Onrler:;feL"'ort Journal of Vetermru,1; Science rual Animal l'lld'usLty, Volwne C), Number 1, July. 190-5.
The Effect of S upplements of Different Fo rms of Sulphur to the Diet upon the Wool
of Merino Sheep.
Hy C . .M. VAN WYK, M.Sc.,
.JI. L. BO'l'}L\, lLSc.(Ar;mc.), l~ese<ueh Ofht'e1·s, and
J. G. JJEKKEl~, B.Sc.(Acmc.), D.\~.Sc., Yete1inary l~est>ulch
Officer, llnclt>rstepood.
INTRODUCTION.
Col\SlDJ.:JIAIILI·: p1·omint>nce has lately been giYen to the effed of
.~ulcling sulphur supplPmentc; to tlw diet of sl1eep. vVhatC'Yel' tlw
results may he from a n ntrit ion:tl or physiologi1·al point of Yie11·.
the IJOssiiJle effer:t on thP \Yool, as reg-ards both quality and total produetion. Jl:durall:•.- <tssuJtiE':> impodaliU'. and ,-;]wuld lw ilwec;tigah•d.
This aspe1:t "·ns iirc;t n•nwrkecl upon h_,. StP)'ll ( l~):)J, l!JJ:!), \\·ho (;Ull-
d ude!l that a ;;uiphur SUllplement in the diet ltad a. beneficial eftec-1
011 t ltP loLd procluctiou of "·ool. Suh:>e!ptenU:y Seddon (J D&3) reeonle1l that he ha<l fou11d 110 signifit'ant eHeci on the ,,-ool ,vielcl of shet'P·
entirely g-ra;~,ecl, while Pierc·e (J9:)J) f01llld no beneficial pffect on sheep kPpt on a maintenant'e r.ation, or one slightly aho\'P mainteuancP.
The follo11·ing are the results of an inve~tig-ation of the wool of si:d.\· .Jferino "·ethers \Yhich hn1l J·ecei,·erl supplem<•nts of sulphm in ntriou,; forms. The influence on the bodv " eights of the ~amP
~heep has heen dealt with in anothe1· publication (du 'l'oit, :Malan.
Groenewalcl an<l Botha, 1935), \YheTe it \\·as shown thai, u11der the conditions of the e-xpPriment, the s11pplements hacl no sig-nifit'ani effed on tl1e bod,,- \YPig-ht as compared 11·ith ihP 1·ontrol sheep. Fm·
this and othPl' n~pects of tlw (lue,;timl, ii i~ mtl~- liPI'e,;snry to JPfer (·o thP abon• public-ation, "·hPrC' Full drl:til;; '"ill1w found.
EXPERIMENTAL DETAILS.
A g-roup of :;p,·enh·-fi,·e '\fe1 i no ,,-pther.'i, hol'll at Urooifonlein hetwePn l0.0.JD:CJO nnd 9.G.l930. were selecte<l for unifmmitv of type, flee1·e, and body "·eight. They \Yere shorn het11·een 31.:1 .. 1901 and 8.4.19:n, .aml suh;equentl~- sent to On<lerstevoort, where ihey a.rri,·ed on 8.10.Ul31 as t11·o-tooths. Here thev 11·erP shon1 in DeceJn- ber, 1901, and s i st,v of them plncecl on a l1af<al ration for eleHn
177
:EFJ:'ECT OF SULPHrR ON TI-IE -woOL OF MERIKO SHEEP.
mouth~. Durino· this (pre-experimental) period all the sheep receivec1 identie1J treatment but were divided into six uniform groups and placed in a grav~lled paddock with pens and boxes for indi,·i(lnal fee(ling. At the conrlnsion of thi;; period (~ovember,
1932). they \Yere shorn again and placed on the same basal ration for a pe1·ioa of t"·elve months, during \vhich the sheep in :fiYe of the groups were closecl with various forms of sulphur, the sixth group acting as a control. They were finall.'· shorn in Kovember,
19:~a. For brevit.'· the two periods will be called the 1902 and 193;1
periods respectively. The conditions under which the wool was
gro"·n may thus he SUllll11arised as follows:- 19!32: Eleven months on basal ration.
19:-J~i: 'l'weh·e months on basal ration and supplements.
