Relationship between glycerol administration to livestock 24 h before sacrifice and indicators of physiological and oxidative stress

The objective of this study was to evaluate the effect of oral administration of glycerol, as a source of energy, to steers 24 h before slaughter on biochemical indicators of physiological and oxidative stress. Fifty Zebu x Swiss-or Simental-cross steers were selected at random at the finalizing stage impending slaughter. Blood samples were collected from the jugular vein before administering the treatments and 24 h afterward. After sacrifice, samples of the Longissimus dorsi muscle were collected. Biochemical indicators evaluated in bovine serum were hematocrit (VGA), lactate dehydrogenase (LDH), lactate (LAC), cortisol (COR), glucose (GLU), β-hydroxybutyrate (BHT), creatine kinase enzyme (CK), free non-esterified fatty acids (NEFA), antioxidant activity (FRAP), thiobarbituric acid reactive substances (TBARS), and glutathione peroxidase reaction (GSH-Px). The variables evaluated in meat were TBARS, FRAP, pH, texture and shelf life. Analysis of the stress biomarkers evaluated in bovine serum did not reveal differences (P>0.05) between treatments T0 and T1 for the variables COR, VGA, GLU, NEFA, BHT or CK. There were, however, differences between sampling times for the variables FRAP (P = 0.021) and GSH (P = 0.006). The indicators FRAP and TBARS in the sampled meat were not different (P>0.05) between treatments. Meat pH changed over time (P=0.0002), but not its texture (P>0.05). It is concluded that the administration of glycerol as an energy supplement 24 h before sacrifice did not modify the balance of physiological constants of the evaluated steers, nor did it produce significant changes in shelf life of meat.(AU)

Relationship between glycerol administration to livestock 24 h before sacrifice and indicators of physiological and oxidative stress

The objective of this study was to evaluate the effect of oral administration of glycerol, as a source of energy, to steers 24 h before slaughter on biochemical indicators of physiological and oxidative stress. Fifty Zebu x Swiss-or Simental-cross steers were selected at random at the finalizing stage impending slaughter. Blood samples were collected from the jugular vein before administering the treatments and 24 h afterward. After sacrifice, samples of the Longissimus dorsi muscle were collected. Biochemical indicators evaluated in bovine serum were hematocrit (VGA), lactate dehydrogenase (LDH), lactate (LAC), cortisol (COR), glucose (GLU), β-hydroxybutyrate (BHT), creatine kinase enzyme (CK), free non-esterified fatty acids (NEFA), antioxidant activity (FRAP), thiobarbituric acid reactive substances (TBARS), and glutathione peroxidase reaction (GSH-Px). The variables evaluated in meat were TBARS, FRAP, pH, texture and shelf life. Analysis of the stress biomarkers evaluated in bovine serum did not reveal differences (P>0.05) between treatments T0 and T1 for the variables COR, VGA, GLU, NEFA, BHT or CK. There were, however, differences between sampling times for the variables FRAP (P = 0.021) and GSH (P = 0.006). The indicators FRAP and TBARS in the sampled meat were not different (P>0.05) between treatments. Meat pH changed over time (P=0.0002), but not its texture (P>0.05). It is concluded that the administration of glycerol as an energy supplement 24 h before sacrifice did not modify the balance of physiological constants of the evaluated steers, nor did it produce significant changes in shelf life of meat.