GROWTH INTENSITY AND BIOCHEMICAL STATUS OF KAZAKH WHITEHEADED BULL-CALVES WITH DIFFERENT GENETIC POTENTIALS UNDER THE CONDITIONS OF THE ZHURGIMBEKOV PEASANT FARM

Abstract

The article investigates the influence of different genetic potentials of Kazakh Whiteheaded bull-calves on their biochemical status and growth intensity against the background of balanced feeding under the conditions of the Zhurgimbekov peasant farm in the Kostanay region. Two groups of 8-month-old bull-calves (15 heads in each) were selected as the research object: the first group consisted of crossbred animals, and the second group included purebred young stock obtained from "elite-record" class dams. The nutritional value of the daily ration was evaluated according to the classical Weende proximate analysis and contained 84,2 MJ of metabolizable energy and 1015 g of crude protein. The following blood serum parameters were studied using biochemical methods: total protein (68.4–74.2 g/L), albumin (31.2–34.8 g/L), urea (3.4–4.2 mmol/L), creatinine (88.4–96.2 µmol/L), aspartate aminotransferase (64.2–71.5 U/L), alanine aminotransferase (26.4–29.1 U/L), alkaline phosphatase (115.2–132.4 U/L), and glucose (2.6–3.1 mmol/L). The dynamics of live weight was also determined: by 15 months of age, it reached 397.0 kg in group I and 424.2 kg in group II. The average daily gain during the period of intensive growth was 890.6 g in group I and 933.8 g in group II. The results showed that balanced rations optimize metabolism and maintain physiological parameters at a normal level. Group II bull-calves with high genetic potential significantly outperformed their counterparts from group I in terms of biochemical status, absolute and average daily live weight gain (p≤0.05; p≤0.01). The data obtained confirm the importance of adequate feeding and high selection value for increasing the productivity of beef cattle.