LIFETIME WOOL. 9. PROGENY BACK FAT AND EYE MUSCLE DEPTH

摘要

Differences in body composition generated by plane of nutrition and diet composition are minimised when animals are compared at the same bodyweight. In a review by Black (1974), it is evident that poor nutrition early in life can increase the proportion of carcass fat when animals are compared at the same bodyweight. Greenwood et al. (1998) found that low birth weight lambs (2.2 kg) contained more fat (14.1 v. 11.9%) at 20 kg liveweight than high birth weight lambs (4.9 kg). Nolan (1999) lends credence to this evidence, suggesting that metabolism can be programmed by poor nutrition during foetal and infant life so that when nutrition is later improved, the animal is less productive. Therefore, progeny from ewes exposed to poor nutrition during pregnancy and lactation should have a higher proportion of fat compared with those at the same body weight from well-fed ewes.