Songklanakarin Journal of Science and Technology (SJST) (Apr 2015)
Effects of different finishing feeding strategies for culled cows on lipid and organoleptic characteristics of the meat
Abstract
Culled dairy cows (n=32) were either slaughtered immediately after culling-off (control) or subjected to a finishing period of 12 weeks. For finishing, three different diets were tested. A forage-only group was fed with ad libitum with corn silage. Two other groups either received a high-fiber concentrate feed (crude rice bran) or a concentrate feed with lower fiber content (cassava pulp). Cows were slaughtered on four days with two cows per treatment each. Samples of the Longissimus dorsi were individually excised 24 hrs post-mortem. Feeds were analyzed for proximate contents and fatty acid profile. In the LD, apart from fatty acid analysis, thiobarbituric acid reactive substances (TBARS), color and sensory grading was determined in LD aged for 0, 1, 3, 5, and 7 days in vaccuumized form. Treatment effects were determined by analysis of variance. Finishing on corn silage only increased the proportions of conjugated linoleic acids, docosahexaenoic acid and total polyunsaturated fatty acids (PUFA) and led to rather dark meat. The other traits remained widely unaffected. Adding crude rice bran to the finishing diet did not cause a lot of differences to control. The lipids in the LD of the rice-bran fed cows had higher PUFA proportions and a lower shelf life. Finishing with a diet lower in fiber increased intramuscular fat to 6.7% vs. 3.4-4.2% in the other groups. Concomitantly, sensory scoring in terms of tenderness, juiciness, flavor intensity and overall acceptability was mostly highest. Concerning fatty acid profile (except palmitic acid), TBARS and color the meat of the group receiving cassava pulp resembled that of the control. In conclusion, it seems advantageous in terms of lipid- and sensoryrelated sense to finish culled cows either with high-quality forage alone or this forage supplemented with cassava pulp.
