Shanxi Lean Pigs New Line (sd-iii System) Genetic Analysis

Genetic Analysis of Shanxi Lean-Type Swine(SD-llI) ABSTRACT The paper presents the estimates of variance components and genetic parameter for 18 trains of Shanxi Lean-Type Swine (SD-Ill) population using animal models by multiple traits derivative-free restricted maximum likelihood. The phenotypic parameter, the generational average inbreeding coefficients, the animal additive genetic effects were calculated. Animals were ranked according to their BLUP-EBVs of main economic traits to provide information for selection. The phenotypic and genetic trends of the main economic traits per generation were analyzed. The results suggest that the heritability estimates of birth weight, weaning weight, 70-day weight, 6-month weight, 6-month length of body, 6-month height of body, 6-month heart girth, 6-month circumference of cannon bone, back-fat thickness, average daily gain, total number of piglets born, number of piglets born, birth litter weight, birth weight per piglets of litter, 20-day litter weight, weaning litter weight, weaning weight per piglets of litter, number of piglets weaned were 0.17, 0.33, 0.16, 0.26, 0.27, 0.33, 0.23, 0.16, 0.33, 0.30, 0.16, 0.12, 0.25, 0.19, 0.20, 0.10, 0.24 and 0.19, respectively. The results also show that there were remarkable positive genetic correlations between 6-month weight and birth weight (0.36), weaning weight (0.30), 70-day weight (0.49). Genetic correlations between weaning litter weight and total number of piglets born, number of piglets born, birth litter weight, birth weight per piglets of litter, 20-litter weight, weaning litter weight, weaning weight per piglets of litter, number of piglets weaned were 0.30, 0.41, 0.53, 0.30, 0.65, 0.45, 0.81, respectively. Genetic correlation between birth weight per piglets of litter, weaning weight per piglets of litter and total number of piglets born, number of piglets born alive were ?.08, -0.10 and ?.07, -0.03. Genetic correlation and phenotypic correlation between back-fat thickness and average daily gain were 0.02 and 0.02, respectively. Genetic trend of total number of piglets born, number of piglets born alive, weaning litter weight, 6-month weight, average daily gain, back-fat thickness were O.Ol3SSpiglets/generation, 0.01 426piglets/generation, 0.0541 5kg/generation, 0.41 708kg/generation, 1.07452 g/generation, -0.00024 cm/generation, respectively.