Factors affecting reproduction in Merino ewes.

In this article the influence of the mating season, nutrition and age of the ewe upon the fertility of Merino ewes was analysed. The reproductive rate of the flock depends upon the percentage of ewes that lamb, the number of lambs born as a percentage of ewes lambing, percentage of lambs that die at birth or shortly after birth, and percentage of lambs that die before weaning. These factors together determine the number of lambs reared till weaning as a percentage of the ewes mated, a figure which must be looked upon as representing the efficiency of reproduction of the flock.