The value of dehydrated alfalfa and antibioticsfor growing steers fed cottonseed hulls

Item Type text; Thesis-Reproduction (electronic)

Authors Varnell, Thomas Raymond, 1931-

Publisher The University of Arizona.

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EIE VAOJE: W . BOnBRATEI? MFHFA. ilB JSilBlOTICS

, E©R' aROilMG-STEERS PEB GOTMSEH) H O m .

Thomas R . Vazaell

A Thesis Submit ted to the .Facial ty- of the

> . s m m r o o : # m m m ' seimcE■. : la Partial • Etflfillaeat, of' the -'Reyairemeats

■ !'.■■■■ ; Lpor fee Degree of' ' . MASTER OF SCIENCE

In the Graduate College

WlfERSITY OP ARIZONA . '

1957

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STATEMENT BY AUTHOR

This thesis has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library.

special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in their judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author.

Brief quotations from this thesis are allowable without

SIGNED:

APPROVAL BY THESIS DIRECTOR

This thesis has been approved on the date shown below:

Assistant Professor of Animal Science

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TABLE # tigBaTjENiRB;

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3EMTRO0IIGTIQN . „ » . „ . » « ‘« . . . , « . „ > .7.

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SXj BfBfZAZ. » o o * " ' \ J i O b ,b o « «. 7=REsam.: ;»,' 6 o, » . ov O ° o » O O 0 <■DIECUSSIW:' » :» * » » O <> O e O o b O b o 0; © ? 0 0.0 oStiMMRSb =• =, » V o » » o o o o p 9 ' o 6 b ° O O O Q

9 O . o ' o o ' b ;o o o a O 0 O 9

v.

1

4

12

16

29

38

41

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M s r «= ' ,Table -

1.2;30

'Femest. Goasti'tgea-ts im %$ieted Sagplememts »

.Feseeat ebeaibaT Crosiitisents of Stitp IeseBts » «

Malysis ©I Variance @£ •■Meiglat. 'Galas aai Feed£3.©2.eaG - p-. .0 « o . tf '* * a. ;b ft • & ft ft "ft '_<? ft ft"

4. Feed Gonsti$apti©H .aad Body' WeigSt GB^g;es ©£ . :v. . .Steeds Fed; Skpeslaental'-Ratioas 'DEplag '110

Bto-y .".®0®5tad o ' ft'* * o*. © ft 0 0 * a # & *.«•. * a * a * 0 a <CatotMe lalaW said HepaM© #f Vitamlrn A ■■ aad Garateae .0 o .» » . « (» » ft « atoalf sif' of Vafflaase \©£ tlejpatlc ..¥it^£a ■•A sad Camteae Retention Bmrlag 110 Days.» »"»- » =,. »'» <*

to '. lsta&e;"":©£: Di e: t$,sf Gassteae ,aad 'Hepatic Retea ties • ' ■. ' : , ©£ fitaaia A aad Caseteae as TaflMea.ced; 6y Peevioas ' ' Hepatie Stbts.ges . 0: > : ® "v v ='■ « » o. <, » .» V ■

8« Aaalysis ©i ¥arimee;;©£: Hepatic fltasiia A aadCatoteae Reteatioa asMaflEeaced by, teevioas . i .Carotene Intakes '„ 0 »'. ,"■> ;= » ® « « .» ».', = ® «>

Page

» "12" ft 14

» 17.

/ 18 *

<. 23;;

» 24

ft / ' "26 : :* • : ,

« 28

LIST OP PITRES' , .;

Figures ' ' : . ... ........ : ... , ' '■ . ' " ; ' ■It'- 'S ■ ?, '■'■I ' ‘ . ■

i0' Atresage T©tal 6a£a.Bet ;G£oti'Fi;''®Bs3,Bg' ll'O Bay Period'

3.' Average HepaMc Reteatioa of Vitamin A tod

Sage

, 10/

Carotene Dssriag. 110 'iMy Period ° » o • ° °Average lepatie 'RetentioB of Vitamin A arid ' '.Carotene as InfItseneed- fof W.e'viotas Carotene .Intakes* « 27

.' x

AGtoetoEESMEMT

feieadly attitpde :of.Ms Bajear, ps©£ess®f s:*: Ss«. B. S»" Emiaie Sincere

tiamks s$e als© extended 4® the'©ther faculty members %#© served .

as M @ exaaiaitig; e®£iiMittee$ lr» G, Bo ReoMeek, Br» % B,. ' Eemmerer

sad Bz« H. 'IteidBeSo tteis: '■ advice and dncdQir&get&ent daring the .

cbBKse ®£ this stedy.Ms been inraiisable. .lithe assistance,@f Mr&o Jo Aaa MeGlbiMiSii, is the pregaratiea. and: typing @£ this thesis,is' also ■ acknowledged,

•r ■ C@tt!0ffiseed :B e lls ase a bf^pkodiset, ®f f$a© :6®tt®s giBHiag pee®-

. edss aad & g & pzediaced £b la tg e qeaasitities daeiag. f&e ■ e@t ton hmcvestieg'

said, g ia a iflg seaam im tiae aseas e f tMe EnBited S ta tes tiaeiee e@tt@a is

g®@M;0 la pge^ieiBS yeags: @@tt@a@esd teeiils ■,e?eg'e @easideg@d t@ be a

- "waste pg®dmet- aad wes© B S E a lif - Sispesed @f by tosaiage I t has Beett \

feygnd ia seceat yessSy tfeat eetteaseey k l l # - smd Sthee :

s is iila g m te g ia lS g s®©& as e@tt@a g£a tgasb.smS e6M-:eabs^ tS@a ■ ■

stippleaeate# w ith sei "adegtaate ©eaee&tsatey es® segwe as ' & va laab le

seEagee" e f •;’K@tighag©.- f@g f©ed£ag' aatege . gaB iBsatiaaitta lSo T h is fia S ia g

hss .iaegeased the ia te g e s t o f gesessd& weglsees aad. e a t f ie feeders in .

the dete lopaeat @f" ad^gBate ©©aeeatgated saappieseats t-iaieh x ^ il l a ile w

these'3.@w <i«islify g@eg:h®g©S. fe be pet t®. s." beaefieial." ssse' im sheep.. : " 'vrr .■ - .;. . , - :":V;L:;V" - ' : . / - -' ■ . . ' - J,sad ©attle feedSsg's 'iastead @f "beiisg des"te@yed; as .s' xgsste pg@d#et«

The effieieat MSe ®f these l w qgalify geegteges depends , t®.

a ggeat ®3st®at0 #®a theig ,pg®pee sappleBiea-tatipa mth a ©bHeentsate .■

' ©@ataaaiag: adeieate sad Salsaeed aetgieais wMefcwili aegglsh. the :

,aieg®®gg@Sisas ef • the, ggaea sad eaable the® t®. Segsade the’'indi*i".. . -.

usable '.im" .gegazd has be eh ceatezed azoiuad the - dwelopsen t" of ©©aceatfated

tsraea*s lacKim# .- ; #- qmality i. soughages e ■:.' f :v ’ , • ■ • '

,,,J..;geadiiy available seiarce of enezgy is ©ae- ©f; the-’-maia

mutzitieaal seqiBireeenfs of the sumea 'Mezoflqra.e It. has beea

reported that eolasse® provides sm esseeUeat easbohydrate soiree

that; fulfills the eaezg'y, the srnousa mi65s©@sgaais®s

1m the digest!®®: ©f Mgloe‘ellisl©se- feedSo, Molasses tos beta used

. widely aa this ; zesgeet 0 ’ . '' ■ \

. ; . / ■Behydeated, alfalfa has beea reported:t@ esataia uaideatifled

groi th faetosCs)9 past of whleh ase eoatalaed la the ssh fsactloa of.

. the Beale •Bgseeisieais have iaileated tMt these m%a## faetosCs)

stiaMlate gala m41s#s@w the feed' ®£fsusie®ey ©f sheep aad settle- ,:

©a .both. gsmmag @ad-fatteaiag sat!@sSo!; .H@®ews& the fladiags '

doacesalfflg■the- value ef dettfdsated alfalfa seal @s alfalfa,ash ip■ saffiiaaaf aatsiti®® as® ©f a eoaflistisag astiase ®ad further study Is

heeded ia'this field 0, '' . - ' .

■. BspesiaeatS iaw@lvlag. the £hel$as!©h '@f aa.tibid43.os-: ia- all

kiad’s of livestock.’satioas have secelved: a great deal ©f aftemtloa' .

In seeeaf yeass» .Ss-’mth^dBsldsFteS slfaifa« the results @£. the ''

studies ©©ffleehaSag' the value ©f aatifeiotles _Sh rasiaant mmtritiomg

as far ss stiEwlsMma @f lieight galas improved healthy amd feed

ntilisatiaag are' sosetiiat: eoafilctingo - S®*vers the use of various

gaf£bi©ties is .-laereasiag ia both- e^erlmehta! studies mad commercial

' ' ..ISaowledge-of the.factors iaflueaeihg the hi®logical value

of saseteae fer cattle Is'-- laekingc: :¥ita®ia A def ieieaey; is a

serious problem WiM cattle are- fed a. ..die't eeataiaiagr-aa laadefuate

aa©@at;@f carotene® ; Beflciehcj. of- this vltmmlm results ih.lowered

weight gains@ lowered feed effi©ieacy9...-'.as4 :va£i®tts pathological'. ■ -

"Wadif ions < Imeludlag blladaess - mad reproductive disorderse .

As -the feeding @f low; quality roughages as cottonseed

hulls ' increases»: & knowledge of the earoteae and vitamin A require­

ments M 'the ruminant animal.•hedomes of great importance sinee'these-

low quality roughages, almost without , exception;, are devoid of .

caroteneo fheir,use in cattle or-sheep feeding operations without

an adequate supply of caroteae or vitamin A could, mean the difference

'■between-prof it and loss. ; Specific information on factors' influencing

biolegieai utilization of carofene would be of great value in -the

development of. adequate supplements iSieh will further increase the

practical feeding of lew quality roughages.

IB?IBM "OF ■ tEEpRATlim '

YV;'-’’-'•> la sebeat f'esrs w e h ;aafesesf Mas ibeem shew' im the feeding

©f l®w qiasLlity reeghages f© beef espeelaiSy ia:. th©se teeas

- ia t&ieh eeisgMges ©f this type Site psodaeed M iaege :q«aat£t£eSo Ha® -teamy “low ■qm&S.tf* is ased t© d@a@te these'roagteges

@f-a ©estzse e0asi,stea©y sad sattes eadigestiMe aattt$e .®Mch also

•age defieieat is several aMtg£ti@aiBl faetegSg'pgiasg£3.|, ps®teia aad

aloo IfSSg Etestegaasi ■ et •.&!«> ISSSg........ _^s=5t ■ 1 ' C=Ste^ <5 3=3

BBg$©ag$a@' et M e 0 1945) tea sh#m' that these yasieas g©tighagese tiaen

.pgepegly. sapplmeatedg as® ©spable of paroiaeing gsias ia beef cattle: ii&aeb sSe ©©gapsgaMe 't©. these'psedMeed by- feedissg sere e^sasiw

higher #mlity: rbrnghagea« She n@,£a iaterest ia resesroh @a the

feediag vilse @f, .lei^sBaiity r@Mghsges has beea8 fheseferag the

:8ewl@pBeat @f .s@pple*eatsvihiA'©©ataih. adeqaaate sad properly ,

b&laaeed aimtri<mts tha# sieroesgMisss ©f the r$jss@a

aad' all®#'them te degrade. #W' indigestible roeghages iate.a form

which may. be mtilike# by the h@@t ®aiaiale: .- .

