Sex regulation in pigs by different-age selection of pairs

The efficiency of animal husbandry is closely related to the reproductive capacity of animals. At present, methods of diagnostics and functional state and stimulation of the reproductive system are successfully used in practice. The article presents research materials on the influence of parental age on the sex ratio in the offspring of pigs. It is more profitable to get boars on commercial pig farms, as they grow better. In the formation of sex in the individual development of the animal such factors that depend on the organism as a whole and affect the organism in the process of its development are important. The sex ratio of the offspring of mammals and birds depends on many factors, including the nature of the metabolism of the parents, the intensity of which changes with the age. The work was performed on Large White pigs. It has been experimentally established that in the offspring of young sows and old boars twice as many gilts are born, and in the offspring of old sows and young boars, on the contrary, twice as many boars are born. For other age combinations, the distribution of gilts and boars in the offspring is approximately 1:1. The indicators of productivity and reproductive functions were slightly lower in sows of the second experimental group (age 2 years old) compared to sows of other groups. The lowest productivity indicators were in two-year-old sows: multiple pregnancy - 9.3 heads; milk yield - 47.2 kg, nest weight at weaning at 35 days - 86.1 kg. The longest period from the weaning of piglets to the start of the hunt had young sows (second group) - 8.3 days.