Later Lambing Under Study At Winchmore

Press, Volume C, Issue 29536, 10 June 1961, Page 6

Later Lambing Under Study At Winchmore

MUCH later than normal lambing on irrigated pastures is being studied at the Department of Agriculture’s irrigation research station at Wmchmore Commenting on the results of t'.e work in the past season t'te superintendent of the station. Mr W R Lobb, said it seemed that late lambing in itself did not prevent lambs doing well and provided that there was adequate feed it seemed that it would be possible to draft all lambs before winter. In the past season six and a half ewes and their lambs were run to the acre on a 32-acre block on the station's automatic irrigation unit The Romney ewes were mated with Southdown rams in June and the middle of the lambing fell about midNovember which is about two months later than normal. Drafting began on January 10 and subsequent drafts were taken on February 7, February 28. March 17 and April 10. By April 10 a total of 192 had been drafted at average weights of between 31 and 32!b and only four of these were graded as seconds There were then about 12 lambs left. At equivalent ages it was found that growth rates for the

later born lambs were as good, if not better, than for other lambs on the unit. Comparing results on the late lambing block with the rest of the automatic unit also stocked at 64 ewes to the acre. Mr Lobb said that there were 124 lambs per 100 ewes mated on the mam unit and 105 on the late unit Dry ewe numbers were about the same on each and ewe and lamb deaths per 100 were the same. Lambs sold to date per 100 ewes mated were 108 for the main unit and 100 for the late unit and average weights were 314 and 315 respectively. There were 4.4 seconds per 100 ewes on the main unit and 35 on the late unit and rejects were 1.8 and 2. The average age at which the lambs were drafted was about 19 weeks for the early lambs and about 15 weeks for the late lambs. Thirty-two per cent, of the early lambs were drafted off their mothers <weanmg age about 13 weeks> and these weighed 30 4 lb. whereas among the late lambs 51 per cent, were taken off the mothers at an average of 30.1 lb. The weaning age tn this case was 13j weeks “These figures indicate that for the past season late born lambs on irrigated pasture

stocked at the rates mentioned did at least as well as those born early," said Mr Lobb. This winter nine ewes are being wintered to the acre with the objective of seeing whether the technique will also work out at higher stocking rates On this occasion the rams have been put out about two weeks earlier. The slightly earlier mating has some advantages. It means that the last lambs may be drafted slightly earlier and also that joining takes place a little earlier before the onset of real winter and while ewes can more easily be on a rising plane of nutrition. The ewes can then be put on to ration grazing for the winter. The later lambing means that feed shortages sometime* experienced for August and September lambings are of little concern and for ewes before lambing and tor ewes and lambs there should be a plentiful supply of feed In •he past season the trial area was irrigated at a high level of efficiency for grass production so that there was no chance of any feed shortage in December and January when on dry land farms teed is often tapering off or at a low ebb A feature of the technique

is that no provision is made for hay and last season with { a favourable winter no < trouble was experienced in j this respect. A rather interesting aspect of the trial w-.s. ~ however, that the lambing percentage was only about 105 or 15 per cent, below the average for the unit. It is not known if this low percentage will be a regular feature of lambing Romney ewes at this late date. In the past season on the station ewes lambed in October did not have any better percentages and they should have been considerably higher.