Features of the biochemical composition of blood in calves with different dynamics of live weight gain

The biochemical markers of blood associated with the rate of body weight gain were studied in the work. For experimental work, 30 calves on the 1st and 14th day after birth received venous blood and conducted laboratory tests. At the time of birth, as well as after 6 months of cultivation, the live weight of young an-imals was determined and the average daily increase was calculated. It was found that on the first day after birth in intensively growing animals, the activity of AlAT was lower by 56.6% (P?0.01), and AsAT by 45.4% (P?0.05), in relation to the indicators of young animals with a low rate of weight gain. Similarly, calves with intensive growth had a higher concentration of VSNMM in plasma by 30.4...48.4% (P?0.001) and 37.1...48.6% (P?0.01) in blood. On day 14, the biochemical profile of calves with low growth rates was characterized by a higher activity of alkaline phosphatase (by 27.4...46.6%; P<0.05), whereas in intensively growing young calves a higher level of calcium was observed (by 5.9%; P<0.05). The analysis of correlations showed that on the first day after birth, there was a pronounced relationship between the growth rate in relation to the activity of AsAT (-0.510) and AlAT (-0.497), iron concentration (-0.650) and VSNMM in blood plasma (0.626). Subsequently, the connection of these markers weakened, and the growth rate of calves was more dependent on the activity of alkaline phosphatase. So on the 14th day of postnatal ontogenesis, the correlation between the increase in live weight and enzyme activity was -0.744. Thus, it can be concluded that the activity of alkaline phosphatase is the most promising biochemical marker associated with the dynamics of body weight gain.