Meat quality of steers finished on autumn grass, grass silage or concentrate-based diets

The objective of this experiment was to determine the effect of varying the proportions of autumn grass and concentrates and grass silage and concentr ates on the quality of meat from cattle with similar rates of carcass growt h. Fifty continental crossbred steers were assigned to five treatments. The experimental diets offered were (1) grass silage ad libitum plus 4 kg conc entrate (SC), (2) 1 kg hay plus 8 kg concentrate (CO), (3) 6 kg grass dry m atter (DM) plus 5 kg concentrate (CG), (4) 12 kg grass DM plus 2.5 kg conce ntrate (GC) and (5) 22 kg grass DM (GO). The experiment lasted 85 days afte r which all animals were slaughtered. The right side m. longissmus dorsi wa s excised from all animals 24 h post slaughter for assessment of meat quali ty. Treatments SC and CO resulted in animals with whiter (P < 0.05) subcuta neous and kidney/channel fat than all other treatments. There was an intera ction (P < 0.05) between ageing time and treatment with treatment GC having higher (P < 0.05) tenderness, texture and acceptability values after 2 day s ageing, but not after 7 or 14 days ageing. It is concluded that supplemen ting grass with low levels of concentrate produced the most tender and acce ptable meat at 2 days post mortem, but that further ageing eliminated all t reatment effects on eating quality of beef. (C) 2000 Elsevier Science Ltd. All rights reserved.