0/lllerotl'jJOOI't ./uurnal of Veter1nruy Scic1u·e and clll'illlal lnd11stry, l'ol1111113 11, .\''lllnbn 2. Octobe1·, HJ:38.
l'rint<'d in the Union or South .Hri<·a by the
Gon't'l11llC'Ilt Printer, Pretoria.
Plant Proteins. V.-The Biological
Lucerne and Lucerne Supplemented Cystine in Sheep.
Value of
by
By D. H. S:MCTS antl J. S. (' . .JL\HAIS, Section of K1JtrilioJ1,
Onder~tepool't.
J.\ experiments ,,·ith r<~h-; (H):l7) it was ~hmn1 ! hat lurerue proie.iu ff'<l at <lppl·oxim<~tely 8 per ('ent. leYel, gan' the lmYec-;t biological Yalue of all the plant proteins so far inYestig<tted. This <lefediYe ut1l.i>miion of the lucerne protein by rat,; ,,·as then <lefinitely "howll to be C'<ll!c-lecl b~· a tleficiency of the amino <l('id t·)·stiue, "·hi('h, \\'ht>ll a<l<led to lu<'enle in minimal qu;mtiti.ec-;, enllfln('etl !1:-; biologic<~l Y<tlue consi<len1bly. 1u Yie\\· of these finding,;, together with the
<·ontr-on•1·sial opinions i11 tl1e literature <IS to the rOle of cystine a]l(1 snlphnr-,·mHpouDds ill the• nutrition of shc·t-·p, it \\·as regaJ·cletl a::;
t'"seutial to attac-J; the question hom a some,,·hat differe11t nngle :wcl to :1::>ce.~ tain ,,·hether tlw acl,liti.on of c1·s!ine to lucerne has nnv eftect
Oil the biolog-il'~d utili7.:1ti.on of it,; nil.rogen by sl1eep. ' Until qnite re<'euily ihe iJl(li,;peJL~abi.lity of eysti11e in the nuh·ition of !he rat has been re('og-nize'l 111liYPnmll.v. Rosp (10~7)
no"· queries the indi,;pensability of this amino arid and stat·es that it onl)' ads as u stimulant to gT<lldh 11·lwn methioniJlP is pre,;e11t iu suboptimal quantities, nn(l that tl1e Jntter is in re<.dit)· ihe indispensable ('Omponent. HmYeYer, u lllUllher of "·or];er~ IHnng-,
'1'. R. (HJ:I:l), Mitchell, H. H. (lWW), Smut,;, J). B. (HH7),
Sc h rewslnu-' ;md Brutzler ( 19:1>l), \\-ei('hselhaun1 (10~0), and Scoz
(1W~2) J ha,·e shown that ihe addition of cysti11P enhnneeR tl1e g-ro,dh- prollloting properties of a protein feed rlt·fieit>nt in this amino a<'itl, :m<l that it is neces;.;a1·y fm· Jlormnl m1trition. .Furtlwrn1ore, it l1as been shown that ihe arl<lition :1f mi1nll·e qu:mtiti.es of ('_\',;tine io a ('\·stiJJe defi<'ieut ration markerlh in('rense,; the utilization of the a·bsorhed nitrogen of s11d1 :1 1·ati1;n. 'l'hese ol;sen·ati.onH, it appears, C<lll only be explained b_,. assuming that the nrlded c~Ai11e
snpplemente<l tlw <·xi;;hng- amino :witl complex in the p1·otein n10lecnl<·', then'b.'· n eali.ng <Ill assortJnPnt· of amino aci,ls more suih1hlP for the :-;electiYe need:; of tissue ,,·nthesi;.;. The <'vstine indusion ihc•i'Pfore a1·oids that ,,·n~tage .of .:olnino a('id nit.r~gPn ,,·hich, in
it" ahs~·nl'e, \YOlll(l hnYe bee11 illt'(llllpleiely utilized anrl mu;;t
collsequeJ;tl)' be reganle(l ns <'""('llti,Jl in the proct>ss of iiss11e con:-drur·1 io11. On the othe1 l1nnd, .Tar·ksoll :wrl Block (1:)32) h:we
~99
PLANT PROTEINS.
shov.·n that on a cystine-methionine free diet cl-methionine a1Hl formyl l methionine" ean stimulate growth in rats. \V eichsel ba um (l!Ja5), on a Sherman-Merril cystine defieient <liet, founr1 that rats deYelop a syndrome 'dticlt can be preYeHted by eithr'r methionine or cy::;tine aurl that cy::;tiue alone ronld overconte sympt.omt:~ whell they have definitely appem·ecl.
