Piotrovych N. Formation of sows reproductive characteristics of and their combinational ability assessment

In the dissertation the efficiency of using sows according to reproductive qualities depending on the number of farrowing, the duration of fertility and the unproductive period, as well as multiplicity is substantiated. It has been established that the best reproductive qualities are characteristic for first-generation sows (F1), the optimal fertility duration is 114 ... 116 days, the unproductive period is 6 ... 10 days. Higher reproductive qualities of sows in the studied herds were obtained at multiplicity of 12 to 14 piglets and 15 piglets or more. The influence of the sows' farrowing number on their reproductive qualities fluctuated within the range of 9.8 ... 16.4%, the fertility duration was 2.4 - 8.1%, the multiplicity was 10.3 ... 54.2%, the duration of the unproductive period was 1, 9 ... 41.2%, of the breed of the kennel-pedigree - 18.3 ... 57.5%. The influence of the breeding stock of kennel-breeders on the reproductive qualities of sows is established. In the investigated herds, higher economic efficiency was obtained for mating with Pietrain (PrAT "PC Podillya") and Duroc of American selection (PAP "Agroprodservice"). The general and specific combining ability of sows and buds of different breeds (breed combinations) is assessed and the best variants of selection are determined. It was established that the deviations of the calculated values of the parent breeds for reproductive qualities of sows, in comparison with the actual ones, were within the range of 0.5 ... 13.1%, maternal ones - 0.1 ... 5.9%.