Alfalfa ash @r seal has received e©asid©rable atteat£@a f©s’

sesetiaep. dee to the psesigaee @f ^Qaideatified atttrititre f.detorsli,,: that wr&ers.'iByrrdBgha:et: al:o.e 1950g Sm.ft ®t sJleS 1§51| Sloetemaa

Mtessa?# O 9- 1@SS) haw. repbfied' ft® effeetiwely iiidreasiag the. digestif

■ roighages:,resBlfiag is iaereased. weight galas sad'higher

feed @ffieieaefv ' - . ’ \ ' -

Shorn t&at the feediag @f alfalfa hays alfalfa Beals te alfalfa.

r@SBlt._5si. iBpr@wS dig@stShality@ faster gais® 3 -smd iBeressed. -

'.feeti etilisat£@a> Beesba etialo- Cl§52) aeted isgrowS perfomasee

fr@a-'g£©wisig steers tiseh., alfalfa meal m&' iaoosrposr'ated- ss. a sapple«

Seat t© a hasal diet-of e©ra e®hs0 Klestesmsai et al© :(1S53> SSumed

§,M g@w€& feed Mtilisstioa fey steers fed alfalfa' ash plas trace

miaerals with l@w fesallty r®©ghag@So ' ' . ■■ -

. . MptiLee Cl§53)o .®a the ether h®ad;0 r@p@st@d "that beef ealws

fed - a hasal- diet .©f e@rii, e@fes .ate .less asid. grew at a ; slews rate ' :

wfeea -trace aiaerals were addeda ©ther %#rkess. (Tillmaa et al«H 1953)

r©parted ■that’ higher. digeatibility ©f diet aad- faster gaias with .

sheep did" K©t eesBlt w&eai either 'alfalfa ash ©r. trace aiaerals were

added t© a diet, @f lei» qe&litf r@Bghag@0 . •. ' ■ ■ ' : : . ' ;v ■ ' - ' ' '■. " ■ ' .

•M@lass@s has- l@ag :b@pa believed fa escert a teeaefieisl • effect

ia ■ i^reaslag:. the 'digfsS&illtf ;@i: lew 'iiaality rernghage# - mad Im* ;

prWiag feed' effieiefflcf; @f affliaals ©a. this type @f raticao (Bray... ' : , ... ' ■ ' •" ; ... .' ’ . 'et:: ala g .:lf 45 g ■ Barreaghs et ale.a 19S0g Galley sad Car see 8 11.90$

Madsey et M 0 3 1907) 0 Siwevers tMs e@acept w s a@t'.ib®riae out ia

asa ejsperiaaeaf ©©adaetigdi- at the. Srisea® Statisa ia 1§556

■ ' \ The Arisdaa stiady was desigaed to test the eff @etii?@®@ss

©f - three. sapplemeBtal levels ©f ;dehydrated alfalfa fed with aad

’ mel'asses sea the mtlll$atl®a @f e©tt@aseed .feBlls. by«:gr@wiag

sad fetteaiag steersp' Cetteaseed meal m s fed t® egeal thel d£==

gestiMe grefeia iatak®' of the asiimels* .Beriag the growiag sad.

fatteaiag -perieds iacreased gaims were observed ia these- steers fed

Mglier levels M ddMydsrsf$d alfalfas. ■ HoBevear9' - # e • reverse w s found

ySisb molasses sssas'added t® tbe satis®e Bast, is 9 as the • aaiount ■ of

d^aydsated alfalfa tsas iaeseased in f&e safisas ©satsisaiag nolassesg

gsegsessiwly desseased s#t@s ®f gsia wes@ @i®es¥@S9','. v '

®®sMaafisa mas&edly l®%@s®d feed, effieieasf ia the saimals# the feediag @f: b®1sss@s . teadM. i© iaeseBse feed e®m@m#ti®ag pesMpsdtie f© aa i^sswmeat to. palatalbilatf' ©f tlae estl@®g:>bwt b®lasses

ted ®@ effect>® the sates ®f gatoo , ftese fiadtogs did ®©t beas out

the genesally^aeeepfed. belief that aolaoses aids to'the at&lization

©f lew qiiaaMt'f-.seisgtegeso A posttoa ©f the pseseat stady %ms dem ■

sigaed t® se«@WlBat©' . the ftodiags sad ©assy @®' the %ask, to thisv. . ' ' :v:' ' ;v-' ' ' " .. - . . ' .. - . - - , -segted.fr

tes to^easedfiav seseif yeasso. ■ ihea fed i® psfiltsyj, m toe' @md

ealte.Sp astibi@ti.es haw be@a sh@« t@ sig8ifie@a.tly toese8.se feed

atiltoati#® - aad ii#s®w@ the geaesal health sad appeasaaee #f the •

Itoesteek (MeEay et al0 l@53g ICesleso 19541 AMzdoeic et ale> 1951$

m d ©tbes#)* : . : - '.... -

: $he-:add£ti@a @f chl@sfetsaeyeltoe'os peBieillto t© satieas

f@s BatBse 'beef , eattle to easlies studies. CBeli et 1##@$ #@sm .

•et tie g-'llSS) ts®:, f@®!hd t@ eatsse iaaait£©$r sad degsess; the ?digestie?

Misty @f ©sttSe ffibes 0 Siailas -xesnlts W s e sepsst@d" by ■ ©©toy

et ...ale p <1$50) Wen-, an-ilbioties taese fed t© £atteaiag lambs*' How"v y . ' . : ' ■"■; ■; . ; ■■eyes® it is possible the aatibtoties fed to these" stHdies wse

iapz&pegJLy administered" and' to excessive amounts *- since--other

r: Tso&keta CFeesf et &201? 1954g Btiitaaaa et ali8 1953) later, found: that . the feedlag ©f sht£M@ties at-lore levels iaereased wight gales sad feed, efficiency of beef cattlee

. lacreased galas smd' feed effieieaey ®f fatteaiag lasabs, haw

been ■ reported $iiea cMostetr&cyeliffle isa® iaeltided ia the ‘ ratios , .

•(Bridges et glog 1953? Hatfield et alo0. .1954? Jordan et alop. ISSl)* .

Beesoa .et ala"(1954) reported that" yearlisg steers gained.' signi*

ficastly faster with less feed-when fed ©M@ftetracyeliae at a.level -

®f 15 ago per. p@«d @f ©esacesfsateo^" jBspsm' et5 ill (1956) riperfed •• " - ■ ■ - ' - ;"‘V ■■ ■ ' - '■ , "

cycline at a level of 5 % „ per of ratios c, ©tfeer wrkers5

however g. (Bell - et alog 1951 g. ■■ Metsis® .et si o'g 1951? and Bridges et, tie t 1953)'have fossd" that the feediag, "<safiba*tids.;tota . ramisaafs

did not resnlt . is ipereased''gains ©r-feed"eEficiemCfo ■ • •■■■.:'

Xn ssoyed gsia and feed atilis&tios are sot'; the ©sly criteria

by tshieh the feeneficisl effects ,®f; antiMotie® css be 'peasitieed#.

be as i#i@rtsnf as increased . gains' sad • f eed satilMatioa s. ssch as

improved''carcass gradesp- eontrol; of' disease loss8 mad rednetiom of

• shipping stresso • . ' , , . .• - ' ; . ■ •

...,■ .' ' .Althotigh aatibioties Mawe Srhowi promise.' ef great benefit in ,

the livestock -• iadnstsry, - t&e preseat ■Hefhods' of administrafioa. ia -thd

f eediag operations are not ■ c©kpl®tely satisfact@ry „ ■ Furthermore $, •

the addition of .antibiotics directly to. the ratios involves the 'cost 'ctae to the .necessity for eatsa storage..space

and. additional. lab®s'0 The problem of variability M' eating habits

is enee'tottteiced'.. t&en m antibiotic supplement is fed to cattle on range ©r jaasture, Sbaa'e .of. the sniaais m i l invariably, eat large

»©«ints while others' will eat'l i v -i&us9 it is difficult to- .

control intake of the supplements •

The iacorposation. ©f am antibiotic supplement in salt fed free ehoied: i© the animals a,, offer s' a conwaient low cost 'method by

which antibi®ties . esa' ,be ''adainistered t@' aBiteals; in feedlotj, on .

ranges, ®r. pasture'. The-use of: salt: as, a carrier for the antibiotic

has:an advamtage:ih that it tiould. act as'an intake regulator and■ . v- ' . " , , - : ; “■ ' . V ;- ■ ■ - ■ ■: ■ . . . ' ; ,■ ■ ... . ■

thereby result in a less variable intake of an antibiotic mong theanimals, , It would also'be a cheaper; method of:.-administration than

would miring the smtibiotie directly into.the-ration' since^ the use

..of s a l t - s p a c e and labor

:in airing. The feasibility ©f ■tois method of antibiotic'administrae

ti«m has been shown.in a preyious : .study in teisona (Erwin €t al,* 1957) in thieh:.the intake of oxytetracycliae was effectively .

controlled when fed in salt mixture free choice to feedlot lambs.

It has.Been indicated 'that the greatest; effect of antibiotics in

the.stimulation of weight gains and feed efficiency occurred in

.mature ruminants fed high roughage rations, (Beeson, 1957)„• > Fart

of the present study tras designed t© determine the effect of :

oxytetr'acyeline. in salt fed free choice, to yearling steers fed a

roughage ration of cottonseed hulls.. - - ■ ; ■ -

■ :.. . The. importance of viismin A 'for cattle, was revealed in a

recent 'Stirvey CBxsminger et gl,,. 1955) in lAich vitamin, A deficiency

was shorn to be second only to pasture bloat relative to nutritional

ILow qmlity eBagtiages siael| as eottonseed iiulls m d eotton -

gin' teashg ase: deva£ti>f e a r a t m e ■ With; the increasing -ttse of these

. roiuighage's in feedlet Operations'it is'"essential that supplements

.ade^iate ■ to meet the -earptend md. mtsmn, & requirements .df the

cattle 'he. snapplied. = . '," . . . . i _',v ■ . - . ; '' _ ;,;;; -

.:; Guildert and. Hart €1934) fora# ;'thatvffi®st ©f the total store

of.vitamin A in beef animals"©eenrred'in the, lives an# that the -

feody fat fuas a major site of'carotene storage. In a farther study

(1935)' these mfkers determimed the minimum daily caretene 'require

ment of beef animals to be from 26 to 33.isg9 per kg. of body weight.

