Blood sampling and drug application in large farm animals using a mobile system

Various methods of blood sampling and drug administration together with a n ew mobile automatic system are described. The use of mobile blood collectio n is necessary to examine diurnal and ultradian hormone cycles in free-rang ing animals, An absence of interference is required for the estimation of t he basal episodic secretion of pituitary and adrenal hormones such as ACTH and cortisol. A mobile pump system was therefore developed for continuous b lood collection which allowed undisturbed sampling using a double lumen cat heter implanted through vein-puncture. Potential applications range from bl ood sampling horses whilst racing, cattle at pasture and at AI centres, Ini tial trials with this new system have been successfully conducted on grazin g cattle for the repeated estimation of cortisol levels.