Effect of age at first joining on lifetime production by Border Leicester × Merino ewes

Abstract

Three hundred and fifty Border Leicester X Merino ewes, born March-April 1961, were drafted to two flocks, A and B. Flock A only was joined with rams on February 14, 1962. Subsequently both flocks were joined in November or December each year from 1962 to 1965. The flocks were depastured together on all occasions except for joining and lambing of flock A in 1962. There were negligible differences, between the flocks, in ewe deaths, wool cut, lambs born and reared, lamb birth weight and lamb carcase weight for the mean for the four years or in each of the years 1963 to 1966. Meat production in flock A was increased by 12 kg per ewe as a result of the extra lambing. On the other hand, 3 per cent of the ewes of flock A died in 1962 but no deaths occurred in flock B. Joining when 10-11 months old in early autumn did not disrupt the practice of joining when 20-21 months old in early summer, and, in the experiment, was the most profitable procedure.