Onderstepor!I'/ Jo11rnnl of l"t1er/11ury ,'.:.cie"i'l' 0111! .-1/(iJJllli l11d11slry, 1'ol11111e 10, .\'11111/icr ], .Jr1111ull'!J, UJ:JS.
P;·int<'d i11 thL' l'11io11 of :-;outh .\fric;1 iiy the Go1«'rn1111•11t l'ri11k r. Prdoria.
Protein S t ud ies .
Plant Proteins 1.-A Comparati v e S tud y of the Grow th-promoting P rope rties o f the Prote ins of Peanu tmeal , S e sameme al , C o prame al , Luce rnemeal , and C ottonseedm ea l.
1h D. H. ~\lrTS. ~1'1lio11 of Hiocl11'111i,.;tn and Xutritim1.
( li11Jpr,delJUOrt.
]:-i the comse of e:s:knsiw inwstigation,; at ihis Jn..;titute on the llliner;Jl c]pficie111·ip,.; ]lrt'\·aiJing 111uJe1· natural C'<lllditioll,.; of p;r;1;:ing,
llldicniion~ poiniing ((J ~I iot:11 ()[' rrnrh;il protPill 1h'fiC:iPllC_\' during 1·ednin ~e::isons of the \·e;1r lwnc' 1;ern ob.-;l'n·ed. Thi,.; oh..;ery;i(ion, logetl1Pr \\·iih ih1' fad th:d tliPre exists a complete lack of relinble
<lain 011 the co11~titu!io11. ,Jip;l'..;lihility, u!iliznti011. 111ul nutritiYr Yalne,; of mu protein feed.-; in gPneral, "·hid1 ,;p:-iou,.;ly impair an.\·
n!lempt at <«llllponrnlinp; r;i!ion..; m ..;uppl<'menti11p: 11rntei11 deficient gr;1;r,111g 011 ;1 ..;ci<'1it ific ;111c1 P1«Jll0l11ic,d ha..;i..;, g-.1\1· 1 i;:;e tot.hr iuit i;dio11 al lhis lnsti1ute of :1 foirly 1"de11si1·e progr:1111rnl' e;OYl'ring lhe Y;1rious
;1spec1s of i1ro1.ei 11 nu! rition.
'l'ht- prohlt-111 of pro1Pi11 "<'qt1irr111e11(..;. althoug·h n11 PXJl'('lllely irnporL111t ph:1s1· "t :111in1:1l 1rnfrilio11, ha . ..; on ;11Tu\llil of it.-; co111ples
·na1 un' ;;o for 1lt'fi1'11 <111110,t 1'\·l'1·y ;ii tern pt <II <1 co111ple!o and. s.\·si.e111;d i1·
solutio11. ThP 111<'lhod :if l''\l11'("''i11g pnd1'iu requin'rne11t,; 011 tl1<' li:hi:; of <1ig\'..;lible protein, <ls i..; thP popnL1r j)l'01·edurP, i~ ;1 s111\iY;1l of (!te lime,; \1·hl'11 dw111ic:1l diftPr<'llCf'" 111 the co11,;lliutioil of prnteills
\\·pre not <l[llJl'<'(·i;itt-11. :\c·\·erili0le~..;. !hi,; uw!hud of exprps,;i11g prntei11 reljuirernPnt:; Lrn;:; lw1'11 of im11u'11;;e practical \-;1lne in thP past a11d \\·ill prnlialil,v con!intw in ih po11ularii_\. for th1· !illlP heing in lieu of a rnon· sciPntific nnd ;1pprnpri;ite u11it of PXlJr<"'"ioll. I-Io\YP\·er, i( is foidy clpar I lint tiiP dige.·diLlt- protei11 concep1.io11 is ;1n Pxpt·e,.;- sion without any physiologic<il sig·nificanr·p or i111.e1·111·pLdi1111 in tlrnt it is <'11tirely b;1ser1 011 t}w 11ih<'relK<' bet \1·ee11 11itrnge11 intakP and nitrogen eY<1l'l1;1tl'<1 in the foeu•,.;. Co11selJUPntl~- it afforlls no inr1ic:a- lio11 as to tlie lll<lllner or ;111101111t of Jll'OtPi11 uhlizecl by tl1e ;111irnal
193
l'LA'.'<T PROTEINS I.
Ol' the r1ua11hty nece.-;,;ary for maintaining the integrity of the iissut>~.
It lias ali;o been ;1mpl:v <lemoustrate<l that protein feerl.-; or mixture~
of such ±eell,; rlifter 11·itlely in their nntritin• Yalnes, anrl that these difference., ;ne clil'edly attri1rnlahle to the <lifferent prop01ho11s and am o uu ts of amino acids present in the respect. i 1 e prntein molecules. Expressing', therefore. the i·equirernent;; of protein in tel'rns of digestibility inesped i1·e ot the differences iu the amino acid con:-;ti- t ution is not only e1 misrepreseutntioll of the adunl biological Y<1l11P of sue: Ii pro lei 11s but also inc-ongru011s with !lw pre,;ent ('OJlC·epi iou 011
1Yhid1 ihe metabolis1n of protoi11:-; i,,; based.
