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Evaluation of glycated albumin as a metabolic marker for marbling in commercial feeder cattle
The objective of this study was to determine if glycated albumin can serve as a metabolic marker for marbling in beef cattle. This project utilized 113 crossbred steers consigned to the NDSU Beef Cattle Research Complex. Steers (391 ± 2.80 kg) were randomly assigned to a 2 × 2 × 2 factorial arrangement (n = 14 or 15 per treatment) to determine the effects of conventional (CONV) or natural (NAT) feeding strategies and grain adaptation length (14 vs. 28 day). Diets consisted of corn, dried corn distillers grains with solubles, and 10% forage (hay and corn silage). Blood samples were collected on days 28, 56, 84, 112, and 140 to determine serum glucose (T-GLU) and insulin (T-INSU). On day 140 prior to slaughter, blood samples were collected to evaluate total serum protein (T-SP), total serum albumin (T-SA), total serum glycated albumin (T-GA), and percent of T-GA (P-GA). After 140 days on feed, all steers were delivered as one group to a commercial packing facility. Hot carcass weight and carcass measurements (subcutaneous fat thickness adjacent at the 12th rib [FD12], 12thrib ribeye area [REA], marbling score, and kidney, pelvic, and heart fat percentage [KPH]) were measured following a 24h chill. Total serum protein and T-SA were not influenced by treatment relative to marbling score and feeding strategy and did not correlate with marbling score. CONV possessed a greater concentration of T-GA and P-GA (115.02 vs. 74.43 μmol/L, P = 0.001; 38.88 vs. 16.3%, P = 0.001, CONV vs. NAT respectively). Neither T-GA nor P-GA correlated with marbling score, however, both had a negative correlation with KPH and FD12. Carcasses from NAT fed steers had greater T-GLU concentrations than CONV (115.86 vs. 107.21 mg/dL, respectively; P = 0.02). Steers possessing a slight degree of marbling had the highest T-GLU vs. other marbling categories (P = <0.0001). The average of T-INSU for modest and moderate marbling scores were greater than small (33.18 and 36.59 vs. 26.84 µU/mL, respectively; P = 0.01), however, all were similar to slight and slightly abundant. Glycated albumin was found to be negatively correlated with the fat depots KPH and FD12 but not associated with marbling score.
Keywords:
feeder cattle, glycolated hemoglobin, marbling score