The nutritional needs of foxes: energy

Organic nutrients in feed are the source of energy for foxes, which release energy in the process of metabolism in the organism. Now the calculation of the total nutritional value of the feed diet and the need for animal energy is usually expressed by metabolic energy. The usual unit of feed energy and nutritional value for fur animals is 418 kilojoules (100 kcal) of metabolic energy. The unit of feed energy is expressed in kilojoules or kilocalories. one kilocalorie is equivalent to 4.184 kilojoules, or one kilojoule is equal to 0.239 kilocalories. The variation range of basic metabolic energy per kilogram body weight of adult foxes was 255-280 kJ (61-67 kcal) from June to August, 209-243 kJ (50-58 kcal) from September to October, 176-218 kJ (42-52 kcal) in November, and 172-1970 kJ (41-47 kcal) in December. Basic metabolic energy is the basic energy requirement for foxes to maintain life, accounting for about 72% of the total energy, that is, the energy utilization ratio is 100, or 1.39. For this reason, the average metabolic energy per kilogram of body weight per day and night of adult foxes is: 389 kilojoules (67 kcal) multiplied by 1.39 kilojoules from July to August, 339 kilojoules (81 kcal) from September to October, 301 kilojoules (72 kcal) in November and 272 kilojoules (65 kcal) in December. It takes 19 kilojoules (4.6 kcal) for foxes to gain 1 gram of body weight in summer and 27 kilojoules (6.4 kcal) in autumn. In winter, foxes often lose weight. Female foxes lose 8-12 grams every day and male foxes lose 15-20 grams. This range of weight loss is a normal preparation for the transition of foxes to the breeding season.