lt avpe:in>, iherefore, that an entirely new line of i1n-estigati.on sh011ld he follo" eel in order to arrive at a means of expres.-;ing proh-i n 1·equireme11 ts, "·hich "·ould 11ot only be applicable i u practic-e hut
;ilso re:;peds ilrn hnn; go1·erning prntein metaholisw. N11d1 a rnethocl has been prnposed by Mitch ell (192G), 11·ho recognised two 11isti nd phase,; i11 the probli>m of lleterrnining tlte prntein 1e;1uiremenb of animals. l<'irstly the determi11atio11 of prntein requirements in i.e1rnf>
relating to animal tis,,ues a11d <tnimal prodnc;t,,, for the preserYation
:ui<l elabol'atiou of \\'bich foo(l p1otei11 is uPede1l arnl, secondly, the
detenni11utio11 of p1·,oteiu 1-;1hrns of brn1 feed:; allll mixture of feecls lo coYer i hesP l'e<]uiremenb. Ar·r·ordi11g to }Iitchell these brn prol1- lems, although closely conHeded, 11rnst be inYesi.ig;1ted sepata1Pl.Y and by <liHe1eut 111e;rns in order 10 aniYe at a complete solution. 'l'he fonner may he 111easurt><l hy Hie total nilrogen content of the tissuP
<·onstitue11ts c-ab liolizell eu(logeuousl~· (mainte11ance) or b.1~ the total nit rngPn !'Onient of the i1e1Y tis,.;U()S for11rn<l in gro11th aucl reproch11·- t io11 or by the total nii:rogPn ('Ontent of tlte milk prorluee1l in lacta- tion. A 111easurp1ue11t -of the latter component must !'ousi<ler the total ptolein co11tent of the fo0<l or nit-ion, the lo"s or wastage of protein in 11igestion ;1nd the lo:-;s or \rnstng<, of protein in the process of its 1·011Yersion i11to tissue 1·011si ilueuis or the constituPnts of hoi!v secretions. If, therefore, ultimately by this method the amount ~f protein ulili;1,ed fm· the elaboTation of IIP\Y lis,.;ue, for insi:rnC'e, :rn<l on the other haml tlie l1iologic:1l Ynlue of a prntein fee<l for grn11·ih he cleterrni.ne<l, it bel'omPs a sirnple rnaite1· io sinte or r:1kulate the quantity of cligestihle nutle pro(ei11 11e!'e,sar1· to ('OYe1· the protPin
l eqUll'elllPHb for gro11·tlt. f 11 a sirn ilar lllflllllPr the protein requirn- ll1PlltS for the other form,; of pro1luction rnn.\· be c·alculaie<l.
Thus for a ge1wr;tl appli<·:dion of thi, meth{)(l of PXpressing the protein i·eqnirnrnents of a11irnnls l1as heen re11dere1l imvossihle tltrougl1 the lack of sufficieui. dnta. It is the intention i11 this pr-ogrnrnrne of proleill i1westigatio11 lo a1;pl,Y ihis rnethod ihronghout aud n1·<·u111uJalP F;uffi.cient <lata. for ili; pr;H·tical applil':ilion. In ol'(ler lo <l]>prn;wh the problem systernatically it \\';tS de<·icle1l to 1·ot1!'entrale inYl~stiµ·a
tions at firnt entirely on the sec01Hl i1hase. namel,1·, ihe llPtPrrni11ntio11 of the pl'Olein Yalues of farm feed,; <111<1 inixhne of fee1L for the different requiremenb of farm animal8. These inYestigations are first c:1rriPd out "·ii It rnts arnl later externlP1l to incln<ll' il1e <littereut types of form animal,,. Su!'h n, study \Yonlcl necessaril~1 ind11(le:
(1) a !'ornparison of tl1e nntriiinl values of ihP prnieins of fe>e<l" u1·
mixtures of foods; (2) the hiologil'al ml ue of tlte ]ll'Oteins of sncli fee<ls: (3) the supplementary effect amongst their proteins; (4) the
194
D. H. SMUTS.
::rnnno acid deficiencies limiting i.he pl'oper utilization of the protf'ins oJ' feed,; or (;(Jmbination of feelb. It "·ill be appreciatell that 011ce this iu fonna hon is ;1vaila ble it "·ill be po;.;sible for practical purposes to select protein feeds or mixtur0 of feeds of tlie high0st biolog1cal values.
Althongh it is ge11erally recogni.t>ed that protein feeds differ drntrndly in 1111trifrrn ·rnlue, ver\· fe11· c01nparisons linYe actuall:1 been caniell out in ,d1icl1 foocl intake was controlled and the result"
treatell siatisiically. The orni,;sion of these two factors in experimeu!,;
of i.hi;; Jlature detract; gTeatly from th0ir significance. }litchell and Bea(lles (HJ30), Braman (E.J::l] ), Hnag (1931), and }litchell and Smuts (Hl02) liave founcl the paired feeding method, <leYeloped by }lii.d1ell (l!X~O), very efficil•nt in rneasming the nutri1.i1·e <lifferences het\rnen proi ein f eecls as 'rnll as their amino acid deficiencies. Brnrna11 \l!J:H), applying i.his method, <Lscertainecl tliat cottonseed- meal is inferior in nnhiti rn Y<l htP io linseeclnieal. Hl)\\·eyer, iheii·
hiologitni rnlues 1rnre almost icleui ic:d, the difference detected in the growth studies Leing due pro!Jably to the lm»e1 cligesiihility of thl~
protein of cottonseedrneal. I 11 pigs, }li tdiell and Hamilton (J 901) 11·ere able to substantiate the results of Braman ancl fmrncl no difference behYeen the hi ologica l rn l ne,; of cotton seeclmea l <tllll li 11 see<l- rn eal. N eYens (1921), in comparing the proteius of coi.i.onsee<lrneal and lucerne, founcl 1.lrnt the former is superior to the latter. H i.chanl- .;on and Green (lUl 7) ,;tate that cottonseed meal and flour are sati;-J- fodory soun:es of protein for the gT01Yth of oats. Bethke aud Go-1,·orkers (Ul28), using the 1nethod of Osborne aud }h1Hlel "·iih rats, fournl no difference LeL1reen the protein (,f limeedu1eal 1rnd cottonseed meal. With beef cahes they could not cle!ed :my rneasnr- a lJle cl i.fference when cottonseeclmeal an cl liu,;eerlrneal "·ere fell in combination wiih lucerne-Jrny.
