrc.isc,.
7 km
I lic~ c t, felt d c i e ~rn~nationi lepol tcd 111 tlic I ~ t c ~ a t ~tl1,lt u e ilu,lnt~t\ the c.ttc3ct of L\ a l h i n ~or1 eilt'rg). c~pc.nditurt\,and most ot the expt~riments ha\.[. been carried out in respiration chamber:, tor short periods ( 1 or 2 11). C'l,lpperton (19(11),Ribeiro 1.i 111. (1977) , ~ n i i L,,icvrc.nce ,111d Stihb'lrds (19C)0) estim'lted, usir~g thc cited ,ippro,ich, tli'it cncrgy expendit~~rc of gr'l~ingsheep and cattle mav increase their dailv m'iintenance cost from 1.10 to 1.25 times. Ho\vc\,c,r, tlicsc, results ~1pt)c"rto conflict with recent dat'i of Lamb 1.f ill. (1979), Nicliolson (1987) ,111d Thomson ,111d Barnes (1990), who did not obser\,e significant effccts of walking o n reproductive parameters, weight gain, ~ I I C rnilk ~ production and composition. Moreolrcr, tliesc, authors did not obser\,e a higher food intake that m,oi~ldexplain the absence of ditferences between treatments. , l
111 view ot the discrepancies bctwee~iestimates o f tile effects of w,ilking on energy expenditure, and considering the importance of the subject on pasture production systems, a11 experiment was conducted to estimate the effect of horizontal walking, at three activity levels, on CO, production rate which was itsed ~1san indicator of the relative animal energy expenditure.
Material and methods Es~~e~~iiirc~iitnl sift nild iirliirr(i1s Two experiments were carried out at the Integrated Unit INTA - Facultc~dde Ciencias Agrarias of Ralcarce (37" 45's; 53" W; altitude 135 m) during September and October of 1993, to estiniate the CO, production rate (CPIi) of steers resting and walking~ This wds used as an indicator of the animals energy expenditure. Two groups of three Aberdeen-Angus steers each, arith 1 ' 11 average live weight of 296 (s.e. 7.6) kg for cxpminient l ancl 285 (s.e. 1.00) kg for experimelit 2 were allocated to 3 X 5 m indi\ iciual pens.
-
L3~~tl~rii1iiliitie1il 11f1111, C'(], j ~ ~ o ~ i ~ ~17tcj ~tic~ir CPR ivas dctcrnnined by the carbon dioxidc dilution r,lte technique (S6nchez and Morris, 1983). 1)ic~unintioiic~t tlrcr iiilrriinl~ I h e da\ before the) experiments each animal w,ls fitted with a vinyl catheter (id.: 1.8 mm; o.d.: 2.5 mm) in the duct of the ~ s ill the parotid gland. A sinlilar catheter w ~ placed steer's right side into the peritonea1 cavity. Tllrougli the latter, and by means of a peristaltic pump, 5.4pCi / h of NaH1-'CO, diluted in a 0.1 mol/l sterile solution of carbonate-bicarbon'ite buffer (pH = 10), were continually infused for 92 11 at a rate of 250 ml/ day (di Marco pt ill., 1990).
Sanlpling of saliva started 20 h after the beginning of the tracer infusion. In experiment l , c ~ c c ~ ~ m ~ ~ l a t saniplcs of saliva were collected from 09.00 to 16.00 h (day) and thereafter until the next morning (night). 111experiment 2, periods of the day were divided as follows: prior to the activity (09.00 to 10.00 11) 1st and 2nd h of ,lctivity (14.00 and 15.00 h) ,111d post acti\rity (16.00 h) (Table 1). Ailil1ljtiai/ iie~tc~rirriirnfim. Concentration of CO, in saliva samples was determined by the Neiss's technique as described by Sahlu 1.f 171. (1988), and expressed as rnl CO, per nil saliva.
