Influence of the fixed "father" factor on the protein content in milk and the yield of milk protein in cattle

Abstract

Increased productivity in cattle is performed by using the methods of genetics and breeding. Currently, one of the promising directions for increasing the milk productivity and manufacturability of domesticated cattle is the use of the genetic potential of breeding bulls. During the research, the results of a one-way analysis of variance of the influence of the "father" factor on productive indicators were analyzed. The factor "father" was used as the analyzed factor, and the content of protein in milk and the yield of milk protein were used as dependent factors. For each fixed factor, standard indicators of protein content in milk and milk protein yield have been determined. Also, the degree of influence of the investigated factors under their action, both independently and together with other conditioning factors, on the protein content and the yield of milk protein was determined. The determination of the simultaneous influence of several factors on the effective indicator was carried out using a two-way analysis of variance. It was found that the degree of influence of bulls on the protein content in daughters' milk was 7.9%, on the yield of milk protein-19.6% with high confidence levels (P>0.999). Among the factors studied, the most strongly influencing pair was "calving number-father". This combination of factors also turned out to be one of the most significant against the background of the final comparative assessment of all investigated ones in the work. It is essential that the "father" factor, as an independent factor, has a lower power of influence on the protein content in milk than when interacting with the "calving number" factor. Thus, the factor "father" causes 7.9% of the protein content in the milk of daughters, and in combination with the factor "calving number" the influence is 5.4% greater. At the same time, such a pattern is not observed in the yield of milk protein. In this case, the opposite trend is observed: the "father" as an independent factor has a higher influence compared to the options of its interaction with other studied factors. Thus, the value of the bull-producer is one of the main factors that determine the protein content in milk and milk protein yield, and one of the most important evaluation criteria.