Haag (Hl0-±), in a rno<li:ficatiun of tlie paired feeding method, found that the protein of bran 1ntt> :mperior to that of lucerne. :Jlo1ris an<l \,\Tright (l9;):J), in a <leten11inatio11 of tl1e relatiYe efti.<.;iencies of protein feeds fo~· rnil.k production. fouud that decorti- cated eari.huut cake ,,,-as inferior to bloodmeal, peameal and henu- meal, but t>lighll.Y bette1 thau linseechneal. Schunclt (193.J.) a1u1 GO-
\YOrkers obbinecl a higher nitrogen retention with yeast protein thau 1Tith pea11nt in pi.gs, the nitrogen retPJJtiou of peanut being higher than that of soyabeans. Daniels and Loug,hli11 (1918) c011dude that peanut contains a good quality protein. }fitdiell au<l Villegas (1920) in their work on <.;ocoauut1nenl ancl soyaheans fom1d fit to state that at i) per 1·ent. leYel i.he1·e 1rns 110 distinct difference in these two proteius. Ho1YeYer, nt 10 per cent. leYel the prnieins of <.;ocoanutmeal are slightly but distinctly less effectiYe than the protei11s of soya-
beans for strndurnl purposes in lhe body of the rat.
K:s:rEHDLlcXTAL.
fiimullaneouslv ,,·i.th ihr <letermi11.dion of tl1e biological Yalues, comparati1·e growth sturlies of the different protein feccts, based on tllP pa ired feecling rnetl1ocl, \\·Pre also concluded. Data referring t·n
195
the Litter :1rp 1n·psc'11tell in lhi~ paper. Hah 11·pre ]J<1irt>cl tu·conl111g·
to agl', ~P:--:, ,,·eight a11d liiler. l•::1ch p:1ir rer-<'i1·p([ t'ht> s:lllle rna11<1gP- me11t an1l \\·:i;; kPpt under i(l<'llhl«ll ('Ondil ions, tl1e 0111.v difrere11e;p bei11g ihP mun·e of proieiu i1H·orpor:1tP1l in ihe i·e.-;pt>cti.1·e ntiions.
1"00<1 1n:; cqu:decl b.1· the methorl oi 'J[itcliell (JU:l()), na11rnly, tlwt·
in <"<1l'h )lflir liolh r:1t~ ,,·ere ~~·in•n the same :1H)(Jlll1t of foocl :11 ilJ('
~t:1rt and tliPre:ifter iltP d'.lil_1· :111101111(·~ \\ere rE-'gttlated lJy the 111emlJPI' of tlJP iiair eating illl' least. Hnts "·ere \\Pigl1P1l 1n'ekl.1·: tl1t· i11iti:1I :rnd fi11:1l 11·pights lwi11g ilH' :1q'rage 11·cighL of tl11·pp c"msP<·utin' d:1.1·.-;.
'f.ll~LF I.
('nm11r1s///1111 of Notions.
l'i•a1111t .\Leal.
l,u"crn<' \kal ............. . Scsallle \lea I .. .
Copra. i\lcal ................ . Cottonseed \lea I.
~lH"l'ORC' .. . . .. . . .. . •. . . . .•.. .
ll11ttetfot ...
\'east Extrn"t ( '). .\µ:ar (2 ) . ..... .. .•..
('od l,i1er Oil ............... . :\;icCI ..... .
;-ialt \lixt111·e (3) ..
~tan·h.
TOTALS.
I \·r Cl·.1t. Xitrogcn
Iii· 7
Ill (I S·ll IO·ll l+·ll :?·II l ·II
4 . )
:{4· s
100·0
L·±.-,
.)7. ,)
:?:)·()
lll·U IU·I/
K·O 8·11
10 () IU·(l
:?·O :?·II
I ·O l·O
..j. .) {·;)
7 ·II :J\). i)
11/(1·0 lOO·IJ
.:;1 l·iil
3:l·U
22.• :)
10·0 lO·U
S·O 8·U
J(l·ll Lll·ll
:!·ll :!·O
I ·II I ·U
4 . .-, 4·:) :l 1 . :i +:!·U
100·() IOU·O
I·;;~
~-~-~-~-~~-~--~=-- ~~~1------ -----~
I
(1) \'ei!st extrnct ""ls prep;11·cd ;icc:cH·ding to the method of' Jttcr S. Orent E. H., and
\lc('allum 1,;,._ .f.('.IJ., \'111. L08, :\o. :?, pp .. )71-.)77. l!l3.).
