SOME RELATIONSHIPS BETWEEN BLOOD GROUP FACTORS AND ECONOMIC TRAITS IN SWINE

Twenty-four sires, 168 dams, and 653 market pigs of several breeds were typed for up to 32 blood group factors to investigate possible relationships between blood group factors and economic traits. Least squares methods were used to study the effects of blood group factors on five measures of reproductive performance (numbers born, born dead, alive at birth, alive at 21 days, and alive at 56 days), four stages of growth (weight at birth, 21 days, 56 days, and 154 days), four carcass traits (length, total backfat, loin eye area, and lean cut yield), and on susceptibility to atrophic rhinitis. A greater frequency of low F-test probabilities than expected was observed for both growth and carcass traits. F-values for 10 of 107 factor-growth trait combinations (9.3%) and 16 of 104 factor-carcass trait combinations (15.4%) were significant (P < 0.05). Of the significant F-values, five growth (4.7%) and six carcass (5.8%) were highly significant (P < 0.01). No excess of low F-test probabilities was observed with...