Studies of the coat in the New Zealand Romney Marsh N-type sheep / Code Number 148

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:JRTI-<, NZ.

STUDIE OF 11HL CO T

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NEW ZEAU. m 0 NEY f\l-T iPE .. HEEP.

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PAhT l K· P IN THE NEV lEAl D r.O!NEY N-T£PE •L.EC • .

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Il

P' E-NAT L Dt.V i.:.10 E'N'l' 0 THE N-'l ... P BI 'I'HC0¹¹T.

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BER 148.

P A ^1:\ T l

KE P IN 'IHE NE~ Z,..~ IA lD RO ~Ef N-T!PE FLEECE.

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INTRO DUCTlO N.

Kem, •s may be defined as hairy fibres which are shed after a short ?eriod of ..,.rowth. Birthcoat kemps a.re succeeded ^by fibres in the same folliole, and there ^may be varying amounts of thia second generaLion that ~re also shed.

Thus, sue ,eesions of kemp often continue throu·4hou.t the life of the sheep making the fleece uneven in a way usually tmdes- ira.ble. Previous studies ( Jry 194.-0 / have shown that selection against high abundance of halo-hairs is effective in elimin .. ting kemp. \lthough kemps a.re associated with coarse fleeces with hi jh btn1danoe of halo-hairs, they are not always present. A hairy birthcoat follicle after growing

and

^{shedding ~ kemp}

may produce fibres of persistent growth; hence this study should have- significance for breeders of ountain Sheep which

characteristically have hairy bir thcoats. It is understood that a thick, hairy biL thcoJ.t of h lo-hair·s . i th a minimum of !:erup in the :Ldult fleeot is desirable in the Scotch Black- faoe lamb ..

The various ~haracteristic fibre troes of t.he

sheep's fleeoe hJVe been studied and classified by Dry {19J3}.

According to the collection of these ty ,es present in-one sample of wool, oe:i:t'1.in characteristic arrays can be reoog- niz ed( Dry 19.341. These arrays c·m be arranged in o. se.Lies :-

those with sickle-fibres are non-nlateau wi·h fe¥ halo-h~irs

..

-- z -

and include

s

^ddle, R~vine, Val~eJ and Plain arrays; those

~

without sickle-fibres are Plateau, co ree arrays with many

large hairy halo-hairs. The former type Qf array, non-Plateau, is found on finer woolled sheep such as Vensleydales, fine

hot1'meys etc. while the latter type of array, Plateau, is fotmd on N-type Romne s and ountain breeds such as Scottish Bla.okf ce.

The time needed to deternine whether the fleeoe will be kempy is .the time required for a kemp to shed and be followed by succeeding fibres, i.e. about six months. It would be of advantage to breeders if this determination could be made soon f ter the birth of the lamb. Por earl.r recog- nition and also for a basis of selection, co1re1ation of

productive capacity with other characters has been a favourite subject with livestock breeders e.g. milking capacity. If corr·elations are re,-1 they can thus be very advantageous ..

_'ow, by ma.king use of previous knowledge of tibre types of Plateau a ray, i t has been possible to find a

correlation between the presence or absence of kemp in the adult fleece and the char cterisation

or

fibre types in the birthcoat.

In the case of non-Plateau arraJs, Dry (1~40) has derived a theory, based on a correlation, ror early reoog- n · tion in the lamb's coat of presence of ke p in the adult

fleece. Sic~lt-fibres which 1ave provt;)d to be the determin~ite

fibres in the classification of arraJs, are the det0rminate

1

and

..

•

- 7 -

ASU DANCE OF KEMP

co

^{HEl TED}

vr·rn

f<'LEECE CHA . CTERISTICS.

In spite of the large numoer of halo-hairs on the birthcoat of these .J-t.rpe sheep, they do not always show successions of kemp, and ma.r not whow any kemp at all.

The second generation fibres (G21 may be of persistent rowth ( F'irY· 13 J.

In this study,. a measure of the amount of 2 kemo

-

is ,iv~n in terms of the number of halo-hairs that are succeeded

uy

kemps, ;.:md is calculated as the nu be of G2

kemp~ er 100 h lo·hairs in a sampl~ of wool. In some cases, follicles of lai~e birthcoat fibr~s other than hal - hairs may also produce e~oondary kemp, the number exceeding 100. In othex c~ses, a few halo-hair follicles as 1ell as

those of other birthcoat fib es, ~ive rise to ~2 fibres of p·er.;si.stent :.ro th, and then there is little kemp, the numbc bein:7 less than

loo.

