Chemical composition, fibre types and enzymes activates of longissimus thoracis muscle of the one humped camel

Thirty samples of Longissimus thoracis (LT) muscle were collected from 2-3 years old male camels slaughtered according to seasons of the year (winter, summer and autumn). The samples were then subjected to chemical analysis to study the chemical composition, fibre types and metabolic enzymes activities and variations among seasons. The results showed that chemical composition, ultimate pH (pHu) and calor were significantly influenced by season. Enzymes activities of isocitrate dehydrogenase (ICDH) and phosphofructokinase (PFK) were higher during autumn season compared to summer and winter (2.7 and 1.8 uml/min per g muscle, respectively). Quantification of muscle myosin heavy chain isoforms by SOS-PAGE electrophoresis and image analysis indicated higher proportions rn winter for type I muscle fibres and in autumn for type I la muscle fibres. Positive correlation was observed (0.84) between the proportion of fibre type I and lsocitrate Dehydrogenase (ICDH) enzyme activity. These findings indicated that muscle characteristics in camels are highly regulated by season. (Resume d'auteur)