title: Relationship between pre-slaughter stress responsiveness and beef quality in three cattle breeds.
abstract: The relationship between stress responsiveness and beef quality of 40 Nguni, 30 Bonsmara and 30 Angus steers was determined. The L(∗) values, pHu, cooking loss (CL) and Warner-Bratzler shear force (WBSF) were determined. Catecholamine levels were determined from urine samples collected at slaughter. Bonsmara steers had the highest (P<0.05) levels of catecholamines with respective epinephrine, norepinephrine and dopamine concentrations of 10.8, 9.7 and 14.8nmol/mmol. Nguni steers had the lowest (P<0.05) levels of catecholamines, with respective catecholamine concentrations of 5.1, 4.3 and 4.0nmol/mmol. In the Nguni steers, there were significant (P<0.05) correlations between catecholamines and L(∗) and between dopamine and tenderness in meat aged for two days (WBSF2). In the Bonsmara, dopamine was correlated (P<0.05) pHu, WBSF2 and CL. No significant correlations were found in the Angus. Therefore the relationship between stress responsiveness and certain beef quality traits may not be similar in different breeds.
authors.affiliation: Department of Livestock and Pasture Science, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa.
authors.forename: V
authors.initials: V
authors.lastname: Muchenje
authors.forename: K
authors.initials: K
authors.lastname: Dzama
authors.forename: M
authors.initials: M
authors.lastname: Chimonyo
authors.forename: P E
authors.initials: PE
authors.lastname: Strydom
authors.forename: J G
authors.initials: JG
authors.lastname: Raats