It was also found that a daily carotene intake of 29 ug. per kg. of

body weight m s sufficient .to; alleviate arid prevent symptoms of vitsimin. A deficiency. Hart Xl942=>l-943) determined the minimum ■ .

daily requirement of vitamin A for cattle, sheep, and horses to be

from 5.3 to 7»1 ng. per kg.'of body weight, and the minimum daily

carotene requirement to.be from 24 to- 34 ug. per kg .‘of body weight.

.Other workers. (Jones et.®!. , 3,944)- found that a daily carotene itt -

take/of 5 t© 20 ag. per kg. of body weight was not sufficient to

prevent; symptoms of' vitamin A deficiency, -in dairy -bills. - ' In this

. same-study» a daily carotene intake-of •approximately'25%g'j per kg.

of body weight was found to; -be sifficient for' normal growth and. to

maintain blood carotene'levels of .30 .parts per million^, Other

workers"(Hart, .1942=1943) found that a daily'carotene.intake of 75 ig. per kg. ©f. body weight m s .essential to maintain normal growth and vitamin,A stores of Holstein calves, Davis et al.g '(1941) .

10reported tliat the vitamin A eonteiat ©f fee blood £a eattle was

elosely associated with the,.carotene level, .Vitamin'A values tended

to reach & staple level and did not increase proportionately with

increasing carotene intakes, ' In'this same.study it vjas observed

■that normal calves were'borne to beef heifers receiving;a daily '

carotene intake of' 00 ,ug, per -'kg. "of body weight previous t© and

during gestation',' Heifers receiving :'a daily carotene intake of 30

/to.40 ug, per kg.• of body weight remained-normal^ but produced

calves deficient in vitamin A. ■"

, Previous studies (Byers et al,*. 1935; Erwin et"^, g 1956}

have indicated, that cattle subjected' to suboptimum intakes .of earo=» .

tene over prolonged periods suffered^ a loss of ability to itiliae ■

dietary carotene„/■Byers ’et; all:(1S55> reported that 50 Mg, per kg.

of-body weight appeared-t® be insufficient to maintain normal levels

of carotene and vitamin ;A' in tiie blood$ liver8 and milk/fat of dairy.

cattle, Ms®, cows that were fed low carotene rations .prenatally '

and over long periods of time after parturition had low liver and

vitamin A values which failed to inGrease with dietary carotene

supplementation as high as'330 ug. per 'kg. of body;weight. A.

failure of the hepatic- stores of vitamin A and ■ car©tene to;increase

was also noted with repeated' injections every five days -'of: 250,000

,to 1,250,000 ioU, ©f vitamin A, either, in normal or depleted animals,

; ' ' . Johnson e$ all" C1948}..'found 'ihat-rats grew: well.on vitamin A

deficient rations as long as the diet .was adequate in all .other .,

respects. Eatsilxose growth was hindered by.inadequate food or a

deficiency of thiamine.or tryptophan retained higher hepatic vitamin

S. stores tfeaa t&e gs©Mag mad. vitmmim A '

Eetefflt£@ai beteeim i?8Lts ©f slsilag sa^e suggested that the aetabelae

sate Mfliaeaees witsmiia A Seipletien,,; , ‘

' " ■ , ©Eilbest asd Mast C1S34) ,:£©»$ that steers sh@*d mbM era::

'weight iaesesses @f. 10@, t@ peoads .daily m l dressed, ©at W,th a

■ high degree of fstaess imp t®' the time' rfeea' their sitaaia A reserves

were e®apl@tely .eAstasted aad defieieaey sfaptsss ■ appeared y, There

Is evideaee fr@® studies eemdmeted bf ether wrlers Osavles et ale 8.

' if 37g Sie&aSflc lf4Sg Bavies et .al e g . I§4S g- Fsey- ®t .ai0. s l@4f> that -

• the less of vitaaia A at amyrtlme' dmriag a period of deprivatlw is .

‘pr©p®rti©Hal t® the aagalttide: of'the reserves semalaiag at that

..t£a@0 Bavies #md Moore ,Cl93f); wrfciag with rata, observed, a rapid

Initial fall of vitswia A'stores which became progressively slower

as hepatic stores were depleted,,. Frey amd Jinsesi (1947) wrkimg

with beef calves ©bseryeS that; :the rate of loss of hepatie - vitsmin ■

Jk slowed markedly a# the .reserve- stores were Wpletede - These stMdies

SBggest fMt the initial reservis of vltsaiM: .S,- -are- a- major factor .

to consider Sa fetiare research work iavolvisg th© study of vitamin

A and cew^oteme-requirements for cattleo , , ■ ■ , ■ . -

EXBMIMEMm

■ ‘Biisty yeafflxas steess' i#$e /placed iia' iadividaal pens and

fed file - five supplements shown in table 1 fpr 110 days. Table 2

-shows the eheaieal analysis of "the ration ingredients. A potent

e^ytefraefeliae SEppleaen.t .CSO/ng. per/ponnd} was mi%ed with tt&ce ;

mineral salt to approximate • sn antibiotic aetivity of S.-S gms. per

ponnd of'salt' and fed free choice to half the nwmber of animals that constmed.each snpplemento /The remaining animals, received plain. "

trace mineral salt. - .. v/ ' ' //' ■ ■ ; ■ : ' •"

T6BUB 1. SBRGEHt C«STIOTMTS IR ggjLBTBB SPggiaCTTS .

Aatioh' Hnmbers '

Constituents. \ ' ■ ./• ■ - .'2 :-/ ' *

' 4 ' " 5

Cottonseed'meal "'' 68.4 , 58.3 49.8 " .36.0 . 16.1

dehydrated alfalfa : .12,5- ■ 22,8 /. " 40,0 64.5

Bone meal ." ; ' 5.3' " 4.? : 4'6 .4,0 3.3

Molasses ■ ■ ■' ■ ; 26.3 ''24.5 22.8 20.0 16.1

Botmds of stipplement per '.100 ponnds -of. body weight ".Ml ■. ..■.582' ■. .625 .714';- : .860

The study, therefore, involved"ten treatments of .three

animals each. The treatments were raodomly; allotted in three, blocks

©f ten pens per. Mock.".. ./// ': ■' ' , /'" . v - "

; " .As" shorn in table Tg" all snpplmeats were fosamlated with,

cottonseed meal» dehydrated alfalfa meals and molasses, and were fed

• to eSeto aaiml in aeeeed .to foodiy weight in ©rder -t® equalize peeteia

'imtake’» 4fee ^otaat-ef SBppiemeat'ms :£ea<ljtiisted after each 30 day

weigh geried* ' se-,'fedvdo'ttoti®eed>;htitils ad' iibittm :: '

titi.ee daily and'the ..respective 'SMa©mts-; of-. SMpplemeats sailed with .the

hells 'at time of feedingo% Feed aad salt eensmptim ?jere retiorded

deiEitig the 110 day: feeding''period and rate of gain and feed efficiency 'were saietilated .f@r :©seh iuBiBa.'1'o. . #11 .data were suti jeeted t®: analysis of varianee "as osatlined. by Ssededor (1956). ' ' .

■ After 50 days of experiment$ a digestibility ..trial i»as.

eoadtaeted. . tihremie oxide : CGr2°3) '*8 mixed t ith the supplement • # -

■approximate 0„5 persent of the total daily feed, intake and this stipple

ment m s fed for. an adjustment period of 10 days, At the end of the

adjustment period,, a morning and evening fecal sample m s eollected

'ffqB each .animal,. The'samples were dried and mixed thoroughly and'

analyzed f@r a®istur®9 ether-extracts.:total nitrogens and crude.

fiber by approved procedures,-: Chromic oxide (Gr^Og) liras

determined in feed and feces (Bolin et aJLg 1956) and the apparent

digestibility, of each, factor calculated'"by a ratio technique. ■ :

The hnisals were 'subjected to .an initial liver biopsy

(Erwin et al,0 1956) and the liver samples•were immediately frozen

with dry ice and later placed in' a deep freezer .until time of

analysis; for vitamin A, and. carotene (Gallmp and Hoeferg ;■ 1946), ■ ', , -/ After the 1 M day feeding periods the animals were' subjected

to b second liver biopsy and the liver samples analyzed for vitamin

m m a 2» B m c m t .cmmicm emsTimmTS. m sroaLBMBMxs

Sappiemeaf ': '' 'ifeistuiEe'' % . '

-EitEOgeh' ' mg/gm.. ■

' - ' etude iat• % .

' ' Grmde B; %

: / 1 T' ' ':'.. : V r .

'v49.5f;::':' 3.03 8.25

: : ::.2 ,.;■•■■ ,, 2.03 - . -. 46,34 3.62 . ■ : S.86-.

'; .' - 3 ' -. 2.15 : 44,31, ' 2.21 ■ '8,91

■: : 4 '2,24 - , 35,04 ■ •''.■■■•3.03 13.26-:. . , ,•. ■ .

..... 5 2,51' - 30.6© ' 2.30 17.27.

Oo t toaseed. Hull s '1.55 - ' : 5.i4 4.16 ‘ V.34,49 -

. The' iBilneade of tra yiag leveSs ©f c&mteiie intake hepatic! stossge of vatamis• A am#- eas.®t©ae '#etewined. both g^sSMeally ■-smd by statistical treatHeat ®f :the data.. ^alysis - ®f ■r&riaaee was. eeadaeteS ©a hepatic' $et«i tioa of. witami® A sad eaffoteae dasiag t&e 110' ■day 'geeied aad /stedeatised Q' rzasage tests '(fekeyg 1953> .sere: utilised i© detemiae 'differences. between the group''means The /liaeas .feg$ession: @f awirage Mtsmin A storage per group @a dietary intake of carotene, w s ..al#o.' determined .and" correlation coefficients were • caicalated for 'retention of 'vitamin A- and care tame; during. .this pesiedo'. - FertheswEes. . the total 'araoant of vitamisi A KeaniiaiBg at the' end of'.the 110 daf period;.was correlated with initial stores.

The supplements.. i$ere' .then. rtiaoved and the animal's ere f ed

. e©ttoaseed hslls alohe for- a f ive- day adjustment .-.period.-'. 'Alfalfa

hay was then fed t© each animal‘f®E IS days in the.asorat ©f 1.5

pdtiads :©f M y for each 100 pohads of body weight. This method of v ' feeding equalised the.'oaEoteae intake ©f the aaisials ©a a body

weight basis over the 18, day period .so that ea§h steer'received'

approximately 40.22 mg. o£ earotene per 100 potmds’ ©f body wjeight.

J)iffieaitf'was eaeoantered at. first ia. that some animals would mot/

: eesssdme ebapleteiy thei$: daily ratiW .W/ hay.' - The amoeint 'bf hay . •

refnssd * s weighed back smd- added later s© that all steers e©a=

stsmed the same amomt ©f hay dhring .the 18;day period.

