Effects of concentrate level on carcass traits of Boer crossbred goats

Boer crossbred goats (n = 46) were used to assess the effects of dietary concentrate on carcass composition, primal cut yield, sensory properties, and fatty acid (FA) composition. Goats were fed diets ad libitum, with no concentrate (range) or with one of three levels of concentrate (low, 50%; medium, 70%; high, 90%) for 126 days before slaughter. Carcass measurements were taken at 24 h postmortem, before carcasses were fabricated according to Institutional Meat Purchase Specifications (Hotel Style). Sensory properties, cooking loss, shear force, and fatty acid (FA) composition were determined on longissimus samples. No differences (P > 0.05) were observed for carcass, subprimal, and longissimus sensory traits among the three levels of concentrate feeding, except that carcasses from goats fed a low-concentrate diet had a higher (P < 0.05) percentage of trimmed shoulder than did carcasses from goats fed a medium level of concentrate. In contrasts comparing range and concentrate feeding, goats fed concentrate diets had increased (P < 0.05) live weight, hot carcass weight, dressing percentage, ribeye area, actual and adjusted 13th rib fat, body wall width, leg circumference, carcass length, marbling score, and kidney and pelvic fat values, compared to range-fed goats. Longissimus muscles from goats fed concentrate had greater (P < 0.05) a*, b*, hue angle, and chroma values than did those fed range diets. Chops from goats fed concentrate diets had less (P < 0.05) off-flavor and cooking loss than chops from range-fed goats. Concentrate-fed goats had heavier (P < 0.05) weights for leg; trimmed leg; loin; trimmed loin; rack; trimmed rack; shoulder; trimmed shoulder; trimmed leg, loin, rack, and shoulder; foreshank; ribs and breast; flank, but lower percentages of trimmed leg; trimmed rack; trimmed shoulder; trimmed leg, loin, rack, and shoulder, than range-fed goats had. Longissimus samples from goats fed concentrate diets had higher (P < 0.05) percentages of total, saturated, monounsaturated and n − 6 FA; but lower percentages of n − 3 FA, compared to longissimus samples from range-fed goats. Overall, goats fed concentrate-based diets had heavier carcasses and primal weights, but lower percentages of trimmed primal cuts and less off-flavor intensity compared to range-fed goats.