Thanaporn Bunmee, Sanchai Jaturasitha, Michael Wicke and Michael Kreuzer

pp. 109 - 117

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. 

Keywords

• culled dairy cow
• diet
• fatty acid
• lipid oxidation
• organoleptic properties