Effect of dietary energy source on in vitro substrate utilization and insulin sensitivity of muscle and adipose tissues of Angus and Wagyu steers

摘要: Angus (n = 8; 210 kg of BW) and 7/8 Wagyu 174 steers were used to evaluate the effects dietary energy source on muscle adipose tissue metabolism insulin sensitivity. Steers assigned either a grain-based (corn) or hay-based (hay) diet fed similar final BW. At slaughter, LM s.c. i.m. samples collected. Portions tissues placed immediately in liquid N for later measurement glycolytic intermediates. Fresh incubated with [U- 14 C] glucose assess vitro. All vitro measures presence 0 500 ng/mL insulin. Also, [1- acetate quantify lipid synthesis Glucose-6-phosphate fructose-6-phosphate concentrations 12.6- 2.4-fold greater than tissues, respectively. Diet did not affect incorporation into fatty acids (P 0.86). Insulin increase conversion CO 2 , lactate, total hay but caused an (per cell) 97 110% 46 54% 65 160% content from corn. On per-cell basis, had 37% oxidation 0.04) 290% 0.04). addition corn-fed failed stimulate acids, exposing resulted 165% acids. These results suggest that feeding limited both supply capacity utilization response without altering Because consistently utilized more oxidized adipose, these diets may alter less effect tissue.