Within litter effect of halothane genotype on performance and conformation

Abstract

A DNA test is now available for use in pigs to identify halothane genotype (Fujii et al, 1991; Otsu et al 1991). It has been established that the positive phenotype (nn) at the halothane locus shows advantages in lean yield accompanied by disadvantages in meat quality and stress susceptibility (Webb et al, 1987). The aim of this study was to accurately estimate the relative performance of the halothane heterozygote (Nn) within litters for both production and conformation traits in two breeds of pig.Halothane genotype was determined for 1131 entire boars and gilts from 389 litters, 145 sires and two lines (Table 1). Line A was derived from a single breed, and selected on rate of lean growth for over 10 generations as a closed population. Line B was a closed synthetic population containing Pietrain and Hampshire.