On the feeding of a phosphorus supplement to mother-reared calves, prior to weaning, under open range conditions in Bechuanaland

Ondnsle;Joorf .lounwf of Feteri11ory .'i~.;u'IU'C and dninwf

!"rl"stry, r ol1111u' 1:), .\'11111111'r ~. O!'iolu"r. J~J:HJ.

l'rintc-,1 in tht• l'nion of ::South ,\fri"a l,y til<·

Gm·erll!llL'IIt 'Printer·. Pn•toria.

On the Feeding of a Phosphorus Supplement to Mother-Reared Calves, prior to Weaning,

under Open Range Conditions in Bechuanaland .

Hy .J. H. R. DISSCTlCll>, Sedion of Zoot<·chnic~ nncl :Jieat R!-':;ear('h;

A. l. :i\L\LAN, Sedion of J~iodwlllistr:v; ll. P. STEYN.

Seetiou of Surgery; and G. B. T,AUHE~CE, Section of Siati,;l ics.

T .\"l'H () IJU C'TJON'.

TnEILJ-:11, Green and Du ToiL (Ul::?4) f·irst <In>,,- attention to a tnnrke<l pho;,pllOrus <lefil'ien<·y in the pa;;tu n!:-; -of stwh parLi of I he 1_T n ion, ns Hechunnalnnd alld the TransYaal IIig-IIYeid. ])u 'J'oit und lli,s<·l1op (HJ2U) ~ho11·ed how tl1is fleficienc.v rnnteriull_y aifeciP<l gnmLb, deYelopment, pl'OULil'iion uncl reproduction in cattle ou thP VetPriuary Research Station, " Armoe<l:-;vlnkte " in Be<;huanaland.

Henrici (1938), J)u Toil, et. al. (1930-1935) mu<le u.n extensive sun·ey <Jf the fel'ding Yalne of natur~d pasture gra~,;ps in thP T nion, and found a phuspltonts dPfil'i8tH·y to exi,;l. pradi('ally thmughout lite countr\. !11 order to pn .. ,·enl. the eff<'r·b of this rlPfi<·ietf('y, fanner wer<" ach-i~ed to t>upply i heir cattle with the nece,;sary phosphorus supplelllenl fron1 tl1e age of \\'P<Illi 1rg (at G-U IIIOII( Its) onw<Irch. Prior to ihi,; age; e;;II,·e::; of pho"plwru;;-fed I'O\Y,; usunlly sho11· salisbrtory gTo1dh n11d c]p;-elopntellt·, an1l since it is a teclious prol'es:-; to dose young cah es 'vith hm1emeal tl1is lower ag-e limit 11·as introduce1l. l"or the time beii1g· the question "·hether or not phosplwrus ;-;upplentent.rtio" lo l'<lhes prior Lo ~~·e;lnillg-, 11·ould br l''·ofiLilllr, ~~-as left i11 aht'ynn<·r•.

At " ArmoedsYlakte" a long term experiment has been m prugre,;s silll'e 1!)25, in "-hil'h in<lig-enous fenrales ha1e hee11 g-raded up s_yslPmalically 11ith pureh1wl lmlls of huth in<lig-ellou,; ancl pxogenous cattle bn·eds. Jn this experi111ent it "·ns fou11d llrnt the l,alflJre<l cnlf generation, born out of bo11emenl-fed <hms. cleYeloped quite sal isfadorily up to weani11g· age•, 11·ithnut a phosphorus nillt:le- ment. The higher bred exogenous c·nlws, that is, the ~ an1l ⁷ bred

321

l'EEJJING 01' PHOSl'HOlWS SUPPLEMENT TO CALVES.

g-rade;; out of bonemeal mothers, did not do so ,,·ell as the halfbreJ

<:alves up to weaning age, ;md the question \vhether such calves would nol be11efit by bone meal fee<l ing prior to weaning, had to be considered.

0HJI·:cr oF TuE ExJ'EHI~ll·:.xT.

The objed of Ute e::qJeriment "·as to a~certain, whetbe1· during the first U months of life, cah es of honemeal-fe<l mothers "·h if'h run under open range conditions, "~'>·ill grow and develop more satisfac- torily "·hen supplied with a phosphoru;; snpplement, than under the present system of management of the grade herds at " Armoeds- vlakte ", i.e., where no pho,;phorus ;:;upplemt>ut is feel to calves until

;tfter "·eaning- al the age of 9 months.

Tl1e e:-.:periltlt·ltl 11a" t·onduded <luri11g IU:HJ, 1907 ;tlld 19:1s al the Veterinary Hesearcb Stu Lion, " Armoedsvlakte ", near Vr,Yburg, Cape Proviuce, where the origi11al researches of 'l'heiler, Green and

])u 'l'oit \\"Crt> •·;tnied ⁰¹¹¹ 20 Y<·;tr,.; ;tg-o.

A. E:cpe1·imenial Animals.

T1tese consisted of

t

bn·d Hedpoll cahes, born on the Station out. of

t

bred, honemeal-fed Ilf'clpoll co11·s, an<l sired ll.Y purPhred Ueclpoll bulls. These cahes were pa'scd into the " Bonemeal " ancl

" Control " groups alternately in sequence of their dale of birth and ~ex. Table Xo. I gin's (lf'lail,.; of the e:-.:pl'rilllenlal animnJR in P-ach gToup.

i\s will be 8ePn from this table, one calf dierl in each group an(l a furtl1er c;tlf had to he <lisch:ug·ed from tl1e Conlrol g-roup on

;lC<·ount of its dam cle,eloping mastitis. The bonPmeal and control groups, therefore, finally consisted re~pectively of D ::tnrl 7 c:thcs.

