Simmental breed of cattle combines dairy and beef productivity. The crossbreeding cows of Simmental breed with Red-and-White Holstein breed of cattle was supposed to obtain animals with high milk productivity, good adaptability to the industrial technology of milk productivity. Red-and-White breed of cows has been bred in Russia as a result of this crossbreeding. It is a relatively young breed of dairy productivity in our country. In order to evaluate the effect of crossbreeding and study the adaptive capabilities obtained by animals, the synthesis of alkaline phosphatase by its activity in blood serum has been studied. The level of activity of the enzyme reflected the intensity and direction of biochemical processes in animals, affecting the state of homeostasis in purebred (Simmental) and crossbred (F1 Simmental×Red-and-White Holstein) heifers and first-calf heifers. It has been found that activity of serum alkaline phosphatase has decreased with age in both purebred and crossbred animals. Crossbreds F1 surpassed purebred heifers in enzyme activity at 1 and 10 months of age, this difference was significant. The activity of the enzyme in first-calf heifers was different from that in the blood of growing heifers, they had it lower. A close and significant correlation has been found between the live weight of growing crossbred heifers and the activity of alkaline phosphatase in the blood serum at 2-, 6- and 12-month age. Crossbred first-calf heifers were significantly higher in milk yield for 90 days of lactation than their Simmental herdmates. The set of data on the activity of alkaline phosphatase in the blood of heifers and lactating cows is of both theoretical and practical value for zootechnical and biological sciences, revealing the regularities of the heterosis effect, deepening knowledge about the age-related biochemistry of crossbred animals and the formation of productive traits.
Age‐Related Serum Alkaline Phosphatase Trends
