Abstract
The Meat Standards Australia (MSA) grading scheme for underpinning the eating quality of lamb is currently a pathways system with guidelines for best practice feeding, handling, slaughter, product aging and retail presentation of lamb cuts. This paper describes an experiment to determine the role of genetics to determine the continuous improvement in eating quality of lamb cuts. Eating quality data was generated from 745 lambs produced from 97 sires at 2 sites within the Information Nucleus (IN) program of the CRC for Sheep Industry Innovation. Grilled steaks were prepared from 2 cuts (m. longissimus lumborum — LD; m. semimembranosis — SM) with consumers scoring steaks for tenderness (TE), juiciness, liking of flavour and overall liking (OL) on a 0-100 scale. Consumers also assigned a quality rating to each sample: unsatisfactory satisfactory everyday, quality better than everyday quality or premium quality. The data for TE and OL were analysed using linear mixed models in ASReml with fixed effects of IN site, kill group, sex sire breed type and dam breed type. Sire and consumer session were random terms. There were significant effects (P<0.05) of cut (LI) >> SM), IN site, kill group and sire breed. Sire accounted for 5.3% and 3.3% of the total variance in TE and OL of both cuts with a sire range of 8-12 consumer points, sufficient to change the final consumer rating of the steaks. This preliminary study shows that genotype effects need to be considered in the development of a new MSA lamb grading model.