H. /lonemeol .\u;1plemen&.

The " control " c::thf's received no supplement. 1nior to wPani ng. From the 27 ht day of ngP, lo the end of lhe test at 480 days of age,

the:v receiYetl :1 oz. of hollt'IJJPal pPl' ltl'a<l p<•r <lay. '.I.' he '' boncme;1.l '' cal vrs "·ere trea l ell as follows :-

From date of hirlh to :lQ d:~.)·s old, no supplement.

From 31 days old, to GO days old,

1

oz. of bonemeal per day per head.

From Gl days old, to 120 clays old, 1 oz. of bonemeal per day per head.

From 121 clays old, to 180 days old, 2 oz. of bonemeal per day per head.

From 180 days old on,,ards, 3 oz. of bonemenl per day per head.

322

C.:> ~ C..?

BoNEMEAL. No. of

I

S

I

Date of

I

No. of

I

No. of

I

Calf. ex. Birth. Dam. Sire. 6727 M. 24/11/36 4882 5399 67:!0 F. . 26/11/36 3186 5371 6736 M. 2/12/36 4981 5399 6740 M. 4/12/36 4915 5399 6761 F. 17)12)36 4883 5399 6773 F. 28/12/36 3177 5371 6775 F· 28/12/36 4881 5399 6777 M. 30/12/36 3041 5371 6789 F. 23/ 1/37 3321 ;'i37l 6790 l\IL 24/ 1/37 3381 5371 ·--

Remarks. - - - - - - Born dead. - - -

'l'AHLE N 0. I. CONTROL. No of

I

0

I

DoW of

I

No of

I

No of

I

Calf. ,,.ex. Birth. Dam. Sire.

I

6714 lVI. 18/11/36 3117 :i37l

I

6728 F. 24/ll/36 3243 ii37J 6742 M. 7/12/36 5518 53!)9 6743 111. 7J12/i36 4941 5399 6748 111. 8/12/36 3037 5371 6749 F. 9/12/36 3109 5371 6768 F. 26/1.2/36 3302 5~71 6776 :F. 29/12/36 4752 6285 67!)9 i\1. 12/ 2/37 3263 ;)371

Remarks. - - - - -

- -

Died 17/1/37. Suspected Arsenical poisoning. 1/4/37 Discharged on account of its dam, suffering from mastitis.

.... :::; l::i .... (/l (/l (') ~ 0 "0 > ~ 1::: > t"' ~ III "0 (/l ,.., ~

z

>

z

t::i t;l l::i t"' > q 1=:1 t'l z (') !'l

FEEDIKG O.F l'lfOSI'liOKUS SUl:'l'LEm·:ST TO CALVES.

The Yery young cahe,; ''ere dosed by opening thei1 mouths and pouring the dry honemeal .into it. At first a fe"· of the calves ejected some of the bouemeal, but they all soon became accnstomecl to this method, "·hich "·orked quite satisfactorily. When the calves

I': ere olcler they ^II' ere dosed according- to st::rncl a rd method e nt ployed at the Station, i.e., with moistened bonemeal, by means of a spoon.

C. J/ ill.· Hot1on::.

ln order to obtain da,ta concerning the milk-procluctwu of tile cows, and hence concerning the milk intake of the experimental calves, it has been necessary to adopt nn 11nnsunl p1 ocedure in all the experiments at " ArmoeclsYlakte " : \Vhere co"·s are depe1Hlent t:pou the natural pasture for their ;msten::mce and recei,·e no additional production ration, hand-rearing of calYes is unpractical.

!±the calYes are taken U\Yay, tl1e COIYR dry up in about ](J-1~ IYeel\~

aiter parturition. EYen where the cah es are reared on their dams, the a vernge lactation yeriod is relatiYely short. Bonemeal fed cmn usually do not gi \·e more than 2-3 llb. of milk per clay nfter the 30th week of lactation.

The C<lhe~ al'e allon·ed hnl£ their mother'~ milf,. During the first week they suek the two right teats of the udder anti the two left teats are milked for re('ording purposes. The follo\Ying v:eek i.ht calves suck the left hal£ of the udder and the right hal£ is milked.

Each vVednesclay tl1e "hole nllder is milked, iu order r) estimate IYhether the miLk from one half, actually represents 50 per cent. of the production of the whole udder.

For the first 14 weeks (98 clays) the cows are milked tw1ce a clay- for the next 16 weeks (up to and including the .810th day) only once a clay. From the 211th day until weaning at 270 days of age, the calves run ''ith their dams.

D. Calf Mann.r;Pnwnt.

The caiJves were brought to the milking sheds at milking ttme~,

{rom calf paddods approximatelv 10 morgen (

±

21 acres) in extent, where there was good gTazing, shelter and "·ater supply.

E. Borly Tt'eights.

Body weight~:> were taken every 30 days, from date of birth onwards until the conclusion of the experiment at 480 days ·of age.