(') c\gar \\'il.-< ;icldcd to pr'<11111t 1'<1tion onh· in till' <:omp;11·i"'"' "·ith ]LJ<·erne meal,
in <ti! othC'r cast's it wn:-:. di:-:.p!a(·C'<l liy nn equal \reight of :-:.tnrch.
(") .\ modified (),borne ;11\d .\Jt·ndc:I \lixtme dc,nibcd In- P. 13. H;11d< and H. L.
(bn. I H:{ I. Scie11te \'ol. 7+, p.:3G!l.
TIH· <Oll1p<hifrn11 li.1· 11·eiglif of tl1P 1:dio11s .i,; g.i,·en i11 '1':1ble J.
EYer,1· rntion 11·<1~ an<1l.1·se<l for totnl 11ilrngen hdorP tltP ;;tart of 1lw c-:qwri111e11t, i11 onlp1· to equaliz<· thP 11i1rog-Pu c·o11lp11t ol·
tlw r:1tio11~ as Hearl.\· :1~ 110.-;sililP \'i1'11•r by remixing or ;1rl<li11µ; 11w1'l' of ilte proh•i11:; under Pxp1·rimP11t or h,· rn:1ki11g up fre.-;11 h:11c·lws of food. Ju thi~ 111:1111H'l' do~c-' :1gTl'e11H'11t lw111·P<'ll ilt<' 11i11·0µ;<··11 f'o11tPnl of ilw 1lilfrn'nl ratio11s C'ould lie oht:1iu1·cl. .\.ll tl1e prn1ei11 ±ePds p:-;(·Ppt o:ifs. "·h iclt 11·:1s n prnch1d ]ll'<']l<ll'Pcl liy :1 cm11111en·i;tl C'01npa11_1·
as :I b1·e:1 ua~t foorl, \YPJ'P ~i Ill il:1r 1 () illOc'(' used 1lJHIPr prndic·n I feecli11µ; ('011clitio11s e:--:('ept tli:if the.1· 11·prp put il1rnngh :1 mill flnd rerlucPCl to " fine pcJ\\dPr "hich foC'ililatPd rnixi11g- ;rncl en~urel1 :1
more !tom oge n eo11;0; rn ti on.
19G
15
,
,,
,I I
~ii
III. Ii~
~
1·,
::::
-
::::
::
I I -
x ..,. ·~ 1-
'7'1 ':'I
c o M
I "~
:::
~I _ _ _
I "' ~
I ~
t
;;~ I 1- -. :;- - 1. --
El7
1-,-
I ;
I- . -
=
=
=
D. B. SMUTS.
- - -;
~·
~·
~·
l'LANT PROTEINS I.
HESUL'.l'S.
In Table 11 is givPn a summary of the comparisons bet "·ee11 luceruemeal, lucen1emenl plns peairut aml pea11utmeal. ,\s will he noti<..:ed the te,;t was a modifimttion of the paired feeding method in that tripliC'ates i.nsteacl of pnirs \\·ere used. 'J'lie cou<litions of fre<ling an<l pairing of rats "·em i<lcntical lo tho,;e pr;1cti;;e<l under paired feeding. 'l'he amount of foo<l consumed during the e:s:perinHental period "·as of the same rnagui.t ude for each rne111he1· of the trir1liC"aiP.
ltais l'Ecei Ying the pem1 ut ration i 11 most <;ases li mite<l the food con- :mrnpiion (Jf thPir 1md.es by rpfusi11g part of their daily feeLl when the lntter \ms i nerense<l aho\'e a certain leYel. 1'his \\·a" prnlrn lily dur, as .Mitchell sngg-este<l, to the unpalah1bility of the peanut111e<11.
lh1e to the byout of the experiment:, .it is statiRticnlly inc::mTPd to compare one treatment likr lucernemeal \Yith another (peanuinwal) befo1e the significance of the te~t as pbnlle<l is :1scertai11e<l. Tlie mean gain in \\·eight for tl1e <liffPreut treatments oYer the experi- mental iwriod is 2G·5 graim; for lucernemeal, 28·4 gram;; for lucernr plus peanut, ancl ;n ·9 gram,; for peanuhneal. The stnnclnl'<l enor of the mean equals ±2·0!:JG. By an analysis of lhe varian('e it is eYi<lent that the yaria tio11s 1ietwren h eatrnents are by 110 rneam;
sig-ufiC"antly greater than tl:P remainder Yari.rnce. Such an out·cornP 1rnulr1 naturally imply that there is no reason to derlnce from the dnta m1rler obsenation, thnt there \Yas a difference in respmrne asc1ibable to the different treatments. \\'hen, h-oweYel', the lucer11P plus peanut ration is enti!'ely ignore<l ancl. lucernemeal is compared
"·ith pea nutmeal 1 he (hfrerence between t l1 ese brn hen trne1d i:;
becomes significant. Tlie meau difference (m) in grnms is equal io 5 · 417
±
l · 7485 gms.; l is equal to m £ = 3 · 088 and tliesz o 111ea11
degrees of freeclom (u - 1)=5. Under tl1ese comliiions the prol1aliilit.1·
'L\llI,E III.
.Ll Co11111urison of /'he lVeekly Uains l1etween l'ea1111t and /,11cen1e111c11l.
- - - --== ======-=-===== - - --= -= - -- - - -- --
Weeks.
I
Totals per \\'eek.Pai1· Pair Pait' Pair Pair Priir
1. :!.
