In the conditions of the Republic of Belarus there was realized the evaluation of genetic inheritance indexes of producing bulls at a cattle breeding enterprise in Belarus depending on a selection source (in accordance with an average productivity of female ancestors) in order to use them properly for the increasing of genetic potential of black-and-white Belarusian cows in Gomel region. The carried out analysis allowed to draw a conclusion, that bulls of national breeding lines according to the indexes of cow milk yields concede foreign bulls, i.e. delivered of Sweden on 2744 kg of milk or on 27,5% and from Russia and Hungary - on 1272-2906 kg of milk or 12,7-29,1% (Р less than 0,001). In accordance with butter-fat yielding capacity of bull mothers obtained at breeding farms of Belarus and in accordance with groups delivered from the other countries there were stated no essential distinctions (0,05). Butter-fat yielding capacity percentage of bull mothers varied within 3,99-4,10%. However, the yield of dairy fat per lactation the difference was in favour of bull mothers delivered from Sweden (114 kg or 27,9%) at P less than 0,001. Distinctions on milk producing ability of bull mothers from various cattle breeding enterprises of Belarus were revealed. It was established, that at mothers of bulls delivered from Hungary the variability of milk yield was the highest (3032 kg or 23%). Low variability indexes of milk yield and butter-fat yielding capacity percentage was typical for bull mothers of the Belarusian selection. The standard deviation at them made 872 kg of milk yield with 9% variability coefficient, and 0,03% - for butter-fat yield and 7% respectively. Variability on all indicators of dairy efficiency of bull mothers from various cattle breeding enterprises of Belarus in most of the cases was low - from 2,3 to 13%.

In the conditions of the Republic of Belarus as a result of task-specific selection and breeding work there was developed and approbated Berezinsky breed type of Belarusian meaty breed. Sows of the studied breed type were notable for high indices of reproductive signs: the average multiple pregnancy in three breeding swine herd was 11,1 pigs per farrowing; milkability - 55 kg, litter size at weaning stage at 35-day age - 87,1 kg. The predominancy over the forecast exponent indices made 4,7-5,7%. In course of the study there were analyzed the forecasted indexes of the basic breeding signs of Berezinsky breed type of Belarusian meaty breed for 2005-2010; productivity indices of the experimental sows; coefficient of variations of sow productivity.

The Republican Agricultural Breeding Unitary Enterprise Zarechje of the Republic of Belarus is the basic horse-breeding enterprise of Belarusian coach horse breeding. In the enterprise there are 27 mares and 2 studhorses; all animals are purebred. It is established, that unaltered male horses and mares belong to Belarus coaching breed, all pedigree animals have a high class: 15 horses belong to an elite class that makes 75% from all herd, 4 heads concern the first class (20%), and 1 head – to the second class (5%). Measurements surpass the standard that can prove the appropriate selection and breeding work in the enterprise. After studying the measurements of studhorses of the enterprise in comparison with the standard it was established, that the height at crest of stallions on the average exceeds the breed standard on 30%, slanting length of a trunk - on 5,0%, a breast grasp - on 4,0% and a metacarpus grasp - on 6%. For improvement of herd of horses it is necessary to organize correctly a coupling campaign with drawing up of the coupling plan and selection of a uterus to stallions; to use in copulation only the best elite stallion.

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

Development of a new method of boar evaluation taking into account their beef-making and fattening qualities as well as their posterity viability for the further selection of the best ones and for the culling and ranking of the worst ones was realized in the conditions of a large pig-breeding complex of the Republic of Belarus. Scientific and economic experiment was realized at the JSC Sozh, Gomel region (Belarus) at the pig-breeding complex with 108 thousand livestock heads of annual fattening. At a finishing stage of sow hybridization the combinations of Large White х Landrace and Large White х the Belarusian Meaty breeds were inseminates by boars of 990 synthetic lines (N11151 and N11146), the Belarusian Meaty breed (N3495), Landraces of the Polish (N40, N37, N78) and German selection (N11262, N11263, N11266), and also by a hybrid boar of 990 lines х Petren (N11145). Sow insemination was realized in three technological groups. Sows were selected taking into account their breed, age and last productive ability in order to avoid inbreeding. At the same time, each boar was checked up on the breeding stock for identical quality. The final estimation of boars was stated at the stage of achievement by their posterity of selling weight (before sending to a meat processing plant). The offered method made it possible to get an objective comparative estimation of breeding characteristics of tested boars in the conditions of a complex

Influence of 33 imported heads Landrace breed boars of foreign selection on feeding performance and meat productivity of swine of the Belarusian Meaty breed was studied in the conditions of the Republic of Belarus for the enhancement of Belarusian breeds genealogical structure. There was stated the positive influence of Landrace Breed on feeding performance and meat productivity of mixed bred stores obtained after the introductive crossing with sows of Belarusian Meaty breed which was expressed in the predominancy of mixed bred hogs over the purebred ones at the stage of fattening performance test: at the age of reaching 100 kg body weight – on 0,7%; at average daily weight gain - on 1,5%; at feed consumption - on 1,2%. Mixed bred stores also had thinner back fat (on 0,9 mm) and bigger loin (on 0,4 square cm). There was stated the one-sided influence of boars of Landrace Breed on feeding performance and meat productivity indices of mixed breeds. It was established, that hybrids of four lines (Zaboj, Zalet, Zont and Bison) with regard to control groups showed the effect of heterosis at age of achievement of body weight of 100 kg, at a daily average weight gain and at forage consumption in the following rates: 1,5% (Р less than 0,05), 2,8% and 1,5% (Р less than 0,05) for Zaboj line; 2,3%, 4,9% and 2,1% (Р less than 0,01) for Zalet lines; 1,4%, 3% and 1,5% (Р less than 0,05) for Zont lines; 3% (Р less than 0,001), 6,7% and 2,7% for a line of Bison. In meat productivity indices there was stated the in-between character of inheritance which caused the decreasing of fat thickness and increasing of loin eye area at descendants of trial groups of lines: Zaboj, Zalet, Zenit, Zont on 0,88 mm (Р less than 0,05) and 0,6 square cm, 1,7 mm (Р less than 0,01) and 2,1 square cm (Р less than 0,001), 1,3 mm (Р less than 0,01) and 0,9 square cm, 1,4 mm