F. P1:ca Tests.

Pica Tests were conducted at intervals of 14 days. The object was to cletermme the degree of <Jsteophagia, or lTttYing for bones, exhibited by the cah es. The pica tests '"ere conducted in the usual manner (see Du Toit and Bissrhop, 1929) by first allowing the animals access to a trough containing sterili?:ed rotten bones. Any animals picking up and chewing such bones were marked clown as

" rotten bone " cravers. The remainder were then passed in to a pen ('Outaining a rrough 11·ith sh .. rilizecl " SIYeet" bones. The cn¹lves which picked up and rhe\TE'rl these were recordecl as " s'' eet hone '' navers. 'l'hose that dJe\\·erl neither rottt•n nor S\Yeet hones 11·ere recorded as " non-era Yers ".

J. H. R. lJISSCIIOF, A. I. 11ALAN, II. P. S'l'EYN AND G. H. LAURENCE.

G. Body 111 easu1·emen ts.

Docly measurements were taken eYery 30 clays from the elates of hirth onwards. The '"ell-kno1Yn Deriaz system was employed. 'l'he measurements taken "·ere:-

(a) Length of body. (b) Height at withers.

(c) Height at hookbone::;. (d) Depth of chest.

(e) Width of chest.

(f) Length of rump.

(g) \Vidth between hookbone~. (h) Width between thirls.

(i) 'Width between pinbones.

(j) Length of head. (lc) \Vidth between eyes.

(Z) Heart girth or body circumference.

H. Blood flnalysis.

A blood sample was taken from each calf at the ages of 30, GO, 120 and 180 days of age and analysed for inorganic phosphorus. Thereafter all the exp0rimental anima!ls "·ere bled for simil~\l' tests once a month from October 1937 to March 1938, i.e. frr m tl1e approximate average ages of 11 months to 16 months.

I. Histolo,r;icnl Stt((lies of JJones.

The experimental prog-ramme called for rib-resections at the costo-chondral junction, of all the experimental calves at the ages of 90 and 210 days, but on account of the time reqn ired for a number of these operations, it IYas decided to select one heifer aucl one " tol·ly calf "¹ from each group. These 4 cah es 11·ere operated on in the middle of February and ag-ain in the middle of June 1937, approximately at the ages of G5 and 180 clays. The resected pieces o£ ribs \\·ere examined histologically to ascertain 11.l1ether C'alcifleution was taking place normally and at the same rate, in both groups.

J. Statistical A11alys?s of Data.

All data "·ere analysed statistically according to Fisher (1936). On'ly such differences which proved to be significant in terms of Fishers P =0·05 or P=O·Ol have been usecl in arriYi11g at conclusions.

IV. ^ExPERiliiEKT,\L l1ESULTS.

A. lJocly Weights.

Table No. 2, which has been divided into three parts, gives in Section A tlw aYerage botl:v \\·pights of the Bonemeal and Control cah es at 30 Jay intervals from birth until 480 clays of age.

(1

) " 'l'olly calf": A castrated bull c·alf. "Tolli<.>s" are castrated hull cah·es up to tbe age of 1$< months.

326

I'EJ·:IJ/:\(; 01' 1'1/il,;/'IIOHl·,; '-l.I'I'I.I·:~I:·::\'1' TO I'.IL\'1·~,;.

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II

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...

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J. ll . .LL HISSCII<JI'. ,\. J . . \1.\T.,I.'\. H. 1'. STEYS .\\1) G. II. L.\1.111-:SCI<.

Tht• orip:in<tl t•sperinte>nl<ll pmgrmnntP r-o1·ered the period h ottJ birtl1 to \Yenuing. .\t 11ti.~ Litter ,;blgt', it ""'; tll·r-iclPd (o t·ontinue the test to 480 day .. ; of age, hut itt the llleantinw a uulllber of calve;;

had uot. been 11·eiohed 11·lwn :j(J(I daYS oltl. '!'he \\·ei~ht cohmlll for 11Jis age ltas 1.herefore l>t•en ''"chHI•··t!" fron1 (he tahlt•. '

'l'ht· ;t<:ht:ll ditterPnces l:eh•l't'll. the <tl·entgt• \\·Pigl1b of lh<>

l-otteme:tl and coni rol r-fthe.<- :tre giYen on the r>Lh hori~on(:tl lin e.

Tn lJOriwutal lint' :Xo. ti thec;e diffPreltn·~ <tiT gi\E'll a..; llen-t·nbgt·..;

of tlte control ll~<IKal) \\Pight..;. ~ig·nllit·ant difiercnct'ci are prin1t•tl i11 heay~· type and to sho\\· tl1e tlq.u·ce of ,;igtlific<~Jwe Pilher a 5 or a 1 h:t.-; bee>n pLH·<>rl in bn1t·kpt-; <I !:on• nnd lD l i1e rig·ht of snch signific:mt cl ifferem·es.

f-;edion I) gin•s 6illtiLtr tl:1ta nc; Sedion .\, ft>r lht· lteifer c:lht•..;

i11 the t11·o t•xperinlPni:tl gTolll'·" <ltHI 8l'l"liorl (' for tlH· (,oll,· t·ah•·:;.

