Genetic Analysis of Major Production and Reproduction Traits of Korean Duroc, Landrace and Yorkshire Pigs

SIMPLE SUMMARY: Korean purebred pigs are generally selected according to their production and reproduction traits in order to optimize commercial pig performance. It is, therefore, crucial to assess the genetic parameters of these traits to understand their genetic potential. For this reason, we analyzed three production traits (average daily gain, ADG; days to 105 kg weight, DAYS105; backfat thickness, BFT) and three reproduction traits (age at first farrowing, AFF; total number of piglets born, TNB; total number born alive, NBA) in Korean Duroc, Landrace and Yorkshire pigs using animal models. We found that production traits were moderately to highly heritable, whereas reproduction traits were mostly lowly heritable. Evidence of selection improvement of DAYS105 and ADG without increasing BFT was also available. Genetically, NBA and TNB were positively and tightly linked, which further pointed to the need for careful breeding plans that consider the negative impact of higher TNB over NBA on piglets’ mortality. Furthermore, AFF needs systematic attention in relation to genetic progress. Overall, most of our estimates suggested further improvement possibilities through selection. We argue that current genetic parameters could greatly assist future breeding and selection decisions for performance improvements in Korean pigs for specific purposes. ABSTRACT: The study aimed to investigate the genetic parameters of the production and reproduction traits of Korean Duroc, Landrace, and Yorkshire pigs. Three production traits, namely average daily gain (ADG), age at 105 kg body weight (DAYS105) and backfat thickness (BFT), and three reproduction traits, namely age at first farrowing (AFF), total number of piglets born (TNB) and number of piglets born alive (NBA), were analyzed. The reproduction dataset was based on first-parity gilts only. However, the production dataset comprised pigs of both sexes. Genetic parameters were estimated from individual datasets using a multiple-trait animal model in AIREMLF90 software. The heritability values of ADG, DAYS105 and BFT were 0.34–0.36, 0.41–0.44 and 0.38–0.48, respectively, across breeds. Heritability values for AFF, TNB and NBA were 0.07–0.14, 0.09–0.11 and 0.09–0.10, respectively. Strong genetic correlations existed between ADG and DAYS105 (−0.97) and between TNB and NBA (0.90 to 0.96). In line with breeding goals, all productive traits in Duroc pigs, and all reproduction traits except AFF in Landrace and Yorkshire pigs, also showed noticeable improvements in recent years. In conclusion, we believe that our findings on economic traits would greatly assist future pig breeding decisions in Korea.