Field efficacy of enterotoxigenic Escherichia coli-specific phage (ΦCJ19) as a feed additive was evaluated in weaning piglets. Fifty-four piglets at 3~4 weeks old were allocated in three different groups and two of them were fed with bacteriophage at different concentrations (106 PFU/kg feed and 108 PFU/kg feed, respectively) for 30 days. Body weight and feed intake were measured at 10 days interval and body condition and fecal score were inspected every day. Based on the measurement, feed conversion rate (FCR) and average daily gain (ADG) of each group during 30 days were analyzed. The analysis suggests that the bacteriophage may help the improvement of FCR and ADG at 108 PFU/kg of bacteriophage feeding group in 30 days. A result from analysis of fecal score indicates that the bacteriophage also may help to relieve the intermittent diarrhea in post-weaning stage. Those results suggest that bacteriophage might help the growth of piglets in post-weaning stage.

This study was attempted to verify the mechanisms of RBC survival time shortened with vitamin E deficient and decrement of phospholipid concentrations by administration of iron. The concentration of iron in basal ration (group A and group B) was 40 mg/kg of feed, and the final concentrations of iron in the Fe (OH)3 supplemented-rations (group C and group D) were 13,496 mg/kg and 26,973 mg/kg, respectively

In the conditions of the Republic of Belarus there were studied biochemical indexes of calf blood serum against the background of application of probiotic preparations Bilavet C. Results of research showed that administration of probiotic preparations from the first day till the six day and from the fourteenth day till the nineteenth day of calf life with the preventive purpose rendered the simulative influence on indexes of natural resistance, which were accompanied with the increasing of total protein quantity in blood on 2,9-5,9%, as well as the increasing of protein fractions, in particular, globulin-rich fraction on 4,2-6,4%. Administration of probiotic preparation Bilavet С to calves rendered the positive influence on blood biochemical indexes, promoted the uptaking and better accumulation of mineral substances: content of crude calcium, inorganic phosphorus, magnesium, iron increased on 15,3%, 10,5%, 13,2% and 3,6%, respectively.

In the conditions of the Republic of Belarus there was studied the antihelmintic characteristics of the preparative forms of marsh cinquefoil (Comarum palustre): herbal infusion, infusion, liquid, extract, pulvis. The research has shown that these preparative forms in the specified dozes had a rather high therapeutic efficiency against strongylatosis of gastro-intestinal tract of young ruminants. The highest therapeutic effect was rendered by a liquid extract of Comarum palustre after its administration to animals in a dose of 0,2 ml/kg twice with 24 hour interval. In this case during the strongylatoses of a gastroenteric tract the antiparasitic intensefficiency of sheep and cattle by the end of experience was 98,1% and 97,3% respectively, and antiparasitic extensefficiency was 90% for both kinds of animals. After herbal infusion application of Comarum palustre for animals (in a dose of 7 ml/kg of live weight before feeding once a day within 3 days continuously) by the end of the 14 day of the experiment made it possible to obtain intensefficiency of 70% for both animal species, and extensefficiency of 60% for sheep and 70% - at calves. Tincture application of marsh cinquefoil for animals in a dose of 1 ml/kg of live weight of twice with 24 hours interval, provided the intensefficiency of 85% for sheep and 84% - for cattle, and extensefficiency of 70% and 80%, respectively. In the conditions of application of a pulvis of marsh cinquefoil in a dose of 500 mg/kg of live weight twice with 24 hours interval, made it possible to obtain the 63,4% intensefficiency for sheep and 67,8% - for calves, and extensive efficiency - 50% and 40%, respectively.

Influence of various levels of the organic form of selenium of Sel-Pleks on the formation of reproductive function of breeding bull-calves is studied in the conditions of the Republic of Belarus. Feeding of organic selenium to bull-calves promoted volume increase of ejaculate on 5,0%, quantities of male germ cells in ejaculate - on 9,1% and concentration of male germ cells in ejaculate - on 7,5% in comparison with animals in which rations sodium selenit was used. Application in winter period of the premix with inclusion of selenium in a dose of 0,4 mg per 1 kg of a dry matter of a ration allows to increase the quantity and quality of sperm of bull-calves: volume ejaculate - on 9,5%, concentration of male germ cells in ejaculate - on 16,4% (Р less than 0,05) and activity of male germ cells - on 8,9% (Р less than 0,001). Increasing of a dose of selenium up to 0,4 mg per 1 kg of a dry matter in rations of bull-calves in summer period allows to increase quantity and quality of sperm. At bull-calves of the third experimental group the ejaculate volume has increased on 4,5%, concentration of male germ cells in ejaculate - on 15,7% (Р0,05) and activity of male germ cells - on 7,3% (Р less than 0,001).