Th<> tluee agee' of imporLttlC<' i11 til<' te-;t \\·t'n', ii.rsth· thal at :jt) cla:1·R,

\\·ltt>ll ll11~ hot)(• lllll<li gt·oup \\·:;.-; ]·!:;,·etl tl]>OII iL plwc;plttH·uc; ,;upplt•- mt•nt; seeondl.1· :tl '210 day..;. 1dtt'tl hotl1 gmupt:: \ll:'t·e \\·ealll'tl, <111d the• c011Lrol g-roup \\·a,; placed upotl <I honeme:1l 1·;dio1t. Pqurtl tu tlwt of the honenlt-)<ll g-roup; and tl:iJdJ.,· nt -I·RO thy.-;, 11hP11 Loll gToi!Jlci harl recein:d an eclu:tlphoc;plwtll:' 'llJl]llt•Jttt'U1 for "i tllOJltllci. <111(1 "·lwn tht· tPsl 11·as (emt i 11ate(l.

8<>clion .\.of T:1blr· :\o. :! "ho,,., lli:tl ai tlOJH' of tlw,;e <l~e' clid t.lwrP e-.;ist <111 1 sig·nifir-:1 nt ,1 ifte< ence i 11 Loch \\ t>ight beh1·r~Pll the experimental gTOilJl:'. ( h1ly lllle ;:;ignifit·ant tl rffen•Jtf"E' i..; ci('P\1 in (lie

!able, i.P. in ,'-:Pctiotl .\ :1t ~1!)(1 day,; . .Since, bmYe1·er. tlti" sig·tlific:lllt diflerence is precPrlecl and ;;uccPt•tlec1 lt.\" :1 seri(•,; of iusig-lliiie:lnt rlif'ferew·Ps, it·s <l]tpPnrnnce j..; mocd <liffit·nlt to e:s:plaiD <ltHl does tlot

<lppe~n to be of :111.1· Liologi.t·:tl inl]torLIItce.

Tt <~ppe:lr . ..; \\"<Jtt·;tnt•·tl ttl r-ou··llllle lliPrdoi't' tlt:1t "' Ln· :1~ !~nth­ weight is coneernetl, tlw fePtling of honemeal. to calYes Jllior t·o

\Yt'anillg- "·a,; 11·itltout Pl"fPd.

Sections Hand Cor Tabl(" 2, ,,lllm that thet·t: 1c; 110 :>Jg·nifir·ant

<!iffprenct>s het\\·et'll hmeniP:Il a111l cot1h·ol heifl't·'. attd l:et\\·t·ett honeme:ll allll conl1·ol !ollie,;. 'L'Itrre i,;, lHl1\·e1·n, a n·tT lll;tl.eri:d rliflerence hrt 11·ee!t t lie ( 11 o ..;c·xPs <I ( 1l1e samr· <~gt'. Tit is ;l,pt·d \\'i I!

l;p rle:tH \Titlt in :1 "'PJl<lt<~h· :lrti,·lt•.

H. P1ca.

Tall!(• No.:: ;.::in•,; lliP l'l'"lllls ol tlll' pica 1e,;ts fnr 8<1t·l1 ittdiYi(lu:il

;~nimal :tlttl fr11· P<lt·lt gronp. :1! fodni!!l>tly intPrY:Jb, 11p (o ..JHO th.' ' of age. 'l'hn•p ..;\.lttl)(Jb :1re IINerl:-

(o) A tllinu;; ~igtt, - , dPnt>il'.' a non-n:l\·er.

(1,) A nost>, x, denote,; r: roiteJ1 bone craH't.

(c) A plain circle, 0 . ,]enott•c; " ci\Yed bon(' cr:1Yer.

'l'lw tnbiP i::; tli,·iclerl into two parb. Tl1e npJIPl' half giYes ihr pica resnlts of tliP bo11eme:tl group, tl1P lo11·er lt:tlf 1.hosP for the control group. Tltt• thick Yertical line al 00 dnys i11 tlte uppt•r h:1lf Jenote:i the l;pg·inning of honpme:1l supplemetdatiotJ to tl1e bottelllPal

FEEDING OF PHOSPHORUS SePPLEMENT TO C'J,LVES.

group and a similar line in the lo"·er half at 271 days, the beginning of bonemeal feeding to the control group. In the horizontal line below each group, are found, the group pica totals for all age points.

In the last 3 Yerticall oolumns are found, for each animal and for each group the total number of occassions on which rotten and sweet bones were eaten and the total t.:raving per group.

The table needs no explanation. The calves of the bonemeal group show a negligible degree of craving. Five out of the nine animals never craved at all and of the four that did, the worst (No. 6777), chewed rotten bones only on one occasion and S\Yeet bones on:ly on 3 occasions, during 34 consecutiYe tests. The total craving for the group amounts to 9 out of a possible number of 306, i.e. 2'94 per cent.

The total craving for the control group amounts to 88 out of a possible 238, i.e. 36 · 97 per cent. 'l'his is 12~ times as much as in the bonemeal group. This high degree of pica is, howeYer, not common to all the calves in the control group. It "·ill be noticed that although no calves were non-craYers throughout the course of the experiment, t"·o were practically so. The rest were a!ll marked cravers. As a group it will be noticed that the degree of pica increased up to the time ''"hen all the calves were weaned, i.e. as long as the animals recei,-ed no bonemeal. From then onwar<ls the pica in the control group, dropped steadily until, for the last 3 tests, only one caH showed craving.

From the data given in Table No. 2 one is justified to conclude- ( a) that in the bonemeal group, the phosphorus supplement

prevented craving almost entirely;

(b) that in the control group, until "·earring age, the degree of pica, indicatiYe of aphosphoro,sis, increased steadily;

(c) that the bonemeal supplement given to the cah-es of the contro'l group, from weaning onwards, reducecl the clegree of pica to a negligible amount by the end of the test.

