Ashley Dene Lambing Performance

Press, Volume CIII, Issue 30592, 7 November 1964, Page 8

Ashley Dene Lambing Performance

By the end of last month 1033 lambs had been drafted from 1180 Border Leicester Corriedale cross ewes on Lincoln College’s Ashley Dene property. I’hese ewes had been mated with Dorset Down rams.

Apart from 168 which were taken out for experimental purposes on the research unit and which it was estimated would have killed out at 261 b, all of the other drafts killed out at 301 b or better. Two hundred and ninety . two lambs were drafted on October 12 at 30.81 b with five grading as seconds, 450 on October 27 at ah average of 30.11 b with 45 seconds, and 123 on October 28 at 301 b. Not many of these lambs were more than 10 weeks of age and many not much more than eight weeks. Professor I. E. Coop, professor of animal science, told farmers visiting the college this week, that on the research farm, which had been overstocked this season, 330 first cross Border Leicester Romney ewes had been mated with Southdown rams. From this flock 175 lambs had been drafted on October 22 at an average of 27.31 b and 200 on Monday at 251 b, so that from 330 ewes already 375 lambs were away at an average of 261 b.

Professor Coop recalled that when he was first associated with Ashley Dene in 1949 lambs were first drafted in the first week of December and not as many were got away prime off the mothers as today. They had killed out at about 321 b. A revolution had occurred since in that they had gone from drafting in early December to taking drafts in October.

Looking at the reasons for the change, he said that one was the price schedule and the current preference for light lambs. They had changed from NovemberDecember shearing to prelamb shearing, which might have had some effect. They were now tailing at birth so that ewes and lambs were not disturbed from birth to drafting and they were also dosing lambs with selenium at birth. When he had first come to Ashley Dene, ewes and lambs had been rotationally grazed, but work at Ruakura had showed that set stocking was

a factor in growth rate so they had started set stocking and this, he was sure, was a factor in the improved lamb performance these days. Pastures were still of the ryegrass-white and subterranean clover type, but to obtain performances at current levels standards of management and of pastures had to be reasonably high. On Ashley Dene they were now using first cross Border Corriedale ewes and Dorset Down rams. Compared with the straight Corriedale ewes it had been shown that the crossbreds gave a 20 per cent higher lambing and the lambs had a 51b to 61b greater liveweight or a 21b greater carcase weight. They were bigger sheep and required more feed, but this was another of the reasons for the good early drafts. As a result of experimental work done 10 years ago, Professor Coop said that it had been shown that the Southdown, although a very early maturing breed of good conformation, was too slow growing. It had also been demonstrated that the lamb by the Dorset Down was not greatly inferior in conformation but was 41b heavier on a liveweight basis and 21b heavier in terms of carcase weight. And practically as many lambs could be drafted off the mothers.

Compact Lambing Part of the successful lamb performance in the current season had been due to the ewes lambing close together. Normally the breeding season of sheep in this district began during the first few days of March, with sheep coming in season in dribs and drabs and not in great numbers until about March 15 to 20. Seventeen days before this they had a silent heat—this was from about the middle of February until the end of that month. Where rams were put out with the ewes about March 10, Professor Coop said that quite a number of the ewes might not have had their silent heat and that there was quite a big spread of the dates on which the ewes came into Iseason.

There was a technique by which this pattern could be altered without too much trouble. The method involved keeping the rams well away from the ewes in January and February and then putting the rams with the ewes just before they were likely to start coming into the silent heat period. The appearance and the smell of Die rams then brought the ewes into heat all about the same time. On Ashley Dene the rams had been put in with 900 ewes on February 10 and in about two days the ewes were coming into silent heat. They had been moved out again on February 19. Only four ewes were put in lamb at this stage. The rams had been returned to the ewes again to catch the ewes in the second proper heat period—these periods followed at intervals of 17 days. The effect was to concentrate the lambing into about one week and also to put forward the mean lambing date of these ewes by about two weeks. At lambing up to 110 lambs had lambed in a day. The lambing went on for a week, then there was a gap of 17 days and another week of lambing when the operation was virtually finished 28 days after it had started. Professor Coop said advantages of the procedure were that the time of lambing could be predicted and the lambing could be advanced—this could be an advantage in some seasons and a disadvantage in others. Professor Coop said that by joining the ewes and rams

again in the first real heat period it might have been possible to draft lambs in the last week of September. Disadvantages of the procedure were that a concentrated lambing was susceptible to weather, and in the event of having to move large mobs to shelter there could be a mismothering problem. Ewes and lambs also had to be shedded off twice a day instead of once. . Dr. J. D. Stewart, acting head of the farm management department at Lincoln College who now supervises Ashley Dene, said that 2520 ewes had gone to the ram in the present season, which was 150 more than last year, and there were 600 hoggets giving an over-all carrying capacity of 3.7 ewe equivalents to the acre. Under the kind of management that had emerged on the property he said that a carrying capacity of four ewes to the acre was not beyond possibility on light land. Noting that 472 acres of the 878 acre property was now in lucerne, he said he was convinced that any further progress at Ashley Dene would be related to the pace at which the lucerne area was expanded. He was not at present concerned at where they should stop in growing lucerne. He said that they had to think in terms of sowing 70 or 80 acres of new lucerne a year.