B. FEEll.
The basal ration throughout the two periods 19;i2 and Hl;3a con- sistecl of half a pound of crnsherl yellow maize and half a pouncl of green feed-lucerne or maize stalks or 1nair.e ensilage during about three months in winter, when no green feed ''"a~ available. In .addition the animals had free and continual access to teff hay. For further details of the methocl of feeding and the l'onsumption, as also of the general care and management of the sheep, the reader is referred to the paper quotecl above (du Toit et alia, 1935).
Dm·iug- the experimental period (19~13) the sheep were dosed d.ail)· excer)t Sundays, the follo\\·ing being the supplements g-iven to
<each animal:- Group I : Group II: C:l-roup III:
(houp IV: Group V:
Group VI:
K o supplement. 0 · 45 gm. cystine.
0 · 7 gm. of a mixture consisting of 0 · 2 gm.
K2S04 , 0·3 gm. ?lfgSO, and 0·2 gm. C'aS01 •
0.:15 gm. KCNS.
5·0 gn1. sulphur.
0 · J 2 gm. sulphur.
The quantities of supplements, exeept in the ease of Group V,
>Yere caleulated to contain the same am.ount of sulphur as that con- t.ainecl iu the Q·45 gm. r'ystine giYen to each animal in Group IT.
C. :YIATElUAL.
Immediately before shearing- in December, 1931, a wool sample
"Of about 15 gm. was cut from the shoulder of each sheep. A pair of fine scissors was employed, and the wool cut as close to the skin as pos,;ihle. The area of about one and a half inches square, from ''"hieh the sample had been cut, \Yas then tattooed on the skin, aucl at subsequent shearings the wool grmving on this area was first remo\·ed. In addition a further stnnple was taken acljncent to thi~>
aren for chemical analysis, which is still in progress. 'l'his metho(l ensured that the samples obtained at the end of successive periods were taken from the same area on the skin of each sheep.
178
r;. ~~- V:\N " 'YK, M. L. JH!TH.\ AKIJ .J. G. liEl\1\El<.
The Halllples haviug- been remo1·erl, the sheep 11·ere "honJ a11(l the fieee<>:s stored in linPn hags for examination.
]) . METHOI>S ov Ax.u.Ts 1 s.
(a) The 1:n·ea~t> \I' Pi gh I, dean weight and y iel <1 pe1-een tage of the ftee<·e.
AJ the time of shearillg each fieeee 1va,; properly skirteLl in the nwnnPr <·nstomar.\· in shE'aring she(b. ThE' "1\irtiugs "·ere transferre<l to a slnooth-toppP<l h1hlP and again "·orke<l throug-h <'arefully- heavy dung-lock,; "·ere discarLled, Khile all the lightest pieces that ,,·oulrl bleml "·ith the fleel'P were nm iu with the latter. l<'leeceR .aml loel\", imliYirluall)·, were then tnmsfened to suitable liut>n bags aucl fitore<l in a non-1·eutilatPrl room. Suhi.;equentl)· tht>sP were \Yeighed under irlentical conc1itions, rlne allowance being nw<le fm the weights of the ::;houlrlt>r :samples 11·hil'h had 1wen remo1·erl for ph_\·sil'al and l'hemil'al anal.1·sis.
For the determination of the deau \\·eight,; anrl yield pereentag-Ps of inrliYirlual flet>ces, a modification (Botha) of the method rleseril1ed b.\- \Vilson (1928) IYas followerl. 'l'ht> methorl ma)· hP sulllm.arisecl a."
follows :-
(l) Subse<lllt!Ut to the weighing refen t>d to ahoH. each ftt>ece
\His pa,.;,;e<l three times through a Heece-llJPaking machine, tht> ohjec·t being- to blend Hw Yarious pads of the flee<·e thorougbl.1· .in order t·o enahle I'Pprt>st>nbtiYe ;;amplt>s to he Llra\YH hom it.
(2) The fleece \Ytlo; \Yeigherl .agniH to :tllmY for impuritit>s lo,;t during the process of hleudiilg' nn<l for probable fhwlua- tious iu moisture content.
(::1) Immediately after thi,; 11·eighing hYo samples of a hundre<l grams each were made up of small amounts of wool, of approximately twenty grams, taken nt random from
\':tl'iou" parts of the bulk of the fleece.
(4) These samples \l·ere lH-)Xt S(·ourefl in a Reolll'ing liquor c-on- sisting of a mixturt> of potassium oleate soap and sorlinm carbonate.
(5) After being allowed to become air-clr~-, the air-<h;i' weights of thP samples, and of a st::mLlarrl sample of known dry
\Yeigh t- in hygroscopie e<[ n ilihrium- \l·ere recorded.
