1. Guidelines for male separate feeding in the laying period. Ross-Tech: A technical bulletin from the Ross people;Anonymous,1987
2. Dietary protein and fertility of chickens;Arscott;J. Nutr.,1963
3. Official Methods of Analysis;Association of Official Analytical Chemists,1970
4. The Amino Acid Composition of Proteins and Foods;Block,1951
5. The reliability and efficiency of various methods for estimating spermatozoa concentration;Brillard;Poultry Sci.,1985