Abstract

Kidding and multiple kidding rates following artificial insemination (AI) either at the second oestrus after CIDR withdrawal or after vasectomised buck introduction to isolated does were compared in a factorial design. Other factors were a comparison of cervical and laparoscopic AI; Regulin melatonin implants 4 weeks before AI versus no implants; and once daily oestrus detection with AI 2-5 hours after detection versus twice daily oestrus detection with AI 9-18 hours after detection. AI was carried out from 6-14 April, 20-28 days after CIDR withdrawal or 6-14 days after buck introduction. Laparoscopic AI resulted in a high kidding rate (65%) than cervical AI (34%). Regulin implants resulted in a lower kidding rate (38%) than no implants (47%) but a higher multiple kidding rate (68% versus 50%). There was no effect of once versus twice daily oestrus detection on kidding rate. CIDR treatment led to a higher proportion of the does present being inseminated (98%) than buck introduction (88%) during the 9 day AI period, but had no effect on overall fecundity.

VJ, Moore

Proceedings of the New Zealand Society of Animal Production, Volume 49, , 137-142, 1989