Review article Methods of measurement of milk yield and composition in nursing mares: a review

Summary- This review describes and analyses the most commonly used methods of estimating milk yield of nursing mares: milking without or with oxytocin injection, weighing the foal before and after suckling, dilution of labelled water in foal body water: milking only does not appear to constitute an accurate method. Weighing before and after suckling requires numerous measurements, due to the foal's frequent sucks. Foal body water dilution does not disturb the mother-offspring relationships, but can only be used when-milkis the sole water source for the foal. Conditions of sampling and analysis for milk composition in nursing mares are described; incomplete milking (without oxytocin injection) involves a bias regarding milk fat content because milking is unusual. An oxytocin injection allows evaluation of the composition of secreted milk. The period of mare-foal separation should be short and close to the natural interval between sucks. Milk analysis should take into aceount the composition of mare milk fat and protein; infrared spectrophotometry should be calibrated for mare's milk.. Some of the differences in the Iiterature on milk secretion data can probably be explained by the methods of measurement of milk yield and composition