title: Selection for increased muscling in Angus cattle did not increase the glycolytic potential or negatively impact pH decline, retail colour stability or mineral content.
abstract: This study determined the impact of selection for greater muscling in Angus cattle on myofibre characteristics, muscle enzymatics, retail colour stability, pH decline and mineral content of the semimembranosus (SM), semitendinosus (ST) and longissimus thoracis (LT). Muscle from 10 low muscled (low) and 11 high muscled (high) steers were analysed. The high steers had myofibres 22% and 24% larger in cross-sectional area in the SM and ST (P<0.05), and 8.6% less type IIX myofibres in the LT than the low steers (P<0.05). The highs had 4.9% lower lactate dehydrogenase activity, 10.2% and 12.3% higher citrate synthase and isocitrate dehydrogenase activity than lows (P<0.05). The highs had 27% more iron in the LT (P<0.05). The results indicate that the oxidative capacity of muscle can be maintained in more muscular cattle with no detrimental effects to mineral content, pH decline or retail colour stability. Myofibre hypertrophy is one mechanism leading to greater muscle mass of these high muscled cattle.
authors.affiliation: Australian Cooperative Research Centre for Beef Genetic Technologies, Armidale, NSW 2351, Australia; School of Veterinary & Life Sciences, Murdoch University, South St, Murdoch, WA 6150, Australia. Electronic address: p.mcgilchrist@murdoch.edu.au.
authors.forename: P
authors.initials: P
authors.lastname: McGilchrist
authors.affiliation: Australian Cooperative Research Centre for Beef Genetic Technologies, Armidale, NSW 2351, Australia; NSW Department of Primary Industries, Beef Industry Centre, Armidale, NSW 2351, Australia.
authors.forename: P L
authors.initials: PL
authors.lastname: Greenwood
authors.affiliation: Australian Cooperative Research Centre for Beef Genetic Technologies, Armidale, NSW 2351, Australia; School of Veterinary & Life Sciences, Murdoch University, South St, Murdoch, WA 6150, Australia.
authors.forename: D W
authors.initials: DW
authors.lastname: Pethick
authors.affiliation: Australian Cooperative Research Centre for Beef Genetic Technologies, Armidale, NSW 2351, Australia; School of Veterinary & Life Sciences, Murdoch University, South St, Murdoch, WA 6150, Australia.
authors.forename: G E
authors.initials: GE
authors.lastname: Gardner
mesh_terms: D000818:Animals; D002417:Cattle; D002950:Citrate (si)-Synthase / Q000378:metabolism; D003116:Color; D006019:Glycolysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008460:Meat / Q000032:analysis*; D008903:Minerals / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism; D009210:Myofibrils / Q000378:metabolism; D010084:Oxidation-Reduction
chemical_list: D008903:Minerals; D007501:Iron; D007770:L-Lactate Dehydrogenase; D007521:Isocitrate Dehydrogenase; D002950:Citrate (si)-Synthase
keywords: Carcass yield; Fibre type; Longissimus thoracis; Meat quality; Oxidative