Mter the 18 day period ©n alfalfa hay? .the animals were .

biopsied a third time m d /hepatic retention @f vitamin A and earo^

tene- determined. ‘Eae biological valne ©£ carotene as-af f ected by

previous levels of intake was plotted graphically and treated

. statistically<, . ■ , • ’

' Analysis of variance, was conducted on hepatic "-re tehtion. of

vitamin .A and', carotene during this per led, and the Z..S.®.' and'

studentired. Q range.tests were utilised to determine differences

between 'the. group means. The linear regression of vitamin A,

. storage: oh previous levels' of carotene intalce was determined, and

a .correlation coefficiest w s calculated for these -' tiro '.variables '

. from these data. ■

I

RESULTS

Peed Efficiency and Rate of GainThe average daily gain as influenced by treatment are shown

in table 4. Figure 1 graphically shows a progressively decreased rate of gain as the amount of dehydrated alfalfa was increased in the ration. When these average daily gains were compared in an analysis of variance, no significant differences were found (table 3).

POUNDS

60DAYSMAR.JAN. APR.

MONTH

Figure 1. Average total gain per group during 110 day period.

Tables 4 and 3 show the data and statistical treatment respectively, as influenced by the oxytetracycline-salt mixture.The small mean square due to the antibiotic was non-significant in all statistical analysis and no antibiotic-diet interaction was found except in the analysis of variance of hepatic carotene retention during the 110 day feeding period.

16

17

- , -Feed efficiency of the aaMal s a s - iaf lEeseed.' by treatEent^ is sMoiffl in table 4,, Slt&oisgM no ■ significaat diffesedces tfefe fetffltd in weigM gains "between any: of die g2©tiips? tbe feed efficiency m s

somewhat-diffeirento- The amount of feed consumed per 100 pounds of gain,rose progressively higher as the level of dehydrated alfalfa '

meal indreasedo . Statistically significaat differences were found -

.(B< ,06). between all treatments except' group III and IV (table , 4) ,.

The steers in group V, with an Intake of approximately 4,0 pounds of

dehydrated alfalfa meal per day s gained,at the slowest rate with the

lo%#st feed efficiency, These results indicate a lowered feed"

efficiency-due to the addition" of dehydrated alfalfa meal fo a basal

diet: of Cottonseed hulls-, -

TJsBiE 3, m m y s m . QP v m i m c m op m i G m GAims m o peep bpficiswcy

Mean'. Square

Source ' ■ . d»f. . Total-Gain - T,bs, Feed/100 lbs, gain -

Diets " 4 - : : 1902,75 ; ' 311012,25* ', * ■' .Jsstibiotics - ■ i 30,00

, " ' / '3456,00

Diets, X ABtibipfies- 4 ■; 1565,50-'. • 135599,25.

Beror - : ' > 20 - - :667,35' . 102427,30’

# D m 40 F U B CfflJSDWlCIW A # B # Y lEIdiT WBm-Ems&iMmmE, w i m s mmwG no pai bbrxcp.-Croup Mumbeg- - . ....- ■ ' ' ' ’« ' ;

" .. II 111 ' ' . IV. V

■Ebs:» ' peg . day - d#y%.ated,: '. / : teifMfa; meal ■ " ; . o ..

X;■ 0,5 • ... 1.0 '2.0.' 4,0

Wo. steers: ' . _ : ■ 6 6 f : 6 6-^atiMotlcs .;■ ■■; .AWo tetal gala, lbs. . 200 463 183 ' ''165 163

Aw. • dailly gala, lbs,'; 1.81 - 1.48 1.68 1,50 1.48No .Aatilbietles ■Aye. .t@#l gaiav' lbs,: . ;•: . If2-; ; - 207 - ,160 ' ' 494 .: .133;: AWo gaisi lbs,'; ■■ '-x/' i,#: : 1.88 11,76 ' - ' 1.20

AW'. Ssl-t CbasMimjptiQsi• (g&s. per. day) V ' : : V V.: '

iatlblQ-ties ' " ' . 140.3 115.6 168.2 ;119.7 48.7Mo aatibip.ties 173,3 ' ' 66.0 '■ 136.2 173.3 90.8Mg, aatibi® tics per . ' ■ ■ ’

daf Wr'steer ' , ' ■: 25715 :212.5 308.3 ' 220.0 89.1Aw, Bally Feed . \ ' ■ 1 ■ .Comsimed lbs. ' . ■ - .

Supplement - •■;■ •. ' 4.18 4,28 4.44 5.37 6.66Cottonseed Imlls 18,68 . :17.93 18,20 18.57 17.15Total ■ . ■ 22,86 23.21 22.64 23.94 23.81

Feed Cossmed Per 100lbs. @f Calsg_tos. '

-Supplement ■ - :V. - . , .

. U : ;: 235;: -:’-\;27l; ' 296 i s # :/ 529 ’■. . -■ , ' - V • • ■ ' , - . . -

Cottonseed bulls <T}\ 1057 /; 1089 1185 .4lso:4 :yl350Total / ' - : 1 -- -- ' . , . ; V 4292. ,, -1360 : 1481 ' 1480. . 1879-Feed Bffieieneys Q ® '13 s,56 % '

.Sagoteae Repairemesats.- : ■ ■;, :' . : ■ v '■ . ' ■ ■ . ■ ■ - .. ; " ■ '' . - "

’ the absence. e£ eairbtens is Imv quality rcnghagesg stsefe as

cottonseed halls, is a major factor to consider .in the formulation

of adequate, supplements, therefore, -a knowledge of the Specific'

carotene :reqtiireisehts for sheep aad cattle would be . beaeficial., ' i. ../• part of this, study, was degigaed to (1)'study.farther the carotene ■

requirements of growing steers, (2) to determine the influence of

Wrions levels, of carotene intake ©a hepatic retention of .vitamin A

.and.carotene, C3> to determine the effect:of suboptimn#:iefels ©f. .. ■

carotene intake ©a hepatic'storage of vitamin A and carotene, and

<4> to correlate 'the relationship between the dietary intake of - •

carotene and the hepatic storage of vitamin.S ''and :eardtene'o. '

, As quoted by Moore C195?> froia a study by Harms ’<1942}, the

. average content of. vitamin A in: normal cattle has.been fotild t® be

approximately 45 'i.«d per gram of fresh liver. However, pSesumably

due to.varying-dietary carotene intakes, the reported average values

fbf hepatic'vitamin A cover a wide range, Moore. (IPS?) .reports an; ;

average-value for cattle of 150 i,u, per gram of liver, :MddsenLand.,

Davis (1941) reported'that the vitamin A content of‘the blOod .was

closely associated i ith the carotene-content although the - Vitamin A :: ' - ' " ' " ; ' . . , ■ ■: -v \content tended, to’ reach "a. stable"level 'and -did. not increase pro® '

" ' . . ■■■■•'■ . portionately with,.increasing carotene intake, Bie results of, the . .

study reported herein indicate-that there: is no relationship be® -

' tween hepatic.storage of vitamin A and carotene.:. the'gain - and loss

©f hepatic'vitamin,A and,,carpteae;during the:110 day feeding .trial;. 'h. :■

- g.is shown in figure 2, Table 5 shows the-, retention - of- hepatic-Vit® amis A and, ear® tene as .influenced by .carotene intake,. ,. ;

MICROGRAMS MICROGRAMS

+ 10

+ 5

<Z2 o <>

-6

-10

0 0 V ITA M IN A

J CAROTENE

I n rn h T + 1.5

+ 1.0

+ .5

o

- .5

LlIzLlII-Ooc<o

- 1.0

- IS

Figure 2. Average hepatic retention of vitamin A and carotene during 110 day period.f

As shown by figure 2 and table 3, the hepatic retention of vitamin A and carotene do not follow a similar trend. The only significant correlation between the hepatic storage of the two sub stances (table 5) was found in treatments I and V. Treatment I consisted of no carotene intake, while the animals in treatment V were on a very high intake. These results indicate the fact that there is no relationship between hepatic content of vitamin A and carotene in the bovine when the animals are fed a daily carotene

21■ intake of 4*52 t® 41087 mg.,: per .10§ petods ef body weight, . , ;

V : .IBe hdp&ti©; ffefeation :#f vitamim A- (flgwge, 2> appeared at ■

first to foliow a lineas tread la-gglatlonship t® the intake of.

dietary earotene, A /statistical application ®f linear regression

with mg, .of -earoteae fed per 100 potaatds of body weight as the %

.variable yielded .a regression coefficient of ,40, indicating an .

increase of,. ;40 ng, of ■yitamin S,.'per' gram of liver with each mg, of

carotene intake per 100' pounds of v.body''Weight , However $, ' the cor** ;

relation coefficient Ctable ;S3>.: ealenl^ted from the regression data ••

was aon significant.,' This led to the eonelnsion that tberd is no

linear relationship'between car©teas intake and hepatic retention of

vitamin A, However, the hoh»linear relationship between the ' tw%..

variables, may 'b:e,.shot«ii: t»ithpM.t-:.r@o©:;iirs'e to statistical analysis by.

graphically plottiag fhe .'*teepatie 'retention of vitamin A against .

carotene intake, , A graph of this type indicates, a linear trend, of

.vitamin A retention np to a carotene intake of 7,54 mg, per 100

pounds of body weight, . This indicates a threshold effect in vitamin

.A retention'. These data indicate that- the efficiency of carotene

utilisation by the bovine decreases beyond the amount necessary.for

normal hepatic storage of vitamin A and normal metabolism, r Ihe

analysis of variance of. vitamin A retention during this period is

presented in- table 6, The use Of the Q tests Ctable'5) show a

significant difference in vitamin A retention.betweai groups 1 and

IT,, and. a. signif icant ' difference' between these groups:- and - the other

three, #o difference was foandvbetween groups III, and t,

further indicating fbe threshold effect #f vitamin A storage,■ The '

-significant difference in vitamin'- k: retention’between the .different.

groups indicates -.'that '& carotene 'intake-df ,4,52 .mg. per. 100. pounds

of body weight is sufficient to result in a significant difference

- in - vitamin A retention between" # e groups,. A carotene intake; between

7p.54 and, 41,87 mg, per i€>0 pounds of body Weight" revealed no signi" '•

fleant differences in vlt#3im A retemtlong further bearing' out tbe

indication that the intake .of- dietary carotene over a’ certain aaoant,

in this, ease 7.54 mg, per 100 pounds of body weight» has little

-influence epos hepatic storage -of vitamin.:A»"; . : ' . .. ' . -' '

;: ’ % © n graphically, plot ting hepatic carotene retention against

carotene intake in mg« per 100- pounds of body weight»..an ■ increase ■

in hepatic storage of -carotene is shoxito up to a daily carotene; in«=

take .of 7,54 mg, per 100 pounds of body Weight, , At -this point' the

’ curve breaks and assumes a ;dpimwrd^-si ,;. So 'sigaifipint eorie”,

lation; between carotene intake and hepa-tic yetention; of carotene

-was found-(table 5),- A. threshold effect'of care tene retention is

indicated., the liver retained a certain asotint: of carotene-'in

reserve while the excess utilized'lb Other processes, "Table 6

... shews the .statistical. analysis, ef hepatic carotene .retention as - -- :

-'influeaced by intake, ’' M signifiesint ■ diffef6nee ClBC 01) was found

'between the groups during the llO day feeding period and-also an

-unexpected diet .by antibiotic interaction. The presence-©f a large

interaction indicates that the animals in'the; different groups did

not respond uniformly to the antibiotic la regard to hepatic ear©^ - :

.tene; getea-tiba, but. the' 'interaction at this time is uhexplainabl-e.

