Sheep Breeding For High Performance

Press, Volume CVIII, Issue 31862, 14 December 1968, Page 8

Sheep Breeding For High Performance

In the last week or so rams of the new Goopworth breed based on the Romney and Border Leicester breeds have been leaving the Brenley Stud of Dunlop Farms, Ltd, at Greenpark, for the North Island. A group of more than 60 left Greenpark at the beginning of this week and 46 a little earlier. About 150 or two thirds of the rams the stud will have for sale this season are going to the north and interest is so widespread and marked that the demand is now far in excess of the supply.

i In a country where modest | lambing percentage levels (have been the rule, the Dunlops have gone a long way in proving that high performances can be attained in this country with existing blood, but they also lay stress on ! producing a ewe that will stand up to conditions of stress and require a minimum of management throughlout the year and still outproduce any conventional f (breed. L A merciless policy of cullLing has been a vital part of i the programme to develop a I I sheep that comes up to this j standard. i There is obviously no pointl I in producing a sheep that will, ’ not stand up to pressure on I J the commercial farm where ithe aim is the maximum conicentration of sheep per acre ‘for maximum profitability, ‘(says Mr W. N. Dunlop, man--1 aging director of Dunlop I Fanns. 1 With that arm in mind, the i Dunlops had 220 ewe lambs I running this year from May > to the end of September for i about four months and a half i on three acres and a half, be- , ing fed only hay every sec,l ond day, except >vhen it was The aim here has been to pick out and eliminate those sheep that do not icome up to scratch under hard ; going as far as wool and bodyweight are concerned. These 'sheep are now about to be shorn.

Ewes are run on a similar pattern after mating and i only at the first signs of dopi■ness or sleepy sickness develj oping are they moved on to , the grass paddock where they (will remain from lambing . through to weaning. , The aim is actually to in- ' duee break in the wool to show up the superior sheep ‘from a wool point of view ' j and to enable the inferior ‘(performers to be culled out. > Just how rigorously selec--1 tion and culling has been practised can be gauged from H the fact that of 343 ewe lambs; /born in 1964 only 82 were: ij still in the flock at the six-1 /tooth mating, and at this' J point 76 per cent of the fe-1 imales that had been weaned; (had been culled.

( At the beginning of deve-1 llopment of the Coopworth flock in 1955, the Dunlops: had 650 ewes. Thirteen years ( later there are 550 ewes in) the flock.

A prime objective has been to lift the level of lambing percentage and in the early stages of the breeding programme at Brenley two-tooths were averaging about 125 to 135 per cent and the over-all percentage for the flock at docking was about 145 per cent. Over the last five years, says the stud shepherd, Mr A. G. Dunlop, the over-all docking percentage, based on ewes going to the ram, has been between 160 and 168 per cent, with the two-tooths doing fractionally better than the 150 per cent. The poorest performance was in 1967 when ewes were badly affected by ryegrass staggers at tupping time and the over-all percentage was then 160. Multiple births are understandably common in a flock with such lambing perform--1 ances. Again over the last five (years there has been an overall drop of triplets from 5 to 7f per cent of ewes, ini eluding incidentally two sets 1 of quadruplets just for good measure. Actually up to 20 per cent of older ewes have produced triplets and from 2 to 5 per cent of two-tooths have done likewise. Five ewes in their lifetime would have a performance of more than 250 per cent of lambs reared and three ewes have produced three consecutive sets of triplets at the twotooth, four-tooth and sixtooth lambings. Two fourtooths had the quadruplets.

Mr Dunlop says they cn- ; deavour to leave triplets on their own mothers and no special treatment is given to these ewes. Where a lamb has to be taken away from a ewe, he says, it loses its identity as a triplet. The aim is to have the ewe ' flock set stocked from lambing until weaning at six to • eight ewes and their lambs to the acre under irrigation, and an important aspect of management at lambing time ■ is that ewes are not helped at lambing unless the situaition is absolutely hopeless.

in which case the ewe in question and her progeny are culled. About 1 per cent of ewes have had to be assisted and over five years only two ewes have had bearing trouble.