\VhateYer explanation may be fortltC"oming, tlte pn•pmHleran(·t' of evidenee at present f<lyours the indispensability of eystine in the nutrition of th<:· g-ro11·ing rat. I1 furtlwr appears that apart from methionine no othPl" kno11·u amino aritl can repla<"e c~·stiiH' i11 a ration o1· that the biter can be Hynthesi7.<'rl by tlte rat hom ;;implPr
org·~mir· or inm·g-;mir· snlpltur-coutaining coJnpottJHl,. Hose ;tnrl Huclclleshn (192G) and Lewis and Le"·is (192G) foun cl that taurine,
:t der.iYa1iYe of l"y:;tiue, C'·ould not supplement a c_y;,;t.iJH:' clPfieil'nt d!l'i
f,~r maintenaFce aud g-nm·tb. \Vr':.:tPrmaH ancl Rose (Ul:27) ohl;rined un e,·.ir1Pnce 1lt:d l11i.og-l::collic acirl aH<1 r1ithio-tlipropiouic-<tC'ir1 ("ollld he utilizerl for synthesis of e,p;tine by the rat.
A;;; far,,,; s_yJdhel'iR of l":'-·stine hom inmg-anie Hulphtn j, conC'eJ·Jter1 only n<-'gatin' rl:'suli,; h:tYe hrt·n obtain<'cl. D~1niels and H.ieh (1!11~) founr1 iuorganic :;ulphates incapable of co1·ering- a cystine defi<"il:·nr·.'· either for gro,,·th m· maintenance. Ueiling- (l!.J] 7) ohtain€'<1 no chang·<' in thP rledining· ,,·eight of mice on a <"yshne rlPfici.ent rl.id ,,.h<•Jt flo,,·ers of sulplntr were added to it.
\\Thile the in<1i,;pensaLilit;.· of c-.Ystitte in the ahsPnce of sufhcient tnethionine ho1rb h·ue fm· rats anr1 ollll'r OllllliHn·ps, ii sepms qniie possihlt· thnt rumi n;tnts ,,·i.lh l heir complie<llNI nnrl cli-IYPrPnlh r·onshnder1 ;tlimPnial·_y hact mny rl'ad oilH't">Y.is<·. fn fact, ilt~·
synthesi,; of ,·.ihtmin 11 hy the ru111en flont of utitle, ;ts posinlaled h.1· He("hrlell, Hone_,.,,.<·'ll, ])urcher and Knuhwr (18:28), strongly i.Hrlit·<lil:'s that therp are dis! i~>ct rli.ffererwes in i he r1ig-<'stiYP activities of these two types of animals. Heasoning· on more or lr~s analogous g-rounds, H i•ui.np;lon <llll1 BPkl,er (In:\2) su!:!:ge,;te<l that shePp ma~- lw ahlt, to syntlwsi:re C'_n;line throug·h a "nnhioti1· "' tion of the iniesii11al flont. Frasf•r anrl Frn:;er-H-ohPrts (Hl:J:2), .in trying to Pxplain llw hig·h percentng-e of cyslin<' .in >Yool ,;ugg-cd ihat ihe woe] follir1l:',;
t.hemf'Phes mn,v perform this sperial function of ir<tnsfonnatioJt into cystine. 'l'hec;e thenries, nlihough probable, ean cnly be "oher1 one 11·ay or tlw other if sueh fadors as the cystinP content of the ratimt, percentage ulili7.ahon of r;.·shne for maintenance, gTo1dh, :mr1 wool proclur·iion, ~1nd the cystinP contPnl of ihr' firer<'. arp r1elerntiltNl.
In the ah;enee of the latter information, it appears hut nahu·pl to aceept vVoorhnan anr1 Evans' (19:32) expLmation that there is enoug-h ey:;tine in pashtre to sati,;fy the tJE'erls of g-rmdh and \Yool prochtr-iion in sheep.
