Effect of inbreeding on pre-weaning and sow performance traits in Large White Yorkshire pigs

The present study was undertaken to study the effect of inbreeding on pre-weaning and sow performance traits of Large White Yorkshire pig population. Data on 7596 Large White Yorkshire pigs maintained at PGRIAS, Kattupakkam from the period of 1990 to 2015, were subjected to least square analysis to study the effect of inbreeding and other non-genetic factors viz., period, season, sex, parity, litter size at birth on various traits using general linear model. Inbreeding was calculated as Wright's path co-efficient. The mean inbreeding co-efficient of LWY population studied was 2.45 %. Among 7596 animals in the pedigree, 2088 were inbred and the range of individual inbreeding co-efficient (F) was from 0 to 37.5 per cent. The average inbreeding in the inbred population was 8.92 %. The effect of inbreeding was found to be significant for weaning weight, pre-weaning average daily gain and litter weight at weaning, where the traits were found to increase with inbreeding (enhancement). The absence of depressive effect on fitness traits observed in the present study could be due to lower levels of inbreeding, which was possible due to periodic introduction of breeding animals and planned mating.