A testösszetétel, a genotípus, a GnRH- és a hCG-kezelés hatása a nyulak ivarérésére

In rabbits the stimulation of the sexual maturity, the earlier breeding date is the same kind of economical interest than the utilization of the better nutrient digestibility occurring in the case of a restricted feeding regime. At the same time, we also have to consider that nowadays hormonal interventions are widespread in the rabbit breeding, and these methods may modify the breeding age and the occurrence of the pregnancy as a function of the genotype, stage of development and keeping circumstances of the animals. In their study the authors followed the development of the sexual maturity in rabbits of two different genotypes (New Zealand White, early sexual maturity (n=46), and Hungarian Giant, late sexual maturity (n=48)), applying two different feeding regimes (ad libitum and 30% restriction) and using two types of hormonal treatments (GnRH and hCG). Considering all these factors, they examined the development of the sexual maturity in relation to the raising intensity, the body composition and the applied hormonal treatments. They established that the 70% restricted feeding regime is not suitable to raise breeding rabbits, independently from the breed and sex. In the case of does, the decreased reproductive performance is due to the decreased fat content of the body, and in the case of bucks the background is the stress due to restricted feeding, and in consequence the considerable decrease of libido. In sexually mature does the probability of the pregnancy is higher applying hCG treatment, due to the increased inclination for mating than in the case of GnRH treatment, despite of the more expressed ovulation inducing effect of this treatment.