(6) Immediately after this a snh-sample of twent) grams of
air-dr,~- wool was taken from the last-scoured sample of each fleece and dissoh·erl in 200 c. c. K /NaOH solution (i.e. 4 per cent.), in orrler to <lt>tennine the amount- of vegetablt> matter present after scouring. The clean rlr.'- weights of the fleeces could then be ealculaterl and con- verted to clean conditioner] 1night at 17 per cent. regain (International regain). The clean c~oncl itionecl weight of wool containrcl in the loch "-a, ohtainrrl separate!,~- i11 a slightl:v' moclinerl manner.
179
EFFECT OF SULPHUR OX THE \YOOJ. OJ:' )JERI::-<0 SHEEP.
Next the ai1·~dry grease "·eight of the locks \\as .a<ltle<l to that ot the corresponding fleece, anrl similarly the clean con eli tion e<l weight.
From the resulting totals the '"eighted mean of the condi.t ione<l yield percentage of eaeh total fieet:e was calculate<l.
The g-rease and clean conditioned weights gi ,·eu belmY represe11t the mean production <Jve1· twenty-four h.ours.
The eond it ion eel yielu percentage is defined as the eoud i ti on eel clean weight of the fleece expressed as a percentage of thP original .air-dry grease "·eight of fleece prior to machine ll·eatment.
K OTE.- All grease IYeights haYe been expressNl on Ull air-llry basis inespective of actual moisture coutent. )._ hig-ht>r or lower moisture content o£ the grease '"ool at the time of the initial \Yeigh- ing \Youlrl be reflected merely iu a lm,·er or higher ~·ield percentage.
Such clifterences in the aetnal moisture content of the gre:1,;y wool could be brought about (a) by rlifferences in atmospheric temperature and humidity in the rli:fferellt years at the time of weighing in<liYirlnal fleeces and (b) by the possibility that when the fleeces "·ere stored in u closed non-YentilatNl room, e(juilibrinm of moistu1·e ':on-
tent may uot have been attaiuerl. ·
It must he emphasised, ho,,·eYer, that, by the nature of the l'alculations, the result for the conditioned dean ~~-eight remains totally una:ffer:ted by fluctuation;; of the moifiture coute11t of the
g-reas~· \nlOl, no mattr>r ho1Y wide t.hese ma~' haYe been. J•:,·ell in the case of ~-ield percentag-es, <li:fferences will be of the ordet of a fe,Y per cent. only, since the adual flnctuatim1s ill humidity will be comparatively small.
(lJ) ~fean length. ihiclmess a111l fibre weight of a sample.
1'he weight-length method (H.oberis, 1930), was userl for the analysis of the RampleR. It l'Onsists briefly of (J) a lllf'thod of sampling, (2) the counting- of a number of fibres, (3) the measure- ment of the lengths of .a certain proportion, and (4) the <letermina- tion of the dry weight of the fihres counted. From the 1lata i.huR obtained the follmYing- are calculated:-
Mean length : l,
:Jfea.n thickness :
v / - 7T_ X _,
-:1:-.4;-;;t-x-,-n-X---c;ZMean fibre weight .
w
, nwhere TV= dry weight of the counted fibres, n =number of fibreR counted,
l =mean length of one-tenth of the counted fibres, 1 · 3 =specific gravity of cl ry wool.
In addition, a cher·k on the sampling and on the accurar;y of the result is obtained in the form of a coefficient of fineness rlis.persion.
It should he pointed out that Roberts expresses his results aR fibre fineness, which is the length. in centimetres, of fibre whi.rh weighR
C. M. VAK WYI\, .ll. L. HOTHA .\ND J. G. HEJ\:hEJl.
011e milligTam. The thicknes~ gi1eu in this paper is the diametPr of the fibres call'nlated on lhe ;t.-;stllllption thai thPy .are uniform circular cylinders.
'l'be ~alllplP:; 1\'t'J'P divided inlo tPJI alJJ>ro:-;illl;tlely equ;d zone:;, all(l tPII ~uh-:;;~mplt', Jmule UlJ, each l'Oll~i:;l i11g· of one slll:ill lock from ead1 zone. 'l')ip:;t• snb-s:llll]llP::; therehn·e t·ollt-·diYely consi~ted of a hundred small lot·k.-; taken frolll difh-'rPJd points in sul'h a 11ay a:; lo represe11t the 1d10lt· of lhP nurkP<i <~rPa. i':<~clt sllh-:;ample 1vas analy,;c>d separ:dp(_,-, so thai IPn diflpn•nl P:<linwlr.' ,,[the leng·th, finenPss :11t1l fibre 1n•igbl of tht• or1gin;~l ,.;;~Jil]lle 11·ere obtained.
