Level of phenotypic consolidation and correlation analysis of reproductive qualities of sows of different breeding value

Abstract
The results of research activities of reproductive qualities of sows of different breeding value are given, the level of their phenotypic consolidation is determined and the correlation analysis is carried out. The study was conducted in agricultural formations of Dnipropetrovsk and Sumy regions (LLC “AF “Renaissance”, research farm of the Institute of Agriculture of the Northeast NAAS of Ukraine, LLC “Druzhba – Kaznacheyivka”), livestock laboratory of the State Institution Institute of Grain Crops of NAAS of Ukraine and livestock laboratory economy of the North-East of NAAS of Ukraine. The work was performed according to the research program of NAAS of Ukraine № 30 “Innovative technologies of breeding, industrial and organic production of pig products” (“Pig breeding”). The object of the study were sows of large white breed. Indicators of reproductive qualities of animals of the specified production group were investigated taking into account the following quantitative signs: multiplicity, head; milk yield, kg, number of piglets at weaning, head; nest weight at the time of weaning at the age of 28 days, kg, safety, %. The BLUP index (maternal line) was calculated on the basis of the Main Breeding Center for Pig Breeding (Institute of Pig Breeding and AIP NAAS of Ukraine) according to the general model of a single animal. The index of alignment (homogeneity) of the sow's nest by live weight of piglets at the time of their birth, the index of reproductive qualities of the sow and the coefficients of phenotypic consolidation of the main quantitative traits were calculated according to the methods of V. I. Khalak (2012), M. D. Berezovsky (quoted from A. Vashchenko, 2019) and Yu. P. Polupan (1996, 2005), respectively. Biometric processing of research results was performed according to the methods of G. F. Lakin (1990). It was found that the maximum indicators of fertility, milk yield, number of piglets and nest weight at the time of weaning at the age of 28 days are characterized by sows of group I, in which the index BLUP (maternal line) is 109.78–128.75, the index of reproductive qualities (CPI) – 101.43–161.72 points. The correlation coefficients between the characteristics of reproductive qualities and integrated indicators are reliable and range from + 0.648 ± 0.0492 (index BLUP (maternal line) × milk yield) to + 0.984 ± 0.0086 (index of reproductive qualities (IRQ) × nest weight per weaning time at the age of 28 days). A high level of phenotypic consolidation on the basis of reproductive qualities of sows was found in animals of group II by milk yield (K1 = 0.561, K2 = 0.499) and nest weight at the time of weaning at the age of 28 days (K1 = 0.521, K2 = 0.472), peers of group I – by multiplicity (K1 = 0.315, K2 = 0.410) and the number of piglets at weaning (K1 = 0.296, K2 = 0.397). The calculation of economic efficiency of sows of different breeding value shows that the maximum increase in additional products was obtained from sows of group I, in which the index BLUP (maternal line) is 109.78–128.75, the index of reproductive qualities (IRQ) – 101.43–161, 72 points – +13.08 %, and its value is +332.08 UAH/head. These indicators of evaluation indices are a criterion for selecting high-yielding sows of large white breeds of controlled herds.