Residual effects of short term grazing of red clover pastures on the reproductive performance of ewes

Abstract

Two experiments were conducted to test for the residual effects of grazing of red clover pasture on the subsequent reproductive performance of ewes. Two tooth (18 month) ewes, grazed on either control (ryegrass-white clover), or red clover (Grasslands Pawera) pasture for 13 weeks as weaned lambs, had similar mating and lambing performances. Mixed age ewes grazed for 12 weeks on a red clover sward from weaning in December until 1 month before joining in the next season. These ewes had higher live weights (58.0 v. 54.7 kg, P < 0.01), more returns to service (35 v. 14%, P < 0.05), and had a higher percentage of barren individuals (18 v. 5% P < 0.001) than sheep in the control group.

Keywords:

• ewes
• formononetin
• ovulation rate
• mating performance
• lambing performance
• red clover