C. Body M eaS1trements.

Because all the calves were not measured at 30 days o£ ag·e, Table No. 4 does not include data for that age. It gives the average body measurements in em. of the ralves in both groups, for the ages of 60, 270 and 480 days. As in Table No. 2, the actual and percentage differences (in terms of the control measurements) are given for each age, and significant differences are printed in thick type, with the degree o£ significance given within brackets above and to the right of the significant differences.

It will be noticed from Table ~ o. 4 that no significant

<lifferences were found het,Yeen the bonemeal and contro'l groups, in the body measurements, at any of the three ages given. In fact, although the cah·es were measured eYery 30 days, no sio·uificant difference between the 2 groups, "·as found at any stage du~·ing the test and it is, therefore, justified to conclude that the bonemeal supplement had no effect upon the body measurements taken.

328

p329-330a

p329-330b Table No. 3

Pica

p329-330b

p329-330b

p329-330c p329-330a

(Cont.)

p329-330c p329-330b

Table No. 3 (cont.)

Pica

~ ~ C.:> C.:> ~

Age of Calves in Group. Bonemeal '"" C'nntrol. Length of Hodv.

i

lfoight I at T.llll.l< .2\o. -1-. /Jot!y M eoS11remP71t.l. J30LJY :\11·;,\SifRBMl':"'Tc>. lfcight 1 Depth ttt of Hook-f'he•L !JlHH'~.

Width of Ch0•t.

J-kart nirth.

Lt-•ngth of Hnmp. I

Width Width between I between llook-Th~t·]". I JUIH·:-:.

\l"iclth between

I

Length Pin of B01ws. Hearl.

Width between E.vo~. ---_:. __ ~~-~~'--.

I

Withers. I I 60 days.······ Bonenw'<l.. 76·5 78·\1 8:{ ·6 33·fl lfi·R 80·-1 :W·7 :?11·11 ;!:{. 4 ,)·5 :!7·7 11·1) Control.. . . I 76 · 6 7!1 ·!I 81 · I :l:l·li Iii· 6 88 · 8 26 · 6 I !J · ;; :!:; · I .; ·l:i "27·7 11·11 Aot=l differeooo....

r:~ o . ' _I_ ,., _ _,. ,

5 ' I 0 3 _

1

;t:2 1 '

0 6

I . ". ' '_ " ,, - -;; ' 1:: ~ · ' P o.~ ""'' "

])lfforeore

I

0 "

I

I ,,; ___:: , U ·NO 7 · 6U "· 6S

•+ " :

3H

I '

06 I 3U : 1·7U

--- 370 days.···· Actual difference .... Percentage difference 480 clays. . ...... . Actual <l i ffercncc ... Percentage rliA'erence

Bonomeal.. !)6·1 97·5 IU~-fl ~n·U Control. I !)4·9 !l(i·!l 1111 ·() H·~ ---I

1-l---- -- +

]·2 -;-0·6 · 1·0 ,-j 0·6 I · :?6 : !-IJ · 62 /-U · !J!l 1-'-I · :lii Honem('a! .. ll3·4 110·0 I l:i · I ij:J·(i ( 'ontrol. I I J · (i 11!8· I J I · 7 .):!· ·> ---1 ·I 1 ·8 I 1·!1 I; I

--;- -~-

il.

~

I· 7(i I·:!.; 11·75 1!1 s 115-:l :;~·(i I :!8 ·;) I!) :! ll:l:_ _::_

1~ :_

'

~-- II

li I ~~(IJ·:!_ ·-U<l I :l·l:l I .. )II I)· :)l' I l·ll(i :!4·G 140·0 :l!)·(j :{:). ~ ~:{. :{ 1:!6·!) :!H· 7 :l~. ,, ·:! :l· ! f II·!) il·S I-

I :W U :!IJ 6 -- o-:l I·UI

7 .. i 7 :;

3,;. I :H·:l

1:!·:{ I :l· 6 0·:! 1. ll-8 I o-=l --------~-- -:!·H J-:!<lH -:!·:!L

~ ~~

H. I

I

:;:!·S -7~--411·:! ~-~~ o-:; ,

o- ~ I +

11-1

~

u-:l ----· .; · 15 1 ·i · :! :!(i :! <l:l ~ <!:! · I II· K!l

+ .; ·

I !l I· 7-1 -I ·fll I 61 I . -~-1---~~----I --~----~1 -~-·-

'-<

=

~ "/ . . ,_

~

;,.. :::::: :.- ~ :::: z ...: '/. '.I, ::: ;/. n :-::

FEEDINli OJ: PIIOSI'l-lOltCS St;PPLEiHENT TO CALYES-

D. lilood clnalys1.:;.

In 'lable ~o. 5 is giYen the inorganic blood phosphorus in milligrams per 100 c.c_ for each calf, at different ages throughout tl1e experiment. Below each group the group totals anll <Herages, at the g-iYen age, art> found. ln the last 2 horizontal columns the adual and percentage differences (in i.erms of ihe control figures) are giYen. Significant differences are shown in the usual wa:v-.

For reasons alreaJy explained uo analyRil' >Yas conlluded when lhe calves were 270: clay.s old. Unfortunately it is, therefore, impossible to compare the 3 important ages of 30, 270 and 480 day;;;.

