Genotype by Temperature Grouping Interaction for Farrowing Rate at First Insemination

This study examined the effect of temperature grouping (T-group) on genetic parameters for farrowing rate from first insemination (FR). Further, this study investigated if genotype by T-group interaction for FR exists. The lowest FR was observed in T-group 1 and 3, which were both characterised by high mean maximum temperature (>29⁰C) prior to mating. The heritability of FR across all T-groups differed only marginally from each other and were low (0.03, 0.00, 0.03, 0.02, and 0.03 for T-group 1, 2, 3, 4 and 5, respectively). Genetic correlations between FR recorded in different T-groups were generally positive and high (>0.70), with the exception of the genetic correlation for FR between T-group 1 and 5 which was lowly negative and close to zero (-0.10±0.27). This is an indication that FR in T-group 1 and T-group 5 were two genetically different traits and should be treated as separate traits in pig breeding programs.