The Q tests (tabid 5) show a significant difference in

23casrotesie retenfien betueem all gMuips except gE@Bps I' aad II'aad

g»baps II aad' III, indicating aa inconsistent retention of hepatic

.earoteae since the retentiisn .increased linearly up to an intake ©f.. -

7d54 iBgo per 1Q0 pounds of body weight and then dropped sharply down

.witte higher levels of.Intake. These results indicate that there.is

little relationship between dietary intakes of carotene and hepatic

retemtiond. ; : i : - ' ■ -

T a m s. imtake # # meATic k e t m t i ®' ' ' # v i T m m

'."1; "v; ' 11 '.. ■

■Ill':: IV V

■ • .. carotene- per;: lb. ,@f ...'. ■;. •;?

: .' -.- ; . supplement . 0 7.76 12.03 “ 24.40 48.69: ' • ■' ' : ■Mg.. - carotene per 100 lbs.

.. ; body ifeight ' : ': 0 '7.54 • 17.40. ; 41.87;':. 1%. of 'Carotene per kg." of

body weight 0 - ' 9K4 165.5 383.3 927.4Hepatic re ten tion 110 days, ' ■ ■■■ % j -:%■. - ; -

' . Cug. per gm. >g ’ - ;; ’ ;c Vi [ ' .. - ■,. -Vitamin A. . ... ' '• ■ -13o23: =7ol3'' 02.15 -❖5„67;; ❖6.79

■ ; ' Carotene: . " ; ^ o 33-, ^ o 00# ;fl..23 ■ ❖ .91 46-' Correlation of hepatic. :r

vitamin A .and earo teae

; 3; .53 .38 ',.82*

. Statistical Relationship- of'- - •• . Carotene intake to:.-' .

Correlation'.. ■■.Hepatic vitamin A ' \ . oT7 . : 6.55 ' ;.

Hepatic, carotene ' ■ ' ,60 ... ,65: ■ "■ "”r~" ' ' - ~J ~~

■V ■*' P<i®5 • ' ■

: ■ ; ^■#<.01 .. -6 /, ...

‘ ■ • ' -

TAB#- e* mmi s i s # wAs m e s q f hbpatio i i t m e m a amb ■ ". ■ : efficsMB tetaiTW .B111E6 u o bzW :

Sousee d.f-._Mesm Square

Vitamin A. Carotene

. Blete :. • \ ,

AatiM®ties' v •

Biets X AntiMoties:'

.Errorr

■ i

4

20

.** -P< ,01

-446.3

' S6.f7:

12.20 32.5$

. ' - 4.1.2**

; -;,2o;.

1.60**

• , .11

Effects-of Previews Carotene Intakes oa Cstgoten'e, Btillaation

At the ead .©f the 110 daf.'.feediag- trisil" 'the smisals were

Mopsi^d -aad' fed - a diet: eoasistiBg :solely ©f . a%f#lf# hay - for 18 daysu .ih order to stddy the effect of 'preyloms levels, .of sarotene on .

hepatic storage ©f 'vitamin A and-, eardtehe. Ihe hayvms ©f fair

-.quality with aa. average" carotene content of 38.10 mg. - per pound..This material xms fed t# the steers in accord to.body-.weight so .

that Approximately' e<q$ial .earotene' intafees irotald "be received .by all

animals. At the end ©f the 18; day period "the-'animals were'biopsied -

again and the respective samples analysed for vitmim A and ear©® ■

fene. The steers were;then, -placed on a fattening ration: f#r another

experiment. ' : v: ' ■. ' ’ • • . . '

Figure.3 graphically shows the hepatic retention'of vitamin A and carotene as influenced by .previous hepatic storage. Tables

7- and 8 shew. the -data and; statistical treatteent of the hepatic

retention of .vitamin A and carotend .during the 18; day .period. ' -

■•.No 'significaat - coirirelaticMi Ctable ?> .was fotxM betweeis tlie total wouat of hepatie vitamin A .at the .beginning of the 110 day feeding .pe$£ed and the amomat xemaiaiag aftern 11G days. A sigaifieaaf " ■;

difference CFC o01> la hepatic vitamin 'A-' retention tsas found between the gtonps chariag.the 18 day period (table 8).. The Q tests (table 7)

show a , significant; difference in, vitamin. A retention between groups •

1 and IIo' The.vitamin A retention of these te© groups was also : f

found to differ .significantly from groups III and ¥, -Offbup .IV also 1

. differs from group I and II is vitamin A .retention during•this. •

' per i odo . : :v _: - / y /_ •'

■ A comparison of figures 2 and 3 .show almost a symmetrical

reversal' .of vitamin A retention during the IS day period except for

. groep il»Byers et ill»‘ CltSSj . and Brwin, et :Sl i <1956).. r repot ted

results which indicated that:suboptimum Intakes of oaroten#' over- , ' ' :: v ’ .: ,.c .prolonged periods markedly;influence the 'biological value of. earo= .

tea® for /cattle,, Bart of tMs/.e3Eperiment■.was designed- t®'-!further ,

■study this subj'ecto ' HoweverP steers' in 'ggoup .I» ^ich; had- pre=

viously received a ear©tene deficient di®t» markedly increased■■■■ " : - ' - ■ ■ '■ ,' ■ ■; ' ' 'their hepatie vitamin A during the MS day period, •

The loss ©f vitamin: A (figure 3) by 'groups 111 P' IV'# and V

further indicate the existence of a threshold-effect e£ .vitamin A

'retention. It may also be .seen from figure 3 that there /is no correlation between hepatie vitamin.A'and carotene reteatioh during /.

this period, Hepatic storage ©f vitamin A and carotene as influenced

by carotene intake is shown in table 7,

26TABLE 1 a 3 E W E ©F BIEFM'i CARQTME AI® HBB&fIC RETEETICP/OF UTMMIM :■■. & # i m w m c m ) BY mwtffis h b m t i c gTQiigm . .

' Group. Humber, ; • v

: ' r- II III.;' ' ,iv v \ v y

Mg„ caratene' per lb. of M&f .'30,1 " ;3Sol .. 38.1 '' 38 .1 • 38.1.Mg0 eagoteme per 100 poundsbody weigW. 40o 22 40,27 40.38 40.18 40.06.

ugo carotene per kg„ body wt« . '',88$::y ; 886- 888 • ' .884 ■ ■ 882' ; ' yAve, 'hepatic level at start; of ■ : . ; : ' "■ IS: day period Cngo' per y

■ Vitamin A ■ ; 5 0,65 .,14,21 27.09' 25.94 37.06. ■ • / ■■ /* ,Cag&±e%ie ' lo28' . 1.81 . ' 5 (,21 ■■ 3.03 4.80

Hepatic retention'(ugo/gm.) " V ‘Vitamin A •> : ' - '«o»5t;lt ■ylo40 ' «=6.(,34 “3.55 -7.96

' .. Carotene „ ' ^ ‘

. =& <5*2.13 » .25 *2.17. '+ .75 '■ - ■ , . „ ■>‘V' ; ■ . .: ' .Correlation ■'" •' .v .' 1 \ A. ;>■

Hepatic vitamin A and. . . ' / ... '' carotene ' " - o W " . .10,'. " ..14 J .21- / ,

Correlationg . ' . 'v.. Initial reserves, of vitamin ,. .. A with- amount remaining at . : -

the end ©f the 110 day period /' f" ;. '■ .76.;;'.. >38 " , .79 , • ..82*: .80 y ■ y

• • ' ' • •" '• . ,

Statistical'relationship ©f '■ ■; ■; : • • ' ' • . yprevious carotene intake to:

. ••Correlation .. ■ y y g

- .Vitamin A . . , ' \ • • .72 : 4.25 '

Carotene . ; x' , ,79: ■ •. 57. • '

*■■ ,f < o©5 ; : ■ yy'.'; '■

27

MICROGRAMS

+ 10 g VITAM IN A

| C A R O T E N E

i n m nr tt

W II

Figure 3. Average hepatic retention of vitamin A and carotene as influenced by previous carotene intakes.

Vitamin A retention during this period was subjected to an analysis of linear regression. With previous carotene intake as the independent variable*, a regression coefficient of -.22 was calculated. However, the regression coefficient was non-significant. A comparison of figures 2 and 3 indicate that retention of hepatic vitamin A and carotene was influenced, to some extent, by the caro­tene intake during the 110 day feeding period. However, the cor­relation coefficients calculated from the regression of hepatic

^Previous carotene intake cannot technically be used as the independent variable during this period without special consideration.

28: 'mtaaiaffl A sad ear© teae re ten ti©a 0m prem©ns'earoteae'iatalce were

set. significant? indicating' that in t!$is ease there is n© statistical , relation between .the tw©» the carotene vrefention daring: this period

■ >®s found to. he significantly,different :ttf&bie 7-) between, all -groups

'/ except'groups II and II1% and groups ,11# ahd I?^ which seems t# in-/'. / :

dicate that there w s little rdlationstop be tureen the intake of ' ■

dietary carotene and the retention of 'hepatic'carotene during this

periodo. : ; . /; " ;v . / :' /" " . : / V '■"//• ■ • ; '

. T a m s* #' y m i m c b -of h e m i c - w « i m.a c m m m E/ ' m T m t i m m - W B m m c m , - m m m m e m m m E m i m m «

Source dot.