Table l S ( I I I I ~ pizriotf> / J I I ; ~f i ~ rL ~ X , I ~ L 1~(7ii~i ~ ; I2I J ~ , I I ~ S
Sample Fcc7dii IS Fxpt.rinient I Anin~als were given food to rnsc'~it.in incremt,nt oi 0.03 I / m per kg \/I < ~ b o \ c tlic cnerg! t ~ \ p c ~ t i d i t ~ of~;In r c ~,in~m,il,I[ reit ( 4 -l 7 kl:' Thc an,~l!.sis ot result5 in c,xperiinent 1 iho\\.s thcit l1 per kg \ I ) . ciduring the d,l! did not sign1tic'intl! ,~ttc.cttllc CPR,either during tlic s,Imc ci'i! or during thcs tollo~\ing night. Ho\\,c\,cr, in cxperiment 2, Discussion \.\-here s'l~nples~ v t r ct'1kc.n ~t different times o t thc The effect ot \v~~ll ~vliilc~ tlic animals wertx rcsti~lgor csxcrcising, been st~tdiecill!, sc~\~c~r,ll rt~searchi~rsin shcep and diffc,rences of Cl'li ot short dur,ltion were detecteel. c'lttle, using ciitfc~rc~nt ,ipproaclit~s.C'l;lppc.rton (1964) 170rexample, at rctsting CPR WCIS 817 ml CO, pcr h \ \ ol-ked \\.it11 slicep, in ,i respiration cl~amber, i~sing'I protocol iiini1'1r to tli'lt ot c\ptlrimt.nt I, c~stimciting ~ t ' rkg M".' rising to 1191 ml CO. pcr h tx,r kk M''-', a n cffcct that dis,Ippeared after-no Inore th,in 1 h thc cffect of 'In cxc,rcise of 411 on the energy folloct~ing tlie exercise. This increment in energy cxpuiditure ot the 8 1 of the d,il and the following expenditi~rewds three times lower than that intcrred l h h ot the night. His findingsiindic,ite tliat walking from ttic results of Ribeiro c2t (71. (1977) or Lawrence ent,rg), expenditure may incre,ise energy expenditure and Stibbards (1990) for the same exercise in I' L>c~t\;\,keii 1.38 and 1.72 Ih'it of ,lnirnc~ls at rest. Graham respiration chamber: 326 rl. 1095 m1 CO, per h per kg (1964) suggested that g r u i n g sheep could have M";', respectively. This striking differ;ncc m ~ i yhe recl~~iren~ents abo\,e 1.40 of those c'1gt)cl. In cattle, attributed to the fact that anim'lls forced to walk in a Ribciro cJt ill. (1977) dnd L,lwrencc dnd Stibbards respiration chamber, as in the experiment reportcd (1990) detc\rn~inedan energy expenditure of steers by these authors, have a l~igllerenergy expencliture w'ilking h kin/day as 1.12 tinies the mainten;unce than those of frcc-ranging animals (Grahc~in,1964). cost of stccrs in respiration chamber. In the, present experiments, although activity was forced, aniinals had been trained already to the Results from calorimeters or respiration chambers exercise and they were not confined as in rcsyiration differ from experimental data from other chamber experiments. Thus, animals' disturbance dpproaches. [,edger (1977) measured the extra was minin~aland increments in energy expeiidi ture energy expenditure of actility by the increments in other than tliat produced by walking were not food consumption required to sustain the li\,c weight expected. of steers walking 5, 10 and 15 km/day. He concluded that due to the effect of walking, steers of 275 kg According to the suggestions of Young and Corbett increasecl their mciintenance coilsunlption of DM (1972), animals with greater energy expendit~~re proportioncltel y to 1.24, 1.49 and 1.73, respectively. incrcascd by walking could con~pensatefor this by l~a\.inga greater rest time. However, the results of On the other h ~ i t d Nicliolson , (1987) determined that experiment 2 did nc~t show diffcrcnccs in this n g only onein cows the weight loss duc to ~ ~ i l k i was ~ d r i ~ j b,~mong le tre~ltmentsduring thc night (M,). third of tliat