Reducing nitrogen excretion of the laying hen by feeding lower crude protein diets

Several experiments were undertaken to investigate nitrogen excretion for laying hens fed diets varying in level of dietary protein. Reducing dietary protein levels from 19 to as low as 5% resulted in a concomitant decrease for up to 50% in nitrogen excretion. Depending on age of the hens, dietary protein levels as low as 11% gave reductions in nitrogen excretion for up to 40% when compared with a conventional 17% protein corn and soybean meal diet, with a minimum reduction in egg mass output. Because exceptionally high intakes of dietary protein are required to maximize egg size, there is merit to optimizing rather than maximizing egg mass output.