Technical and economical consequences of modifying reproduction in goat herds

Abstract

At European latitudes, goat reproduction is characterized by a strong seasonal influence. In order to meet the needs of the dairy industry, breeders are forced to advance the kidding period by using oestrus hormonal synchronization programmes.

The aim of the present article is to analyse the technical and economic consequences induced by modifying the reproduction season of caprines over a long period of time (from 1989 to 1992).

The average annual milk production per goat does not improve with the change of reproduction season, whereas both the average proteic rate and the proportion of milk produced in winter increased (up to 20 % for births in November). Units resorting to out of season reproduction do not get better results than those which maintained later births, owing to disturbances due to hormonal synchronization programmes. Their progression over 4 years tends to be inferior as well.

Out of season reproduction hinders the regrouping of births. The kidding period increased by 40 days (+ 41 %) between 1989 and 1992, reaching 4.5 months. Consequently, the age of young females became heterogenous, resulting in difficulties in breeding management and reproduction.

However, the units where out of season reproduction and breeding of the youngsters are well managed, tend to be more efficient. The quality of the breeding of young females therefore gives a good indication of the technical level of the breeding.