In the conditions of the Republic of Belarus there was analyzed the influence of the following paratypical factors on cow productive longevity: age of the first calving; milk yield at the first lactation; and a birth season. At the experimental animals there studied the indices of dairy efficiency: a lifelong milk yield (kg); a lifelong yield of dairy fat (kg); the total duration of the lactation period (days); duration of practical use (lactations). There was noted a tendency of increasing of a term of productive use and lifelong productive efficiency at the animals the practical economic use of which was begun in later terms. The insemination of these animals was approximately realized at the age older than 21 months. Also it was stated that in accordance with all investigated indices (except for a milk yield per one day of lactation) the highest indexes were typical for cows which had the least milk yield at the first lactation.

Results of determination of yielding capacity, chemical composition of initial weight and silage quality of forages prepared from the binary mixtures of Japanese millet (Panicum curs-galli var. frumentaceum), millet (Panicum) and saccharine sorghum (Sorghum saccharatum) realized in the conditions of the Republic of Belarus were presented. Research results showed that the binary mixture of saccharine sorghum with blue lupine (Lupinus angustifolius) in ratio of 70% + 30%, respectively made it possible to obtain the highest efficiency (62,4 t/ha of green material, 15,1 t/ha of dry matter, 13,1 t/ha of fodder units). Mixed sowing of millet, Japanese millet and saccharine sorghum with blue lupine surpassed in productivity the single-crop sowing on 15,5-32,6%. It was established, that the silage produced from the mixture of sorghum and Japanese millet with lupine had higher energy and protein nutritive value: 0,86 and 0,98 fodder unit, respectively; 9,77 and 9,92 mJ of exchange energy per 1 kg of dry matter, respectively; 103, 3 and 108,4 grams of digestible protein per 1 fodder unit. High nutritive value and the best palatability of trial silos promoted the increasing of milk yield on 4,4-5,4% in comparison with the control tests. Haylage which was produced from drought resistant crops had high energy nutritive value: per 1 kg of dry matter there was noted 9,40-9,48 mJ of available energy, 0,89-0,94 fodder units with fodder unit provision with 102-114 grams of digestible protein

In the conditions of the Republic of Belarus there was developed a production technology and there were produced samples of lyophilizated live vaccine against Aujeszky's disease of swine which corresponded to all parameters of control. The vaccine had an expressed phylactic power, induced the development of long-lived immunity of vaccinated piglets.

Usage of biological preparation of high antibacterial activity allows to decrease the air pollution by bacteria of colon bacillus group at 25-100%, increase productivity at 17-67 g, safety – at 0,4%, resistance, protein metabolism, protein fractions and some other indices (lysozyme and betalysine activity, leucocytes, erythrocytes, hemoglobin, calcium, phosphorus, iron, magnesium, AST, ALT, urea, cholesterol, bilirubin and glucose)

Determination of the efficiency of young fat stock feeding with wet rolled maize grain which was preserved by means of different preparations was realized in the conditions of the Republic of Belarus. The following preserving agents were applied: HV-2 (by- product of amino-formaldehyde resin); AIV 3 Plus (mixture of 62% formic acid and 24% ammonium formate; KEMIRA, Finland); carbamide (30 kg/t) with 40 g/t of complex mineral supplement. Feeding of young fat stock with rolled maize grains preserved by NV-2 promoted the increasing of nutrient digestibility on 1,5-5,0%, nitrogen use - on 2% in comparison with control. Application of rolled maize grain preserved with AIV-3Plus and carbamide with the complex mineral supplement made it possible to increase the digestibility of nutrients on 1,0-4,8% and nitrogen use - on 1,6-1,7%. Introduction of rolled maize grain preserved with NV-2 into rations of bull calves increased their productivity on 4,7% (P less than 0,05) with the simultaneous lowering of forage expenses on 1,9%. Application rolled maize grains preserved with AIV-3Plus made it possible to increase daily average weight gain on 3,8% and lower the forages expenses on 2,6%. Use preserved with NV-2 and AIV-3Plus rolled maize grains in rations of young fat stock lowered the production cost price on 11,9% and 10,8% that proved the efficiency of the studied fodder