About t11·o tltmJsand fihre.s in;~]] 11·e1·e t·uuniP<l hon1 e<~t·h of the pre- expPrinJent<~l :;alll[l]P,, ;~nd four thon;;:111d fro1n eac-h. of Uu-· Pxperi- menlal ,;amples, I ht·' t·uPHiciPJiis of finene;;s tli:;version ranging from oue to fmu· pt~r cent. 'l'ltP lt-•ngl h of eq•ry tt>uth fibre was measured, and the dry \\"E'ights \\e1·e dt>lt>nuined by t·omp:ui,;on IYith a standard sample of kJ1o11·n dr_1 11·eiglli., ihP IIPighing,.; ht>ing- repe.:ti.Pd rl::tily for ~PI·E'ral dt~\ci i 11 ~u•·<·t>::;~ion.
'l'ht• mino:;r·opic:d met hod of lllt'a::;uring- lhit·l;nt>,;s (J)eunlen, l!J:(!J), 11·as applit>d tu a JIUllllJer of tl1r ."~llllplt-':3. Tlti~ mf'i"hod g·a,·E' esseuiiall_,. the :;anJe results, thougl1 ilw Yalues "·ere all sonle\\·hat higher: 11·hen routine :111aly:;i~ haYe to lJE' Jlt<lrlt' the authors arE' inclined (o fa1·ou1· thP mino:-;l'opir·aJ mPihod. e.,;pt>ci:dly in ille t·a,.;e of .JIPrino "·ool, 11·herP t·hp fihn•s :u·p 1·t'ry finP. :\. fud ht>r <'Ollljlarl~on of I liP !.11·o nwt hods, in1·oh i11g- measu,·enJenl~ on al.Jo11i a hnndrerl san1ph·~. 11·il l lw re~t·n·Ptl for :1 la!eJ· pnlJlil':ilion.
RESULTS AND STATISTICAL ANALYSIS.
Below are g-tl'eJI the group llJP.UllS fm thE' tin) period,;. ]!):12 aml l!J:'rl. L\ methotl of :IIJalv;;is of 1·arimwe anrl t·o-Yarianr·e (J•'islter, UJ32). has been Pmp lo1·erl
i
o test t l1 e sig·n i.fi ran l' e of gTo ll] 1 diflere11 ces. Tt i~ reali,;erl th:1t in r·oJilWCI ion 11·ith ,,·ool a YPl'\' largt• proportion of the variation hei11·ern rlifft•rrnt sht>ep under simila1· t·oll(li(ions i::; tlue tD 1dwt may he ,]p,;I'J'ilwd in W'llPrnl ten11::; a:; ill<liYttlunlily, n1Hl is inrl()jWudeni of 11ormal nutritional tre<ttment. This part nf the v:n i:mce of Yalut>.s of ll1P expt>riment:tl pt>riml m.a;. l1e regartletl as ba1·ing- !wen fort>,;lwrlm,·t>d in tlw Y:d11E's of thE' JHP-r~perimental pt>riorl. Tlw <t]lJHO]Jriate •·oefhcient of lint>m· l'E'g're;o;sion i,; gtYeii hy the raLio of the t·o-,·:~rialii'P to ihe Y:niance of the inrlP]JE'ntlt>nt Yariaie,11 hi .. h i11 this r·:t~P is il1P Y:niance in lh<· pn'limin:n·y Y:iluPs.
(u) Gre:1~1' 11·Pighl~ of tl1e -Art>(·es, in p:m. calr·ubtt>tl for one cln;.·':;
g'IOid!J.
(; •·ou p. I. If. ITT. I\'. \'. Vl. 'VIenn.
- - - - -
19:n .. 10 7 JO \) G 10 R 9 9 JO R 10·4
19:!:1 .. . • •• • • 00 •• 14 2 I+ :l 1:! !) I+ 0 J:l 7 J4 0 l:l-8
lRl
El:' I:'EC'l' OF SULl'IITR ON ·n-IJ<: \\'00 r. Ol' ~IEIU'!\0 SHEEP.
'l'he sums of squares .ancl produeh are g"lYPll Jll the fol1o11·ing·
trthle.
x2 Grease weight in 1!JaZ.
x3 = Grease weight in 1933.
