It is vital that lambs receive at least 50ml/kg body weight of colostrum as soon as possible after birth. Without this, the lamb will be deprived quickly of energy for thermoregulation, as well as antibody protection. Colostrum contains high levels of fats and lactose, proteins and vitamins; however the consistency and colour vary between individual animals. Little is known of the cause of these variations. This experiment aimed to examine whether there were breed, age, genotype and litter size differences in the fat and protein levels of ewe colostrum collected within one hour of parturition.