Genetic Parameters of Semen Quality Traits and Production Traits of Pure-bred Boars in Thailand

The objective of this study was to estimate genetic parameters for semen quality and production traits of pure-bred Finnish-Norwegian boars raised in Thailand. Data used in this study were 9,760 records of semen collection and 108 records of performance tests (from 25 Duroc, 59 Landrace, and 24 Yorkshire boars). Semen quality traits considered per collection were semen volume (SV), semen concentration (SC), total sperm (TS), and total abnormality (TA). Data were recorded from 2001 to 2009, except for TA, which was not recorded until 2003. Production measures from each boar were average daily gain (ADG) and backfat thickness (BF). Results showed that heritabilities varied from 0.29 to 0.49 for semen quality traits; besides, they were 0.40 and 0.18 for ADG and BF, respectively. The repeatability estimates for semen quality traits ranged from 0.30 to 0.61. No significant genetic correlation between semen quality and production traits was observed, except for a relationship between SV and BF (rg = -0.52 ± 0.19). Among the semen quality traits, significant genetic correlation was observed only between SV and SC (rg = -0.45 ± 0.18) and between SV and TS (rg = 0.57 ± 0.16). In addition, ADG had a negative genetic relationship with BF at high magnitude value (rg = -0.76 ± 0.11). These results suggest that semen quality traits have sufficient genetic variation for selection. Furthermore, traditional selection for AI boar using ADG and BF as selection criteria will not reduce semen quality.