13ctwc~n groups . .............. . Within groups .............. .
TOTAL ... . .•. ...••...
Degrees of freedom.
47
;)~*
I Z ·:>1 n-4a
8!'\ ·94
X::2
10 25 10·92
I
j .U4·0a
----~---
76 ·i\i)
86·80 J:H-05
1===~1~~===--~=~=~----
* There was one value missing in each of the two years. These were supplied by cal-
;:ulating the best-fitting Yalue from the rla.ta for tluee years (Yates, Hl33). This accounts for the fact that these is one degree of freedom less.
The result of applying the con edion for ilw 1·egressiou, as explaine<l ahoYe, and analysing the YariaHce of the acljusted yieldc, may be deriYe<l directly from the analysis of sums antl procluf't,.;
already pre~entecl. If
u
,;hllllls for the regression coeffil'ieHt, com- varisous of t·he adjusted Yalues \\·ill }w !'Olllpari~Oil::l of lpl<ll1t jj jp,;(:~:"-h.1·J. X ow
(.c3 - lJ.I:,)" ~ ( b'.r, 2- 2b:.c":t:3 + .1:3 ' ) .
In the pre,;ent example,
u
~ 1·0425-271~-2·0860 b, = 1·08G8
antl applying this directly to the sum~ of squares anll proclncts alHwe, the following- unab·sis is obtained.
Analysis of adjusted grease "·eights:-
I
'Degrees of Sums of
I
Mean
freedom. squares. squares.
Between groups ................ 5 3 ·1446 0 ·6289 = yl Within groups .................. 46* 40·973 0 ·8907 = " "
TOTAL . . ............. ;)1 44 ·1176
-
-
182
C. ~l. Vel:\ \\'YK, .\I. L. IIOTll.\ .\.\JJ .1. (:. IIJ-:1\1\EIL
Thr ralio N,_ 1-,
f
I" 1~ used to fiud the :'ig-uiiic-aiH't' of LLe(liffe1·ence bet ,,·rpn t·he tiYo Y:tnallC"e:; (Snrdr<'lll". l!J:~-l). l1t the
pre~Put C<li:ie,
p- t
=
~907 l -1-lGt 6289 ' . . '
111 =4G,
11 0 = 5,
,,·hich 1::; Yf'n· iu~ignifiulllt and doe~ not indil"atr all\. diltPrPnti:d effed beh,·epJ~ the tTPatlllrnts.
(/1) UlE>:IIl wrig-hts of thP fi<'f'Ct'" in g-ram.-;, •·:Jl<-uhted l"or one ,LJ_y',; g-ro1dh.
(:roup. I. II. Ill. \'1. .\ll'an.
lU3~ ........... . -~. 7(i 8(i -~ .):l -~. !)+ + 60
l!l:l3 .. (i. -~7 (i :!li (j ;j!) (j ·;);) 6·81i 6 :;.)
'_l'itp ~alllP pnH"edure iws IH'Pil foliOI\'Pd Ill <lll<tl_\·:-;ing· t!J,. l'i<•:Jil ,,.Pig-Itt:-;, ll'ii II t liP follo,,·ing J·p,;ulh:-
.lh ~ l'le:w ,,·pight. I'm I !):J:l.
y, ~dPHil \l'f'ight For I!J:j:l.
- --- - - --___ I .Degrees of freedom.
!
y/- - - -
!hY:~
Between group~ ............... . :; 2 871H ·!1-!;'\3 ·070:!
I
TOTAL ..
1
_ +7
J:l
17 ·806:l 16 ·81U8 I - - - ,
18 76.il
\\'ithin >;roups ...
:W 0781 31 ·%:!.)
~--~--=--~---~ --~---- - - -
b = 0 ·U4-Hi.
J)egrC'cs of r,·ecdolll.
- -
~11111 ol
NCjllHI'l'R.
"'lean
Nquan·~.
---'---~---
Between groups ... ........ .
\\'ithin groups ....
TOTAl.
;} () ·,)i)/6
46 l+ <39+:! 0 <ll:!!l
- - - -- -- - - -- - - - -
51
R-3 = 2 806.
11 1 = 46.
1?2= 5.
183
1+·!1518
EFJ'I·:CT 01•' Sl'LPllUR ON THE \\'OOL OF :-11~1~100 SHEEP.
'l'here i~ again no significant <lifterence bet11·een the va.ria nee~ a.nd consequently there is no reason for as~uming that the dean 1n•ighi,;
wen• afff'decl by the sulphur ,;npplem!'nts.
