A prospective cohort study was undertaken in a farrow-to-farrow swine herd to describe patterns of pneumonia, and to identify host risk factors associated with the extent of pneumonic lesions in 2 weight groups of slaughter swine. The risk of coughing and pneumonic lesions increased with increasing age of pigs within the herd (P < 0.0001). The age-specific prevalence of pneumonic lesions was low (2.7%) in pigs < 16 weeks old at slaughter, but increased rapidly when pigs were between 16 and 22 weeks old (8.6 to 67.9%). After 22 weeks, the prevalence remained relatively constant at about 80%. Associations between possible risk factors and pneumonia were investigated by use of multiple-regression models. Age at weaning (< 24 days) and birth weight (< 1 kg) exerted small, but significant (P < 0.002), effects on the extent of pneumonic lesions in pigs slaughtered at 30 to 50 kg live weight. For pigs slaughtered at 90 to 110 kg, pneumonic lesions were more extensive (P = 0.007) in pigs sired by Yorkshire boars than pigs sired by non-Yorkshire sires (Duroc, Hampshire, Chester White, or American Spotted). Other host factor variables including weaning weight and clinical diseases (atrophic rhinitis, diarrhea, and arthritis) were not associated with pneumonia extent in either weight group. Higher pneumonia percentages were also associated with reduced growth rates in the grower/finisher phase. Pigs sired by Yorkshire boars grew significantly (P < 0.0001) more slowly from entry into shed 2 (mean, 38 kg) until about the time of exit (mean, 92 kg) than pigs sired by other breeds (747 g/d and 795 g/d, respectively).

In the conditions of the Republic of Belarus there was realized a comparative study of meat productivity of mongrel Gereford х black-and-white heifers ad purebred black-and-white heifers in the conditions of different levels of concentrated feedstuff in cattle diets; and determine the most efficient and long-term method of animal breeding for meat. Research results showed that breeding of meaty of hybrids of Gereford х black-and-white heifers of the second generation without using the feeding concentrates in their diets or on using rations with a low rate of feeding concentrates (10-20%) proved to be more effective, than breeding of purebred black-and-white herdmates (for which specific density of the concentrated forages in diets made up 20% through pregnancy). Hybrids on Gereford breed in accordance with meat productivity level surpassed the purebred black-and-white animals. The most considerable results were marked at hybrid heifers with relative density of concentrates in a ration of 20% which in accordance with slaughter weight indexes surpassed the herdmates of black-and-white breed on 39,1 kg or on 23,68%, in accordance with slaughter yield - on 8,2%, in accordance with fresh carcass weight - on 37,9 kg or on 23,8%, in accordance with weight of inner porc - on 1,19 kg or on 20,62%.

In animal feeding technology much attention is given to application of biologically active substances for metabolism stimulation. One of such biologically active substances is carnitine, an anabolic preparation of nonhormonal nature, cofactor in system of oxidation of fat acids. It participates in processes of acetylation at oxidation of fat acids together with acyl-CoA and other enzymes, promotes carrying over of cytoplasmatic Coa-derivatives of fat acids inside mitochondrions. It increases absorption speed from a digestive path of nutrients of forage, raises use of fat acids for the power purposes. Under its influence synthesis of triglycerides decreases and synthesis of phospho-lipids increases. Carnitine also protects cells against toxic accumulation of components of acyl-CoA of endogenic or exogenous origins, such as acylic groups of carnitine ethers which then can pass into liver for dissimilation or in kidneys for allocation in urine. Carnitine synthesis satisfies body requirements, but in the conditions of a hightened stress, high productivity, as well as in the conditions of lowered carnitine content in forage or in the conditions of the increased content of fats it should be applied as additive to diet. As a result of the realized study it was established, that the optimal quantity of carnitine application in diets for stores husbandry and fattening is dose of 50 g/t of mixed fodders. Application of carnitine in an optimum dose renders the positive impact on animal organism, promotes the increasing average daily weight gain on 5,1% (Р less than 0,001). Application of carnitine in diets of swine stores increases a slaughter yield on 2,1%, meat content per carcass - on 2,3%, a loin eye area - on 8,8%. Carnitine application in a dose 50 g/t of mixed fodders makes it possible to receive the additional profit at a rate of 4,57 USD per 1 head