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This Article Full Text Full Text (PDF) All Versions of this Article: jas.2007-0756v1 86/7/1678    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Faucitano, L. Articles by Berthiaume, R. PubMed PubMed Citation Articles by Faucitano, L. Articles by Berthiaume, R.

Comparison of alternative beef production systems based on forage finishing or grain-forage diets with or without growth promotants: 2. Meat quality, fatty acid composition, and overall palatability

L. Faucitano^*,1, P. Y. Chouinard, J. Fortin^#, I. B. Mandell, C. Lafrenière, C. L. Girard^* and R. Berthiaume^*,2

^* Agriculture & Agri-Food Canada, Sherbrooke, Québec, J1M 1Z3, Canada; and Département des Sciences Animales, Université Laval, Québec, Québec, G1V 0A6, Canada; and Department of Animal & Poultry Science, University of Guelph, Guelph, Ontario, N1G 2W1, Canada; and Agriculture & Agri-Food Canada, Kapuskasing, Ontario, P5N 2Y3, Canada; and and ^# Agriculture & Agri-Food Canada, Saint-Hyacinthe, Québec, J2S 8E3, Canada

¹ Corresponding author: faucitanol{at}agr.gc.ca

Five beef cattle management regimens were evaluated for their effect on meat quality, fatty acid composition, and overall palatability of the longis-simus dorsi (LD) muscle in Angus cross steers. A 98-d growing phase was conducted using grass silage with or without supplementation of growth promotants (Revalor G and Rumensin) or soybean meal. Dietary treatments in the finishing phase were developed with or without supplementation of growth promotants based on exclusive feeding of forages with no grain supplementation, or the feeding of grain:forage (70:30) diets. Growth promotants increased (P < 0.01) shear force and tended (P = 0.06) to increase toughness of the LD muscle due to limited postmortem proteolytic activity (lower myofibrillar fragmentation index value; P = 0.02). Grain feeding increased DM and intramuscular fat content (P = 0.03 and P = 0.05, respectively) in the LD but decreased the sensory panel tenderness score (P = 0.01). Growth promotants increased (P 0.05) the proportion of C18:0, C20:0, trans isomers of C18:1, and cis-9, trans-11 C18:2. Exclusive feeding of forages increased the proportion of cis-9, cis-12, cis-15 C18:3 as well as several other isomers of the n-3 family and decreased in the ratio of n-6 to n-3 fatty acids in the LD muscle as compared with supplementing grain (P < 0.05). In addition, the forage-based diet increased (P < 0.01) the concentration in the intramuscular fat of several intermediates (cis-9, trans-11, cis-15 C18:3; trans-11, cis-15 C18:2; trans-11 C18:1) of ruminal biohydrogenation. Forage feeding also increased the proportion of cis-9, trans-11 C18:2 (P < 0.01) and decreased the concentration of trans-10 C18:1 in the LD muscle (P = 0.03). It is concluded that quality demands of health-conscious consumers can be met through a forage-finishing and growth promotants-free beef production system.

Key Words: beef cattle • beef production system • beef quality • fatty acid • shear force • taste panel