Using Suffolk sheep for improving lamb production from sub-tropical Egyptian sheep:1. Reproductive performance

Abstract

SUMMARYThe present study deals with the reproductive performance of an imported Suffolk flock and the cross-bred ewes resulting from upgrading the local Ossimi sheep with the Suffolk. A total of 1738 ewe records were available for the study.No significant difference was found between Suffolk and Ossimi ewes in conception rate or proportion of multiple births. However, the Ossimi ewes (mated to Suffolk rams) weaned 25 more lambs per 100 ewes lambing than the imported ewes. The cross-bred ewes were of better reproductive performance than both pure-breds. The best Suffolk cross-bred ewes were those of 40–49 % Suffolk breeding. They weaned 21 more lambs per 100 ewes run with the rams than the local ewes. Reproductive performance of the cross-bred ewes declined with increasing Suffolk genotype above this proportion.Under the prevailing sub-tropical conditions, the Suffolk ewes have an anoestrous period of 200 days from late January to late July or August; the local ewes showed oestrous activity throughout the year, but with some irregularity.