In our >York on the detenninntion of !he hiologir·;tl Yalue of lucPnlP for sheep, it seenwc1 as if 'Ye e.onlcl obtain ,;onte information on the e.vsti11P problem hy supplenwnting- lucerne ''"ith c.1·stine and determining its hiologiral ntlue. If cystine is in<li;;;pen,;ahle for slwep anrl thP cystine alH1 1nethioninP r·ontPnt of lur·erne ioo lo\Y for mni.ntenan~e, then onE' >nmld expecl nn enhanC'Nl bi.olo~:6cal Yalm·
with the addition of CYo>tine if no synthesi::; of this amino ;lr·ir1 i.s
accomplish eel. · ·
400
D. H. SAllJ'fS AND .1. S. C. :MAltAIS.
ExPJ-:Hll\lENTAL.
Four mature 11·ether meritws 11·ere used in this experin1ent. They were transferred. from a stan<lard protein ratioll to a nih-og-en-lm1·
ration for 15 clayH, after which period they were put in mebLolism cag-es. The rolleetion period;, lasted ten days, and the preliminary feeding pe1·i()(ls of the P!·otein rations also ten clays. 'l'he feed for each experimental period was weig-hed out at the start, and from it the daily food 1equirements "·ere weighed out and placed in paper bags. Hepresentative ,;ample,., were taken and analy,.,ed in triplicate.
Sheep IYere fe<l once daily anc1 an:;· unconsu1necl feed of the <lay co llede<l, a ir-<lrie<l an <1 stored.
r rint> \\'[IS eollecte<l rbil_v irl :2 !WI" ceJlL IICl and the Ul"llle, tog-ether 11·ith the washing-s ll![Hle up to a kno11·n Yolume, frolll 11·hirh a 10 per cent. aliquot was b k<'n :mrl stort><l. The daily collection of faeces 11·as air-driPd, 11·eig-ht•<l, aliqno!Nl and store<l in air-tig·ht rontainers until analysed. The ~-on1position of the rations is giYen in Table 1. By lucerne hay iti meant 8liJHhie<l hay which 11·as chopped in <·onYenient leng-ths to prevent spilling·.
T.-UILE 1.
Colllz!osition of Hation.,.
Lucerne hay . . . ... . . . Cystine'-.. ·_ ............. . . . CodlivcroiJl . . . ......... . SaJt ................. . Hone ash2 • .. . .•••• • • •••••••• . •.. . • . .
Dex starch ......... . Agar .... .
TOTAL .. . . .. . . .. ....•..
A.
:Z·O :Z·O 3·0
-1--~ ·0
100·0
H.
;)6·0
·:20 :2·0 :2·0 3·0 :36· 8
LOO·O
c.
2·0 :2·0 3·0 73·0 :W-0
\_loo._ o __
1 Cystine was prepared from wool a,nd contains ·li.J. per ecnt. X in eomparison with the theoretical value of ·116 per cent. 11/. The latter Agure \1 as ntil:sed.
2 Bone ash contains 42·:'i per cent. Ca and 17·04 re1· cent. P.
ExJ•Jilll ~~ U\'TA L REs"GLTS.
Tlw re;;ulls of the metabolism experiment;;, h)O'etlwr \Yith tl1e
(' ~ll:oulahon
o1 the biological value", are giYen in'l'~bl e
2. As 11·ill be seen, thP ordpr in which the> rlifferent periods appPar \YUH as follom;: Nitrogen free period, 8 pt•r !'ent. luceme prott>in, 8 per ceni.'lnrernf-' protein ~upplemented hy cy~tine, follo1rerl by a nitrogen h·ee
pe1·iod. 'l'he 1·e:mlt;; o£ the fir"t nit-rogen free perio1l IIPre utilized i11 the 1·ah:ulation of the biological value of the 8 per cent. luf'erlle prot Pin ra lion. 'l'he same procedure 11·as followed in calculating the hiologif'al Y:tlne of lucerne supplemented by rystine hy using· i.he
401
0 t
e ..
,
PLANT Pl10TEIKS.
figure,; obtained in the second nitrogen free period. In g-raph 1 thP metabolic faecal nitrogen for tl1e two nitrogen free 1wriods ir; ploHeol against the COJTeSJJomling· quantities of ch_,. matter intakE'. These points, except for one, Yer.\· 11earl~· nssn1ne a shnighi lint:' showing.
whnt is generally acc·epted, thai there is a ~trollg positiYe <"on elntion betwef'n ilry matter iutnke nncl metabolic faecal nitrogen t'li1ninaiioJL
T.un.F 2.
The AJIJ)(lrent and True !h_rJestilu"lity of /,1rccn1e (lllrl J,ur·en1c SuJiplelllenterl hy ('ystine.
