Unveiling the Biochemical, Enzymatic and Hormonal Stress Biomarkers: Effects of Transportation and Lairage on Sheep Welfare and the Meat Quality

The objective of this study was to assess the impact of transportation and lairage on biochemical, enzymatic, hormonal changes, and meat quality in Nellore Jodipi sheep. Blood samples were collected from two groups of sheep, L0 (slaughtered immediately after transportation without rest) and L12 (12 h of lairage) during exsanguination to analyze biochemical (blood glucose, creatinine, and total protein), enzymatic (creatine kinase [CK], lactate dehydrogenase [LDH], aspartate transaminase [AST], and alanine aminotransferase [ALT]), and hormonal (cortisol, triiodothyronine [T3], and thyroxine [T4]) parameters. Meat samples from the longissimus dorsi muscle were examined for pH, r value, instrumental color, water holding capacity (WHC), shear force, drip loss, cooking loss, and thiobarbituric acid reactive substances (TBARS). Lower (P<0.05) levels of glucose, creatinine, total protein, LDH, CK, ALT, cortisol, and T4 were noticed in L12. Meat quality parameters indicated higher (P<0.05) pH, r value, and a* values during the post-mortem period in the L0 group compared to L12. However, no difference (P>0.05) was observed for cooking loss, drip loss values between the groups. Current findings suggest that slaughter of sheep immediately after transportation without lairage results in increased stress levels in animals adversely affecting both welfare and meat quality. From the present study, it is concluded that a minimum of 12 h lairage period will allow sheep to regain normal homeostasis.