:\'evertheless, the :figures in the last horizontal column are mosi interesting. At the age of ;~o days there "-as no significant <lifference in inorganic bllood phosphorus bebveen thP bYo groups, a li.houg-h the average of Lhe contr-ol gr·oup is slightly higher lhan that of the l:onemeal gl'01111. At 60 days ihe <lifferPllr-P is still not sig-nificant but no\\- the bonemeal group is slig-htly higher than the controls .

• 'd 120 clays the bonemeal calves sho11· an inorganic blood phosphorus

1 ontent, \Yhich is 21 per ceut. higher than that of the controls. At 180 days this significant difference has iHcrea;;ed to 45 per rent. It ,;eems safe to assume that at 270 days, ,,·hen the controls 11·ere placed upon a bonemeal ration, the differPnce '~'Ollld probnhly haYe bePtl at Jeast a" marked ns at 180 cla~·s.

The next analysi:-;, at 11 months of age, i.e. after the controls had been ou a bonemeal ,;upplement for ~ month" sh-ows a distinct drop in the percentage difference between the 2 groups. This difference, howeYer, remains highly significaut. Ai 13 mouths of age, the inorgauic blood phosphorus of the controls ,,-as actually significantly higher than that of the honemea-l groups. From this point onwards there was no difference between the two groups.

Comparing the average P₂0.-, figure;; for the two groups, it will be noticed, that n fter the high figures of all the experimental cahes, up to 60 days (a high inorganic blood phosphorus content is normal for young calves- see Green and }iacaskill, 19.28) the bonemeal group retains a leYel of approximat.etly 6 milligrams per 100 e.c. throughout, while in the control group there is a distinct decline until weaning age, but from the time IYhen these eah es too were placed upon a phosphorus supplement, the averag-es show a definite npwarcl trend.

From these figures it is concluded, that the bonemeal group of calves received sufficient available P 205 to maintain a constant level of inorganic blood. phosphorus, as judged by our analysis. On the other hand the control group of calves probably did not receive sufficient available P 20.,, and although no conformational evidence of an insufficiency could be detected, the analysis neverthe¹less revealed a drop in the inorganic blood phosphorus. After the control calves had also been placed upon a bonemeal supplement, their inorganic blood phosphorus, rose to a level, equivalent to that of the bonemeal ca¹lves.

In addition it must be emphasized that the average values ot 5·52, 4·33 and 5·10 milligrams phosphorus per 100 c.c. blood of the control calves respectively at 4, 6 and 11 months o£ age, are

332

C.:> c.:> c:.•

Group. 13onf'meal. ............. . TOTALS ..•..... AvERAGl~:-; .... Control. ................ . TOTALS ... . Avl:RAl:l-:s ..... . c\t·twd dift'erences ... I'L·r·ccntap:c rl itt'crence~ ...

!\o. uf .\nimal. ~~ 6727 6730 6736 6740 6741 677:{ 6777 678\J 6790 6714 6728 6742 6743 6748 (l749 6768

I

I

I

I

I

TABLE No. 5. llluryunic IJloorl Plwsplwrvs. fNOlWANIC BLOOD I'HOSl'HOitlTS OF (',, L\'Es ,,.,. ll.1 y Afn:s OF. :lO (ill 1:20 l8U ~ +·:i S ·I 6·6 G·O H -:{ 8·X 7·3 6·:! X·:! (\·7 ;) . 7 8· ·) < -7·S (i·l) ;) . !} i ·II li·H -H·4 ;)·6 6· .I 8· 7 8·:2 ;I· H (j. :1 8·8 7·U O·S 8·7 8·0 7·3 (i·G

I

INORGANIC llLOOD PHOSPHOHL:S OlT' CALVES A'l' THE FOLLOWINI: APPHOXIMATE "''foNTH Afms. II I~ I:{ ' l.i I() (j·l) 6·.] 6·0 7 3 6·3 6·11 (j-(1 ;I· 6 8·5 ii·O H <l (j-:2 6·2 (i. :1 6·2 (i·4 !i·O ;) . ;) 4·4 5·7 7·:2 5·!.1 6·:2 7·3 6·2 7 ·I 6·:1 fi·:! 8·7 I ;)·!l .-). 7 {i. ;) li·l 7·7 ,, . :l s :! 1·2 (j-1) ()-;) 5·8 7 ·;) 6·4 6·3 8·2 5·7

,-- -- -

-~----- 4i'i·4 67·3 60· I ii0·2 60·+ ----

-~~------ 7·!\7 H·4l 6·68 6·2S 6·71 ---- 7·7 8· 7 li·(i :l-8 ;) ;) :1·() 8-:l ;)·7 ;)·!) ;) ·7 U·7 8·2 11·7 4·2 ;I·V !l·ll 7·6 .;. 6 :l·7 ;) . ;) 9·0 4-:l 4·1 5·2 8·:2 -:) ·S :l· 9 {)·:2 8·:2 8·:2 5·U +·7 I :3·8 ---~ ·---·--- 48·7 :)0·0 37 6

- ~ -1

3;)·7 --- ,., . 5:2 4·33 :"i·JO I _, [·16

+

1·9i'i

+

1·61 I +21·01(') I 1-45·03(') +31·57(1) (") Inclil'ates significance at. I' = 0·0;1. (1) fnclicat-Ps sil!rlifimncc at I' = 0·01.

