Control of reproduction in cattle : score in 1988

Abstract

Fecundity has important technical and economical consequences. For a better control of fecundity, there now exists efficient techniques for controlling sexual cycles. Progestagen treatment complemented on occasion by a prostaglandin analogue and/or a PMSG injection, and followed by only one AI allows breeders to choose precisely the conception dates without detection of œstrus. Using such a technique, fertility results are comparable or higher to those of herds without treatment (50 to 60 % according to the type of animal, the breed and environmental factors). Social improvements, good genetic level and real technical and economical results can be obtained when these techniques are used every year in the same herd. Thus, although the variability of these results does not suggest any possible simplification of such treatment, the control of reproduction is possible without œstrus detection, using one timed AI and resulting in a high calving rate.