Reproductive Development of Hybrid Goats
The study of the purebred and hybrid animals reproductive function is a necessary stage in the creation of the new breeding forms based on the stud and local breeds. We analyzed goats of different genotype: second filial hybrid (Saanen goat х Siberian ibex, n=2); first filial hybrid (Karachai breed х Caucasian tur, n=2); second filial hybrid (Saanen goat х Siberian ibex х Karachai goat, n=3). After weaning age (3.5 months) we observed their behavior. From 6 months of age, testes morphometry was carried out; sperm was sampled. To assess the sperm concentration and activity, we used the video camera and program “Zoosperm 2.0”. The surveys were carried out in the L. K. Ernst All-Russian Research Institute of Animal Husbandry. Puberty of the hybrids of the Carachai goat and the Caucasian tur and the complex hybrids occurred at 12 months of age. Puberty of the purebred animals occurred at 6 months of age. At 6 months of age, the purebred animals had the biggest scrotum circumference (15.4 cm); the hybrids of the Caucasian tur and the Karachai goat had the less one (10.1 cm). The purebred specimens under 24 months of age exceeded the hybrids in the qualitative and quantitative parameters of sperms. The volume of the semen produced by the purebred goats at that age comprised 3 ml, which was 1.5 mL and 1.4 mL more than in both the hybrids of the Karachai goats and the Caucasian tur and the complex hybrids (Saanen goat х Siberian ibex х Karachai goat) respectively. The sperm concentration in the purebred goats aged 24 months comprised 4.01 billion per mL semen, which was 2.81 billion per mL and 2.71 billion per mL more than that in the hybrids of the Caucasian tur and the Karachai goat and the complex hybrids respectively. The goats of the Saanen breed are fast-growing animals; the reproductive system of the males aged 24 months is completely developed. In the hybrids, this process continued, because puberty occurs in the third to fourth year of life of the wild animals.