:3·---- ~ --5 _ . _ (J~ 1 ,_
1 - 1 __! ..... ..
:2 ............ . :J ........ . 4 ........... .
:} ... . 6 ....... .
+
I ·I ' I ., () I II (): I I I '
I~·
I+
I ;~ ~ _ _ +
l _ _i _ _ _ I_ + !_.L _ ~~-- ~ _ _ _2 _ _
l_\ _TOTAL FOH EXPERll\1 ~;~T ·);) l l ·)
__ - I==~~
+ lmlicates greater gain by Pcauut ~leal.
- Indicates greater gain by Lucerne Jleal.
± Indicates equril gain.
198
D. lJ. SMUTS.
(P) that the clifterem.:e in hnour of peanut is not a chance effect is 0 · ln. Siuce a value of P ~~ 0 · 06 i::; in cunent biornetrie::il prnctiee a r·rih•rion of significance, it is obYious that pe::iuut, by this method of eo1up<1riwu, is ,;uperim· to lucernemeal. But in view of the actual lay-out of tl1e expc>ri.111eut this signi.ficm1ce, "·hen judged by the entirP datn, lllllst he considered ;iecidPntal (Probability approxi- rnately 11 pe1· cent.).
A comparison of \Yeekly gain,; is orcl inarily a less re lia hle aml legitimate melhocl of comparison than tlrnt of total gai.us, clue to the fad that \Yeekly foorl i·esi.dues may appreciably affect the gai11s.
The 11eces,;ary '"ornlitions for sta l isti<"al imlepe1Hlence between inclividual nlues are also seriously i11fringed in that the weekly gains for the same p:1ir of raH are uot i11clepencle11t in ~o fo1· a,; they reflect
<m inherent difforenee bel1Yeen the two rats. If such inherent cliffere11 ces exiRt the weekly gains are not comparn ble on a basis of ran(lom Yariation Oil the ::issumpticm that each mt in <lily one pair has, except for 1 reaimeut clifferellC"es, an equal chance to g::iin more than itt> mate during a particulnr week. Hence, <lne to this Lick of independence in weekly gL1ins £01' tlie same pair of rnh, it i;:; not quite correct to <·omider the prncluct of the number of pairs arnl
"·eeks ::is t]ie total iiumher of clegrees of freedom.
Furth enuore, the 11 u u1ber of 11 ee kly gains is by no means inde- pendent of the total gai11s. If a pa1·ticular rat of one pnir gains rnore in "·eight than its "·eight dming the experimental period, it is likel.v that it shonlcl ham gained more in "·eight during the greater number of 1\"f~e!;s. Hence the t\YO comparisons, tofol gains and number of greater \Yeekly gains, are by no means imlependent, but to some extent 011e and the sc1rne cornpari,;011. Cousequeutly it is doubtful 11·hether any extTa i11for111ation is gained hy comparing 11·eekly gai11s aftpr ::i.n fnrnlysis of to(al gains has beeu m~ule. 1'he inclusion of comparisons heh1·eeu \\·eekl.v g:1ins in this paper .is merely h.v reason of its acloption by oiher 1rnrkers and to illusti-ate \Yhat
\Yas alreacly sho1Yn hy the analysis of total gains.
111 .c com pa ri son of 1 Ul"en1 emeal an cl peau n tmea l the "·ee ld.:v fo-ocl inbke 1rns the snme for the cliffe1eJtt triplicates. This naturally girn,; a greater Yalue to the siatistical a11al.v,;is of ihe "·eekl:v gains. If the 11u111ber of ecp1:1l 11·eekly gaillS is divided equall.v bet,rnen i,eanut an<l lncernrmeul, it "·ill be seen that out of the 35 comparisons 24 favoured peallu1.meal and ouly 12 lucernerneal. This fact also points to a superiority of peairntnwal ove1' lucernemeal.
111 Table 1 V the daia pertaining to the comparison of peanutmenl and ~esmnemeal are talmlatecl. Here, again, it is ohvious from the number of refusals thDt the pe:11uct feel rat in all but one case \\"as the one 1.0 lirn it tlie ioocl iHtake of ihe respectiYe pairs. A stat istieai analysis of ihe total gnins sl10\rn that the rneun differeur-e of the 1:;ix pairs of rats is zero and, conseq11ently, there is no indication what- soever of an exi,;ting differe11ce beh1·een the prntein of peanutmeaJ and sesameme:11. A comparison of the \Yeekly g-a ius in Tnhle V affords confinnatmy eYicle11ce as to 1 he equnlit5· of these two i>rotein feeds. If r:l1ance alone operntecl, it \rnul<l be expected that of the
;;u compm·isons the ideal ouif"ome \Yould be 18 for both treatments. 199
'l'Am;E IV. Summary of flody1re£ghts, Gains, Feell Records and llef11sals on Feani1t and Sesomemcal Rations ('in gms.). Pair 1. Pair 2. Pai1· il. Pair..!. Pair i'i. Pair H. --------------I Pettnut I Sesame l'eannt I Sesame Peanut
I
Sesame PeanutI
Sesame Peanut I Ses>eme l'e;cnutI
Sesame l\J Mea.1. .i\leal. l\leal. 3lea.I. l\Ical. .\'I eal. !\lea!. :\lea l. 3Jeal. 3leal. 3Ieal. ~J0al. c 0 InitialWeight .................... 185·0 8:!·0 77·0 77·0 74·0 77·0 87·0 8i)·0 94·0 94·0 70·0 74·0 Final Weight... 131·0 129·0 128·0 124·0 120·0 121·0 l:H-0 129·0 1:12. 0 137·0 110·0 117·0 Gain grns ...................... 46·0 47·0 51 ·0 47·0 46·0 44·0 47·0 44-0 38·0 4il·O 40·0 4:l·O Total Food Consumption ....... :rn1 361 369 :l69 :164 3G4 ;394 :J94:mo
386 351I
3i:il Itefi;sals Prri >d ........ _ ... 3
!
l lI
;~ 6 0 4 0 2 () I 5 I (l.... :--< ;o. z
'"" ..,
;::; 0 ...: i:,j ....,z
<r. ~D. H. S~ll'l'S.
