Biochemical profile, oxidative metabolism and meat quality of lambs subjected to road and treated with vitamin E

Author(s)

Giovanna Rocha Nunes

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
• Defense date: 2013-08-02

Examining board members

Maria Claudia Araripe Sucupira; Stefano Carlo Filippo Hagen; Ivanete Susin

• Advisor: Maria Claudia Araripe Sucupira

Abstract

The present study aimed to evaluate the effects of intramuscular alpha-tocopherol (vitamin E) administration on markers of oxidative and physiological stress, as well characteristics related to meat quality of lambs subjected to road short transport. Twenty-four lambs, Santa Inês and Dorper crossbred, age and average live weight at slaughter of 138 days and 43.6 kg, respectively, were divided into three experimental groups. Each group received an intramuscular application of saline solution or 10 IU or 20 IU of DL-alpha-tocopherol per kg of metabolic body weight at six and three days before transportation. The transportation lasted four hours until the slaughterhouse. After unloading, lambs rested in pen for 19 hours until the time of slaughter. At T0 (immediately prior to boarding and transportation), T1 (immediately after transport and unloading), T2 (three hours after transporting and landing) and T3 (immediately before slaughter) rectal temperature was measured and blood samples were collected by jugular vein puncture for determination of serum urea, creatinine, albumin, total protein, cholesterol and cortisol; plasma concentrations of glucose, beta-hydroxybutyrate (BHB), lactate and non-esterified fatty acids (NEFA); serum activities of aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT) and creatine kinase (CK), erythrocyte and total leukocyte count, ratio neutrophil: lymphocytes, packed cell volume (PCV), erythrocyte activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR), concentration of reduced glutathione (GSH), serum total antioxidant status (TAS) and the concentration of thiobarbituric acid reactive substances (TBARS). After slaughter, carcasses were kept for 24 hours under refrigeration at 2 °C and were analyzed for Longissimus Dorsi pH (pH24h) and color (L *, a *, b *), and collected samples for subsequent evaluation of shear force (SF), cooking weight loss (CWL) and products of lipid oxidation after 30 days of freezing (TBARS 30). There was an interaction between time and treatment for lactate and was observed a linear effect at the time T2, with increased (P = 0.0111) values of this variable in the animals receiving 20 IU of vitamin E. A linear effect of treatment (P = 0.0149) on the TAS values was observed. Deviation from linearity effect for albumin, L * and b * were seen. Animals that received 10 IU of vitamin E showed lower concentrations of albumin (P = 0.0447) and higher (P = 0.0042 and P = 0.0082) L * and b * values. Except for rectal temperature and GR, moment effect was observed for all other markers of oxidative and physiological stress. The short road transportation, even when done properly, produces stress in animals. Potentially harmful stimuli at the time prior to slaughter led to higher stress intensity than that coming from the transport. Intramuscular administration of alpha-tocopherol increased serum total antioxidant status of lambs subjected to short duration road transport, however was not able to minimize changes arising from physiological and oxidative stress and improve the meat quality of these animals. (AU)

• FAPESP's process: 11/04153-0 - Study of biochemical profile, oxidative metabolism and meat quality of lambs subjected to road and treated with vitamin E
• Grantee: Giovanna Rocha Nunes
• Support Opportunities: Scholarships in Brazil - Master