Détermination de l'état physiologique des femelles par analyse des niveaux de progestérone

Abstract

The physiological status (anovulatory anoestrus, ovulatory cycles, pregnancy) of females of the main species of farm animals can easily be defined by analysis of progesterone in blood (or milk) samples. Simple rules are given to determine the number of samples which are necessary and the interval between 2 consecutive samples according to the information available on the management of the female or the group of females (herd, flock). Theses rules have to be adjusted to each species (bovine, caprine, equine, ovine, ...). The limits of this methodology are also mentioned. The methodology described is useful to ameliorate the management of the herds or flocks. However, it cannot be a substitute to the detection of oestrus which is the main tool of a breeder. The method has been and is still a relevant implement for field research (in the past, adaptation of hormonal treatments for the control of oestrus and ovulation to the physiological status of females ; today and in the future, development of new and alternative methods to these hormonal treatments). The development of «on farm kits for progesterone assay» offers new possibilities for these field experiments or the management of reproduction of farm animal females.