Genetic parameters for lean meat yield, meat quality, reproduction and feed efficiency traits for Australian pigs 1. Description of traits and heritability estimates

Data from 1799 Large White and 1522 Landrace boars were used to obtain heritability and litter effect estimates for performance, carcass and meat quality traits applying a REML procedure fitting an animal model. Analysed traits included average daily gain from three to 18 weeks of age (ADG1) and average daily gain, feed intake and feed conversion ratio from 18 to 22 weeks of age. Carcass traits included two backfat measurements and one muscle depth measurement taken on the live animal using realtime ultrasound and on the carcass using Hennesy Chong equipment. Further carcass traits included weight of the whole back leg (BLW) and weight of the ham (LMW). Meat quality traits included pH recorded 45 min and 24 h after slaughter, colour of the m. longissimus dorsi and m. multifidus dorsi, drip loss percentage and intramuscular fat content. For ADG1 heritability and litter effect estimates were 0.10(60.05) and 0.20(60.04) in Large White and 0.48(60.09) and 0.08(60.04) in Landrace. Data structure might have limited simultaneous estimation of these two effects. Heritability estimates ranged from 0.13 to 0.27(60.04 to 0.05) for further performance traits and from 0.45 to 0.62(60.05 to 0.07) for backfat measurements. Heritability estimates were lower for Hennesy Chong measurements in comparison to realtime ultrasound measurements. Heritability estimates for BLW and LMW were 0.22(60.05) and 0.38(60.07). Estimates of heritabilities for meat quality traits ranged from 0.14 to 0.35(60.04 to 0.06).  2000 Elsevier Science B.V. All rights reserved.