Calpain and calpastatin activity in muscle from genetic lines of lambs selected for divergent levels of fatness.

J.D. Morton, R. Bickerstaffe and R.W. Purchas

Animal and Veterinary Sciences Group, Lincoln University, Lincoln

E-Mail:

Proceedings of the New Zealand Society of Animal Production. 1998, 58: 143-145

There is widespread interest in the extent to which genetic factors influence meat quality. In this study we examined meat quality characteristics and the activity of the calpain protease system in M. longissimus lumborum (LL) from backfat selection lines of Southdown lambs. The high fat line produced heavier carcasses with greater soft tissue depth GR. LL from the high fat line animals had a lower ultimate pH and was significantly more tender at 24h post-mortem using the MIRINZ tenderometer but not the Warner-Bratzler peak force. There was a decline in u-calpain and calpastatin activity but not m-calpain in the 9h post-mortem. There were no significant differences in the levels of the calpains or their inhibitor between high and low backfat lines. However, when the results were adjusted for pH, the 20 min calpastatin levels were highest for the sire group that had the highest peak force value.

Keywords: NZSAPAB; sheep ; selection lines ; backfat ; tenderness ; calpains.

Last Updated 12-09-1998