\Vlt011 the equal gains are clivi<lecl equally hebwen peau11t ancl :;esamemeal, the respedive 1rnmb0rs of \Yeekly gains becorne Hi·
o
forsesamemeal and 19 · 6 for pe~rnut. These figures Yery nearl.'·
approach the ideal oukome nnd therefore confirm ibe non-existing- diff0rPnce in the two treatmt>nts.
T.rnLE Y.
!1 Co11111arison of TrrrUy G((i11s bet1rec11 Peoin.1tmcal and Srsmnemeal.
·weeks.
l ................. . 2 .......•........
3 ........ . 4 .............. .
;) ... .
ti ............ .
I
'I I I I
Totals per Weck.P~.1t· P
2
t."'P;.ir
P4
~.tr 1'~1.ir Pi.ir+
±1+1 I+~ ~ g g
I
+
IIt ! ~ ~ + ~ :
2~
I -=--l + __ ~ - _ _l_-_1~-=--- + - + -~ +
_ 4 :! _ __ 24 ___
0 o _TOTAL ExrERDU:KT . . . .
+
Indicates greater gain by Peanut J\lea.1.- Indicates greater gain by Sesame :\Ieal.
± Indicates equal gain.
15 18 3
In a comp:uison of peanutmeal and coprarneal in Table VI, it is fairly clear by inspecting tbe total gai11s of the different pairn, tlwt 110 obYious difference exists as a result- of the different treatments.
The mean <lifference in total gain is 0·330±1·8!37 grams, showing that the mean (lifferern.:e is much les,; t]rnn its stanclrtrd error. The nlue of t=0·1G4 is insignificant and the probnhility that the obsen-ecl difference in favour of peanutrneal is flue to chance nlo11e is approxi- 111::del.v 89 per cent. In a comparison of the weekly gains, Table VII, i.he <leYiation of the bo treatments from the ideal outcome of 18, wheu !he eqnal gains are allotted propmtionately to peanut and coprnrneal, is so small that it becomes entirely insignificant. It is, t1iernfore, safe to con cl m1e that coprnrnea l aud pem1 utmeal do noi;
(1iffer signific~rntly in nutritive value.
T.IHLE VII.
Co11111a1ison.s of 11.eel.·.'y Uo/11 hPhceell l'ea1111tmeal and Coprmneal.
Weeks.
1 ... ..
2 ............. . :! .... . . ..... . 4 ........... .
,) ... . 6 .......... .
I I I I I
Totals per Week.
P~t:r
l;fr
1:~1.11 P;,ir ~~fr P~t.ir+
-+-+
Indicates greater gain by Peanut Meal.- Indicates greater gain by Copra :\Ieal.
± Indicates equal gain.
201
I\; 0 l.\:J TABLE VI. Sumn1aT,1/ of lJorf,11u·c1ul1!s, U11111s, Feed Heco11/s 11111! Hefusrds 011 !,!'111111/ 0·111 ('''f!t11:111·11l N11!1u11s (i11 q111s.). .Pair I. I J';cir 2. l'air 3. I Pair 4. ! Pair :).
I
l'air 6.I
1- l'canut IC'op r < ~ ' ~ " = ' t f
('opni l'ca1111t Coprn J J'panut J ('oprn i'l'anutI
Coprn I l'canut I Copra \leal.I
\lea!.I
}Jeal. I \leal. I .\!cal. \lea!. / \[ea!. I :'deal. .\lc·n I. I ~lea!. I :'lll'itl. I \kal. ·------ I I I initial \Vcight... .. . . . . . . . . I 99·0 I ()()·() I 92·0 !13·0 I 8ii·O 8.)·0I
83· o 8-l·O 17·0I
/7·() I 87·0I
80·1) finrt! \\' ei1! ht. . . . . . . . . . . . .. . .. .. .. 1:12 · u I 126·0 I 1:i6-o U7·0 1:21 I 2ii·O 118·0 ll8·0 12G·O I 11+·11 11 :l·(J I I ll · U Gains gn1s ................ :33·0 27·()
I
3-1·0 :34·0 :lG·O -ll ·O :\3·0 :H·O .J.D·U I :n-u :l.)·(J :i I · 0 I I I Tot·\! l•'ood (',11isi11n!'ti·rn .... I3.J.l :qJ I 338 :>:JS :J4:3 :J.1:1 311
I
:Jll :32!) I:J:l!J I :l J.) :i1:; l{cf11s•1ls ....................
I
-~ lJ 3 () I l .) 4 I 6 -~ :l I,) .-, I I ----------------- T.11:1,i-:
nn.