The objective here is—as already mentioned—to produce a ewe that requires a minimum of management the whole year round yet will still outproduce any conventional breed in the country.

“We consider a lambing percentage in excess of 200 per cent at docking is not beyond our breed of sheep if a system of good breeding and feeding is maintained,” says Mr Dunlop, looking to the future.

Throughout the breeding programme, in conjunction with breeding for fertility, importance has been placed on selecting the best twins and triplets so now the flock is also producing lambs with a very good weight gain. One of the best efforts to date was in 1966 when an exceptional set of triplets at 100 days from birth weighed 941 b, 861 b and 681 b respectively.

This season the Dunlops have a set of triplets born to a two-tooth ewe on September 5 which, when slightly more than 90 days old last weekend. weighed 791 b. 641 b and

' 631 b. The mother of this [ ewe incidentally was a triplet out of a two-tooth ewe and it is likely that this ewe will be used as the basis of a ewe line and one of the three ’ ram lambs in the triplet ! group this year is likely to be used for breeding. The : Dunlops believe in concen- ! t rating on such potential as is exhibited by these sheep. The Dunlops attach importance to conformation—in ensuring their lambs have meat in the right quarters—particularly in the hind quarter —and Mr Dunlop says this i work is also showing considerable promise. ’I It is interesting to note 5 the results obtained last seaI son in what is known as their I conformation line of ewes. I Here 50 ewes and their pro- | geny were run on six acres I from birth to weaning. Three I sets of twins and their i mothers were removed beI cause the mothers were culled i for various reasons. The reI maining 47 ewes had a total j of 75 lambs—s 6 were twins ; and 19 singles. The over-all average weight of these lambs j when the oldest was 100 days i was 721 b. I The 19 singles then avert aged 78|lb and the 56 twins 1 701 b, but six of the twins ' weighed more than 801 b, 10 ■ weighed better than the average single and 25 were equal ( to the average weight of all !i of the lambs in the group. I In the course of the breed--1 ing programme ewes that ' would not draft prime single I lambs at 10 weeks were rei jected and likewise any ewe s that was not successful in | rearing good twins.’ It has ' been found that the milking ' ability of ewes can only be assessed at the two-tooth < stage and then only when i carrying twins or triplets. ' Older ewes when fed well can produce more milk in early lactation than two lambs can handle but not too much for three or four lambs. Incidentally, no single lambs have been retained for breeding. These have all been slaughtered. Initially rams were only

selected from top performing i two-tooths and had to be twins of exceptional weight gain and of good constitution and | acceptable conformation, i These were often used as ram i lambs to hasten the breeding ; programme. No shy breeders were given ; a second chance. After mat- : ing for one cycle of 17 days I Southdown rams were put out ' with the ewes and any ewe I producing a Southdown cross i lamb or turning out to be dry was culled. For a number of I years now lambing has occur- i red in the stud in the first 10 1 days but no good reason can i be given for this. i | As far as wool has been concerned they have been aim- i ing at wool of good quality | and weight with sheep being i culled for weak backs, hairy ; britches and kempy fibres. Culling for wool has been i done by Mr L. Galloway. 1 sheep and wool instructor of i the Department of Agriculture, when ewes are 18 months : old. In general, however, sheep i Shave been left to establish I | their own breed type and wool t count, with only poor pro- 1

ducers and definite off-types being culled. Sheep that are short or suspected of being light boned or showing constitutional weak nesses have also been rejected. The Dunlops are convinced a square male type of i shoulder on a ewe is a definite factor in reducing fertility.! The desirable attribute is al finer more essentially female I structure. Considerable importance! has been attached to sound-! ness in the feet. No ewe has had her feet trimmed. Any, ewe requiring this sort of treatment has been culled. ; | Any ewe considered to be! (flighty and consequently aj poor mother has also been put! out, together with her pro-i geny. A comprehensive system of! records for the flock has been ■ kept and only after a review; of these does culling proceed.! In their work, Mr Dunlop! says, they have been seeking! to combine the constitution of. the Romney with the fertility, milking ability and mothering instincts of the Border Leicester.