Three stages to tackle lack of oestrus signs
Three stages to tackle lack of oestrus signs
COWS showing no signs of heat can be treated with a three-stage synchronisation treatment and inseminated without any oestrus detection with similar results to prostaglandin injection and service to detected heat.
Jean-Paul Mialot, of the Alfort Vet School, France, presented results of trials comparing two treatment protocols at the French conference.
The three-stage treatment involved using an injection of buserelin, a synthetic form of luteinising and follice stimulating hormone, followed by a prostaglandin injection on day seven of treatment and buserelin again on day nine with insemination on day 10.
For the prostaglandin-treated group, where heat was not observed after a single prostaglandin injection a second injection of prostaglandin was given after 13 days followed by timed AI.
Not in oestrus
The three-stage treatment did not result in 100% of cows ovulating on day 10 of treatment. In fact, 20% were not in oestrus on day 10, and 11-15% were observed in oestrus at other times, according to Prof Mialot.
Results using this protocol without heat detection were similar to treating cows with prostaglandin which requires heat detection.
However, of the cows served successfully, half showed no sign of heat when they were observed, so cows on this three-stage protocol should be served on day 10 whether bulling or not, said Prof Mialot.
Success rates for three stage treatment may, however, be improved by serving cows that are seen bulling before or after timed insemination on day 10.