عنوان مقاله [English]
Population growth requires extending agriculture and ranching to meet food demand and optimizing water use is necessary for a sustainable agriculture and ranching activities. To water use optimization in livestock production procedure, Amount of water utilized in diet ingredient producing and livestock drinking and servicing water should be noted. This amount of water used to produce livestock production called virtual water of production. The aim of this paper is computing virtual water of Holstein milk production in East Azerbaijan considering three irrigation efficiency 33, 60 and 90 percent. Average virtual water content of wheat, barley, corn, soybean, beet and alfalfa were 1.2, 1.5, 0.13, 3.8, 2.2 and 2.4 cubic meters per a kilogram production by considering 33 percent irrigation efficiency. According to 33 percent of irrigation efficiency the virtual water of milk for after parturition, high yielding, average yielding and low yielding durations were 1.5, 1.4, 2.4 and 3.3 cubic meters per a kilogram production. If percentage of irrigation efficiency increased by 60 and 90, virtual water of milk would decrease 43 and 60 percent respectively.