Even hen only three- u rters of the halo-hai s are followed by secondary kemp, t.,i s amount is still regarded as undesi· able. An a_ bi tra.1: figure

between 7!.rllO kemps per 100 halo-hairs, is fixed as an intermediate amount of e111p.

Of the 81 sheep available ith 12 kemp in the

JS"

fle~ce on the back, tnere were "4 with bundant kcnp i.e • . ith

~/?;,

more t1an 110 "'2 ke .. ^11:::: per 100 halo-nairs, ~with nedium

i

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In this table the nunber of animals having varying amounts of kemp are classified and tabulated into two g oups,

th se with a distinct precipice and those with ¹ gradual reduction in hairiness and four doubtful c ses.

Distinct . .L'ecipice

Doubtful precipice No pr cipice

T\BLE 11

A bun a mt kemp

1 ..

7

Medium kemp

8

Little kemp

1 14

'lh~ fi1ure~ in the table refer to the nu ber of animals in each g oup.

There is found to be a te1dency for the occurrence of abundant kemp when a de ini te preci ice is recorded and

simil rly ·in cases of little k p, the majority sho a l'r dual reduction in hairiness along the array series.

GE 'f.. L FEA¹TURES IN THE

ne of tha chief f ctors causin5 per islence of

fibr s, is the pre-not 1 check (Dry 1933), a restricting 'orce cting b fore, thio check howinq many effectJ on the

-.

-

fibres of the ^.1. le~c • It may d termine fib1· ch acterioa ion, and a:oti as a settmck, m y d pen 1 ts vi ou.r, thus

11 .... a.mples were t ie.refore arranged in ot·der of

stren₀ th _,f the pre-natal check as far as this could be jud ·ed on pres nee of checked birthc at f'ibres. Thos·e arrays with

1

1

ter~

. istios on to the kemp situatiQn •

4

9 7

- 16

-

b No. Av. length in ems. of halo-hairs Grade of

Kemp Abt.mdance

P1·e-natal Post-natal Total

141 3.0 5.2

a. 2

1·edium

144 3.6 4.6 8.2 Medi urn

158

.3.::::

^5.8 9.0 ^}, di um

162 3.6 ^.!;.7 7.3 cdium

169 3.6 5. 2 8.8 b da.nt

177 4.3 4.9 9.2 bunda.nL

180 .J. 7 5.0

a.-1

i edirnn

182 3.8 3.9 7.7 _{Abund nt}

18¹1 3.8 4.5 8.3 Little

139 4. 2 4.8 9.0 edium

l 3 ^{3.8 5.8 9.6 bundant}

>

197 3.2 4.9 8. 1 Abundant

198 ~.7 4.9 8.6 Little

264 2.9 4.. 8 7.7 Abund t

209 3. 6 4.4

a.o

^~edi

231 3.2 4.2 7.4 edium

267 3.8 5.1 8 .. 9 .bund t

The f i u es a ... e a.pp.r:oxi. 1a te as the re..,.ion o t.he l1 ·.ir at

..

the t ii e of birth or the li:i ... 'Tlb cannot l.vays be accurately

judged.

It, wus SU~,, stcd by Dry ( 1~40 in his e rly rk

in each group.

10 1§

3 2

2

ble ref er to the numbers of 2

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details.

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267 22 31 19 ^67.0

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DISC S:sION

Many ch· 1·acteristics of tr,e fibre t.1pes su.,.gest that s dding can be r~garded as a vigorous activity of the

follic~e and persistent growth of fibres is the result o~

a check to this vigour. Halo-hairs, .vhjch are the fibres with the largest pre-natal re.;sion, are thJ most freely shed, then the other types in order of tou~h.~ess. ool fibres which are slover rowing, rarely shed.

On many ?Jii als, the post-nat 1 l~n0^th of most of the hairy-tip-curly tip fibres that shed, is longer than the post-nutal len::rth of the halo-hai s. It would ~eem that less vi_,our has enabled them _to persist lon er. fl~on-genetic

I

f ctors, such as bad environmental conditions which affect and reduce general activity, rJ y also reduce the vigour of

the follicles. oor ff.eding of pregnant eves has been assoclat-

ed

by I.eslie (1935J .vith a reduction in the abundance of halo-hal s in the birthcoat of their lambs.