Animal Ko. 1- -
1 Appa.rcnt.
i I -~~1 True.
I
Ll"CllRKE CYS'l'lKE.
App>trcnt.
I
True.- - - - -
.1 .•. . . . .•....•...••...••••••.. 71 90
~' I
76I
77 97 39 79
7~ II 88 64
I
8279 87 6> 82
~~~~-;;~~~~~-;;,~~ 1 ~---;;,--l-80-
2 ..............•............
3 ...................... .
;) ... .
GHAL'H l.
Relatio11 bet11·ef'n Meta hoi ic Ft-c a I N a 11cl Dr.'· .\I nttc•r Con~umt>cl.
470
450
/1 -
I
430
/
I
I410
/
390 ·-
/-0
I
~70.
/-
350
3~
330
~
v
0 0310
0
7
290 270
/
v
0250
·60 ·65 ·70 ·76 ·80 ·86 ·80 ·95 1·0 1·05 1·1 1·15 1·2 1·26 1·30 Metabohc Fecal N per day.
402
Jl. B. Sl\il:TS AXJJ J. S. C. )lAHAIS
The a1·erao·e bioloo·ical value obtained for lucerne protein <It <Ill S per cent. le;'el is
GO.
Sheep 1 and 2 in both periods of protein feeding- gnve highe1· biological values than sheep ~~ and 5. This ±act i::> not ac2ountecl for by a difference in <1ige;:;tibility, but is in all p1·oba bility clue to a better utilization of the ab;,orbed nitrogen, ,.;iJtU' there iR not much clifferenee in the magnitucle of endogenous nitrogen e:\cretion beh,·een these Rheep per Kg. bo<ly \Yeiglti. The fact that this difference in biological values is so oonsistent in the two different period,; shmY that it must be due to some inherent Jifference iu the physiological abilities of these sheep to utilize the absorbed nitrogen better than their two companions.'l'he Ynlue ()0 ohtainerl by u,; corresponJs "·ell with the value obtaineJ for this 1n·otein witb rats anrl also agrees Yery closely ":ith the Yalue reported hy Satola (19aO) for sheep. Satola's Yalues vary from 5~) t.o 60, with an average of 5G. Tbe value reported by Turk, Morrison and :M:aynar<l (1934) are mu<"h higher and average 78. The HYerage apparent digestibility for lucerne prott•in as reported in 'l'able 3 is 75 :md the true rligestiLilii:v 91. Om figme nvprorwlte,.;
\hat of Satola but is much hig-ht>r thnn 5(; as reporh-'cl by 'l'nrk and hiR co-workers.
The addition of cvstint> to lurerne he~s no effect on tl1e ntil izalion of the lneerne n itrog-~n. 'J'he average biological y·alue under these conditions is 58, a value very similar to that obbint>cl when lucerne 1n1,; fe<l nlont>. In fact the addition of eystine depresses the apparent ,ligestibility of lucerne protein. This effect also shows up in the true digestibilihes. In colllpnrison 'Yiih the first period of lucerue feeding there is a marked inc;rease in the nitrog·en elimiw1tion in the faeees
" hen cvst:ine was a<lded. Whether this is <lue to an incomplete
<I hsorpt.{on of eystine m· an inhibitory effeet of cystine on the other
Hiirog·enon~ constituents, which normally \Youl<l have been absorbed,
i~ difficult to :-;ay. It is, ho11·eyer, evident from these 1·esults, that ,;heep when fe<1 011 :m 8 per eent. lucerne protein clo not need extra
<·.vstine. These ;.;heep as was ::;tniecl were m::tture \Yf'lhen and would consequently not· have put on ne11· tissue'. It HJ:1y I herdore he quite possible tltat a more lihE>ral neec1 ±or cystine may ocnu <luring- periods of actiYe growth.
Fm-t ltermorP, although this \York shows that. ma itne sheep fed on lucerne do not" need cystine for maintPnance mHl \Yool produetion, it <loes not exclude thP possibility of synthesi:-; of this animo H<'i(l.
~ eYertheless from a, pradical point of view these results n re of great YahtP since they e:-;tablish that the utilization of lucenw protein for maintenance nnd wool produdion is uot impaired b:Y a cleficiency of cystine.
CoNCLUSToxs.
1. By me::tns of tlte balance-sheet method, it has been shown that the hiolog-icnl vnh1e of lucerne protein for sheep is 60 and that the :ulclihon of cystine does not effeet this bioLog-ical Yalue.
