Johri T S, Vohra P
Poult Sci. 1977 Jan;56(1):350-3. doi: 10.3382/ps.0560350.
Not more than 20% protein is needed in purified diets based on isolated soybean protein, starch supplemented with vitamins and minerals containing about 2700 kcal./kg. metabolizable energy for optimum egg production, fertility and hatchability. A protein level as low as 16% gave slightly inferior egg production, but the data were statistically insignificant. Levels of 24 and 28% protein were not superior to the 20% protein level for the reproductive performance.