ii6·2 fi4. 1 65·1 :12·1 -·--- 6·24 6·01 7·23 ;1·7!1 (i :2 ;) . 7 7·7 I !)·5 6 :! 6·8

I

7·3 ;)·6 :; 3 (i-7 7 ·I

I

;)·2 7·7 7·0 (i-9 6·6 (i·J 6·7 7 ·] 5·7 5·7 fHl 6·2 5·9 6·9 I 6·6 9·0 5·8 I --- 44·1 4G·4 51 . :~ 40·3 6·:10 -~--(i·6:l ------- 7. :J:l :)· 76 -0·06 -0·62 -0·10

+

0·03 .. -0·9!i -9·35(1) -1·36

+

0·52

'-< -< ~ ;:: :::. YJ y;

s c

-:: :... ~ ::-< :.- ~ ~ '-j 'f- ~ ><! 7, '/, 0. .:;, t< ~ --: ~ ~ 'Z 0 t>1

FEEDI:\'G \H' YHOSJ'.HORUS SliJ:'L'LEM:ENT TO CALVES.

indicative of aphosphmosis. The value 4 · 44 especially, is only JUSt above the minimum accepted as .sufficient for mature cattle, and IS therefore 1·ather :low for G months old cahes. This provides evidence, that the Gontrol calves suffered from a phosphorus deficiency, which

howf'Vf'r. '"as not manifested conformationally .

.E. JJone lhstology.

The histological examination of the costo-chondral junctwns

>·howed good calcification '"ith long and closely knit primary

trabeculae, both in the rib-resections taken at 65 and at 180 days of age. Up to 6 months of agP. tlwrefore, the skeletons of the calves examined were f.ound to be nonnall in terms of phosphorus. It is unfortunate that no histological examinations wNe done on resertions from cal ,·es at 9 months of age.

ln the resections taken iu June 19~n (180 clays old) the cosTAl- chondral junctions of calves ~os. 6714 (control group) and 6727 (bonemeal group) revealed the presence of a fibrosis, probably osteodystrophic in nature, which is, J10wPver, as far as we know, not associated with aphosphorosis.

\". 1 hsCUSSJOC\.

NoT.r-:.- In the discussion of the experimental 1·esults the word

« function " is used in such phrases as " fundional efficiency ", ''functionally subnormal " , " fuudional abnormalities", etc. Tl1e reader may interpret thP word " function " as the ;;;um total of an animal';; physiological manifestations. In the p1·eseut discussion ,;uch an interpretation is not intended. 'l'be <1du::d functions referred io are clearl:-;· clescribed in paragraph~; (IJ) (1) and (b) (2), below.

'l'he results of the experi1nen'l ~how, that m terms of the experimental criteria employed:-

(a) The bon.enwal swpplP1nent had no effert ·upon g1·owth and development, i.e. U]Jon e.?;ternal con/0?"1nation : At no time during the eour e of tl1e inYestigation. either before or after weaning, were s1gnificant differences found between the average body weigllts or hody meaHurements of the two groups.

(b) The l10nemeal supple111Pnt improued .functional ef/icie11cy:

The hmlf'meal ca:lves, functioned on a higher plane of efficiency than did the control <"alves, from the time they were plared upon a phosphorus supplement, until

nw

control calveR too received the same supplPment.

(1) In comparisoll '"ith thl' controls, they exhibited practieally no osteophagia, and sbmYed " higher and much more constant level of inorganic hlood phosphorus up to weaning age.

(:2) From the age of weaning 01n~ards, "·hen the controQ calve,;

also receiYed bonemeal, the manifestations of a phosnhoru,;

deficiem~· exhibited by them abated and finally diRappeared. A.t

1 he conclw;ion of the experin1ent, the eont1ul calves were, in terms of the experimental criteria, in every '"a:'i' comparahle to the bonemea 1 calves.

334

J. H. Jl. HJSSCI-101', .1. T. ~!ALAN, H. l'. STEYS .\:>;JI (;_ II. l .. ll'ID-:NC.E.

The experimental results tlho\1 up an apparent anomaly. At ,,·eaning age the control caih-es, although conformationally normal,

\\'ere functionally subnormal. How can subnormal funetion maintai11 norma 1 confonnational deYelopmen t? Theiler, D u Toi t au d Malan {1937) conducted mineral metabolism inYestigatiou:-; on pig-s. They found that a g-roup \Yhich received an arlequnte ratiou, t>xcept for a deficiency in phosphorus, showe<l as ra pirl a weight innease, a;;

<lid the group on a completely adequate 1·ation, fm· the first 5 month~

of the experiment, i.e. up to a liYe "·eight of approximate:ly 140 lb.

This normal f'onformational development took place notwithstanding the fact, that 4 months after the commencement of the test, the inorganic blood phosphorus of the g-roup on the deficient ratiou averaged only 0 · 60 milligrams P 205 per 100 c.c. as compared with g.g milligram~ TWr 100 c.c. for the group 011 fl ('Omplete ration.

Up to a point, therefore, the deficient skeleton \Yas able to support normal increase in body weight. After this limital point had been passed, the phosphorus deficient group showed a rapid clecline in the rate of bodyweight increase in comparison to the pToup which received phosphates.

It would appear as if, vp to u point, the ~l,elel.ou:-; of growiug- animals are able to d·o with less than their normal mineral require- ments, and nevertheless function sufficiently well to support normal increase in body weight and size.