403
...
0....
TABLE ::_ .lletuhohs111 lJatr~ rwrl Calculatio11 of Bioloyical T"alue (JJoil.IJ llosis). Metabolic
I I Enclo ~enous
I.Fecal N. ::--1. Total ______ Dry N N in Footl NAb-l:ni-TJJiha I l<'inal Average M.atter Intake feces !'cr N in sorbed. narv l'cr l'n Weight. Wo:ight. \\'eight Con- Daily. Daily. Gm. Per
I
feces. :-J"." Kg. Drv.I
SillllCd. Dry Day. \\'eight. Animal No.I
\I ,·,tt<'r. Kg. J(i!.I
Kcr.~ n '. I
Gm.I
Gm. I_ Gm. I Gm.I
Gm. I Gm.I
Gm. I Gm.I
Gm. N FREE RATTON. 1 ............. I :36I
31 2 .... · ... ·J 3~ 3? 3............. 3, 3o :;_. . . . . . . . . . . . 40 44~~
I~~~ I - I ~? ~~ I : ~~~~
I 3fl 308 --. 677 . 0022I
42 4G1 -I I ·29 ·0028 ---'--- fl PER CEl'T. Li'CERNI~ RATlOK. 1. . . . . . . . . . . . . --:11 _1_ 32
2........... 34 3.~ :~... . . . . . . :~;; 3i'i "--...... 41 4331· .11 i'i2:~ I 8· 291 , •• 1 0030
I , , I
0 871 34·.1 i'ill ! 7·82 1· 79 ·0031 1·58 0·:21 35 ;)23 I 8·41 2·20 ·0022 1 · I 5 l·Oi')I
42 ~61 7·33 1·53 ·0028 1·:!9 0·2+, ., I
7·61 7·3G 7·091·20 I· 70 l· 26 1·39 3·91
I
4·:21 ,l-62 c[-;)H --·---·~·036 ·04H ·03i'i ·0:13 0361 ·0+8 ·035 ·033
t :: I
1·23 I ·3!)Foorl X l{c-Biolo- Jn . utca.l l'r·inc. tamer!. \7 alu
c. Gnr.
I
Gm. I 2 ·78 1 4·64 63~:i~ I
;)·0666 3·97 M 3 ·19 3·90 f);) A\·crago .......... 60 N P'REE R;ITION.
r
33320 960
I
0030I
-- 1 10I
·03:~I
--
I
-I I
35 270 -837 . 0031 -1·40 ·040 3G 400 -1 16 0029 --1·29 ·033 42 3;)0 . 980 . 0028 --1·30 ·033
---- 1. ... :34 3:! :! ......... 3!i 35 3 ...... 3;) 37 !5 ...•.... 44 40 ~ Prm CE:<T. LuCEl~NE RATION PLl'S · 20 .PElt CENT. CYSTINE.
1.. 1 4 I
362 .......... 36 36 3 ....... 3i'i 37 5 .... J2 42 3 .. 5_
I . ~ 6
::16 16 :16 l6 4:! 168·131 3·47 1
·0030
I ~ :~~ I
I· 921 6·21 3 ·:)6 ·0331 1" I
~-40I
;~. 81 61 8·13 :~. ::13 . 003.1 1· 73 6·40 3·80 ·040 1·44 2·36 4·04 63 8·13 2·94 ·0029 I ·.50 1·44 6·69 4·28 . 033I
l· 19 3·09 3·60 i)4 8·13 :!·88 ·0028 1·44 1·44 6·69 4·!')7 ·033 1·39 3·18 3 ·;)] .12 -- Average ...... 58 ==---...,
~
..., >-o...
"' 0 ..., t-j ... '7, rP.Jl. Jl. S~JCTS AND .1. S. C. 1JARAlS.
2. The apparent digestibility of lueerue p1·otein has been found to be 75 per eenl. and the hue <ligestibiht:v 91 per cent. The atl<litiou of cystine depret>ses tlw appurent digestibility an(l to a slight exte11t the true digestibilit~·, ihe average :figm~;-•,; beiJJg (il and HO pe1· rent.
respecti ,·ely.
:1. Tt has OPen sbo\Yl1 thai cYstine i.s not a limiting fador m lucerne proiein "·hen fed to mah~re shPep.
