ASSOCIATION OF SERUM HEMOPEXIN, TRANSFERRIN, PREALBUMIN AND ALBUMIN1 TYPES WITH PRODUCTIVE TRAITS OF YORKSHIRE AND LACOMBE BREEDS OF PIGS
Sera from 354 Yorkshire and 97 Lacombe pigs on official Canadian Record of Performance test were analyzed by starch gel electrophoresis to determine their hemopexin, transferrin, prealbumin and albumin1 types. Estimates of the possible effects of different serum protein types on daily gain on test, age at slaughter adjusted to 70.37 kg carcass weight and seven other carcass characteristics were obtained by least squares methods. Significant associations were observed between each of the four serum protein loci and at least one of the nine productive traits in the Yorkshire breed. In the Lacombe breed only the prealbumin locus, which was associated with total backfat thickness, had any effect on any one of the nine productive traits. Since the results for the two breeds were not in agreement with each other and the magnitude of the difference between extremes was small, it was concluded that a correlated response in swine performance could not be expected from selection on the basis of serum protein polymorphism.