Optimization of exchange energy in feeding foxes of the «savvatievsky» breed type during the preparation period for the rutting season

Success in breeding foxes largely depends on a rational diet in preparation for the rutting season. Before the start of the rutting season, the body weight of adults should be 5–10 % less than in December, while they should have good fatness corresponding to the factory condition. Being overweight, especially in adult females, increases the risk of rape. In cases of excessive fatness, it may be necessary to reduce the body weight of animals by 15–20 % before the start of the rutting season by limiting the daily calorie intake (up to 350 kcal per head) or reducing the concentration of metabolic energy (OE) in the feed. Domestic standards for feeding fur-bearing animals describe the recommended consumption of OE per head per day by a silver-black fox during the entire production period. In the process of long-term breeding, the phenotype of animals changes. This entails the need to adjust approaches to achieve optimal condition, taking into account the individual characteristics of the constitution, metabolism and other factors. The article presents the effect of feeding with different levels of metabolic energy during the preparation period for rutting of female silver-black foxes of the «Savvatievsky» type on reproduction indicators. As a result of the study, it was revealed that in the control group (feeding according to the Russian standards of 2007 for domestic fox breeds), female reproduction rates were significantly lower than in the experimental group, where the level of metabolic energy was lower.