JOINT EFFECT OF 21 MARKER LOCI AND EFFECT OF REALIZED INBREEDING ON GROWTH IN PIGS

Four litters produced by father-daughter matings (back crosses) result ing in 35 animals with a theoretical inbreeding coefficient of 25% wer e typed with 21 independent informative markers. The differences betwe en the two founder animals were estimated, based on the marker informa tion, and it tons found that the founder boar had higher genetic poten tial for proportion of lean meat and lower genetic potential for growt h than the founder sow. The proportion of the genome of each offspring which was identical by descent was investigated On the basis of these markers the realized inbreeding teas found to vary between 7 and 47%. The linear decrease in weight at days 1, 26 and 136, average daily ga in and proportion of lean meat regressed on the realized inbreeding we re estimated to 0.6 kg, 2.4 kg, 18 kg, 95 g/day and 15 g/kg, respectiv ely. For weight at day 88 a corresponding linear increase of 11 kg was observed. The joint effect of founder differences and realized inbree ding were as expected negative and statistically significant for all g rowth traits.