Protein and electrolyte contents and histopathology of longus colli muscle in cachexia of Red Bororo beef cows

Bovine cachexia as a multi-factorial clinical syndrome of severe emaciation is a reason for salvage slaughter in Nigeria. Cachectic cows have sustained neck strength despite muscle atrophy and weakness in the limbs. This study evaluated the protein and electrolyte contents and histopathology of longus colli (neck chain) muscle in cachectic Red Bororo (RB) beef cows. Body condition score (BCS 1–9) was the basis for selection of slaughter cows in a case control study. At antemortem inspection, cachectic (n=39) and control (n=15) cows had BCS of 1–2 and ≥ 5, respectively. Longus colli muscle was collected after slaughter on ice pack. Protein and electrolyte (sodium, potassium, calcium, chloride, bicarbonate, inorganic phosphate ions) contents in aqueous supernatant of the muscle homogenate were estimated. Stained tissue sections were examined histologically for lesions and cross-sectional images were digitally analysed to estimate fascicular size as percentage fascicular myofibre area (PFA) and fascicular myofibre to interstitium ratio (FIR). Protein and electrolyte contents, PFA and FIR were not significantly affected by cachexia. Muscle lesions were myofibre atrophy (40.0%), myositis with myofibre necrosis (13.3%) and Sarcocystis cyst in myofibres (51.1%); and their frequencies were comparable in cachectic and control cows. Therefore, longus colli muscle was likely spared from electrolyte-mediated fatigue and cachexia-related muscle atrophy, but had lesions not associated with cachexia with implications linked to physical welfare and meat hygiene that could warrant further investigations.