cxyectcd from the data of Ribeiro 1.t nl. (1977). This author stuclied the effect of walking It is 1111port~intto point out that tlie lowcr thaii 40 km every 3 days cluring an 8-mo11t1i pt,riod in a breeding hercl. Despite the severity of tlic trc;lt~l~ent, expected Increasc of CI'R m~glitbe cxplamecl bv ;In ,~dnptationprocess of ~1111mc~15 to exelow, as \\as no significant differences dc~c to walking were suggested b\ N~cholsc~n (1987) and TIiorn5on and clt~tectcdin the rate of wcight gciin of the calves. h r n e 5 (1993) Honrcver, differences in food intakes coulcl expl,lin these results. After a periocl of increo/isiri ~ of riiiiiiriiiiit~. Ch,irlcs C. Tliom\el 'ind 011 gr'ldients. Kriti.11 Jo~iiiiiilof Nlitritioii 18: 47-44. Cocimano, M,, Lange, A. and Menvielle, E. 1'175. [Cdttlr rei~uirernentse~clui\.alcnces.] l'ioii~rciiiiiiAiiiiliiil 4: IOl- IeN. Di Marco, 0. N., Mendet, D. G. and Corva, P. M. 1Yi)3. I Use ot (lie 'C-c,r rbon ciioxide cnt ry rcltc iech~~icluc~ in studit.5 of cuergy expenditure ot unrestr,linc~ci cattle.\ lic~r~istii Ai~(~iitiiin iliz Proillicc.idii Airiiiiiil 13: 117-126. Elia, M., Fuller, N. and Murgatroyd, P. 1988. l h c potetltinl usc ot I,~hclled b i c ~ r b o n ~ ~~nctliod tc for estirn'1tilig cni,rg>
44
M e n d e z , d i Marco and Corva
Graham, N. M. l'l(14 Ilnc,r.;\ ~ o . ; t of i ti~ci1112 ,lcti\ I ~ I C Y ,111ii e \ p t ~ ~ i d ~ ot t~~ gr.uing t - ( ~ il1t.c.p. . \ii~ti~ri/iiiii /~iiiiiici! ill ,'1:;i i~.ii/iiiriilRcw>iirc-/r15: ')h1)-'17:
Quinn, I. A. and Ilarvey, U. F. ILJ;0 I ~ - , ~ l n p l liv.ie\ i n ~ atid ~ I - < I \ L , I l?! c. i l t l i i ~ r\ ~t ~~ \ iVl(,\ico I l ~ ~ i g /oiii.iiiiI c'. 1il I < i i i / ~n/liiiiii~;i'iiii7iii ~' 19: l73-17h.
Ribeiro, J. M. d e C. R., Brockway, J. M. a n d Websler, A. J. F. 1977. :\ notc on the enL1sg\ i.i>st (,t \\,,lll,~n:; tn cattl. ~liiiiiiiili ' i . ~ i ~ f i i i - / i i l 25: ~i Ill71 10
Lamb, R. C., Barker, B. O., Anderson, M. 1. and Walters, J. L. 1')7CJ Etlt.,ing,>lid p ~ ~ l l i i ~Io~ici\ .; 1111 f l ~ t~ I I I - ~ l>\' ~ I C Brnlim,in c,?ttlt. and S\\,llrlp bullc>lo./Iiiiiiiri! i'ri~i!ic~iioi~ 50: 2')LYI.
(it
Ledger, H. P. lC177. Tlic utili/alion ot iliet'll-h eljclrgq h!, \trnd \ ;ilici,itio~lo t a 171-idlctio~i t>ilu.~tloi~ c,\hni,~tingl~cx,~t prod~tctionb~ c-.~t-honc l i r > \ i i l ~ >e ~ j t s \ trait. IOIIIiiii! I I ,~~ I I I I I ISI c~iIi/~ ~66: f l ~20?(>-2043. ~2 ~tt~i.Ii~i~cli~?. Sanchez, M. D. and Morris, J. G. IC)X4.Tnt.~-,q\e\l>t~nti~lurc, ot beet cattle. Sr~lzlngannli'>l gr,ii\l,lntt of 9-4 dnd 8.1 p C i / l ~for 38 h (experimcllts 1 and 2 rcspecti\.clq ), using portdble peristaltic pumps c'lrried h! e x h The ttnct.gy cost ot e'lting is \,er>,hdrd to e\.dl~~dtv animal (Syropuni, Everest Electronic, Australia). dirt,ctl\ 0 1 tree-grazing c,ittlc, therefore its Pumps were modified to 'ivoid d i t t ~ ~ s i ootl ~I4CO, fr(rom i n f ~ ~ s i oton sC1mplinglines, s c y , ~ r ~ ~ tchC~~1nels ing contribution to the total tmergy expenditure is diffici~ltto c,ilc~~latr~. Holmes i't (11. (1978) me'lsurcd of infusion and c ~ t r ~ ~ c t ihq o n a 2 m m ,~luinin~~rn tlie cost of g l u i n g , measuring the rtI' 5 0 06) t Average of 1-5 l1 ol glazi~igin thc tnornlng 'incl 4 h i l l tht. ,~ftcrnoon. Energy ecl~~ix alcnt ot 2 1 k l / l C O , r(g/kg) 270.0 A\,ail;~b~lity (g/ni2) 148.0 10.5 Height (crn) 1 15 Llcnsitv it. DM/m2 13t.r c m ) 610.0 ~igestihliit~ (g/ kg)' 140 O Crude, protein (g/kg)
s.c.