(c) Yielil per cf'nL ol' thP flN•<·es:-
- - - - - - - - - - - ! -~-
Group. I I. II. TIT. I\ .. \'. \'I.
I
- II
1932. ... 4+ 5 4ii I +7 + -1oi) 9 .J.(i ;:") +8 I
I933. .j.;) 5 4:) 6 +8 ·I +7 3 +S 0 49 ~ +7 +
li'rom thr above analysis it j,; rlP:lr i.hat no ~ig·nificant v:liue :1.'-'
reganL yield per cent. can lJP expedPd. z2 = :-iPld per cent. for 1932. z"=yitel<l JH~r cent. for lD:n.
Sv.rns of Squares and f'roducls.
I
' Dc<>TecH of ,.. ' 1l freedom. Zz2 : 2z:J _ ______ ! _
I
:) 77 ·52 85 ·:2:{
\Vi thin groups. 8-!I '27 Mi5·<l0
TOTAL . . . 9lS·79 ()40·5:\
- - - - -- -- - -
b = 0. 660l.
:l nalysi:; of Vw·iwu·e u/ Adjusted r·ol11es.
Variance.
Between groups.
Within groups ............. .
i)('~I'CCS of freedom.
;)
+6
Sums of
I
--~8 57:: -
I I -
I
Z:l2
107 :u 601 ·ilO - - - - · - -
70S 81
l\[ea"
squares.
i\ ·ill47
5' 107fi
TOTAL...... . . • . . . . . .
l
.)1I
2G3 51\)3 -,-~~-~~- 1-~~==~~~--
R = 1·0797.
Hl = ;), 112 = 46.
As was expected, the nnianL·e bPt \\'E'en groups is not sig-nificautly dilferent hom that within groups.
184
C. M. VAN vVYK, M. I". BOTHA AND J. G. BEIG~ER.
(d) Mean .filne length 1:n em. claclllatecl for 30 days' growth.
Oroup. T. II. ITT. IV. V. VI. :\fean.
1932 ............... . 0·791 0·809 0·820 0·824 0·829 0·820 0·814 19:{3 ............... . 0·909 0·944 0·968 0·981 0·934 0·953 0·930
Analysis o.f Variance.
Z2=1932 length, Z3=1933 length.
S1.tms of Squares and Prorlw;ts.
I
___
I ,_
! Between groups ............... . Within groups ................. .
7,866 ·:{ 122,135 ·4
10,769 ·1 llS,446 · 8
l 2
"
25,633 ·0 1!)2,028. 6
TOTAL .........•.....
i
! I --
130,001·6 129.213 .!) I 217.663 6
---~~-. ---
b = 0 ·9939.
Analysis of Ad.ivsted Valtws.
Variance.
Between groups ............... .
l~.'ith in g-roups ................. .
TOTAL .. . . ..•... . .. ..
Degrees of freedom.
.)
44
R= 1·259.
-n 1 = 5, n2 = 3~).
Sums of squares.
i Mean squaref'.
I
- - - - -- - ' -- - - - -
1 _ :::~ : __
11,998 3 74,307.6
86,306 ·1 I '
In the <.:ase of length, the1·efore, this insignificant Yalue shows that the variance between groups does not differ from that wi.thi.n groups.
185
EFFECT OF SllLPHL'H OK THE ""OOL OF MERIKO SHEEP.
(e) J[ean .filJre thickness tn /J. (we·i_qht-leu.!]th method).
Group. I. TL nr. IV. v. VI. }lean.
19:32. ... .
..
. . . . 16 ·65 15 85 15 29 15 82 14 93 15 ·59 15 ·521933. ... 17 ·66 17 ·86 17 ·13 l7 90 17·22 17 ·56 17 ·55
.Llnalysio of Variance.
Su/11-' o.f Squares onrl P1'odvr;ts.
Between groups ... . Within groups .......... .
TOTAL ... . . . .
( 2 2
4 ·540i) 46·43:37
:3 ·86:21 42. 21.~6
---
I
4·0138I 53 9736
50·974~
I 46·0777 I 57·9874. ===~=~~1=~--~~====~1-~==="='=
b = 0 ·9094.
A.nalysis o.f .-ldjllstecl l-allles.
\ · ari::.tnce.
Between groups . .............. .
\\"ithin groups ... .
TOTAL . . . .
R-1 = 2·683.
n1 = 39, 112 = 5.
Degrees of freedom.
