Alkaline phosphatase is a key enzyme of mineral metabolism and a marker of bone tissue condition. In fast-growing broiler chickens, disturbances in its activity may indicate an imbalance in calcium-phosphorus metabolism. Para-aminobenzoic acid, as a vitamin-like substance, possesses metabolic potential. However, its effect on alkaline phosphatase activity and, consequently, on bone formation processes in broilers during different seasons of the year has been insufficiently studied. The scientific and economic experiment was conducted under production conditions (at a broiler poultry farm) in the Amur region during different seasons of the year on Hubbard F15 White broiler chickens. The bird was divided into a control group receiving the basic diet and an experimental group receiving para-aminobenzoic acid in addition to the basic diet. It was found that para-aminobenzoic acid supplementation exerted a modulating effect on alkaline phosphatase activity, the nature of which depended on the age of the birds and the season. In the initial rearing period (15 days), differences between groups were insignificant. Nevertheless, during the final fattening stage (30–43 days), the experimental groups in most seasons showed a statistically significant (p <0.05–0.01) decrease in alkaline phosphatase activity compared to the control. The most pronounced decrease was recorded in spring (by 21.9% at 30 days) and summer (by 21.1% at 37 days). At the same time, in the same periods, the bone tissue of birds in the experimental groups showed increased ash, calcium, and phosphorus content. The decrease in serum alkaline phosphatase activity against the background of para-aminobenzoic acid supplementation, accompanied by enhanced bone mineralization, indicates a more efficient and balanced course of bone formation processes.

Atavina Olga V.

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