Influence of climatic factors on the reproductive ability of sows

Taking into account the low level of inheritance of reproductive qualities, it is important to search other factors that may affect the productivity of sows. Therefore, the aim of the work was to study the influence of climatic factors - in this case, the average annual air temperature and humidity on the level of phenotypic manifestation of quantitative traits. In the experiment it was involved a livestock of pigs of the Large White breed of the breeding farm "Ukraine" of Poltava region (factory type "Bahachanskyi"). The research methodology was based on the use of regression and analysis of variance. The estimation of ecological and genetic parameters of plasticity and stability was determined by the method of Eberhart S. J. and Russel W. J. (1966) in the modification of Pakudin V.Z. and Lopatina L.M. (1984). Animals were characterized both by absolute indexes of the productivity and by the selection index (Berezovsky M.D. and others, 2002), and all calculations were performed according to MS Excel 2010. The initial data were formed in a matrix of the type "family-line". When comparing the plasticity of families, genotypes with a coefficient ri> 1.0 were referred to as highly plastic, when1>ri≥0 - relatively plastic. A family in which the plasticity is equal to one and the deviation is minimal is considered as stable. When studying the strength of the interaction influence of climatic factors (temperature and the amount of precipitation per month) on the indexes of reproductive qualities of sows,it has been determined a significant strength of the interaction influence of climatic factors on the fertility of sows (10.62 %). In the study of average indexes of fertility, it was found out the fact that the largest difference in this feature between 2019 and 2020 was recorded in May: fertility in May 2019 was by 1.7 heads higher than in the same period in 2020. The indexes of plasticity (r) and stability (S2) were studied in the context of families. It was determined that the fertility of the sow families are differed by the highest plasticity, and the most stable were sows on the basis of the number of weaned piglets. The greatest reaction in terms of fertility was shown by sows of the families Volshebnytsia and Snizhynka, and the most stable (adapted) were animals of the families Ch. Ptychka and Geran. According to research, a significant effect of temperature and humidity on the fertility of sows of the factory type "Bagachansky", and high values of plasticity of families on this index indicate about an insufficient adaptation of these animals and indicate the feasibility of developing technological measures to mitigate environmental factors. Key words: sow, breed, family, line, factory type, reproductive qualities, selection, adaptation, ecological plasticity, index.