Finishing steers with diets based on corn, high-tannin sorghum, or a mix of both: feedlot performance, carcass characteristics, and beef sensory attributes.

2009 
The objective of this work was to com- pare feedlot performance, carcass characteristics, and beef sensory attributes from steers finished with diets based on corn, high-tannin sorghum (HTS), and a mix of both grains. Angus crossbred steers (n = 11 steers per treatment, initial BW = 404 ± 18 kg) were finished on diets containing 765 g/kg of DM of corn, HTS, or a 1:1 mix of corn and HTS. Final BW (P < 0.01), ADG (P < 0.001), and G:F (P < 0.01) were reduced in steers fed HTS when compared with steers fed corn. Steers fed the mixed diet had greater G:F than the average between corn and HTS diets (P = 0.04), which indicat- ed that mixing corn and HTS had positive associative effects. Estimated NEm of HTS was 1.91, and estimated NEg was 1.35 Mcal/kg of DM. Hot carcass weight (P < 0.01), trimmed carcass weight (P < 0.01), yield grade (P = 0.04), and 12th-rib fat thickness (P = 0.01) were less in steers fed HTS than in those fed corn. Estimated percentage of HCW as boneless, closely trimmed retail cuts was greater in steers fed HTS compared with those fed corn (P = 0.02) but, due to the decreased HCW, estimated amount of boneless, closely trimmed retail cuts was less in steers fed HTS than in those fed corn (P = 0.03). Steers fed HTS had greater pH on LM (P = 0.02) than steers fed corn, but the difference was small (5.42 ± 0.02 vs. 5.36 ± 0.02, respectively) and within the range of normal beef pH. Diet had no effect on Warner-Bratzler shear values (P ≥ 0.72). Multivariate ANOVA indicated a difference in sensory attributes of beef from corn and HTS steers (Wilks' Lambda, P = 0.04). When evaluating each sensory attribute indepen- dently, panelists found beef from steers fed HTS to be less juicy (P < 0.01), less tender (P = 0.03), and more cooked (P < 0.01) than beef from animals fed corn. Data from this study indicated that by using a 1:1 mix of HTS and corn it is possible to finish steers to similar BW and carcass quality as by using a corn-based diet. Also, total replacement of corn by HTS in the diets produced lighter and leaner animals. Total replacement of corn by HTS in the finishing diet changed beef sen- sory attributes, reducing the perception of beef tender- ness and juiciness by panelists but without changing instrumental tenderness.
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