Results of Cage Experiences on Use of Probiotics in Feeding of Bees

Abstract

To develop high-yield dairy cattle characterized by good health and long production cycle is impossible without a regular assessment of exterior characteristics and body type of animals. In our research we aimed to study specific constitution features of cows of the black-and-white and Kholmogory breeds, identify selection and genetic parameters and correlation between exterior parameters and milk production, as well as estimate the influence of external factors on biological features of the studied livestock. The research was conducted on the cows of the black-and-white and Kholmogory breeds in 2016-2018. The initial data was used to calculate the selection and genetic parameters of exterior and production activity of dairy cows in the studied population. By calculating the correlation index, we identified the correlation between all assessment parameters of exterior, body type and milk production ability of cows. The study results reveal relatively low variability of body types among dairy cows. It is found that such features as the cow height (2,50-3,22 %) and the hip width (2,70-3,18 %) are the least variable parameters. The maximum variable parameters are body length (3,30-4,60 %) and chest girth (3,63-4,38 %). Among parameters characterizing the milk production, a high level of variability is shown by the milk yield per 305 days of lactation (15,83-17,78 %) and the yield index (15,72-17,74 %). The correlation between the milk yield, milk quality and exterior features was either weak or there was no correlation at all (r from -0,21 to +0,24). At the same time, it is important to note a weak (r = +0,16) positive correlation between the exterior index of body and the yield index. The research finds that the influence of the environmental factor on the milk yield and the yield index is mean and amounts to 28,6 % and 26,3 % with a relatively low influence on the mass fraction of fat and protein in milk -4,1 % and 5,8 %, respectively. The environment has low influence (10 %) on the exterior index of body type. It proves that body development mostly depends on heredity. Thus, modern methods to assess dairy cows by their exterior type will make it possible to identify and select the cattle of the desired dairy type and improve selection efficiency. РЕЗУЛЬТАТЫ САДКОВЫХ ОПЫТОВ ПО ИСПОЛЬЗОВАНИЮ ПРОБИОТИКОВ В ПОДКОРМКЕ ПЧЕЛКлючевые слова: пчелиные семьи; пробиотик; кормовая добавка; динамика гибели пчел; садковые опыты.