BECHDELLS, HO!\EYWlmL, H., Dn!CFII£H. H .. A:-;-n KNUTSEX, M.
(1928). Synthesis of ,·itnJnin H in the rumen of tllP co11. J.lJ.('., Yol. 80, pJ1. 2:31-238.
DAXIELS, ,\. T, , AXD RTCH, .1. K. (1918). TIH• r61P of inorganic snlphatE's 111 nutrition. .T. 7/.(' .. \'ol. :lG. pp. :27-3:2.
J<'IL\SI•~H, A. H., E D FHASEH-ROBEHTS, J. A. (HH2). C.ntiJJ(' a11cl wool producti:Jfl. ·:-:rdu rc, \'ol. UlO. pp. i)/:1-~-74.
GELLTNG, E. l\'1. K. (Hlll). Tll<' 11ntritionn! ;-alue of tlw cliamino acids oC('UITino- 111 protein for tllC' nlnint<•JJanc-P of adult mice . .f.H.(' .. Vol. 31, pp. l 73-l98.
HAAG, J. H. (1931). Uy~tin.c as a limiting fa<.:tor in the nutritive valnl' of alfalfa protein . .J. N'dr., \Tol. ..J., pp. :lG:l-370.
JACKSON, R. W., A!'D BLOCK. H. J. (1932). The anilnbility of methionine in supplementing a diet deficient in cystine . .J.B.('., Yo\. 98, pp. 465-477.
LE\YlS, H. D., .11-'JJ LEWIS, G-. T. (Hl26). Can taurinE' replac·E' cystine in the diet of the young \\·hite r:~t. J.II.C., \'ol. 69, pp. •589-598.
l\HTCHELJ,, H. ll., HEADLI£:-J,. J. H., A:-~D BllAl\lAK, W. (1930). TI1E' relation !Jet\\·eE'Il cystine defic1enr·y in the diet and gro11~th of the hair in tlw \l·l,ik rat. ./.71J' .. Yol. Rt', pp. 623-621.
RDLINGTO:t\, C., Al\ll BEKI~EH, J. G-. (Hl3:2). Ts prPformE'd cystine essential to sheep for 11·ool prl)cluc-Lion. 'Yahii'P. \'ol. 129, pp. 6R7-688.
H.OSE \\T. C. (19:l7). The n11tritional signiftC"nnc·c- of tlw Amino H('id' and
~ertain rel:~ted compr,llnch. Scienf'e, \"ol. R6, pp. 291:>-300.
HOSE. W. C., .\XD HUDIJLES'I'IK, B. T. (1926). The :11~ailabilit" of tannine as a ,;npplenwnting ngPnt in diets deficiPnt Ill t·ystinP. J. n·.c., Vol. (iiJ.
pp. 559-605.
SA'I'OLA, J. (J9:lO). BiologiC'al vnln<'s and Sllpplcment:uy relaEons of the proteins in alfalfa ha_,. and in c·orn and sunflcJin•r silage• . . / . . -!(Jr. l!C'.I., Vol. 40, pp. 79-96.
SCHH 1~\YSBL!RY c .. ANU BH.ATZLI<;H, J. \\'. (1933). c,,·stine rlefi('icnc\' of soyabean p1:otein :ct 1·nrious lE'vels in n purified ration and as a snr:iplc- ment to corn. .] . A.(fl'. Rrs., Vol. 47, pp. 889-895.
405
l'L.\NT PllOl'Eli'iS.
8COZ, G. (193:2). The intportunce of c~·stine in the economY of the organism and particularly for growth of hair. ATch, Sci. Biol., Vol. 17, pp.
3+1-82.
H.Jil''l'i::>, D.
n.,
AX]) ::\fAHA18, J.c. s.
(1937). '!'he supplementarY efl'ect amongst certain plant protein. Ondentepoo1·t .Jnl. Vet. 8c. and An. Ind. (in Press).'ITHf(, K. L., l\JOJWISON, F. B., AXIl MAYNARD, L. A. (1984). The
nutritiYe value of tbe proteins of alfalfa hay and the cloYer hay when fed nlone and in comhiPntion with the prolein of corn. J . . lar. Res., Vol.
JS, ;}p. 55U-.3i0.
\\'E fCHSE LBA"C .JI, T. 1<:. (193.3). Q,·stine clt'ficienc,· in the albino rat.
C.ilwrt. J. Exp. Phys., Vol. 25, pp·. 363-7. ·
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