To evaluate economic effects and health and performance of the general cattle population after exposure to cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) in a feedlot. 21,743 high-risk calves from the southeastern United States. PI status was determined by use of an antigen-capture ELISA (ACE) and confirmed by use of a second ACE, reverse transcriptase-PCR assay of sera, immunohistochemical analysis, and virus isolation from sera. Groups with various amounts of exposure to BVDV PI cattle were used. After being placed in the feedlot, identified PI cattle were removed from 1 section, but PI cattle remained in another section of the feedlot. Exposure groups for cattle lots arriving without PI animals were determined by spatial association to cattle lots, with PI animals remaining or removed from the lot. 15,348 cattle maintained their exposure group. Performance outcomes improved slightly among the 5 exposure groups as the risk for exposure to BVDV PI cattle decreased. Health outcomes had an association with exposure risk that depended on the exposure group. Comparing cattle lots with direct exposure with those without direct exposure revealed significant improvements in all performance outcomes and in first relapse percentage and mortality percentage in the health outcomes. Economic analysis revealed that fatalities accounted for losses of $5.26/animal and performance losses were $88.26/animal. This study provided evidence that exposure of the general population of feedlot cattle to BVDV PI animals resulted in substantial costs attributable to negative effects on performance and increased fatalities.

Division of selection area at rest and feeding areas and setting the straw bedding norms for heifers of 6-12 months of age as 2 kg per animal daily, 13-16 months of age – 3 kg and 17-25 months of age – 4 kg promotes increases of average daily live weight gains compared to traditional technological solutions and norms at 6,4%, hemoglobin content – at 3,7%, erythrocyte quantify – at 5,6%

In course of a long-term selection breeding activities in the conditions of the Republic of Belarus on the basis of Belarusian Large White breed of swine there were created two high-productive lines - Delfina 37755 and Svitanka 3884. Individual selection of animals was realized in accordance with the main indexes of productive ability, development and conformation type. There were selected parent lines, there were used methods of intrastrain breeding and hybrid between lines, mild inbreeding on parental line. Bores and breeding sows were evaluated in accordance with their posterity productivity by means of a control feeding method. Productive indexes for Delfina 37755 line were 11,7 piglets, for Svitanka 3884 line – 11,9 piglets; age of live weight gain of 100 kg – 189 and 182 days, respectively; average daily weight gain – 735 gram and 749 gram; forage expenses – 3,5 and 3,51 fodder units; backfat thickness – 27,2 and 26,2 mm; ham weight – 10,9 and 11,2 k, respectively

Perfect norms of floor area and feeding front are determined for replacement heifers on free stall management. These norms promote creation of more comfortable conditions of management, increase of average daily live weight gains at 9,1%, hemoglobin content – at 4,8%, erythrocyte quantity – at 6,3%

In the experiment with swine there was studied the influence of ultra-violet and various doses of narrow-band red radiation on efficiency and safety of animals. It has been established, that efficiency and safety of animal skilled groups in comparison with animals of control group has risen. Use of an ultra-violet and narrow-band red irradiation with frequency rate of inclusion of red light three times has a day allowed to raise average alive mass of young plants of pigs on 2,5 kg or on 9,1% (Р less than 0,01), a daily average gain - on 9,6%(Р less than 0,001) and safety of animals - on 10%