Mean Square■ ' : ,i ",

Vitamin A Carotene

. BISCBSSIiB

Feed'Effieleacy and'Rate Gaia -

, -:' Previous''; werkes's (Burroughs et"; al»8M^SOi .Swif t-,et. al.,, y' XfSig

Klostemaa et .al 0 P 1953) .have reported, that’- tfee addition of alfalfa

teys alfalfa, meal» or alfalfa ash to a diet.of-.low quality.roughages. V . . , ■ - . ' . ,7 ' ;"' - " • ' - -

results.in iaereased gains and "feed effieieaeyv Others» however»

CPluElee, •i953:g Tillman ? 1953) /'reported. that higher gains and.

improved feed utilisation .did a@t' result tdsea' either alfalfa- ash or /

trace minerals were added. to a basal diet of-low quality gStighage„,

. Molasses has;been reported by several - workers (Bray -et al«$ 1945)

- Burroughs get al«s> 1950) t© increase digesiifeility of low--quality

roughages and inproye feed utilisation0 ' The results-of this study

indicate a: trend- of lower weight gains -and' significantly lotrer feed

. efficiency when dehydrated alfalfa meal - and molasses are added in

combination- to a diet of .cottonseed hulls fed-t© yearling steers,

Mi#;'only- @i% animals. per: gsofflp>.' the between aaimal; variation may : -

have been large enough to offset the'presence .of/.significant. '

differences between the groups in rates of - gain. Hie consistent .

trend of lowered gains from groups T to ¥ indicate- that -statistic

cally-significant differences between the group# could -possibly be'

detected with the use of larger numbers, of animals ..per group.. The

lower gains ho fed when dehydrated alfalfa meal and molasses, i-reze

-fed in combination bear out.the results of the study conducted in

-1955 by the Ariaoma Station^ ■sfeen it was -found .that the .supplemental tioa of alfalfa or molasses alone resulted in significantly faster

. 7 - - -

. gaias thaa- isiies ffee Swa tfes@' fed: in eembiaation^

■ - . . Altboagh aafibioties tow bees found ta sigaifiesafly. lm«

Grease weight galas ^ d 'improve feed pf fieieaey #&en fed. to: goal try y . ■- ■ ' ;/ ■ ■ . ' : _ _ =' ' ■/ ■ - ' ; , -

. swine and sal yes fMoKay et kl„s S.t53j fe.slet» 1954 mad others)»■ the' " " «5SatES» ■

reports have been coaflie ting, regarding the toltae of as tibio ties in

; .rbminant an tsition«' Perry1 et .al»> 1954- mad' Bui tstoan ■ e t al » 1953 -

.reported, that the feediag Vdf ; . Bntibi©ties ; at low. levels isereased

"Weight gains '-and feed efficiency of beef cattle» Irwin et'-al „ p 1956

reported significantly■increased.gaihson yearling steers tghea the .

animals were • fed chl#rtetracycline at a level of 5 sg, per ;<pound of

..ratiotto Qther workers, hosjeyer»: (Beli ef a l . 1951, Sewast-et al,, ’

1951 and. others), have reported that the feeding, of antibiotics to'

V A- I

mature' rhminaais- did not result in increased gains or" in -improved'.

: feed ■ efficiency. "In ;'fhis- sfudy'Mt 'ms; found that the feeding of an

©xytettoeyeline^salt• mixture with an'antibiotic activity ::©f 2„5 mg.

■of:. antibiotics per pound of: salt to' ■yearling ■ steers fed eottonseed ■

hulls plus:an alfalfa, molasses supplement tod me significant effect

on improving weight-gains. ,@s'feed' efficiency0 l$se ,administration of

oxytetracysliae in salt, was found t@: ■ significantly increase weight

gains' ©f fattening lambs;, ia-a study coadueted by the Arizona- Station ■ in 1956. It is possible that.the variability in salt intake by ' '

different -animals to® a bearing ©a the' eff ectiveaess of this method

of administratios since some' of the' .steers during the: 110 day. period

consumed a large amount of salt, while: others iti:: the same groups

consumed none during the same period. Since the experiment was

-conducted during the winter'months under mild- climatic‘conditions,-

it is possible., that the &<3m£n£stest£em of .antibiotics eotild produce . different sesiiits if fed:. to cattle that %ere subjected to stress .

•' factors, Stieh as extremes of ■ tessera tar© and weather 9 ©r other factors^ ;' ’ • v : ^ ^ ^ ' v s ;-

'adverse to normal, feed: Btilitatioa aid weight gains» • .•

■ , A digestibility trial yds conducted .-at fifty days of the 110 ■ day feeding period using a ratio method of chromic oxide (GrgOg) in feed.'and.feces to determine'the apparent digestibility ®f the varions

. ntitrieh4sJlthOMgh several.workers CKane et alo, 194#% Giaaptoa

et ale, 1951> have reported successful results using this.method on . ruminant animalsg others. (Basaieoat,, 1945) have reported varying

suecesSo. 'Barmleoat reported consistently 1 w .digestiMlitf eoeffi®

citeats calculated by this, method. as compared, te the total collection .

methodo It was also foundithat these was a posslblity of-'incomplete

, recovery of Chromic Oxide in the feces unless the indicator was

thoroughly aaxed in the ration, aRd at least a five day collection

period was- used, tittle success was'found in the determination of

digestlom' coefficients' in this.study* The calculated results were •

so inconsistent that it was felt that they were not valid .enough, to

present here, Although the method seems to compare favorably with

. other' methods in deteraiaatioa.'of nutrient •digestibility M mono®

gastric ...animalsg it seems ..to have: a Variability of success v&en used '

in ruminant studies# , . ■ ■■

• The results of this-study indicate.that the addition of

dehydrated alfalfa meal t©'a basal, ration-of cottohseed hulls fed

tb growing'steers has no •'beaefieial; effect-as'far as stimulation of -

iaereased weight gains #d: improved feed.efficiency# Furthermore,

. the feeding of ®xytetracfcllae '10 sal’f’a wwlese aomhl. eavissMeatai

6oaditi#as» has little ®$ as effeet’ispoa the stisttlalatioa of fsstez

galas ©s iaipsoved feed effieieaey @f :the g®«als» -

Carotene Re®aigeiaents ' . ; -

■ .-■ :y'Tke reSQlts of i&is Stedy ladieafe that there is a© relatisa^

ship hetween vitamin.''A aad ear© teae'ia' regard .tohepatis re tea tioa.

Fiatthemoreg the sesBlts iadicste a . threshold effect of hepatic ;

reteatiea.' of yitaaia A and carotene since the ttepatie- reteati®n of

the ■teo, SBbst®aees increased nap. t® a daily •carotene intake of 7,54 -

per 100 ©otiinds of body-height. VAt this.point the retemti®®

lewled off and assumed a dowwaird tread „• . A logical explsaation of

the- significant.' correlation found: between hepatic storage df vitamin

A -.and carotene 'on treatments .1 ';and:T is not: difficult. The animals

.subjected to treatment •'$ M d no source of carotene smd ■- the. average

loss, of - 'both hepatic vitamim'A.'and caroteae W # large ° - Therefore a ‘

some ' type of: correlation hetweea hepatic retehtioa' of . vitasia: A khd-

earotehe could be'expected ©a‘ this type-of - treatment.-/ :T&e.'ao£fcals ba

treatment if had .a daily carotene intake, of; 41.87 mg. per '100' pounds '

of body weight .- The quadratic.- trends .of- hepatic: vitamin A. and earo® .

;tene' storage above sa intake of 7.,54 Mag., per -100 pounds of :b©dy:: '

weight -indicates - a threshold effect -©f storage.. Furthermorej, at this

high level of intake, the. variability betweea animals in tie ability .' ' v

to store hepatic, .carotene and vitamin A is very likely overcome;' • , resuitiagj therefore, in a Significant .correlation between.hepatic /

storage-.-Of'. vitamin A and carotene. Tbie;.'-]iMn* gidficaht- cortblatibn"'--

'between.hepatic storage ©f . vitamin A aad. carotene in trestsesats II," i

‘ IIIf\ aad IV» may possibly \be.- .escplaiaed by between amimal variation in

'the ability to utilize dietary.carotene and store hepatic carotene

and vitamin With only six animals per group„ tfce iadividnal

variation in' the utilization of dietary-carotene could be large eaongli

to mask the preseaee of a significant correlation between'hepatic

storage ®f vitamin A and carotene istoefl t&e range of -daily carotene

intake is between 4.52 and 17 =,;40 Bg. per 180 pounds of . body weight. •

However»' the low correlation, coefficients: for treatmmts II, III, and

IV' indicate that with this range of caretene.intake there was no

relationship between hepatic retention of vitamin A and carotene.

■Siese data ■ further indicate.. that the. efficiency of carotene - a'til-i~

zation"by; the bovine decreases' beyond the amount necessary for

normal -hepatic• storage of vitamin & and normal metabolism. •, ' , •

'Brevious Intakes ©f Carotene . : -

; ■ . Byers et al.. Xlf55) reported that a snboptimtim’ eirotene in«=

take markedly influenced'future utilization' of dietary carotene in

.dairy eattleV. Erwin et'al. (1956) in. an unpublished study, reported

resuits'.which -indicated' a lack of 'caroten'e. utilizatioh by .beef- steers

which had pfevibnsly been subjected to suboptimito carotene intakes.

The results of this experimeht, howeverwere not sufficient to

enlighten this subject,- Qne' .of the .difficulties encountered was .

that the animals fed carotene'deficient rations still, possessed

vitamin A in the liver, at the end of the 110 day -period, ■ and showed

no signs, of defieiehey. The- steers fed a ration that; contained no ;

. dietary .source, of earo-teae:. at; the end; ©f M O days ■ still had an

.average1 of 5.05 ug. ef per gram of liver smd sm average of

. . . . ' ' ' • ■ ' ■ ' : : . '

'1 .3 8 tag, o f earoteBe .gi'er gram. ' . i ' '

Brafton et ali ■C194S> fed daisy fetalis .a ratios consisting.of''

straw and •concentrate devoid of earotens- during a period of 16

months, .aad .'obsefwdVB© vitamin A defieieasy syzuptoms. - - ,Davies and Moose (193?)-worting Mth.rats, fed the’ianimals

large, doses' of vitamih ’ A ' isaxtil the liver stores were at a high level

and, them plaoed 'the' animals on a defioient diet. ' Initially, a rapid;

fall of hepatie',vitamin; A stores was observed. Isa later weeks, the

rate"of fall slowed markedly and there was a substantial reserve •

even after 24 weeks'of deficiency. Ihis experiment seems to further

bear out the theory developed' by .Hickman (1946) and "supported by the

work of Davies and MooreC1948) • and Bfey-and Jensen '(194?):;; that the

loss of , vitamin A-at .any time'during . deprivation i.s proportional to.

the magnitude of the reserves remaining'at that time,-, ;prey and

Jensen' (1947)' working with :calves, found that, the rate of loss of

liver vitamin A slowed markedly as"the reserves store'■ ifas :depleted, .

It is possible that in., the' present study the" animals:did not .

.become sufficiently deffieieht .in hepatic stores of vitamin A:..in order

to .adequately Study Mie influence ®f "suboptiatam amounts'"::of dietary

carotene intake on the future biological value of carotene for eon-, ■ • ' ■ . * ■ ' ' '. /. . ,' ; - "

version and .storage of vitamin A. ' ' .

Caro teas Repulr eaten ts ■; ,

/The Matioaal Research Council .'states, the daily' carotene' re-

quifements of Cattle to'be,4 mg. per "100 pounds of body weight. Guilb'ert and Hart (1935) found the daily" carotene requirement, for.1

he^i c&ttle t® fee from .24 to 34 tag. per kg. ©f body weight in' order'

to maintain n©mal .growth and reserves of' ca.rotene and vitamin A-

However» Byers et al« (1955) reported a daily intake of 50 tsg<, ©£;-•

carotene per kg, (of body . weight. i© fee" 'iBsnffieient t© maintain normal

■ stores, of vitamin A' in the-bloody liver j, and milk'fat'©f dairy cows.

Other workers (Hart „ 1942=»i943> have, reported that a daily intake o f

75 ng. peg kg, of body weight is nesess&ry £©r Holstein calves in

order to Maintain, normal. health: .and' adequate reserves of hdpati© ’

carotene'and(M4ssmin;'A.''' ' '.A ' ' . ' .'

kJadsen1 and Savies <19411 reported that normal calves" were

borne to- heifers that were' fed. a daily carotene - intake of 60 tig*- ,

per .kg, of - body- rjeight previons, to $ M :.dhr lag gestation, - Heifers,

that received ;a'daily carotene- intake of 30 , to'45 ng, per ;kg.:of ,

body weight remained' normal,, btit bore" vitamin A deficient calves.

