Effect of season on muscle characteristics of camel calves : [P57]

Thirty 2-3 year-old camel calves fattened by local farmers in Sudan were used for this study. Ten calves were slaughtered according to different seasons (winter, summer and autumn) to examine the muscle characteristics according to season. Muscle samples were taken from Longissimus thoracis (LT) at the 5th thoracic vertebra. The overall chemical composition of LT showed mean values of 3.1, 17.2, 2.7 and 1.6% for DM, crude proteins, total lipids and fatty acids and ash, respectively. Unlike for CP and ash (P<0.001), no significant differences were found between seasons in DM and total lipids. Unlike in cattle, the results obtained from electrophoresis test indicated the presence of two muscle fibers only. The mean percentages were: type I 66.6% and type IIa 33.4%. Higher proportions (P<0.001) were observed in winter for type I (85.2%) and in autumn for type Ha (47.1%). Positive correlation coefficient was observed (0.80) between the proportion of fibers type IIa and isocitrate dehydrogenase (ICDH) enzyme activity. Enzymes mitochondrial (ICDH and COX) activities as well as phosphofructokinase activity were higher (P<0.001) during autumn season compared to summer and winter. In conclusion, muscle fiber characteristics in camel (except intramuscular fat content) are highly regulated by seasonal factors. (Texte intégral