Nutria breeding is one of the most promising sectors of the fur farming, which is based on a relatively cheap and available plant food and the quality of products not only provides valuable pelts, but also nutritious dietary meat. Ukraine has all the necessary climatic conditions to improve this area. This is due to a number of objective reasons, among them – the lack of evidence-based standards of feeding trace elements and vitamins to all production and age groups corresponding to their biological characteristics and physiological needs in order to obtain high-quality environmentally friendly products.

The physiological condition and the level of productivity of animals is largely determined by the work of the digestive tract to assimilate food that must be digested. The level of digestion depends on animal species, age, composition and size of the feed for feeding and feeding regime. To evaluate the usefulness of the feed, it is necessary to know the digestibility of nutrients within them. In the ration may be enough nutrients, but if it is made of the difficult digested components (tree branches, stagnate grass, hay), the its value is low.

Feeding nutria differs according to the age, live weight, physiological state and the conditions (air temperature, the content in cells of different sizes with or without swimming pools). Therefore, depending on the economic conditions nutria is fed in the following ways: wet mixture, granular concentrate feed and the combined method of feeding. Rational type of feeding in the winter period is concentrate or roots concentrate, and in the summer – grass concentrate.

The aim of our study was to investigate the digestibility of nutrients in young nutria at feeding with wet mixture during the production period.

Studies were conducted in standard conditions of mechanization and automation production processes, in accordance with the technology of production. Nutria was being kept in the closed heated room in metal cages with mesh floor. Feeding animals was organized on the basis of existing rules providing the daily needs of animals in nutrients and metabolizm energy for their age, body weight, season and physiological state. In the basis of the norms there were four key indicators: the exchange energy, digestible protein, digestible fat and digestible carbohydrates. Furthermore, the content diets of minerals and vitamins were being controlled. The dry method of feeding and feeding with semi-moist mixture was being used. A method of feeding with semi-moist mixture with concentrated, green, succulent and coarse fodder used for feeding animals, consists in the fact of feeding with 40–45% of the mixture in the morning and 55–60% – in the evening. Approximate ratio in semi-moist mixture concentrated and green or other succulent feed was by weight of 1: 1.5. In case of coarse grasses its quantity in the mixture is reduced to 0.5 parts per part of concentrate.

In the course of scientific experiment the balance of the digestion of nutrients for fattening young black nutria was determined. For the experiment, the 10 experimental nutria at the age of 6 months (5♀ + 5♂) were selected, live weight of females on average 4150 g and 4780 g male. The composition of the feed mixture consisted of the following: barley – 65 g, corn – 35 g, pea – 8 g, wheat bran – 20 g, sunflower seed cake – 5 g, fishmeal – 5 g, alfalfa meal – 25 g, fodder beet – 150 g, boiled potatoes – 150 g, fodder yeast – 7g, calcium phosphate – 1g and a salt lick.

Research nutria rations fully met nutrient standards set under age period. Digestibility of all nutrients in the feed mixture of young nutria was high, but the best digested were the following: anitrogen-free extractives (89.3%) and organic matter (83.8%). The digestibility of crude protein was 76.7% and crude oil - 69.3%. The digestibility of crude fiber was 48.5% of its content in feedstuffs.

Thus, the digestibility of nutrients mixture during the production period in young nutria on fattening was quite high.

Key words: young nutria, fattening, food, semi-moist mixture, digestibility, metabolism, feeding system.