Objective—To determine whether selection for the homozygous A136R171 genotype that confers resistance to classic scrapie infection negatively affects production traits in sheep. Animals—996 commercial lambs obtained from 2 flocks at separate locations across 3 consecutive years. Procedures—Genotyping at codon 136 and 171 was performed by use of commercially available testing or a single-nucleotide polymorphism assay. Carcass data were collected without knowledge of genotype approximately 24 hours after slaughter by an experienced grader. The model to analyze associations between prion protein (PRNP) genotype and production traits was based on genotype, breed, or both as fixed effects and days on feed as a covariate. Results—Average daily gain was significantly associated with only combined codons 136 and 171. In flock 1, weaning average daily gain was significantly greater in AA136 sheep than heterozygotes; the difference between QR171 and RR171 sheep, compared with QQ171 sheep, were not significant although QR171 and RR171 sheep had higher values. However, in flock 2, average daily gain was significantly greater in AV136 sheep than AA136 sheep and in QR171 sheep than QQ171 sheep. Conclusions and Clinical Relevance—Findings suggest there is an advantage for average daily gain in lambs with an arginine allele at codon 171, but there were no other genotype effects on production traits. Thus, selection for the resistant arginine allele at codon 171 to comply with USDA scrapie eradication guidelines should not be detrimental to lamb production in commercial flocks. Effects of codon 136 on average daily gain were ambiguous.

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.

Use desirable alleles allows to raise the reproductive quality of the sows, in particular, amount alive piglets at birth (EPORTT), safety piglets (MUC4CC) meat quality pig (IGF-2QQ) that in turn allows to get the additional income at realization of the saplings

Into the programme hen selection of Belarus Autoseksnyj cross there was introduced the indeks of the so-called quality of eggs which is defined by removal defective on quality of a shell of eggs in 30 and 52-week age. The size of variability of an indicator of 16,0-25,4% and hehtability 0,3-0,4 allows to lead selection on increase in an exit of qualitative eggs. Influence on quality of eggs with defects of a shell of age of hens, intensity eggs, weights of eggs, a linear accessory is established

In the conditions of the Agricultural Complex Belaya Rus the highest productive values of sows are obtained in period of the fourth-sixths farrowings. The highest level of reproductive traits is shown by sows of Landrace and Belorusian meaty breeds

Usage of boars of meat breeds Yorkshire, Duroc and Landrace of Canadian selection for crossing them with cross and pure breeds of sows promotes increase of fattening and meat-fat productivity of the obtained hybrids. The best parameters of feeding efficiency the hybrid young growth of combinations (BMхL)хL and (BMхL)хD at which the age of achievement of alive weight of 100 kg and a daily average gain has made 177,2 day (P less than 0,001) and 803 g (P less than 0,001), 179,5 day (P less than 0,001) and 801 g (P less than 0,001), differed at expenses of a forage of 3,38-3,40 fodder units accordingly

Research of the selection efficiency of boars of Belarusian meaty and Large White breeds for reproduction and productivity indices was realized in the selection and breeding centre Zadneprovski in the Republic of Belarus. The influence of 25-percentage level of boar selection for sperm production with the dominancy of relative average values of an initial population on statistically significant difference within the limits P less than 0,05-0,001 was proved. Application of an evaluation criterion of animal breeding abilities by the degree of frequency of departures from a population level with a value which reflects the intensity of selection in shares of an average quadratic deviation made it possible to raise the breeding value of boar of both genotypes in accordance with the productive qualities of descendants in comparison with average sizes of populations of two breeds on statistically authentic difference at P less than 0,05-0,001. Decreasing in the studied indicators of efficiency of offsprings concerning initial fatherly forms could be explained by a stronger influence of environment conditions rather than genetic predisposition of genotypes to the given traits

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.

Investigation of quality and quantity indexes of sperm production of boars of Yorkshire, Landrace, Duroc breeds of Danish selection was realized in the conditions of the Republic of Belarus. Quality and quantity indexes were analyzed in accordance with ejaculate volume, spermium concentration and activity at different age-specific periods in the comparative aspect. Thorough analysis of quality indexes (ejaculate volume; spermium concentration; spermatozoon motility; sperm quantity) of semen production of studied breeds at different age-specific stages (before 7 months old; 7-10 months; 10-12 months; 12 months and older) was presented. Coefficients of variation of valuation indexes of semen production were stated. Research results showed that the lowest ejaculate volume was typical for boars of Duroc breed, but the quantity of spermium in ejaculate of this breed since 10-month old age was the highest – 92,6 milliard, that made it possible for this breed of boars to take premier place according to the index of spermium quantity in ejaculate. The same index for boars of Landrace and Yorkshire at age of 12 months old and older was 77,5 and 76,3 milliards, respectively. High variability of indexes of evaluation of semen production was due the reason that the research was taking place at the period of formation of productivity over the whole pig stock. Research results proved that indexes of semen production of producer boars of Yorkshire, Landrace, Duroc breeds of Danish selection depended on the breed and high variability indexes

The present research deals with slaughter and morphological characteristics as well as physical and chemical properties of meat of young hogs taken off fattening estimated bearing relationship to back fat thickness of sow. The above data have been obtained in the commercial swine production farm specialized in three-way rotational crossbreeding in its breeding programme