This idea explains the apparent anomaly encountered in the Experiment under discussion. The control cahes, although receiving a phosphorus deficient diet, had not reached the " critical point ''. at weaning age, and therefore, showed no externally determinable

"ympt-oms nf the deficiency, which, when removed h~· subsequent bonemeal feeding, allowed the animals to huil<1 up the funetional ctbnormalities back to normal by the time they \1 ere -±80 days old.

It must. be remembered, however, that the calves of both experimental groups "·ere born out of bonemeal fe(l cows, and received, through the milk of their dams, quite an appreciable amount of aYailable phosphates, up to weaning age.

On the <JYerage each calf of the bonemeal group n·ceived 1,25.1 lb. of milk during the 210 day period over whic·h the production of its dam was recorded. The control calves each received on the average 1,288 ilb. of milk. 'l'he difference of 37 lb. per calf between the 2 groups is insignificant. Even if the difference was significa11t it would be in favour of the control group.

Groenewald (19M) gives an average of 0 · 221 per cent. of total P ₂05 in bovine mille Applying this figure to the average milk intake of all the calves born out of bonemeal fed cows, that is 'to 1,267 lb., we find that each cal£ received on the a.-erage 1,258 grammes of totall P20,, in 210 days or 6-00 grammes per head per day.

This amount, together with whatever available P205 they obtained through their grazing, \vas apparently sufficient for the control g-roup to maintain normal conformational development, aml to maintain functional efficiency, ubove the "criti<;al point" up to 270 days of age.

335

FEEDING OF PJlOSl'IIORl'S SLTT'l'U·:~m='IT TO C.\LVES.

The two group,; of calves ran together in the same paddocks anrl received the same amounts of milk. Therefore the fad tktt the honemeal calves ,,-ere hoth ronformationally and functionally uormal, while the contr.ol cahes, though confom1atiom1lly normal, were funetionally subnormal, can only be attrihntecl to the ex.t1':1 phosphates which the fonlll'l' group received hom their t;upp:lement.

'l'he phosphorus deficiency in the controls 1n1s not ;;ufficiently acute to manifest itself conform:1tionally.

So far we haYe comvared group,; of cahes horn of bonellleal {eel cows, and which receiYecl lhe same aYerage amount of milk from their clams. Let ^n;; next compare the control group of calves, in the test under discusHion, '"ith a group o£ other\\'i,·e comparable animals, but horn out of JJOn-bonemeal fed cows. To clistinp:nish the two groups. the fonner "·ill he referred to as tlw '· bonel1le:1l r:ontro'l group " and the latter as the " straight control group ".

'l'he ll::tta for this latter group ltaYe l~een obtained from the record' of other exveriwents, conducted at " ArmoedsYlakte ". No heifpr calves and onl:y ;{ tolliPs "·ere fomHl, "·h ich were fully comparable i;o the " bonemeul control" calves, awl lhereh,re Table No. 6 give,., the data of tht'se :j tollies against that of the -l to:Uies in the

" bon em eal r·on t ro I " gTo 11 p. (')

The table is di,·idecl into sections. fn Section I, the \\eight,- for each of the " bonemeal control " cah-es are given monthly from birth until the end of the test. Below these "·eight figures, arr found the average daily atnonntt:J of milk Pf1ch calf obtained froJIJ 1ts dam, (luring the preceding month. Because milk recording ::d

"Annoedsvlakte" takes place only for 210 dn.""· only 7 milk averages are g1ven.

Section TJ gi1·es similar data for the "straigbL l·untrol " group.

Tn Section IlJ, the actual clifferences in body "·eigl1t aud in milk ,:upply between ihe tiYo groups, are given in the first and third, ancl in the seconrl and fourth horizontal lines; these llifferenees an"' given as percentage.-; of the " straig·ht con troll " figures. Rignifica nt.

percentage differences are shown iu thick print :IIJd the degTee of Hignificance indil'alell in the usual m::mner.

Section :No. Ill of Table No.

u ,

shows that at birth tilt·

" bonemeal control " cah·es, "·eighed on the averag-e 7 lh. more tha11 the "straight colltrol " <·ah-es. This clitterence is not significant:

in fact Du Toit ancl Bis~chop (1929) found, when working with n much larger nnrnher of grade Iteclpoll ('al ,-es, that t·lie differenCl'

(!) l!Jxplanatory Sc•te by the Statistician.- 'l'lw small number ol' animals in each group, is a ~<'rious objection, since thr co-efficient of ,·ariation tends to he higher than tlia~ of large groups. The statistical test of signifieaJl<·e require' that the ditl'erences between sma II. groups lia ve, in any C'ase, to be much g1·eater than between large groups, but when C'ouplecl with n high coeflieie11t of variation these differences have to b0 even larger. Th0 lack of significunct·

in the ver~· large ]Wrccntage differences in the last horizontal line of Sectio1•

[LI. of Table No. 6 may be explained on this basis. Small groups therefore lead to fewer significant differences, hut it should he noted tl1at the power of the statisticnl analysis is such that the significant differences that are obtained.

may be accepted with the ~amc mensure of conficl<'nee, attributf'd to differences between larger group>.

336

J. II. IL IIISS('ll01', A. J . .\!ALA:\, H. P. STEYK .\KD G. 11. LAllHI-:i\CE.

<