In vivo computed tomography evaluation of the composition of the carcass and main cuts of growing pigs of three commercial crossbreeds

• Pig body growth and composition differs among crossbreeds.
• Composition differences among crossbreeds are visible in the main pieces.
• Fat growth rate relative to live weight is faster than lean and bone growth rates.
• Computed tomography is suitable to evaluate composition of live pigs.
• Knowledge of growth performance can provide economic benefits to all meat chain.

The purposes of the present study were: (1) to evaluate variations in the body composition of three genetic types at the live weights of 30, 70, 100 and 120 kg by analysing live pigs with CT and (2) to determine the allometric growth of the main body parts in relation to body weight and lean, fat and bone contents in relation to the cut weight and body weight. Forty-five gilts of various genetic types: Duroc×(Landrace×Large White), Pietrain×(Landrace×Large White) and Landrace×Large White were scanned in vivo at 30, 70, 100 and 120 kg. CT images were analysed and used to predict the lean, fat and bone contents. The results reflected clear differences in the body compositions between crossbreeds, particularly when pigs were ≥ 100 kg. However, certain significant differences also appeared at the earliest weight of 30 kg, which demonstrates the importance of genetic traits.