The study of features in sperm and spermatogenesis from males of the genus Ovis with different genotypes

Relevance. Interspecific hybridization of domestic animals with wild related species is considered as one of the promising directions in animal husbandry in the framework of increasing the genetic biodiversity of the gene pool of agricultural animals. The article presents the results of studies of the reproductive characteristics in animals of the genus Ovis with different genotypes.Methods. The objects of research were purebred sheep of the Romanov breed, mouflon and interspecific hybrids from sheep of the Romanov breed with mouflon. The qualitative and quantitative indicators of the sperm at the age of 9, 12 and 18 months were studied. An assessment of the morphometric parameters of spermatozoa from interspecific hybrids is given in comparison with the original parental species. The testes histological studies of purebred and hybrid animals at the age of 12 months were carried out.Results. Differences in several indicators of sperm production and spermatogenesis in purebred and hybrid animals depending on the genotype were revealed. A decrease in the volume of ejaculate and concentration of spermatozoa in hybrid animals relative to purebred males at the age of 12 and 18 months was established in 3.5, 2.6 times and in 1.6, 2.1 times, respectively (р < 0,01). An increase in the proportion of spermatozoa with abnormal morphology in hybrid animals relative to purebred males in 2.9–3.3 times was revealed (р < 0,01). The obtained data are confirmed by histological studies. There is a decrease in the area and volume of seminiferous tubules in hybrid animals by 9.7% and 37.1%, respectively, compared with similar indicators of purebred males of the Romanov breed (р < 0,01). It was shown that in purebred animals in the lumen of the seminiferous tubule have many mature germ cells — sperm, while in hybrid males the presence of single germ cells was established, which indicates a later puberty of hybrid animals compared to the original maternal form — sheep of the Romanov breed. 