An important property of living organisms is the ability to adapt to the influence ofthe externalfactors that is constant adaptation to environmental changes, while preserving the constancy of the internal environment. At the present levelof thedevelopment of poultry farming in agro farms of different types, the choice of the most adaptive and competitive breeds and crossbreds of the poultry in the production of eggs and meat is of great importance. Farm animals are affected by various external factors such as technology of keeping, production, veterinary and prophylactic and zootechnical measures. According to various scientific sources, a significant number of poultry crosses are used in Ukraine, mainly for the selection of leading firms in the USA, Canada, and Western Europe (foreign breeds in Ukraine account about 80% of the total poultry population). They provide a high degree of implementation of the genetic productivity potential, butunder rather controlled, almost climatic conditions of keeping and feeding. At the same time, they are very responsive to changing of environment when used in the conditions of the breeding and commodity enterprises of Ukraine. This is due to the fact that the main economic-useful signs of the bird (bearing, weight of eggs, reproductive qualities) have polygenic inheritance and, accordingly, have a small fate of additivity of the operating genes. Therefore, in the new conditions of exploitation of cross-breeds of foreign selection on the indicated signs there is a significant influence of interaction «genotype × environment», which reduces the combinational ability of the family farms and, accordingly, manifestation of the heterosys effect. To preserve the structure of the cross, adaptation of the original family forms to the specific conditions of the poultry holdings is necessary, and then the implementation of supporting selection during mass selection of repair young animals. It should be taken into account that the suitability of imported lines, family forms or final bird hybrids is limited to the limits of their physiological response, since their heredity is formed in the conditions of the country where they are bred. The problem of adaptation of poultry in the conditions of industrial poultry farming is constantly relevant. The intensification of the industry leads to the new adaptation factors, in particular, different technological conditions for repair young animals and adult herds, changes in the recipes of feed and the quality of their components in other regions, the movement of poultry, stresses and so on. At the present, it is important to take into account both adaptive responses, acclimatization capacity of poultry and other animals imported from abroad, and selection according to the indicators of the reaction of the body for different methods of their study. In this regard, it is advisable to use crosses that have high adaptive capabilities.
Selectivity of herbicides in the post-emergence sugarcane seedlings in primary selection fields