The type of animal'nsed. for.experiment and the dietary -

: sotirees of carotene or vitamin" A sbonld be considered in a study of

this : S9f ,t:,'v(Btirf&efmbre, the vnatfire, of . the Specif ie ' type; of re^nire^',

meat shonld'be considered. The 'Mimimum daily carotene in Wee.

necessary to alleviate or .prevent vitamin A deficiency symptoms •'

wonld" almost certainly .fee of . $ mmch lower yalne #an the intake'

necessary -to; maintain aermai hepatic stores.of vitamin A and ear#™-

t e n s T h e past-history of -the animals regarding carotene of vitwain

A nutrition would also be of. importance,. The daily carotene or -

vitamin A reghirements would.possibly be found to differ cSnsiderably

in .various experimenfs depending;on;whether the animals were. brought

to complete vitamin A. deficiency "before the experiment*' or -whether .

' tli'ey possessed stabs tisl Mitial; resestres

IJpott examination of figures’2 and 3

of iritaai£$$,A and carotene^

s and tables 5 m d ?9. which

stow respectively. the graphic retention' of 'vitamin A and the relation”1 ship of.carotene intake" to hepatic vitamin A retention over the 110

and 18 day periodsi, it appears that a level'-.of»' or slightly below, the 1 carotene intake of;group III' is necessary to maintain the vitamin A stores of the animalSo -The average liver vitamin-A eontent of group

111 ,-at the: 'start' ©f the 110, day- .trial ’ was 26.96' eg0: -per gr-aa which

is,well within # e ^normal range** The hepatic stores of;-this group .

showed an average increase of vitamin A at the end. of the 110 day1 -

period of 2,15 mg, per gram of liver. The dietary carotene, intake

of this group during this period was 165,5. ug, per kg, of body weight,

This .figure is considerably higher than the figures reported by -

Guilbert and Hart (1935} and: p-thers,: The variability between the

results of this study and the .reports of other workers iia. regard to.

the■earotene requirement of beef animals seems to point out a fact

which may well be the' most important finding of," thid experiment,

A1 so». one. which future workers might consider, thoroughly when under”

taking a study of this nature, . The fact is that the carotene re­

quirements necessary to. main thin hepatic reserves ©f. vitamin A in

livestock'depend to a great1 extent upon the initial -reserves in

liver; .at. .the beginning of the. trial: , •

ThuSj- the'ear®tene requirements of beef animals? as reported

by different workers,), may exhibit a wide range, depending, upon

whether the experimental, animals possessed large or small hepatic

reserves at the beginning 'of the-experiment, .

Motties pbimt liaieli it may be impostaat foz wskegs to eon=

. sidex' isa A i s ; type ofyStudy a.' tlie; roxistMlity beteeen the initial 1

laepatie stores ©f yitamin A of. their experimentaS. ahisials, - If the ' ■

aaimals withia gmiaps-i, or the different ^Eoups, have a sride range of

initial hepatic stores'of 'vitamM;Ay thesa the gain 02 loss’©f vitamin

A dtariag .the experimental period may be ©f shch a varying nature that

. '.treafmettt differences may' not appear-,. :

m this lights-it

study of .this'sort t© allot'the animals or groups in aeeori. to.the "

initial vitamin A Content of the liver at the start of the-experiment=

mrnwm ■;

' : \ Tlairtf steeies were iaiividiaaUf '€ed. eefteaseed toils;, sappl©”-

aeated five levels pf dehydrated alfalfa dnriag a 110 day stedy»

Aa bxytetirscy<?liae”Sa3. t -ttixtere was fed free choice' te half fhe

aiamber of steers ia .each seppleBeafed .grohp, The -animals were s#b'« jested' to a liver- biopsy at the.begitmiag 'smti ead of the. 110 day

period* @ad the .'respective samples gaalyEed; for yifSEih;':A::ted earo=>

tea©* ■ Dpoa statistical saalysis .of the.' data at the end' ef "the.110 day period, the 'followlag eoneltasioas were reaehedo :

1„ eonsistently lowered'gains were noted ai the level .of

■ ' dehydrated alfalfa was iBCreaseds" houeverg :-'the .differeaces. . ; : ' , . . - . / ; ... ' , ' .• '. '

. in; gaiss;:.i?erev'tot #ghifle^mt.A significahtl^ lowered -

feed;:efffi©.ieaey -ms femad betweem the growps-as the level

- of dehydrated- al f al fa w s ' iaer eased o'-. . - . : ,

. ■ 2„ The'administration of am.. @%ytefrasyGlim#@alt #i±fmre

.ms i<?ith@ut eonsisfeat 'effect relative to' rates of gain

m d feed efficiency. ..■ r

' diff ereabe 1 In' car® tens Intake- of 3.04 mg. "per 100

pottads #f body• Weight .ws 'staffieieat to cause- Significant'

difference's in vitamia A retention between theji-grotops,,

'However p after a carotene' intake over 7.54 iffigs-’per 100

poiaads of body weighty a©.'signifieaat differences la

hepatic retemtioa of .vltamln A were fomid.t.

There tm@ no eonsistent:- reiStionShip betoeen 'hepatic •••; -

- '■ ■ : tetenties:*f v i A : aad ear©teae m between earoteae

intake aad hepatic storage ef vitaaih A SekI eSibteie .

- - except..oy;;. tffe«ee; safe's.i®take0.

5*■ 'A hepatic threshcld i«s indieateti £cs the st©gage of both

": ■ . vitamin A'and caroteneJ.- Beth -sttbstaaces treee :zetaiae# -in-■' '■ ■ - - ' . , . ; v . : ' : ' . ■ . : ; ■ ' -

: ■. a .lineag1 trend np :to. a'daily case teae.- intake; ef' '7,54 mg,

per 100 bomids .of body weight after which the retention

; ' assn@ed'a.-geadratie trends ;

' / /: % , 6>V The daily carotene respiresieBts to Maintain the initial

/ -- hepatic- steres of vitamin A aad -carotene of the steers '

, ; ■ ; ; : in this " Stody was between ;4»52 and: 7«54 'mg. - daily-per

100 poWds of body weighty ' ’ • ,

.. ., ’: Hepatic. retentioh-©f vitmin A and carotene m s determined

daring an TS day period in order to observe the iaflneaee- of previews

. leyel® .of carotene intake on; hepatic retention of vitamin. A.and.

.'. carotene daring this period, Also»■ eompasisons. of the hepatic re«-

. tention of vitamin A asd carotene daring toe.110 and IS day periods

•were made as well as the determination of the optimism daily carotene

reghirements-for. toe steers» : The resnlts are presented below.. . •

v.y'' -: ;:10;: -Previotis earotehe intakes. MflnenCe the ability .of' the.

’ - animals to' ntilise dietaty."carotene,, but not in a

: consistent manner. ' v

'' 2. Ho correlation was f onnd between the total'aoiiat of.

■ • . 1; , . vitamin &. =:at - the. beginning of the 110 day periods sad:

' the amoOTt remaining at the' beginning' of - the-18. day.

.period. ' ' ' ' ' ' '' - ::

403<> S© e©r$eZs.t£©a .w s foand between begatie; retention of •• ■yitamin A and earotene daring this period,, Also, no

.correlation ws.found between.previoes intakes of card- .tfee: re-t^tiofi;of ftepiatic vitamin A during tMs

: 40 Purtber .indications of a threshold effect of the hepatic

storage of vitamin A and carotene were found*

P S B I H E S C l ®

l0 Beeson $ If p M0 1957 0 Hew Setel@|Meats la beef 'cattle B6itKit£®ae ''® a $ 0, Bfise^ aad Cftes Iffie'b. 5i& iaiaQal Reseasela eeaf©2-@tteee ' BB6, 53ea§4o - • '

2a Bee@®m6 mad To Wo Fersfy '19526. .Balaaeiag, the atstsitieaal. • ,'defieiaacies @f 2®aghage fa® SteesS,,. Jo -Miaal Sei* 11s501»

30 ; lellg iMo ttoa/Go 'Ko' Ittitebais sad Wo Bo Sallesp® 1950«,, Bi©' effect !'■'■ sf :aag6®®y@ia @a digestiafl' ti sfeesSo ■ Jq -iaiaal' Scio ts@476

4e; Baliao Bo :Eo:j? lo Fo 'iiag mS; Bo !iS0 Ilaste^Eamo -IfSSo. .£ siaqp*' lified Betted f®2„ the dete$aia&ti®a af dtesiaic xMe' CCagOs) ' iSiea esed as s® ipdex "ssabstsmceo Ssio' MSp H®0 3Q23g634=>635o

50 Srattaap lo Wog. Go W0 Salistesf ? To* lFaaabei) Go W®®f®ae BeMegeies -amd Jo: Eg .tedslio ' !#4#o ■ Beeedaag feehavieffg spere-

. • mat@geae@la g., #@d' @e#em ptedeetiea @f Bateare dsiey tells fed • satiais low iKa eateieaeo- J© Bsis^ Se£0 31g7f9m791o,

.So; ; 'zBgay9 Go I ' Saelle : E0' Eg M®g®is@a @ad M6' B© Jse&sotte ' If45o'• v \ Eeddiag blackstrap'.m#la@$e$ , W steeesl; $i,0 vlgg© ■.: ; '-Bipo; Stag Btalo 394$ ppo.;.l«436 ; * . .' * .v:y:4;.'r - y"

f o BsidgeSs: Jo'Ho p. , Jo Co Millers.:Wo G,» .KasaaladeP Jgq a®d ©o’ H6Em&elo;. If53« 'lffeets @f waeiws lewis ®f ssareettysia M

* ■ .fattesifflg; las*s0 J0 iaimi. Sei© 22sS60a6S5o . ; ; ,:

Sq Bmggemgtep Wo> E© Geslarnghg A0 E©. Shaikh Bo A* Silveraad X0 B« KMaMeo If4:5•' -'The .aatzitlw: vatiiiie of cdraeoBs ia' beef

y ■ , 'Cattle'gatieas’o . Jo Aaisal Seio 4s373e>3S5;e ; ■ ••t ' :9.0. ’ B@gte8SgfeS$ Wo£, 'Eo\ G®2lai3g&9 sad: lo M0 .BetMs®0 l§56€ai': Si®

y fltietee 'of alfWlfa tey sad. fgaefaeasyof alfalfa toy *'Bpoa .: tteydigestioaypf' gsotod ©®me#bSo Jo te'iaal'Sci© 9s-#7^213o

Oo Bagg##gtep Wot, S»'So Headley9 So Sfe Betfe&e sad F0 Serleu^i.' -'.IfSOo Cellulose .dig©sf£®a im g@od sad poer ga&lity-gMghages using artificial gumea© Jo Animal Seio'9g513=»523.'

