Dependence of reproductive qualities of sows on the duration of the sucking period, the option of combination of breeds at different seasons

Abstract

The dependence of reproductive qualities of F1 sows of Irish origin in direct and reciprocal crossing of Great White and Landrace breeds on the duration of the lactation period during the four seasons in the Steppe of Ukraine was studied. It was found that in the winter season there were no differences between groups of pigs of different combinations and weaning dates for the total number of piglets, fertility, sex of piglets and the weight of their nest at birth. At the same time, with both combinations, sows with a reduced suckling period had a higher fertility by 0,02 kg (p <0,01), better by 1,45%…2,54% (p <0,01) survival of piglets and as a consequence greater by 0,17… 0,29 heads their number at weaning, but lower growth intensity - and as a consequence less by 25,58…27,48 kg nest weight and 2,11… 2,26 kg weight of one head at weaning, In the spring, sows of both combinations had better by 0.28… .0.56 heads potential and by 0.47…0.69 heads actual fertility, by 0,04 - 0,05 kg high fertility, more gave birth to boars, had more by 0,51…0,68 head (p <0,001) number of piglets at weaning at the best on their safety, but had a lower 1,65…1,69 kg (p <0,001) weight of one piglet and 17,25…20,72 kg weight of the nest of piglets at weaning. According to the intensity of growth of piglets before weaning, there was a tendency to increase it in the nests of queens with a shortened suckling period. In the summer, no significant differences were found between the sows of the experimental groups in terms of the total number of piglets at birth and fertility. However, animals with the traditional duration of the suckling period of both breed combinations prevailed in high fertility by 0,04 - 0,05 kg (p <0,001), nest weight at birth by 0,37…0,47 kg, weight of one piglet per weaning time, and by 1,83… 1,93, the weight of the nest of piglets at this time 19,18…19,72 kg, the average daily, relative and absolute increments - there was a worse 2,84 and 3,28% preservation and 0,47…0,59 number of piglets at the time of weaning. In autumn, animals with a shortened suckling period predominated by nest weight of piglets at birth by 1,81 and 2,21 kg (p <0,001), their safety by 2,11…3,01% (p <0,01) of their counterparts with the traditional duration of the suckling period, while the latter had an advantage of 0,08 kg in high fertility, 0,26… 0,39 heads in the number of piglets at weaning, 2,57…2,58 kg (p <0,01) by individual weight, and by 29,38…32,95 kg of nest weight at the time of weaning (p <0,001), as well as 2,49…2,50 kg (p <0,001) in absolute terms, by 36,94… 37 , 86 g on average daily (p <0,01) and by 18,21… 18,51% in relative increments. Analyzing the changes in reproductive quality of sows of both genotypes, it was found that their fertility depended more on the season with a reduced weaning period than in the traditional, while the number of piglets at weaning had significant seasonal fluctuations in both traditional and reduced suckling duration in pigs. The season had a significant effect on the survival of piglets in all experimental groups of animals, regardless of genotype or duration of the suckling period. At the same time, the average daily gain of piglets was moderately dependent on the season, with both combinations of the mother breed and the length of the suckling period. The index of comprehensive assessment of reproductive qualities of sows significantly depended on the season for different lengths of the suckling period and was less dependent on breed combinations of sows.