C7a t
+
Di Marco, Aello a n d M6ndcr
4b
rebpirator\ il~~citics~~t i s \.t.r! closc~lo 1-0 i\Vl~itel,i\z,, lL)74),this tc'i.l~~~iili~c t-it~m,>tc>s CO, production ~vith Iligli tp~.ccisiou, lio~z~c~\~er it consistc.ntl\ 11ndcre5tim~ltt.s HP in tastt~is l ~ < ~ ;l> , p ,\\, ;'l Ll-ot7 01 / t ! / ~ / l l / ~ 1t.l liniqi~c' l i l r i i i i t i / o f . \ric/iir!/ i i ii,ii~i. 1 1 l 1 \ 1;011g;11. /l'iiill,i/ 01 .\;:l i t l i / l i l i i l / \ c ll'iiii ' Sanchez, M. D. a n d Morris, J. 6. IL)S4 Cilr,l-.;\ c \ l x , n ~ i i t ~ ~ ~ - c ~ l l l / l ' / ~9s: l i ~547-5.54. '~~ 111 1~,1,t ~ ~ 1 1 1 1 1g~r1c~1i l5 \ l c > ~C~i i~/ /lt ! i I i ~ i/~i ~i i i i i i ~11t i/ S,II,IILL, 64 +II/I/J/: :32-.774. I l e r h e l , C'. H. a n d Nelson, A. R. l'jili,. 4 i t 1 \ 111t,\i ~ I tI c ~ ~ - c l o ~ - i i ,~1111iii~!/ ~
i I L I I I t t I 1 ~ t t l lttlt>. / ' i i / ~ / i ~ i i t i ~iit i i i t i i ~irii.i!,ir~,irii /Ii~i!~iiil-ii~ii (1,' ,>h\o~-lltion a n d mc.tc~Lxilibmi n the I-LII~~III~>II~ g ~ ~ t r ~ i ~ i t c ~ i Aiiiiiiii/ t i ~ l ~ Pi.oiiiii l ~III~I 13: 237-241 tr,iit ~ i i c i li\,c,r. ,l r c ic%\\. ~ /oil1 iicil irt Aiiiiiiii/ Stii.iii.c, 68: Young, R. A. a n d Corbett, J. L. 1072. bl;iinl~~n,>nce encl-gy 2'jL17-.?0 10. r e i l i ~ i r c ~ r n c ~o ift g ~ - ~ i / i n g s l i v ~ p ill r c , l r l t ~ o l ~to herhdgc> Osuji, 1'. 0. 1'174. The. p l i y b ~ o l o g ! ot eating , ~ n dtht. c,nc.Ig! e \ p ' ~ i d i t i ~ ~c11 - t . the ru1lii11~11lt 'it t > ' l i t i i r ~ ./oiii.iiii/ of Inctrgycoit ol \ \ a l k i n g i n c,lttle. Airiiiiiil I'i.ii~Iiic-ti~~ii 25: 1 0 7 1 10.
~ i \ ~ L i i l c i h i l i I.t y .C ' ~ i l o ~ - i ~ric. i i e tc s t i ~ i ilr~rm ' i l h ~ ~ m i n (llS~\)-C!,s-C;l!-C~nr\H priliiaril! h\ th,, ~111~1 t h ~ r ~ l t o r etlie , tnt'1l plasrlla d i l ~ ~ t i o 1n11. addition, on selected datcs, AT w e r e determined at higher d i l ~ ~ t i o n(sI : 160 to b i n d i n g \ ~ , ~ l u c~ sv c r cnot ~ 'ldjustcd. 1 : 40000); dat'l ,lrc, presellted a s pcrcent "'T-C;IIRH tic~lrnrlio~ri~lzl obsc~r.ili7tioi~s bourld a t a 1 : 2560 p l a s m a dilution, tliis w a s the highest dilution e x ' l r n i ~ ~ c da t w h i c h all a n i m a l s (by Sanlpling m r ~ t l i o d s(Altmann, 1974) d n d prc.\.ic)usl!, Jescribcd bcti,1\~iournl '~ctivitic.~\vc9re c \ , c ~ l ~ ~ , l t c d 90 d a y s p o s t prirnnci c1le.L is oftell escrted b ~the . bull (H'ifez ,incl Scllcin, 1962). The ~ i p p e rIlp is ~11rIci1 ~ ~ p ~ ~vtlile v ~ ~tlie r dhull r.iises ,inJ e\tcxntis tlii. neck r i ~ i c i loiver j'iw, occ~lrs~ i s ~ ~ a111 l l responie y to in\,e\t~g~iting c.lirmic,ll \uhst,incc,i, t..g. ,inogeni t ~ sc~cretions l (Schnt,idcr, I l)30; I'rice ,ind IV~ill~ich, l cK) I ). 'Two bulls e n p g e in J hcorilct in,inim,ite ohject, e.g. tlie ditch.