In some c ses, reduc d vi~our mar cause actual thinning f the hair and JVool fibttes are produced. It vill b(. shown later in a pre-natal st ey, th·1t th vi orous fibres which usually ... t1~d, have .fol licles deep in the skin and are much la er than Nool-producin"" follicles.

we

( 1940}

.,

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sufficient vigour to shed e;J.rlier and hence not su fficient

sma2.1 ana tend to the hair.1-tip uily-tip st;le .. The h~.Jo­

.hal .s of li:rob No. 3..J a.re unusus..llJ s.nell OOL ore b.'-rth and

coJld al!i1cst L>e classified as s J' e ... -sicklc tne ~6 All tbese ex:c c; ionc the "'efore :ihow .Ji 1!1S of r·educed vi:Y0¹JI' a!'ld i t 1s

1'lt. surp iL ing t ' J.t tr.c e is 11 t t..le J2 .kemp.

Inmb ¹0. 6,; hoved .very few hairy-tio-·:mrly-tip fibres ^3.! d e ren thou h u~e IIlfijori ty of these are s ied there is still littlE. Kemp. r .is is cl::Lsified as a llr lateau J.rray Ji th many super..:. :Ji ck.le fib c;s and tnes,. are nhcd freelJ'.

T ert. is · ralual reducti n in hair·ine.;.s down Lhc rrey series which st }i tle latter h.emp,. ..:.:.nd no r d'JCti n in h'il)-

h ii· .... uu.11d< .ce on th';.; , i tbe::..s ₁ which su·:cests aoundant later ke· p.. She dinr~ of the ha.ir·y-iip-01 ^.L l.r-tip fi Dr es lo: L'rcer·

t.ho.n ls e ec.t~u in u.n r'ray nith little 12 k .p~

These exceptions again show that the amount of 2 l<emp although 10.1.-rcLr influenceo by the jre-nat'll :;heck, must he dete mined ^i)y .an,f dif ft;l'e" t .:'ere es. It ls concluded that the n.mount of pre-natal check a.2 jud~t:d DJ the numbers

or

hai ry-tip·-cu l.r-tfp fi !)res in a sample maJ !'O ql:ly indicate the ar ou.nt of later .:·c. expect,ed but for n. more aoc r· te Jete.L',.iinut..:.on Of ~emp, the shedt ing Of these hairy~ti.p-cnrl - tip fibres mu!3t be taKen into account .ls in the inal

~eneralisation.

i

l

le

s

II

f er fleece

...

- 51 -

f

1k

of I\ central trio follicles are well thro"gh th skin. Lateral trio fibres lso have .mer~ed (Fi,..,.. 21: . Many seconda-ry fol lie las h'lVe been added "l.nd more art.. being separated ^t ro¹¹

p~im0¢{ial .f"1bto.g,el'\e-t'te.

masses of d rkly sta "rti!"'g ~, Fi·ri •&tic tissue, the mode of

their for aticn being similar to trat descrioed by Duerden (19 2}

Bands of connective tissue mark

orr

^{the follicle}

bundle ... ve y distincly it 11.3 days <'i ;. 22 • lhese ot ands are .Jr'c m· rked etween the r ws

or

bundJ ea th n bet een

· dj

ac nt undlen wt1ile the 1 t t er retain their line' r a.rran~e-

1e t. The first formed secondary fi;res hav grown rapidly and in many cases r. ne r the urf oe of the s· in. The r t size o the 1 rge prima y fibres seen in cross-v a ion is in ^v

otriking cont..rust to tl1e sr all fibres, aince a.t this stage Carter ( 19431 i lluotrates prima

:r

fi bres to be Vt::ry litt le

different in di. .. t::nsions from the secondary fibres. The

re t irrei~ulari ty. in ci ze of fibres, so well illustrated in the different fib e Lypes of the ¹ -type bi thcoat, is ma_ked even at this eu .• :ly stage. lso the si e of seb ceous lands is s all r than C tc;r indicates (Cart r 19 .:;).

AL 11 a.rs \Fi • 2.31 the s. in cont ins bundli.:::s of ti ht-ly o .eked fol i<:l'e~·

~e accessoT\j sfYu.d'uwes

r•im. ry trio f'ollic les h Vr., 1-·'.) vn

~

lar e r.::.. res," s d')I'lfe1ou~ ~l!lnd., ~rrector pili mu cle and

a.:te we..l k.rclopeic(

sebaceous gl '1<.;., ,., , ;:,E;·~ond:n·'J i.'ollicles a e r~oidl;r differ-

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entiating f o s condary prir1oruial tissue. T1 e fibres of the fir•st fonued sec~ndary ollicles vith seb ceous glands

r

•

v.i.. -

follL .. lcs p o uce h.~lo-h . .:.ii.s, :fi JLes of the sickle ;roup hair3- tip-cu lJ-tip fib.L.cG and PeJ.·haps ome curly-tip fibres; secondaiy follicles p1oduc~ t.e re ining cu ly-tip fibres

·hi ch rn lke up the ^bul_k

or

the ^{oirthq ·} t .

t

· LITE. TU .. E CI'fEl).