S11m11wr,11 of Body1ceiyhts, &11i11:;, Fee1l Hccorrfs 1111rf Hef11sufs on l'e111111/ 11111/ Collo11sPetf111!'11! H11lio11s (i11 .11111s.). --------· ---· ----I -I --- -
Peanut I Cotto11-1 l'canut I Cotton-J>canutI
Cotton-Cotton-I , Cotton-, I ( 'otton- .s!'cd seed seed Peanut seed I rn1111t ,ced L t>:llluL ,eccl \Leal. / ill, I \lcal.I
J\I I :\I cal. \lea.I. \leaLI
'I] I I \lea!. I~I .
I \lea!. I \l . I i {a. ca. ~ ca . i ea . . e.t . ---~------ I I II
I I nit!al \\'ei.e:ht. gm' ... !)U 0
I
8.)·() 11-l () I ll-l·O !)8·0 f).)· 0 87·0 87 () !):! ·() I !J.J.·O 87 0 8!)·(1 l1~i11al \\'c~ight, gm."i ........... .... J:!O (I I :!:!·O l.J.(J (J l.J.!J.11 I-.!.:> lJ l:l5·U J :!O·O 117 ·O 1:!6 () I I:).).() 1-.!.::J 0 I 1:r1-u Gain, gms .......... . . . :lO·() :l7 ·O :!G·O :i:;. f) -.!.7 () ·W·O :)3·0 :30-0 :l.J. (II
.J.I ·I.I I 3R·O -l:l·O Tot.a! .Food Co11su m pt ion . ... :i+:l :i.t:l :n:! :l7:! :i:rn 3:HJ :ioo :wo I :{.):! :!.>:! :ns :378 l{cf11'<il.' ......... .) I I I () () I .::; I) -I (I I) ·) ~>-::J "" ;:,. ~ ..., >-::J ;:,; 0 '-' :rj ....
z
JcD. ll. SMUTS.
That cottonseedmeal seems to be su verior to pean u tmeal is indicated by the fact tliat five out of the six pairs of rats shmY a bigger total gain in fayo1ir of cottonseecbnPal. Analysing the total gains in weight (Table YIU), it is fouud that the mean differenf'e fnr the six 1rnirs is ?n=G·17±2·1!)1 grams, aml t becomes equal to 2·808. 'l'he possibility, tlwrefore, that ilie ahrn-e cliifrreuce iu fayom·
of cottonseeclmeal is clue to chance alone is 0 · 04. '!.'his probability is so small, and less than 5 per cent. ,d1ich is usually taken as the limit of significance, that it may he c·onduclecl that cottonseeclrneal
i~ superior to peanutmeal. As no difference w:1;; demonstrated het\Yeen peanutmeal, coprameal, an(l sesamemeal, it seerns reasonable to cleduce that cottonseeclmeal is also superior to the latter tlrn meals.
'J'.~BLE IX.
Comparison of 11.ecl.:ly Gains 111aclP UJJ l'ai1-mates 011 I'em111tmeal and Cottonseedrneal.
-·--- - - -- - --~- - - - · - - -
Totals [l<'I" \\"eek.
Weeks. Pnir Pair Pair P;ti1· Pair Pnil'
l. ., :3. 4. ,,_ Ci.
I I
- - - + -
_Ll................ .. _L
+
2 4 02............
+ -;-
J: ± 2 1 :1:3............ ± I
+
_L :3 24.......... .. .. . .
+
I 5 05 ............. , I , -'- 1 i . 0 4 2
6. . . . . . . ..
_!_! =_!--=_I_ I --=-· -=-- --~- -~- _ ~
TOTAL EXl'ERDIEK'l' ..
+
lndicatcs greater gain by Peanut Meal.- 1 ndientes greater gain by Cotton-seed Meal.
:±:: ln·licatcs eqnal gain.
G g
A comparison of ihe weekly gains ('!"able IX) shO\YS :>ix com- parisons fayouring the peanut fed rat, t\Yenty-one favouring cotton- seeclmeal and ni11e equal gains. If the latter i,; diYidefl equall.Y amongst the peannl and cotlonseecl fed rats, it is found that 10·5 of the c:om1)flrisuns foYotn pennut and 25.5 favour cottonseedmeal, which mean:-; a cleYiation of 7 · 5 from the itleal outcome. The standard cleYiation of the frer1ue11cy distribution of the outcome of 36 eYents, each of \Thich may result with equfll probability either one of t>rn wa:vs is given by i he expression'°'/()· 5 x 0 · 5 x 06, which is equal to 0 · 0.
The de via ti on of 7 · 5 from the ideal chance ou tcorne is, therefore, :2·5 times the stn11clard <leviati011. I11terp1eting- this ratio from t11e table of y;1lues of the normal probflhility integral, the prohability Pxists that chance nlone would prorlnce this <leYinti on approximately once in a hunchecl trials. This comparison, therefore, definitely supports the result:-; on total gains, namely, that cuttonseedmeal is a superior protein feed to pean u tmeal.
203
l'L..1:'\T I'JtoTEIXS I.
