The effective use of Pietren breed at purebred and crossbred selection

The article highlights the problem of finding optimal variants of breeding process in a herd of pigs at purebred and crossbred selection. For this purpose, the control and two experimental groups were formed: ♀ Pietrain × ♂ Pietrain (control), ♀ (Pietrain × Large White) × ♂ Large White (first experimental group), ♀ (Pietrain × Durok) × ♂ Pitren (second experimental group). The analysis of the animals performance in these groups was carried out in 40, 30 and 35 parities, respectively. The research was conducted on the basis of PE «Maglevovany M.I.» in the Donetsk region. It has been established that the higher level of reproductive characteristics have sows of first experimental group, which have heredity of Large White breed, this breed is traditionally considered as a maternal form in cross-breeding schemes. For instance, their litter size at birth is higher than the same indicator in the control and second experimental group (plus 0,5, P<0,05, and 0,3 piglets, respectively); by the litter size at weaning at 28 days (plus 1,6, P<0,001, and 0,6 piglets); by the litter size at 2 months (plus 1,6, P<0,001, and 0,4 piglets). The highest piglet survival at the age of 2 months was in the litters, whose ancestor were boars of Pietrain breed (second experimental group) − plus 3,6 and 2,3 %, respectively, compered to purebred piglets of Pietrain breed and the first experimental group. For such complex indexes as the litter weight at weaning and litter weight at 2 months the first experimental group had an advantage of 18,1 kg (P<0,001) and 31,1 kg (P<0,001) over the control group (purebred Pietrain) and 5,4 kg and 7,6 kg − over the second experimental group. However, the average piglet weight of sows of second experimental group both at 28 days and at 2 months are equal to the average piglet weight of the same age of the first experimental group. The piglets, which are descendants of boars of meat breeds Duroc and Pietrain show a tendency to the faster growth even in an early age. The avarage live weight of pigs of the second experimental group at the age of 100 days and 7 months is higher compared to avarage live weight of pigs of the same age of the control and the first experimental groups – plus 8,5–21,7 kg (P<0,01 for the second experimental group) and 4,4–13,5 kg (P<0,001 for the second experimental group), respectively. At the age of 100 days, the maximum average daily gain was obtained in the second experimental group with an advantage of 190 g (P<0,001) compared to control group and 115 g (P<0,001) compared to the first experimental group. It is obvious that hybrids with the faster growth, which were obtained through crossbreeding ♀ (Pietrain × Duroc) × ♂ Pietrain reach a live weight of 100 kg in a shorter period: they need less time needed to reach 100 kg of live weight – 32 days less (P<0,001 ) compared to purebred animals of Pietrain breed (control group) and 18 days less (P<0,001) compared to hybrids ♀ (Pietrain × Large White) × ♂ Large White (the first control group). By such an indicator as the fat thickness the hybrids of the second experimental group dominate by purebred pigs of the same age of the control group (minus 0,2 mm), that characterize the low ability of meat breed for getting fat. The fat thickness of hybrids of the second experimental group was less by 0,9 mm (P<0,001) compared to the pigs of the first experimental group. Thus, in this herd in order to improve the reproductive qualities of sows, it is suggested to use the crossbreeding scheme ♀ (Pietrain × Large White) × ♂ Large White and to improve the fattening qualities of young animals the optimal is scheme of crossbreeding ♀ (Pietrain × Duroc) × ♂ Pietrain. Key words: pigs, Pietrain, Large White, Duroc, purebred and crossbred selection, reproductive and fattening qualities.