\GARTER, • B.

DRY 1 I .

D i, 'o '•, .c l 0 , P. R.

& ·

u m rr

¹

n, .r. .•

DUE D N, J;. E.

DUE DEN, J. • &

RITC I .E;, ~. I.

FORD, E· B., D HUXLEY, J.

s.

•

1939 A Histolo1ical Technique for Estim- ation of Follicle :'opul1.tion per

Unit fl.re of Skin in the-Sheep.

J. Coun .... c. !nd. ·.es. u"'+ ~,

12 (3 : 250-258. ^•

194;3 Studies in the Biolo~ of the Skin and ,leece of >heep.

Coun.

so .

Ind. Res. ull., 164.

1933 Hai y Fibres of the· omney heep.

Halo-hairs and th ir ^Inhe·~tt. nee. N.

z .

J. ^A~ric., 46: 10-22,

1933 The Pre- t Cheak in t e Birth- co t of the .. erv Zea.land rnney Lamb.

J; ·.rext. Instit., 24 (4J : T16l-.1lG6.

1934 Hai y Fibres of the _ omn , Sheep.

Fibre Type Arrays and H rines • N.

z.

^{J. A,;~ric., 48 :} a3l-..:; , • 1940 Recent ~ork ·Jn the ¹001 olo ·1

the New Ze 11 .d .oimey •.

N. ~. J. ci. & 'I\.oh., 2-Z

t4. )

209 'i-2~0 •

19"0 A . e ldelia.n 'i tuation in the Birth- coat of the New Zeal nd omney

Lamb.

Natu e, 145 : 3

o.

1939 The Arran,ement of ibre ollicles in some aramals Nith Special

Reference to Ovid e.

1924

T?ans. or• Soc. Edin)., 59; 763-7?0.

The .!Jevelopmcnt of the J. e ino Fibre.

s. _

"r. J. Sc., 21 : 480-497.

/Ool

1927 enes and Rates of Develop- ment in ' aruu Cheurcff'i.

Brit. J. • E>ep. 3iol. o (2 ; 112-134.

WIN, N NCY,M.o

.:r 1 BBS, H. •

19b5 he Pre-Natrl Develonm nt of the

Coat of the ^1·1ew Zea.land omney Lamb.

J. \ ~i. ic. Sc. 25 ; 344-36.0.

HM6 Biolo ical ·md StaListica.l Studies of the ew Zealand .nornney lamb with \eference to t.eL t.iv i..J'rowth Gr dient&·

D.Sc. hesis., Edinb. Univ.

l 36 Relationship between Post- at 1 Coat Characters and Pre- ~atal 011 ·.c1e Densitr as Affected ^)J Increase in l"oet~11 ;;; · ze.

aturc, 1~8 : 585-586.

1936 Britoh-PolJ ibre-Tyoe Array Gradient in th ew Zealand ^l o.nne 1ai b.

&n~. J. Exp. ric. ~ ( J4J : 116-128 • 1938 D velon~ent of 1. in nd H·ir

or

^the

ustralian Opossun.

Proc. Zool. Soc. Lond. B 108 (pt. 3 •

.z~J D.::i If·T, 1938 Physiolo";ic· 1 .f netics.

Mc 11·~w-Hill, e · York : 51-77.

de 'EIJE .E, J.

c.

H. 1894 Vb Haa e der

s

^{~ tiere besonders}

uber ihre Anordnun~·

TE ENTJEV , A• A.

ILD . T. .. B.

HL!X ^~, .• J. &

CA 'It:.R, H. B.

CARTER, H.B. &

BELSCHN~R, H.G.

:Or,h. Jb., 21 : 312-424.

1939 Pr·e- at 1 Develop1, ent of the Coat of sone ~ine- Voolled Sheep.

C ... ~. ( .. ok:ad.r Acad. Sci. Uo • • r._.

25 : ...,57-560.

19:62 Coat and Fibre Develoome!lt in some British Sheep.

Proc. Zool. Soc. lnnd., 102 ( '·t. :~ J: 259-285.

19 ~ Pib e-?ollicle Terminol07.f in the

·LB.Ui a.l i a..

Nature 144 : 7'33-734.

1936 Fleece characteristics of Stud Merino Sheep, in relation to the degree of wrinkleness of the skin of the breech.