Mathematical justification of the optimal rate of selenium introduction into mixed feed for broiler chickens
Abstract
In recent years, many countries worldwide have been revising the existing standards for introducing trace elements in mixed feed for high-performance crosses and poultry breeds, taking into account new scientific data. This also applies to Selenium, which is recognized as an indispensable biotic ultramicroelement according to the modern classification. The norms for introducing selenium into mixed feed for broiler chickens have specific differences and range from 0.1 to 0.5 mg/kg of feed, which are recommended in different countries and at other times. The reason for the disagreement is probably that the experiments were conducted under different conditions, against the background of different diets, on different poultry crosses, and using other selenium-containing compounds. In addition, the norms of selenium additives recommended by foreign and domestic scientists in mixed feed for broiler chickens are not always supported by mathematical calculations, and, in our opinion, they should be evaluated as indicative, requiring further justification and clarification depending on the regional characteristics of poultry feeding. Two scientific and economic experiments were conducted to determine the optimal rate of introducing selenium into mixed feed for broiler chickens, which lasted 42 days each. The study was conducted on broiler chickens of the Coob 500 cross. Selenium was additionally introduced into mixed feeds for broiler chickens of the experimental groups in doses of 0.2, 0.3, 0.4, and 0.5 mg/kg. Poultry in the control group did not receive Selenium supplementation. Statistical processing of experimental data obtained in two scientific and economic experiments, using graphical, variance, and regression analysis methods, allows us to conclude that the optimal dose of Selenium administration in mixed feed for broiler chickens should be considered 0.3 mg/kg. Feeding broiler chickens during the growing period of mixed feed enriched with Selenium in this amount contributed to a likely increase in their live weight in the first experiment by 7.8 % (Р < 0.001), in the second by 5.1 % (Р < 0.01), compared to the control group. Higher doses of Selenium (0.4 and 0.5 mg/kg) in mixed feed, as well as a lower dose (0.2 mg/kg), caused less intensive growth and lower live weight of broiler chickens of other experimental groups, compared to young animals fed mixed feed with the addition of selenium 0.3 mg/kg.
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