Finnertv, Enright, Prendiville, Syicer a n d Roche
74
oL7,er\ 0.05) hct\vt\rn Ihc o\ rr,ill mean AT for hulls '~ssignedto tlic M and H gro~lps;it either pl ~ :h41 inclic,itt,s L)C or DFD rne,lt. $$ SccllJiunn
173.4
~7hi 70'" l ilO,lL' 257" 3h'"'
1i1(sk'
13(7"" 4 15,' 58,1" 15'
15"
High C)
1
13~1
50"~' . r)(7 h,.
1'17' 25l' 24
1 L),,,'
40'"'
37'1,
c)2
1' 1
8(3
Total ci~.ti\,~t! -35l
l?(?' 2~12" l l clc' .5$ ntihod! tilrc groups. S ( ~ u , l ,~nci l 'iggrcsbi\ tx hC,h,i\.ioc~r ot ,111 bull5 \\,as obser\.td c-o~itili~~o~~bl!. fo1-4 11 ~ ~ p p r o x i r ~ i ~?\.er\. ~ t e l y7 ci,iy\ t o r 5 ~iionths. $ \'JIIIL+totc~ls tor 12 17~111s. ,'''L
""
Performance ot GnRTI-i~timunizedbulls
Discussion
i L)
\ t ~ l i ~ i~lcilined li initiall) hc.t\tc~~n h0 ,lnii SO clcl\.; poit I'liese ~1,ltapro\ 1~1t'n e \ \ intorlu~iticinon the. ctfcc t ot primarv L ) L I ~persist~~d b t > l \ \ . ~ 1'~ t ~11iJ i hilidin:;, tiitferent Ic,\c.ls ot (;nllH A 1 in tlic, criticcil pcricicl 'it ,I 1 :.i,-lO dil~~tioil, for at Iclc)sttli\ ~hO-d~i\ ~iur~~tion 1.t iil., lclej5). G! l'? prior to tllc' onicst of puhc$rt!. oli s~thsccl~lei~t of the e-qwriincvit (l'rc~~idi\~illo e\.cn tlio~~gli .l I testicul'i~. c1t.i c.lciprnent, hormone iol1cc~ntr~1tic)ns, ( J a \ , s 163 to 2.18) of tliis i.xpc~rinlc~l~t, of thc order ot 20"0 l~inclingA I 1' I : 2560 dilulion riggreiii\,c' those in C' hulls. This contr,ist, in ~ I . ciolls \ (;1111I 1 i ~ i i ~ i i ~ ~ ~ ~st~~ciies, i z ~ ~ t i o l ii11crc.ase in testosteronc coi~cc~ntrationsm,~! be \\,liere AT \yere, c~rpresscd, ~ ciilutions t ranging i r o ~ n re1,itcd to Ihc slight declinc- in AT noted. 1 : 100 to 1 : 1000, c~therse\ csral i m n ~ ~ ~ n i a ~ ~\A tcrc, ions rt,iluirccl to initi'lte thc prod~~ction ot AT or booster rhis I,ick of corl.c~l'itioi1hrt~vccntlie d ~ ~ r ~ i t ot ion the immunia~jtionswrc>re~~Jiiiinistercd to m,iint~iii A ' l biologic,il eftcct ot GnliH AT ,inJ the clur,?tion of thc~ \\'lien tl~c,! startt~Ito decline (Jeffcoate c,/ i i l . , 1'182; persistence ot A r is not nc\v phenomenon. Tn GnRH Ilobertson 1.1 i l l . , 1984). Although Al' iii tlie M and H immt~nia,>tions t ~ ~ d i eins \vhicti AT \,dried gre,itly g r o ~ t p w v ~ not , r ~ 'different after thc first two periods (e.g. ,?O"i, ,it 1 : 640 (I'rendi\rille 1.1 i i l . , 1995), 40°
