Physical studies of the alimentary tract of grazing cattle

Two techniques for estimating the capacity of the reticulo‐rumen of cattle are described, compared, and assessed. One method involved measuring the amount of water the reticulo‐rumen would accommodate, and the other, the volume of air occupying a large balloon inflated at various pressures inside this organ. The use of these techniques, on two sets of monozygous twin Jersey cows, showed that the capacities of the reticulo‐rumens of the dry cows were smaller than those of their milking twins.