| Popis: |
The authors presented the results of experimental studies on the stress-resistant of pigs. The first group is a breed created in Sapphire Ltd. This breed is a breeding group (BG) in purebred breeding and their mixtures in two- and three-breed combinations with Landrace (L) and Duroc (D) boars under conditions of industrial farm technology in Siberia. Two methods assessed stress-resistant of piglets of different breed groups. The first method is “weaning crisis”. The second method is a com-parison of cortisol levels in the blood. Three-breed weanling piglets (SGxL)xD turned out to be the most stress-sensitive. Stress-resistant piglets had an effect on their growth during the rearing period. During this period, stress-resistant animals of all breed combinations had higher average daily gain than stress-sensitive animals (P < 0.001). Stress-resistant animals of the breeding group (SG) showed an average daily growth of 547.5 g during the fattening period. Also, the stress-resistant animals of the breeding group reliably surpassed the stress-sensitive pigs by 461.4 g (P < 0.01), the two-breed pigs by 455.9 g and 404.7 g and the three-breed pigs 451.8 g and 419.2 g, respectively. There was a statistically significant advantage in the indices of the average daily gain among the purebred young-sters of the breeding group (SG) (543 g) compared to the two-breed pigs (447g) and the three-breed pigs (402g), i. e., by 17.8 % and 26 % at P < 0.001. The authors found that the EAAcr/- genotype in stress-sensitive pigs was more common than EAA-/(0.71 ± 0.07 vs 0.48 ± 0.09). Stress-resistant pigs of the breeding group (SG) with EAE edg/edf blood group genotypes were characterized by increased growth intensity and reliable superiority over stress-sensitive pigs. The authors believe that these genotypes can be accepted as preliminary candidates for genetic markers of stress resistant. Blood cortisol levels appeared to be unrelated to stress-resistant compared to the “weaning crisis” method. This relationship (blood cortisol level with stress-resistant) applies to all studied breed combinations, both individually and as a whole. |
