Evaluation of Warm Season Annuals for Forage Finishing in the Piedmont Region on Animal Performance and Meat Quality

The objective of this study was to evaluate the effects of pearl millet (PM), pearl millet plus crabgrass (PMCG), brown midrib (BMR) sorghum sudangrass (BMR SxS), and sorghum sudangrass (SxS) on animal production and meat quality characteristics. Cross-bred steers (n=32) were stratified by weight, randomly assigned to a treatment and forage finished for 83 d. Body weight was recorded on d 0 and 83. All pastures were managed for rotational stocking. Forage samples for mass and nutritive value were collected on d 0 and every 14 d thereafter. On d 86, all animals were harvested, and carcass data was collected for yield and quality determination as well as objective carcass fat and lean color scores (CIE L*, a*, b*) and subjective fat and lean color scores. The left boneless short-loin was removed from each carcass and held in vacuum packaging for 17 d of aging. Following aging, short-loins were fabricated into 2.54-cm steaks and analyzed for proximate analysis, fatty acid analysis, slice-shear force, sensory analysis, and retail shelf-life measuring subjective color, objective color and lipid oxidation. No treatment differences in ADG were found (P = 0.30). Carcasses from steers grazing all treatments had similar HCW, %KPH, REA, 12 th rib fat thickness, and yield grade (P > 0.17). There were no differences between treatments for carcass marbling scores (P > 0.12). No treatment differences were observed for objective color scores of lean (P > 0.50) and fat (P > 0.26), or subjective lean color scores (P > 0.34). Carcasses from PMCG had a greater overall maturity (A 80 ) than SxS (P < 0.01; A 60 ) and PM (P = 0.03; A 70 ) due to PMCG carcasses having a greater lean maturity (P < 0.01) than carcasses from other treatments. Subjective fat color readings of SxS carcasses were more yellow in color than all other treatments (P ≤ 0.03). Sensory panel evaluation found BMR SxS and SxS to have a stronger off-flavor (P > 0.02) when compared to PMCG, with PM being intermediate. No differences in tenderness (P = 0.13), juiciness (P = 0.71) or beef flavor intensity (P = 0.36) were found. Slice shear force evaluation of tenderness found no differences in tenderness (P = 0.36). No overall differences (P = 0.19) in TBARS values measuring lipid oxidation were found between treatments following the 7 d of retail display. Objective color findings indicate steaks from SxS were lighter (L*) on d 1 (P = 0.03) than PM and BMR SxS, with PM having the darkest lean color. Objective color on d 3 showed PM having a lighter (P = 0.03), more yellow lean color (P = 0.02) than other treatments. Additionally, objective color on d 3 found PM to be redder or more red in color (a*), followed by PMCG, BMR SxS, and SxS (P = 0.04). No other differences in objective color were found. These data indicate the four forage systems can be used in warm season annual forage finishing programs without affecting animal performance and having minimal effects on carcass characteristics.