In the conditions of the Republic of Belarus there was determined of a dose of input and efficiency of feeding with rape oil cake and protein meal produced on the basis of a new rape (Brassica napus) variety Yavar as a part of a mixed fodder KR-2 in diets of young stock of cattle. Rape oil cake and protein meal with the content of 1,4-1,9% glucosinolates and 27-30 mcM per 1 kg of a dry matter of erucidic acid can be included into composition of the mixed fodder КR-2 for bull calves in a dose up to 20% on weight. Feeding with the mixed fodders КR-2 with inclusion of rape oil cake and protein meal made it possible to receive daily average weight gain of calves at a level of 827-906 gram at expenses of forages of 5,4-5,9 forage units per 1 kilogram of a weight gain. It was caused by cheaper rape forages. In course of the study there was analyzed the chemical composition of rape oil cake and protein meal; indexes of rumen digestion of experimental bull calves; morphological and biochemical blood structure; changes of body weight; daily average weight gain and expenses for forages.

In the conditions of the Republic of Belarus there was determined the influence of experimental feed mixtures on the basis of humid preserved grain (conserved rolled grain of triticale; barley (Hordeum vulgare); oat (Avena sativa)) and protein, mineral and vitamin supplement (contains rape (Brassica napus) extraction cake; wheat bran; premix PKR-2; chalk; forage phosphate) on digestibility and metabolism of nutritive elements by young stock of cattle. There were presented recipes of the developed experimental feed mixtures and studied their influence on consumption and digestibility of nutritive elements of diets, metabolism of nitrogenous substances, calcium, phosphorous, as well as on hematological indexes. The proposed mixed fodders contained metabolizable energy; dry matter; crude protein; digestible protein; crude fat; fibre; starch; sugars; calcium; phosphorous; magnesium; potassium; sulphur; iron; copper; zinc; cobalt; manganese. In course of the study there was analyzed the consumption of the main nutritive elements; coefficients of their digestibility; nitrogen balance; balance of calcium and phosphorous; morphological and biochemical blood indexes.

In the conditions of the Republic of Belarus there was analyzed the efficiency of feeding of a new protein vitamin and mineral additive containing national local protein and mineral raw material sources in diets of 12-16-month old heifers. Instead of sunflower extraction cake the heifers were fed with the protein-vitamin and mineral additive which contained rape grain (Brassica napus), lupine (Lupinus) grain as well as mineral and vitamin additives based on halites, phosphogypsum, phosphate, sapropel and premix in dose of 20-25% by weight as a part of mixed fodders. The additive was used against the background of rations with green mass from a cereal and leguminous mixture - 56-57%, mixed fodder - 36-37%, molasses - 6-7%. In accordance with nutritional value indexes the proposed additive rendered the positive influence on forage consumption, indexes of ruminal digestion, as well as on the morphological and biochemical blood composition. It application made it possible to obtain daily average weight gains of animals at the level of 812-827 grams within forage expenses of 7,0-7,2 сentner of fodder units. Inclusion of the protein vitamin and mineral additive with local protein and mineral raw materials in rations of calves made it possible to lower the mixed fodder cost price on 12-15% and the cost price of 1 centner of gain during the summer period - on 11-13%.