| Abstrakt: |
Transferrins (Tf) were typed for 343 boars and 1,094 gilts, the parents of 1,208 litters, for an examination of possible relationships between Tf type and litter size in five breed classes (Duroc, Duroc selected, Yorkshire, Yorkshire selected and Duroc × Yorkshire crossbred selected groups). There were three transferrin phenotypes, AA, AB and BB, resulting from alleles TfAand TfB. Since there were few matings involving homozygous AA types in each breed class, they were excluded from the analyses. The Tf BB boars in cross-breds sired larger numbers of piglets born alive (8.67) than AB boars (7.76). Matings of BB males × AB females resulted in the largest numbers of piglets born alive (8.71) and weaned (8.39) in the Duroc selected group. The BB male × AB female matings in crossbreds resulted in larger litters (10.85 farrowed, 8.87 born alive and 8.19 weaned) than the reciprocal matings of AB males × BB females (9.84, 7.65 and 7.13). Nevertheless, there were no statistically significant effects of sire and dam Tf genotype and of their interaction on number of pigs farrowed, born alive and weaned/ litter for any of the five breed classes. This suggests that the use of transferrin typing is of questionable value to improve litter size in swine. |
