Development of New Phenotyping Strategies to Allow for Real-time Belly Primal Selection in Canadian Breeding Hogs
This thesis investigated the use of real-time ultrasound for prediction of belly traits in Canadian breeding hogs. Bellies from 17 pigs had the first sixteen 1” strips removed and analysed for fat and muscle distributions. Locations with strong correlations to the rest of the belly that were suitable for live ultrasound scans were identified as between the 3rd and 4th last ribs halfway down the side of the pig and 2-3” below the first location. 323 purebred Duroc and Pietrain gilts were live-scanned using the aforementioned locations for depths of subcutaneous fat, cutaneous trunci (CT), and belly cut. Multiple regressions adjusted for Weight and Date to predict carcass measures from ultrasound measures produced R2 of 0.34, 0.23, and 0.38, for Fat, CT, and Cut, respectively. Heritability estimates from univariate models of belly traits were 0.42, 0.16, 0.27, 0.20, 0.21, and 0.16 for BF, Cut, Sfat1, Scut1, Sfat2, and Scut2, respectively.