@conference {40805,
	title = {Genetic improvement of meat quality in sheep and cattle},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {157-162},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Genetic variations in body composition are apparent as differences  among breeds, crosses, selected strains and sire groups. Crossbreeding, use  of terminal sires and selection within breeds has tended to concentrate on  total meat output rather than quality, despite consistent consumer signals  against fat. Evidence suggests that, in males selected using live animal  ultrasound measurements of fat and muscle depths, about half of the  selection pressure available to improve growth rate should be sacrificed in  order to maximise economic response through decrease in carcass fat  content. Genetic variations in lean/fat partitioning to different regions and muscles of  the carcass, and in traits affecting the wider sensory appeal of cooked meat,  are also important to the range and consistency of meat products. Indirect  live animal indicators are vital to minimising the high cost of progeny  testing. Meat product tenderness is one example. Much of the variation is  under the control of the calpain system for which genetic differences have  been found among breeds and crosses, related families, selection lines, and  in strains segregating for major genes and genetic markers (e.g. calpastatin  and the CSSM18 and TGLA122 markers of the callipyge gene in sheep).  Decreased post mortem tenderness is associated with decreased proteolytic  enzyme activity which in some cases is related to increased lean growth  rates in the live animals as well. Between and within muscle variations in actin/myosin interactions, lipid,  myoglobin contents and solubilities can also give rise to genetic variations  in tenderness, meat flavour, colour and the heat gellation properties of  myosin. The biochemical basis of these effects suggests useful indicator  traits (e.g. LDH and ICDH enzyme activity associations with fibre type,  intra-muscular fat and haem iron contents) which are likely to offer  innovative genetic solutions to long-term industry competitiveness.},
	issn = {1176-5283},
	author = {Clarke JN and Morris CA and Speck PA and Upreti GC and Nicoll GB}
}