In the conditions of the Republic of Belarus there were studied the productive and interior indexes of bull calves which were fed with dried distiller's grains. Inclusion into bull calves diets of the mixed fodder containing 33% of dried distiller's grains made it possible to increase the concentration of volatile fatty acids on 16-18%, albuminous nitrogen - on 4-7%, quantity of infusorians - on 16-17%, as well as to reduce the ammonia level in a ruminal liquid from 23,4 up to 17 mg%. Inclusion of 33% of dried distiller's grains into structure of mixed fodder and feeding the same quantity of fresh distiller's grains promoted increasing of nutrient digestibility on respectively 4,0-5,9% and 3,5-4,5%, nitrogen retention - on 13%. Increasing of level of dried distiller's grains in structure of grain forage up to 67% increased the digestibility of nutrients on 1,5-2% and nitrogen retention - on 4%. Substitution in mixed fodder for bull-calves of 33 and 67% of fodder grain by dried distiller's grains made it possible to increase daily average live weight gain of animals respectively on 10 and 4%. Feeding of dried and fresh distiller's grains at simultaneous introduction in rations of complex mineral additive promoted the activation of metabolic processes that was proved by increasing of crude protein of blood at 6-7% and 5-8%, as well as decreasing of concentration of urea - on 25 and 22% respectively. Use of 33% of dried distiller's grains as a part of mixed fodder for cattle young stock proved to be economically effective and allowed to lower the cost price of a live weight gain on 10-11%. Feeding with fresh distiller's grains allowed to lower the prime cost price on 7% and to receive additional profit.

In the conditions of the Republic of Belarus there were analyzed the efficiency of application of a new mineral additive produced of the basis of carnallite brine (the national local raw material) as a part of mixed fodders for feeding of young stock of cattle. There was analyzed its influence on digestibility of a diet nutrients in cattle rations and on animal productivity. Inclusion of carnallite brine in mixed fodders structure for fattening young cattle rendered a positive influence on forage palatability. Forage consumption on a per head basis increased on 5,4%. Optimum dose of addition of carnallite brine in mixed fodder - 0,85%. Feeding of young cattle with the experimental mixed fodders did not render negative influence on hematological indices and physiological condition of animals. Use in young cattle rations of the mixed fodder containing 0,85% of carnallite brine promoted the increasing of nutrient digestibility on 3,4-5,7%. In the conditions of feeding of mixed fodders with other doses of carnallite did not cause any changes in digestibility of nutrients. Feeding of the prepared mixed fodder with 0,85% of carnallite brine to young growth of cattle made it possible to increase the growth energy on 5%.

In the conditions of the Republic of Belarus there were determined the fattening and slaughter qualities of swine as well as the evaluation of their pork production in the conditions of inclusion into their diets of a biologically active substance on the basis of field caraway (Carum carvi L.). Research results showed that in the production conditions the administration of the biologically active additive in a dose of 7 gram per 100 kilogram of live weight of pigs made it possible to increase their daily average gain from 627,9 grams in a control group up to 687,2 grams (or on 9,44% (P less than 0,999)), to increase their preslaughter and slaughter weight respectively on 3,76% and 6,42%, dressing percentage and carcass yield – respectively on 1,71 and 1,67%. According to the indexes of meat quantity in diverting weirs of the experimental pigs surpassed the control group on 3,03%, or 2,70 kg. The fat content in the half carcasses of the experimental group was authentically lower than the indices of control animals on 0,48 kg or on 2,18%. The hock weight of experimental animals with high confidence exceeded pigs of the control group on 1,15 kg, or on 10,45%. They practically did not differ from the control group according the indexes of thickness of pork fat at the level of 6-7 chest vertebras, and in the area of a muscular eye surpassed them on 4,0 square сm or on 7,72%.

In the conditions of the Republic of Belarus there was analyzed the influence of a fodder additive Water Trit liquid on quality of water and productivity of swine. Research results showed that administration of the fodder additive Water Trit liquid on the basis of organic acids promoted the increasing of productivity of pigs on 8,2% (P less than 0,01) in comparison with pigs of a control group. Improvement of biochemical indices of blood at experimental pigs was marked. The optimum dosage of the fodder additive Water Trit liquid was 4 ml/l of consumed water. Application of the fodder additive at feeding of pigs positively influenced on quality of water and promoted the destruction of pathogenic microflora in it. The results of tests of water by chemical indices, dynamics of body weight after application of acidulent; fiber fraction, albuminous factor were showed.