\\"hilP it ;1ppPars f1orn this inq•,ligaiio11 tliat c-1dto11"P\'(1rnP;d j, a lwtiPr protein fi.erl than r·opn1lllP•ii, peanutnH•;il or ::;e;;:1mr>111P;il, i1 r1oPs not exr·ludP the po<sil;ilit.\· th;d thPsP fel'<L rn;1Y 1e;1d distiudl.Y rliftPrPnt in otlie1· type' of Li1·m rl!lirn:1k This point· is il\uo;trnt~d
by ihP fod ihai )Joni,; ;1nrl \\'1iµ;lit 1e11ort th:1t pe;111utnH:';1l i.-; sliµ;l1tl:-·
superior lo li11sePdrnPal for milk p10<1uction, \\hr1eas )Jif!'hPll ;111d llflmillon, :1s 11·ell as Hrnmn11. fou11<l 110 differenr-e l:eh1·ep11 1·ott11n- seedrnenl :11HI li11.-;t·e1lme:1l fo1 µ-1·011·(!1 f111<l m:ii1i11·n;rn(·r· ol' t lie rnt anrl tlie piµ;. In thi.s sturly :1µ;ui11 r·olto11seednwal h:1.-; 11('Pl1 fo1111d io be su11erior to pt':111utmral in lhP r:d. Hy i11ferPllCP it s<·rrns 011l:-- 1wtural to ('onr·lrnlr ihnt li11sl'<'tl111e;ll sli01tld he ;\ l:ettPr prntei11 fpp.J for gT01Ytlt lh;111 pra11ui111r;il, "·liie:l1 h:1,; hern .-;hrm11 to l:P prnbalil:-·
not llir (·;1sr fo1 111ilk prndud io11. Tlir 1-.d11e of p1·otei11 h'Prls <«111, l hcrefore, not lie t'st i1n;it·e<l 01· ;1s.su 111ed at 1·:indorn frorn n11y set of dab, hut nrnsi he rletPn11i11Ptl 11·itli diffp1·e11t ;111im;1I-< for !';\('Ii spe1·ifi('
]llll'JHJS('. T\1is ph;b\' ol' 11·ork is ;1111 i('ip;d<·11 ;i.-; i111·pst iµ;;11 i())1s <11'1' (·xt!'1111Pd io 11tl1p1· ;111i111;:L. Tlw s11pe1io1ity of coH01is\'l'(l111e;d r11·e1· I he prntc•i n fe<•th dor•s 1101 tlllpl,\· ;1 µ;P11c•1al a ppli1·;d io11 i 11 Jll'<l!'I i('('
\1·i!\10u(. i;1ki11g into acr-on11( Llie le\'!'l of fee<linµ; ;ii 11hi('h this foorl m;1y 11e iuxit· lo 1·c•rbi11 .-<pP1·J('.-< of ;111illlaL.
Coxcr.rs10s.
B.\· rncall:i of the paired f(•cdi11g rnrthflll on rat:< it ha.-; b\'<'n sho11·11
slati~iically tba1 ihe prntein llf ('o\lo11~Pe1l111e:d j, su1w1ior to that of pe;111ut11H•;11. ,1-liile oH ihe 11(]11•1· ii<lll(l 11.0 sLilistic;d diffPl'e11('e could he rletrcit·cl be!ln~en ll1P proteins of \H'<ll1llill1e;1l and ('Oprarneal, ;111d
pea nui lllf'<il a11 II ses:1111P 111e;1 l. 011 th is ba,;is it seP ms i·ea so 11 ;1 ble to
<ledlll'<' tl1nt thP prnlei11-; ,if 1-ottunsec•dnwal a1·t· s11pPri01· io Sf's:irne ;rnd Goprameal. J•;vi<lPnce is presented 11·bi('h sePms to :rnp:gest ihai lucrrrn-•mp;1l is infr1ior io iwa11ut111e;1l ;1.-; :1 ,;ounn of protrill.
'rhr auihor is inrleliterl io )fr. A. J>. ~[alan for tl1<' statisiic·al ire at rn <'n t of tlH' 1·!'.-;u lts.
HEl•'E:HE?\CES.
llTLUf.\i'I, \V. \V. (1931). Tho relnti1·e Yal11es of prolcins of linsoC'1l1111•nl :ind cottonSC'l'clrn0al in the nutrition of' gron·ing rats. .f. N11fl'., \'ol. 'I, pp. 219-%0.
l\ETl·fl\1~, 11. 1\'L, BOHSTEIYI', C:. S.\SSAM.AN, H. I,,. 1\:1•:1\N.\IW. D. G ..
. 1:-:n l•:DDl:\GTO?\, ll. H. (192s). The 1·<J111p:1r:ni1·" rn1triti,-,• '"d"" of the prnL1-•ins of linseedrnoal and C'Ottonsecdmeal for tliffrrenL :1ni111:lls . . four11 . . I r1ri1._ Hes. Yol. :JG. p. s.).).
]).-\_-:'\ LE:L,S, .\. L., _1:-:n T~OUGHT,rX. H. (19181. FePding 0:qwrimcnt'> 11·itli 1wrrnnts. J.JJ.I' .. Vol. Tl, pp. 205-:JOl.
H.-\AG. J. H. (1931). C\stine as :t limiting f;1('tor in tl1<' nntritin' rnlu<' of .\lfall'a proteins . ./. X11fr .. \'ol. ~'pp. :lG:1-:l/O.
'.\!Tl'C'Hl•;L1,, H. H., Axn YfT~l,EG.-\S, \". (192:~). Tht• m1tritiY0 1·:11110 of tl1P prot1•ins of eo"oanntrneal, soybeans, ricehcan and corn. .T. ])11il'!f 8ri ..
Vol. G, ?\:o. 3, pp. 22i-23G.
204
