Mineral metabolism in laying hens body when using phytase in a diet without phosphate additives

Phytates are an anti-nutritional factor due to their ability to bind nutrients and make them unavailable for use by the animal organism. These compounds create strong chelate complexes with positively charged metal ions such as calcium, magnesium, iron, and zinc. As a result, insoluble complexes with phosphorus are formed, which significantly reduces its bioavailability and absorption by the animal organism. In the present study, conducted on laying hens of the Hisex white cross aged 20-40 weeks, it was found that a decrease in the phosphorus level in the diet leads to an increase in the concentration of calcium and trace elements in the intestinal contents. This indicates low availability of these elements with a lack of phosphorus. At the same time, the absorption of phosphorus itself improves: its level in the ileum content decreases by 47.6%, which indicates a higher efficiency of using this element by the bird’s body. When using Akstra Fy Gold phytase in a diet without phosphate additives, a decrease in the phosphorus level is observed by 42.9% at a dosage of 900 FTU/kg and by 47.6% at 1200 FTU/kg. It follows from this that the laying hen's body absorbs phosphorus better with its deficiency, which also affects the productivity of the bird. The calcium content in the shell decreases by 21.2%, and in the egg yolk it decreases by 3 times. At the same time, the calcium content in the protein doubles. As for phosphorus, its level decreases by about 1.5 times. With a decrease in the phosphorus level, noticeable changes in the concentration of trace elements in the eggshell are also observed: magnesium, lead, cadmium and zinc levels decrease, while copper levels increase. These changes indicate a complex relationship between the phosphorus level and the trace element balance in the bird's body and its productivity.