Collagen Solubility of A-Maturity Bovine Longissimus Muscle as affected by Nutritional Regimen

Abstract

Fifty large-type crossbred steers were assigned in groups of five to one of ten nutritional regimens to measure the effects of diet on collagen characteristics. Initially, steers in a control group were slaughtered at about 280 d of age and weighing 300 kg. Steers in the nine remaining treatment groups were fed either roughage ad libitum, concentrate ad libitum or concentrate at a maintenance (CM) level. Animal slaughter endpoint (SEP) weights were about 400 kg (SEP-2), 500 kg (SEP-3) and 600 kg (SEP-4). Feeding times ranged from 0 to 560 d. Dietary regimen had small and inconsistent effects on total collagen and measures of collagen solubility. At SEP-4, the percentages of salt-soluble and salt- plus acid-soluble collagen were higher (P<.05) in steaks from the roughage group than in steaks from the concentrate and CM groups. Because of small palatability differences among nutritional regimens, data were stratified into tender (n = 16) and less tender (n = 15) groups based on overall tenderness. The tender group tended to have less total collagen (P<.10) and more salt-soluble collagen (P<.14) than did the less tender group. Steers slaughtered while in the A-maturity age range tolerated wide ranges in feeding regimen with little affect on tenderness, amounts of total collagen or collagen solubility.