yeast grown specially for animal feed.
Yeasts of such species as Torula utilis and Manilla murmanica are used to produce nutrient yeast. They are grown on wood waste, corncobs, sunflower shells, straw, reeds, and on the waste products of the sulfite-pulp and alcohol industries. One m of wood waste can yield 200-250 kg of nutrient yeast and 1 m of corncobs, 250-280 kg. Nutrient yeast is a valuable protein- and vitamin-rich food for all kinds of farm animals. The chemical composition of dry yeast is as follows: water, 9.7 percent; protein, 45.6 percent; fat, 1.5 percent; cellulose, 0.2 percent; nitrogen-free extractive substances, 35.2 percent; and ash, 7.8 percent. In 100 kg of feed there are 113.7 feed units and 42.4 kg of digestible protein. The protein is highly digestible and nutritious. (It contains all the essential amino acids.) Nutrient yeast contains the B-complex vitamins, provitamin D2 (ergosterol), minerals, enzymes, and hormones which promote the assimilation of proteins and carbohydrates. Nutrient yeast is used as a protein-vitamin dietary supplement. It accelerates the growth of animals and increases their productivity. The rates at which it is fed per animal a day are as follows: adult cattle, not more than 500 g; calves, 200-300 g; sows, 200-400 g; sheep, not more than 50 g; horses, 400-500 g; adult poultry, 5 g; and chicks, 2 g. Nutrient yeast above these rates is not beneficial. Yeast is supplied to animals with concentrated feed or as part of mixed feed.
REFERENCESKozlov, A. I.Kormovye drozhzhi iz nepishchevogo syr’ia i effektivnost’ primeneniia ikh v zhivotnovodstve. Moscow, 1959.
Andreev, A. A., and L. I. Bryzgalov.Proizvodstvo kormovykh drozhzhei. Moscow, 1965.
M. F. TOMME