PSX-5 Duration of preslaughter stress in winter on physiological responses and meat quality in goats

Abstract

Abstract Transportation conditions can significantly affect physiological status and meat quality in goats. This experiment was conducted to determine the effects of duration of preslaughter stress on physiological responses and meat quality in goats. Fifty-four uncastrated male Spanish goats (8-mo old; BW = 29.7 ± 2.03 kg) were randomly subjected to one of three treatments (n = 18 goats/treatment): (i) transported for 3 h, (ii) transported for 30 min, or (iii) held in pens (control) on two different days. The ambient temperatures were -3.0 ± 1.0 ºC and 1.0 ± 1.0 ºC on day 1 and 2, respectively. Blood samples were collected before (covariate) and after transport for differential leukocyte count and plasma cortisol concentration determinations. Goats were slaughtered using humane procedures for meat quality analysis. Data were analyzed using PROC GLM in SAS with treatment and day as factors. Cortisol concentrations were higher (P < 0.01) in both 3 h (117.7 ± 7.96 ng/mL) and 30 min (130.1 ± 8.05 ng/mL) transported groups compared to the control group (27.5 ± 7.59 ng/mL). Lymphocyte counts were lower (P < 0.01) in 3 h group compared to the other two groups, and the overall counts were also lower (P < 0.05) on day 1 compared to day 2. The initial Longissimus muscle pH (15 min) was lower on day 1 (6.79 ± 0.04) compared to day 2 (6.94 ± 0.05) and the final pH (24 h) was higher on day 1 (6.31 ± 0.04) than on day 2 (6.14 ± 0.04). Treatment did not influence live or carcass weights, nor did it affect the L*, a*, and b* values of loin chops. The results indicate that ambient temperature during transport may be more important in determining stress responses and muscle pH decline than duration of transportation in goats during winter.