The effectiveness of use of red-and-white Holstein bulls of European selection at breeding of Volga-type red-and-white cattle
Red and-white breed, being a young population in genetic terms, makes it possible to breed new zonal types of animals more effectively. The key thing - is to receive animals with 6500-7000 kg milk yield, with 3.8-4.0% fat content, and 3.3-3.5% protein content, adapted to the climatic conditions, and resistant to infectious diseases. One of the types of red and white breed is Volga one, that is characterized by a high content of protein in milk, is bred in the farms of the Volga Federal District. As the improving breed, to improve milk protein content of red and white cows, Holstein sires of European selection are used, whose daughters inherit prepotent signs of high levels of protein in milk. The purpose of this research is a comparative study of milk efficiency, chemical and amino acid composition of milk in red and white cows and their hybrids that were bred with the use of Holstein European selection sires. The article deals with milk production, chemical and amino acid composition of milk from cows of a new type, compared with the original red and white breed. Hybrid animals of all genotypes produce 316-1407 kg more milk than the ones of the same age of red and white breed. Crossbred cows produce milk with better chemical composition, which contains more fat (0.05-0.65%) and protein (0.1-0.25%). The study of the amino acid composition of protein in milk from cows of red and white breed and their hybrids with red and white European Holstein cattle showed that the total number of amino acids is 0.045-0.135% more in hybrids, except crossbred cows of German selection. The biological value of milk proteins is indicated by the optimal ratio of essential amino acids in milk of crossbred cows.
Keywords: milk production, red and white breed, type of hybrids, milk, fat, protein, amino acid composition, milk quality, sires, crossing, production