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The behaviour and blood profile of bulls which produce dark cutting meat
Author(s) -
Warriss Paul D.
Publication year - 1984
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740350808
Subject(s) - zoology , agonistic behaviour , longissimus dorsi , creatine kinase , chemistry , biology , endocrinology , medicine , psychiatry , aggression
Thirty British Friesian bulls (12 months old), in groups of 6 or 12, were mixed with unfamiliar animals for 16 h preslaughter. Before and during mixing, blood samples were collected and behaviour was monitored. The ultimate pH (pHu) was measured in the m. Longissimus dorsi (LD) 24 h after slaughter. Thirteen carcasses were dark cutting (DC, pHu≧6) and 17 were normal (pHu<6). DC carcasses came from animals which exhibited over twice the total number of agonistic interactions ( P <0.001) and showed more dominant behaviour ( P <0.001) than animals producing normal carcasses. There was no difference in the blood profile of DC and normal bulls before mixing. However, DC bulls had higher levels of creatine phosphokinase ( P <0.001), free fatty acids ( P <0.001) and β‐hydroxybutyrate ( P <0.01) in the blood samples collected after mixing. Overall, pHu was correlated with total activity ( r =0.71, P <0.001) and dominance scores ( r =0.70, P <0.001). The conclusion is that the cause of DC in mixed groups of bulls is primarily behavioural. Muscle glycogen stores are depleted when blood‐borne metabolites are inadequate to fuel the intense or prolonged muscular activity associated with agonistic behaviour.