I© Byegg. Jo Hog Fo Bo tfeswigg jo fy-Borne,, and I0 R* Jones© 19550 . -y Gagetene in the ratioa if daisy :cattle0 lo The istiflueoee ©f

. . long periods of suteptisal eazotese intake on the carotene _ yals.es of. # @ bleed, liver,

'■eowo ' Jo'Asiiy Seio '38g.S57'@41-

■ , 1 -■ v / v • 4 2 ■■,120 Go f og Sip J0 SiEttys E0 :i&£teM£s aad R0- MaefieaSo

1952o Effect ©f Mmeirstls :@b 6igest£©n @f View fWlitT teisghage. by steepo J0 Anisaal Sc£e llsfSSo -

13o G©lbyp:R0 Wo> To Jo Ca^a Bo Jo Magtie!c0 : 1950O.;. Effect @f titsais A ; SBppleaientatiea-; ©a tepeefliaetiosa of e?jes .gsa ed, @a grera aad dsy samses raageSo . J0 Mimal Seio 98446=456»

14 o Bayl@p Ro . & Madsem*, 1951 o Gageteae ®ad A' . . la' g&ttl'e bi@@<l pla"@®a'"?Sti| ebsegvat£@ns ©a KepesSiaotiwe' ’ pe$f:©gmiaaee at: resteaeted 1 e t e l S i n t a k e 0 J0 MetKo 21gl5o;

. • , ; • • ■ .... . ■ 150 ?Wf: Mos sma fBo'■ So :;Eessleg J 19530. .■ leef eat tie feeding

■asd'’bteedisg;:.M £®i'i952"530 ■ KSaisas Agio- Exp«,V ... Stae. Gire*;M©0 ;2f8o ; ' ; - • ■' ' ' ■

,16o Bgainj, E0; S09 1;0 :Ao Byesff -To % Meyee. m d IC0 M0 Scott» 1956c' @ses of -asgisatitoi biopsy teeteitiaeo Jo Assimal Seio 15s428»

; 4^ : . . ■ . : „

17 o Bgt3ia8,.iE0 S:oe Co Jo SlaBpfJo -Ao. Byego Ctopitablisted ,data)o 1956»- ' ; Effect @f vitwia. A^bagoiese defieieaey iaa segiam psotein •• ;./£gaot£@as ' sad ; ttee.-«tiiii8ti®ai s€ dietasy eaeet®® 'by $teegs@

: Bepfo, @f Ao So .Mas&iagtea State e@llege;0. ■;■•: >V t, '- ■

13o EmaMv So So0 Id Ao Byes aad Mo E0 BasMagero 1956o . Bffeefs •., of eMogfetgaeycliaep inedible .fflaiaal fatp stilbesttolc aad.,'. M g h smd lew giaality gotaghage ©a pesf ossanee ■ of - yesueling •steeaSo lo Feed e@asi*ptiea aad. gates, ©f ga£Be J0 .Jaimal ieio 15 §710^715 o- . ■ - •

19o ..'.Sgyiffip So S0p Go Bo Rdtotece^p to loseablatt and F0 Fsitdbagdo’; 1957o'; Salt gegBlatioffl ©f .stllbesteol aad teggamyeiaf@g •

• feedldt laabso/ .Ari o Agge Bepo 'Sta0 Teeteieal Papes Moo :420e

’20o-’ :Bg.^jFo':Re£, '&6: Je@sea ’aad lo'Bo Coteado 19476 ' fitasiin A .■ .1 iata&e' Ja. . eattle la .2elati®n:: t® hepatic st®$es .sad- Medd -. ’ .

levelso Jo Htttgo 34g421^30v . : . • • '

210 Fgeyp Be lU smd Re Jess.ea0 T947o " Bepleiion of vifasiin A ■ /gesesves is the lives ©i 6attle0 : Sei0 105g313= .

' 22o Gmilbegf g Ho R® sad, Gq. So Hagto .1934o St®g®ge ©£ 'vitamin A - iffl 'eattleo ; J0 Stateo S$3S<=?44e' . '

23q '©lailtegtp Ho;: Bo sad, So Hq Hasto . 1935o Minimum vitasaia A ' y,,g@^aiteaeats.mfli psgtieislsgfKefegeaee td eattlea Jo Hdtgg:

1 0 l 4 0 ^ 2 7 o . .. ' :: ’ ■ ’'/V. '' • '• :: ...

24 o , StiMey p Po Ao' sad’ Jo tC Gagseas " 1890» Peed .esEpegieeatSo ’'■ 'T@$o/ Aggo Bcpo- -Staq B$alo 10® ppo- l=>I7o / - . . ■,

. ■ . V : . . ■ . ; ' 43

25<> '©essettg Je W» m d : E0' 'Sisss,,- 19560 ;\ttee'' eifeet ;@f de&ydrated/ alfMfa leaf, aeal aad tffisice Eiaemls fed. te gewlsg‘Wef eaives fed j>0®g fmality prairie tey0. . J0 isiaal.'Sei» 15g840o

■266 'Harfeg ©o .Be " 1942*lf43i, -/Hie' biological setimtf @f .wsieus;. . ' : f@ms- of • witaaia 40: Mmtgo Ab@6 Rev* 10:261 *

23 6

39e

'306

Hatfieldg $» ,S0^ S0. Garrigtss 'astd Be W0 H©gt®a» 19540.biotic seippiettWis ia ■ gatims for greMag asd fatteaifflg laabSe Jj"o ^arMal Gcs-o 13syiS^y25.o . -

':' -/■ - \ - " .

Harasi>, F0i' A. 'tod aaiaal bealthe Tbesis0. H@aaoverHQcbss&Ele Cll|42)33g Eiedersaeteiscbe BacMrmc&ersip Be&seno

■; iHi6kBris:. ;X :x;©e #6^ --l##, Soae pibblems ia ■ritaaia' dosage0. - •%, Paterae.■ l&g#7#«,■ ,-'■ : ':■ '■■ ,■: ' .' > ' ■■ ■

ifcgBo :1,6 le: 1.$, Saapp rnd te S0 G a l l o 1955* ’ibe effect

. yearliag steers' mtla baetesiolegieal dateo -J© Aaisal Sci® :: 14§‘243=248o ' ;■■■■ , ' • '

31 o. jebasoBp/ Ro. Mo md. Co. Ao ‘ BatMMfflo' 1948« Relative sigMifiesace of ■ apd. aetaMlie. rate on the atili^atioa .®f' vitsmia A.,by tfee'rato.-: Jo.S0ti-o: 35&703o ’ .

32o J©aes9 Ro aad j* &0 H®ag0 1944o ; Car@te®@ lewis for growth and reprodtaeiaea. ia dairy balls* J6. -Dairy' Seia 2fs6320

33* . Jsrdasiy R* Mo' aad ?*■' #@aald Bello-. 195X» ■ Bff eet @f aareomyqia ’ ©a grets'iag aad .f atteaiag lambs* J© iaiaal Seio 10glG5l6

34* 'ICesl@r6 E* M* : 1954* Effect @f terramyGia. fed to .H@lsteia.‘ • '■. . calves ©a grewthg la vitr® eellBlese digestioa' ®@d l»vitMia

syatbesis* Jo itoiaal Seio I3sl0«>19o . '

35* Mestezmaag- B» "#*»,,.%». % ..fitegakle$-'$o Go Beatley' s®d W* larroagbs* ' : . 1953* Sappleaeats 4®- p@@r Reality hay f@r, fatteaiag. cattle*' ©hi® Agr*' Bsp* Sta* Res* BmI* H®* f326. ■ ,

36*. Kl©sterraas0 Eo: Wo Qo .Go Beatley sad A* L© Mox©ae 1956* Re=. lati®fflship betweea level pi preteiBp mol asses trace .siiaerals mad gesli ty @f. hay. ia satioas for f atf eaiag' eat tie * J*Aaimal Seio''15§45d* : v ;; :. , ■'.. ■

3f 6 .Madseys' J*. B* a ;E« B* Holland- sad B* H* Smith* 1907* , Molasses * and molasses feeds for livestock*: Mass* Agr* Es#* Sta* Bel» .

■; ; iiSg :'pp* 1^32* :• . -

38* .. MacIC®y6 A* Mos: l* Ha. liddell and R* Bltzsimmomso 1#53*Terramyein sapplettent for dairy salves* J* Atimai Sci0 128l9«23*

44 ' ■ ,

39» Madsestg- £c ;!L0. and i.» ;Ee Bavis® 1949® . Carotene Eeiaisetoents .. •1 '.of beef-, eittle for repeeduetiono1 J® Aaiaal Sei® -8i,©25 626®

40® . Moore9 T® lfS6:s Vitamin A® let-M®- Elsevier Seientifio ; Emblleatlom#® - ' - '

: '41® Moorep X®.:ani: J®: i® Safoe® 1§42®v witaBaim A eentefit of tie' ■ i£-res® ©f sleepy oattl@g' and. pigs® Bio diem® J® ;.3§g34® V

-■ : 42® national ReseasoM OOMaeil® ItSO® Report of. tie eoamittee oa animal atotritiia®. Recommended Botrieat aUomaees for

; . ' - domestie-animslSd Me® 1?® Reesnsesided aBtrimt allei-Mees' . fer .beef :eattle-9 Matl® .Res® e©w®ilp MasMagtetig B® jC®

". 43® . leiiaaaffl A® 'Soi:;R« -R® Snapp/Mad $®.vS®:'<@ali® 1951® ' Tie long V.1 ■. .yv;; ■'tiiae' - feeding anreomyeM" f© fattening beef" cattle '■ ■■. ' tyi.tM bacteriological data® J® Animal Sci® 10 §1058® '

44®;.- 'iersy i>.' ,T® W® W® :M0'. BeeseEs' E® ,C® Hoenbaek and M®-, T=: Motoer®- "V " ;19S4® Aweeayein, f©r.growing and. fattenitig beef animals®

v . "v J® Animal Sei® -rl3g 9®. "' .

AS® Flmalee0 M® R®. yetSEsek and W®; M® Beeson® 1953® 'The effect - : ef adding, trase" minerals t@. ratioss of idenfieal beef cattle®

- , ' ' . j®"Apisat Seio’.lSgfSg® : .. ■ . ;

Richardg RO'M®0 C® B® Ronbieek and E® B® 'Stanley® CUnpBblished :, data)® 1955^ the,'sole -or principal , -■ v -■ roBghage ■ fes: growing sad . fattening steers® . - - ;

"Snedec®** @® w® .1§5€® Statistical .methods applied.. te es^eri” . seats in agsietiitnre and" feiolfgy® 5th Ed® The l o w State - . 'Gallege Eress^, A»eSg' lorn,® ’ . . ,

.Tillmsms A® Bo 'ahd l® W® Stoift® lt53®' :The ntilisatioa of -; sesoaiated' iadastrial by prodtiefs"sad area by sheep® . -J®; Mimal „S@i®, 12'#301«211,® '■ : .

Takeyp,". J® - #®.''.1#3® The problem of multiple eoapasisoas®; la Saedee@rD ^Sf atistical Eetheds as - applied t® agrieisltere . had bioi@gy%' Stl M® pp®'251® ;. V ' ■