Abstract

Ewe lamb breeding can result in low and variable reproductive performance which is one of the reasons given by farmers for not breeding their ewe lambs. Ewe lamb twinning rates are known to be increased with greater ewe liveweight gain in the weeks leading up to the introduction of the ram. The hypothesis was that offering lucerne for a one-month period that ended 14 days prior to breeding would alter the pattern of breeding (i.e. cycle of conception) and pregnancy and reproductive rates of ewe lambs. Of-fering lucerne had no effect (P>0.05) on the pattern of breeding in both years of the study, respectively. Offering lucerne, however, resulted in a greater percentage of ewe lambs diagnosed with twin-fetuses compared to those offered unimproved ryegrass pastures in 2015 (35% vs. 18%, respectively). In 2016, however, there was no effect of grazing lucerne on reproductive rate. The difference between years was likely the result of lower lucerne masses offered in 2015 than in 2016.

RA, Corner-Thomas, JM Panns, PD Kemp, ST Morris, and PR Kenyon

Proceedings of the New Zealand Society of Animal Production, Volume 77, Rotorua, 55-60, 2017