Innovative methods of evaluation of sows by indicators of reproductive qualities and criteria for their selection by some multicomponent mathematical models

Abstract

The article presents the results of research on the reproductive qualities of sows of large white breeds of different interbreeding differentiation according to some evaluation indices, determines the criteria for selection of highly productive animals, and the economic efficiency of their use. Based on experimental data, Annex 10 to the Guidelines for Pig Breeding has been modified (Correction factors for piglet nest weight at weaning at 60 days of age), and a new method for estimating sows by “sowing nest uniformity” at weaning piglet weight was developed (IVG60). The research was conducted in the research farm and laboratory of animal husbandry and feed production of the Institute of Agriculture of the North-East NAAS Ukraine and the laboratory of animal husbandry of the State Institution “Institute of Cereals NAAS of Ukraine” (2019–2021). The work was performed following the IPA NAAS № 30 “Innovative technologies of breeding, industrial and organic production of pig products” (“Pig breeding”). Evaluation of sows of large white breed on the indicators of reproductive qualities was carried out taking into account the following characteristics: fertility, ch.; high fertility, kg; milk yield, kg, nest weight at the time of weaning at the age of 32 days (actual), kg; nest weight at weaning time of 60 days (estimated), kg; safety of piglets before weaning, %. The index of uniformity (homogeneity) of the sow's nest by live weight of piglets at the time of birth (Ik2) was calculated according to the method of Kovalenko (2011) at the time of weaning – Halak (2020). A comprehensive evaluation of sows based on reproductive qualities was performed according to the sows' reproductive qualities selection index, M. D. Berezovsky's index and biometric processing of research results – according to the methods of Kovalenko and others (2010). It was found that 26.47 % of sows in the controlled population-based on reproductive qualities (multiplicity, head, nest weight at the time of weaning, kg) belong to the elite class, 65.44 – I, 7.35 – II class. According to the average score belonging to the category of “extracurricular”, the number of animals is 0.74 %. The sows of class M + according to the selection index of reproductive qualities of the sow and the index of M. D. Berezovsky is characterized by the leading indicators of diversity, milk yield, nest weight at the time of weaning at the age of 32 days (actual), and nest weight at the time of weaning at the age of 60 days (estimated). Compared with class M0 and M - peers, the difference according to these indicators is 4.6–4.2 kg, 23.3–23.6 kg, 24.6–25.0 kg, 60.1–58.1 kg, respectively, and is statistically significant. Sows characterize more balanced nests with a minimum number of piglets at the time of birth and weaning (distribution class according to the selection index of reproductive qualities of sows and the index of M. D. Berezovsky M -). The number of reliable correlations between the index “alignment (homogeneity) of the sow's nest by live weight of piglets at birth” (Ik2), the index of alignment (homogeneity) of the sow's nest by live weight of piglets at the time of weaning at 60 days of age (IVG60), the selection index of reproductive qualities of sows, the index of M. D. Berezovsky (I) and the signs of reproductive qualities of sows is 85.00 %. This indicates the effectiveness of using these multicomponent mathematical models in pig breeding. The use of sows of class M+ according to the selection index of reproductive qualities of sows and the index of M. D. Berezovsky provides an increase in additional production at 16.49–16.68 %, and its value is +438.90 and 443.96 UAH/head./farrowing, respectively.