Effect of rams on the onset of breeding activity in Clun Forest ewe lambs

Abstract

SUMMARY: Fifty Clun Forest ewe lambs with uniform birth dates were randomly stratified into two groups (A and B) of 25 each according to date of birth and body weight at 23 August 1971. On 26 August Group A (control) was joined with rams whilst Group B remained completely isolated from any contact with rams until 18 October.The sudden introduction of rams to ewe lambs in the transition from non-breeding to breeding activity resulted in a high degree of synchronization of first matings in Group B. However, it did not affect the mean date of onset of oestrous activity.