3!)
I I
Sums of squares.
0·7443 16 5721.
:VIe an squares.
0 ·148~
0·3993
44 I 16 31M I
--- - _1~---- _ _ _I___ ----
- - - -,- - - -- - -- .- - - -
Here the same l'esult JS obtained a,; in the ca::;e of all the attributes stuclierl, Ylll., no significant di.ffe1·ence between groups.
186
C. "'- Vrll\ \YYJ~, }L L. l!OTIL\ ANll J. G. BEKKER.
{f) illean fibre ueigl1t 'ln 10-o gm., calc1datecl fa!' 00 day's gTowtlL
Group. L
I .
JI. III. n·. \'.1932 ........ 1·98 :l ·09 96 2 09 89 1933 ........... 2 91 3 ·07 2 89 3·17 2 90
A.nalysis of Tim·iance.
W2 = 1932 weight, Lc3 = 1933 \\·eight.
S1nns of Sq11w·es and PTodvcts.
'W2'll,'3
Between g1·ou ps .... :22 ·165 29·59;)
Within groups ... 3;)9·795 349 ·533
TOTAL . . . .. ..•. . ... 381 960 379 ·128
Variance.
b= 0·9715.
Analys1:s of Ad_justed ralues.
Degrees of freedom.
Sums of squares.
VI.
I
:!l'[ean.
1·98 2 00 2·90 2·97
'W32
51·901 630·623 682·524
Mean squares.
Between groups ............. . I 5 15·318 3·0636
I 39 I :2!)1 039
I
7 4630·within gi'Oups ..
TOTAL .. . .•... • . .....
I~== 4~-=J==.!~~~=J==~~-===
R-1 = 2 ·436.
n1 = 39, n2 = ;;,
Here again as iu all the preYious case~ the1·e is no ~ug-ge,;tiou of any response to the ~ulphm· ::;upplements, a::; n'gard:; Juean fibre
\\·eight of the sample':l.
lt '"ill he noted that in all ca~es the Yariance bd"·eeu g1oup::; doe:;
110( !liffer significant!~- from that "·ithin gToups. One i,; therefme lP<l to thP conclusion that undPl' the conditions of the experiment.
neither the fleece as a "·hole uor the fibres of a shoulLler sample ,.;ho\\·
am· indi<'ation of ha\·ing been affede(l by the supplement~.
SUMMARY AND CONCLUSIONS.
(1) Six groups of :voung '"ethe1·s "·ere J\ept m1 n procludiou ration for two :years. Jhning the seeond year fi\·e of the groups TPePiYed supplements of. sulphur alHl of compounds containing-
187
EFFEC'T O:F :-;c;r.l'llrH 0'\" TliE \\'OOL OF .llEIUSO :-;liEEl'.
sulphur, the si:;th group acting a~ control. The grPa.-;e 11eigldt>, dean ,,·eighb, .and .\·ield pen·eutagp,.; of tlw tleen•c;, anc1 the JllP<lll
fibr·e lengths, mean fibre ihickne~s. and Jll<'<Hl fihre ,,·eig]Jt, of ,;houlder :;:un pl<•-; \\'<' re r1Pt erm i nee l.
(:!) 'l'l10 shPep \1·0re fpc] in inc]i,·iclual fppding bo:;p,.;, 0:;('ppt for i.he h:~y, 1Yl1i.ch ,,·as gi,·en or! l//,.
(:!) 'l'IJp follmTing supplemPnL llf'l'P do-;ed <lail~·. e;.;<·t>p( ~ul!d:J\:i:
(trOIJll 1: Ko c;11pplenl<'lli.
Group II: c.,·stin0. Chou p ., J I Sulph:t!Ps. Urou p
n ·
= 1\'(':\ S.(hmlp
v
r) g·1n. sulph nr.(;roup Yl (). t2 g·n1. ,; ulp h ur.
(4) There
,,.,1::;
110 significant difl'<•reJH·e lwt 11·een the gToup-;, .,!J,lll·-ing th:1t tiH•re \I<J:i 110 1·e-;pon,;e to an1· of the :iuppl<'l11Plil.-;, :1,; rPg:1nl,;
the above-JJI<'nLioJied 11·ool :ilirihute,;.
1\ ('1\ !'\ 01\. L 1·: I H; .\1.10::\T.
'l'he :-~ulhor,; :uP imleL!ecl to 'Jir. "\. 1'. -:\l:!iaJJ. -:\I.S,· .. -;(;di,ti,·iau :d Onders!Ppoort, for ilte statistical :mal\·-;j,; of tiH' re,;ults.
