Carcass characteristics of 241 crossbred pigs (Korean wild boars × Landrace sows) were analyzed to examine variations in fasted body weight (FASTWT), carcass weight (CARCWT), dressing percentage (DP), back fat thickness (BFT) and longissimus muscle weight (LMW), and to estimate genetic and phenotypic parameters using three different slaughter-end points. Covariates in the least squares full sib model were slaughter age, fasted body weight and back fat thickness of the carcass. Coefficient of variation was highest for BFT followed by LMW, CARCWT, FASTWT and DP in magnitude. Regressions of three covariates on traits were all linear. However, slaughter age was not significant as a linear covariate for five traits while FASTWT was significant for CARCWT and LMW and BFT was significant for all remaining traits. Genetic and phenotypic variation was considerably reduced by regressing FASTWT or BFT in the model. Heritability estimates of FASTWT, CARCWT, DP and BFT were 0.68, 0.61, 0.11 and 0.49, respectively, using slaughter age as covariate (model 1). Those of CARCWT, DP, BFT and LMW were 0.15, 0.15, 0.30 and 0.11, respectively, using FASTWT as covariate (model 2). Heritability estimates of the traits using LMW as covariate (model 3) were similar to the estimates from Model 1 except that the estimate of CARCWT was reduced to 0.39. Genetic or phenotypic correlations among FASTWT, CARCWT and BFT were all positive and moderate to high. Those between BFT and LMW were also positive and low to moderate. However, genetic and phenotypic correlations between DP and CARCWT were positive while those between DP and FASTWT were negative. It was suggested from this study that differences in carcass yield traits be determined using slaughter age or back fat thickness as slaughter-end point and carcass quality traits using fasted body weight as slaughter-end point.

Records from a total of 202 crossbred pigs were classified by their ear type and coat color to examine the presence of interrelationships with growth performances. Crossbred pigs were F2 generations of full sib family out of ten Landrace sows bred by 5 Korean domestic boars. Heavily drooped ear type was predominant, 195 out of 202 pigs over the other two types (1 straight and 6 slightly drooped). Coat colors were classified as four categories, all white, all black, dominant white or dominant black. Ratio among coat color categories did not fall within Mendelian principle of independence regarding two loci involved. There was dependency between ear type and coat color. However, due to rarity of ear types other than heavy drooped, dependency comes from distribution of those rare ear types. Three least squares models to test the effect of ear type and coat colors on growth performances were analyzed. First model analyzed effects on birth weight, body weight at 3 and 6 weeks and ADG's before weaning and between 3 and 5 weeks of age. This model included sex in addition to ear type and coat color. Second model analyzed postweaning growth traits (initial weight, final weight and ADG between these periods) upon initiation of performance testing. This model included effects of sex, test group and start age (as a covariate) in addition. Third model was fit for fasted weight before slaughter and included the effects of sex, test group and age at slaughter (as a covariate). The effects of sex and ear type were not significant source of variation for all traits. Test group was a significant source of variation for all the postweaning traits. Effect of coat color was not significant until the initiation of performance testing and became significant then after. Least squares means of dominantly black pigs were significantly lower than the other three coat colored pigs in final weight around 195 days of age and in ADG from the start of performance test and final weight measure.