Some specificities of clinical and nutritional blood biochemistry in camel

The idea to use blood biochemical parameters to evaluate the health and nutritional status of one individual is an old practice in human medicine. In veterinary medicine, blood analyses have been proposed to help first the diagnosis of cattle diseases since nearly one century. But they were initially developed only in the sixties in the specialized research laboratories, in Veterinary Services and later in the veterinary cabinets. Currently, a whole set of analyses that are critical for vets' diagnostics and farmers' decision-making is proposed to the livestock and animal health actors to define metabolic, biochemical or blood profiles, Cattle is undoubtedly the more investigated species among farm animals. Data on sheep and goat are numerous, but it is already more disparate for camel. The biochemical investigations are convenient if (i) the purpose of the analyses is clear and based on a clear sampling procedure plan, (ii) the physiological variation factors are taken in account for convenient interpretation of the results, (iii) the sampling protocol is respected (for example blood sampling before feeding), (iv) the interpretation is based on a set of animals due to the between-individual variability, and on a pattern of parameters (v) the confusion between statistical difference and biological significance is avoided. Regarding the camel specificities, the followings could be listed: (i) predominance of polynuclear neutrophils in its white cell formula, (ii) maintenance of hematocrit in case of physical effort, (iii) osmolality resistance, (iv) relative hyperglycemia, (v) absence of ketone bodies, (vi) low plasma cholesterol in plasma concentration, (vii) susceptibility to hyperuremia, (viii) thermo-resistance of alkaline phosphatases, (ix) maintenance of metalloenzymes activities in case of mineral deficiency, (x) maintenance of electrolytes balance in dehydrated animals, (xi) low plasma zinc concentration in supplemented camel, (xii) higher sensitivity to selenium toxicosis, (xiii) richness of camel milk in vitamin C, (xiv) richness of plasma in vitamin D, (xv) seasonal pattern of testosterone, (xvi) decreasing insulin responsiveness with age of the young calves to induced hyperglycemia.