Location: Forage and Livestock Production ResearchTitle: Effect of forage energy intake and supplementation on marbling deposition in growing beef cattle.) Author
Submitted to: American Society of Animal Science
Publication Type: Abstract only
Publication Acceptance Date: 3/17/2010
Publication Date: 7/11/2010
Citation: Sharman, E.D., Lancaster, P.A., Hilton, G.G., Krehbiel, C.R., Phillips, W.A., Horn, G.W. 2010. Effect of forage energy intake and supplementation on marbling deposition in growing beef cattle. In: Proceeding, Western Section, American Society of Animal Science. 61:44-49. Interpretive Summary: Abstract only.
Technical Abstract: Glucose is the primary carbon source for fatty acid synthesis in intramuscular fat, whereas, acetate is primarily utilized by subcutaneous fat. Our objective was to examine the effect of forage energy intake and type of fermentation on marbling deposition by stocker cattle grazing dormant native range (DNR) or winter wheat pasture (WP). Angus steer calves (n = 68; 258 ± 29 kg) were used in a completely randomized design comparing 4 winter grazing treatments: (1) control, 1.02 kg•hd-1•d-1 of a 40% CP supplement to meet their DIP requirement while grazing DNR; (2) control plus corn-based supplement at 1% BW while grazing DNR; (3) WP at a high stocking rate (3.2 steers/ha) to achieve a low rate of BW gain; and (4) WP at a low stocking rate (2.2 steers/ha) to achieve a high rate of BW gain. Following winter grazing, 3 steers per treatment were randomly selected for intermediate harvest. The remaining wheat pasture steers were transitioned to the finishing phase, while the DNR treatments remained on summer native range for 115 d prior to finishing. Steers were fed to a predicted backfat end point of 1.27 cm. During winter grazing, ADG was 0.19, 0.52, 0.68, and 1.37 ± 0.03 kg•d-1 (P < 0.01), backfat was 0.03, 0.10, 0.17, and 0.85 ± 0.07 cm (P < 0.01) and marbling scores were 180, 217, 280, and 340 ± 11.67 (P < 0.01) for treatments 1-4, respectively. There were no differences in final marbling scores (423, 428, 427, and 425 ± 14.92; P = 0.99, respectively). These data indicate that growing programs differing in forage energy intake and type of fermentation can influence marbling deposition at the end of winter grazing; however, final marbling scores may not be affected when cattle are fed to a common fat end point.