Management Of Ewe Flock At Mating

Press, Volume C, Issue 29436, 11 February 1961, Page 8

Management Of Ewe Flock At Mating

Management of the ewe flock just before and during mating governs the maximum lambing percentage of the flock, says the Department of Agriculture. All subsequent management, merely aims at harvesting, as lambs, the greatest proporation of the eggs shed by the ewes in response to their pre-mating treatment. Fly-crutch the ewes and three weeks before they join the rams flush them for six weeks on the best feed available. Experiments show that this flushing increases the number of lambs marked by 20 per cent Recent research at Ruakura Animal Research Station shows that two-tooth ewes require special treatment at mating. Shearing just before joining increases the number of ewes lambing by up to 17 per cent. Separate Mob Again ewes of this age do not remain on heat as long as mature sheep and they do not accept service from the ram as readily. Unless adequate precautions are therefore taken, many fail to get in lamb simply because they are not mated. To overcome this problem, mate two-tooth ew r es separately from the main mob. preferably in small , paddocks of easy contour, and mob them up once or twice daily during tupping.

Ram harness and crayons are now available for marking ewes as they are tupped. If these are used during the first two to three weeks of the mating period, most of those early ewes, which will lamb before the main bulk of the lambs come with a rush, could be picked out.

If they are used again towards the end of tupping, ewes lambing after the main

rush and those which are likely to be dry can be identified. With mating records such as these the ewe flock can be divided up accurately for differential feeding during winter and consequently more ewes can be carried with safety. In New Zealand the breeding season of Romney ewes normally begins in late February and ends in July. From quite a number of investigations it is evident that as the breeding season advances the average number of eggs shed by the ewe at successive heats rises to a maximum and then declines.

For this reason delaying the time of joining until about the beginning of May could increase lambing percentages considerably. However, to fatten lambs successfully on grass they should be bom, ideally, four to six weeks before the onset of spring growth. Time of mating therefore must be related to the seasonal pattern of pasture growth in each particular district.