BOTHA. :H. L. ( - ). .-\.n lmJll·o,·ecl :Hd 1Jod for tl1e lh•tel'lllin:ltioll of tlw Cll'an \\'eigl1t-; of lndi1·idii:JI \reri11o Fl<·<·•·<•s. (l{eport i11 prep:~r:ttioll.)
DUE11 Dl<:?\ . .T. K (1920). \\'oo1 ll<''<'<Hcli in So11t11 .\I' ric:~. i':tp<'l' ~o. Ci-1. /'un- :lf,·iwn .·lyl'i1·. "'"' T'l'l'. ('onf .. Dept. of Agri<·., l'n~tori:~.
Dli TO IT. 1'. J., \JA LAX . . \. 1 .. GTIOK\ 1•:\\'A LD . . J. W .. """ HOTHA.
\1. L. (HI:J:>). Stll<iios in 'II iJJ<•r;d 'llel:~holiwJ, XXXTT. 'l'li<' l•:ffC'd of l)ifl'Pl'!'llt l•'omF of SiJiplull· in tli<• l>it•t upon tli<· Grmdh :~nc1 \\'oo1 l'ro<111dion of Slie<·p. Onde!'stepuol't .fonnwl, Vol. ·1. ~o. 1, pp. 220-239. F ISF-II•:n. IC ..\. (10:1:2). Stnli,ticnl 'lrctlio<h for !l<'><'<tnli \rork .. r.-. l!ir,/o'Jicul .1/onri/Jmphs and .llouuul.;. -l.tli lmp1·•·ssion. Oli,·•·r <'\: Hm·d, 1•:din- h111'gl1.
]'lli;H('I•: . .-\. \\'. (1033). TIH• l•:ff!'c-l on
u,,.
Jkd.l··llt'i;,!;hL and \\'ool l'm<l111'1 ion of nl<'rilln Sl~<•ep of .-\dding f.>ulplllll' to Ll"· Dit•t . . Jul. l'rwnci7 of,<-:,.. nud Ind. t:n., \'ol. !i. pp. 20-1--20'-'\.HOBEWI'S, .f . . \. 1<'. (10:10). FJ,.,.,.,. c\11:d.1·sis for Jl.iologieal nnr1 ..\gricllitllr:d I'III'[JO'<'S. I. TIH' .\n•J·:q . .':l' Filll'llC'" of a S<llllplt• of \Vool. .f. 'J',•.rt. Ius/ ..
\'ol. :21, ?\o. -1. pp. '1'.127-1(j I.
Sl•:DDON, II. ll., ·'"" C'IL\'IrnEI!L.-\L\ , \\·. 1•:. (1!):):1). 011 til<' Ti:ll•·•t of lh<· .-\clntini-;tr:~lion of Sulplllll' to Slil'<'P· .111.<11·. 1'"1' . .Jul .. \'ol. 0, pp. 1:)1- 1.)0.
i:lNI~DI<:('Oil, G. \\'. (103~·). Conqwtntio11 anrl lnlt•rpr<'L<ltion of .-\ll:il\·si' of
\'nri:JIIl'e and Co-1·ariance. f,,u·u :<tote ('nl/erJ'' Oificird l'IIIJ/imlion. STBY\', D. G. ('10:31). 'l'lie ·11;ffcr-L of Sulphur on 'lrerino Sll('ep. 1/fh ]:,.,,.
}){,.. T'rt. Serv. oncb .ln. Ind. Union of 8out1J Africa, pp. 481-10:2.
STKY::\, D. G. (1!):32). The Eff,•d of S11lphm on \lo1·ino S1H•Cp. IP.fh f!, [l.
liir. I' ct. Sen:. Olld An. Ind. Union or Sou lit .-\frica, pp. 59/-(ilO.
\VILSO:'if, J. F. (1928). ,\ :\[ethor1 of Del<'rmining the Ch•an \\'eight' of lncli,·idual l<'leeccs of \\'ool. r:nic. of ('u/if. ;[rJl'it. JO:a'Jl. 8tn. llllll..tin 447.
YATES, F. (193:3). Tlw .-\n:~I.ISI' ot Jll'pltcatc·d E'peruJH'llts when lhe Field Jlcsults are Tncompletl'. Xn1p . .Jnl. R.1·1d,- Jqnc., \"ol. 1, pp. 120-1+2.
188
