PSIII-A-1 - Acute Stress Effects on Physiological Responses and Meat Quality Changes in Goats

Abstract: Duration of stress prior to processing 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. In a Randomized Complete Block Design, 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) or held in pens (control) on two different days. Blood samples were collected before and after transport for assessment of stress responses. Goats were slaughtered, using humane procedures, for meat quality analysis. The data were analyzed using MIXED procedures in SAS with treatment and day as fixed variables. 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). A similar treatment effect was noticed in plasma non-esterified fatty acid (P < 0.05) concentrations. Glucose concentrations were highest in 180-min, lowest in control, and intermediate in 30-min group (P < 0.01). There were significant positive correlations among muscle desmin concentration after 6 days of aging and 24 h pH (P < 0.05) and calpastatin activity (P < 0.05), suggesting that desmin degradation plays a role in determining the tenderness of aged meat from goats subjected to preslaughter stress. Warner-Bratzler shear force values of loin chops were highest in 180-min, lowest in control, and intermediate in 30-min groups; however, treatment did not influence the color values or cooking loss of loin chops. The results indicate that acute stress prior to processing can affect both physiological responses and meat quality in a duration-dependent manner in goats.