For the purpose of determining affections of synchronization of energy and nitrogen on BUN content of the male Ghezel lambs, the experimental in the form of CRD, it contains four treatments a) urea treated wheat straw + whole barley grain b) urea treated wheat straw + ground barley c) urea treated wheat straw + ground barley + molasses, d) urea treated wheat straw + molasses) performed in four replications, also the alfalfa as a roughage was equal in all treatments, and experimental diets feeding to 70 days. Results show that Ground barley + molasses treatment significantly decreased BUN content and reached to 14.63 and 12.71 mg/dl, and this treatment is the best form of energy for synchronization of urea treating wheat straw.
