1. Association of Official Agricultural Chemists, 1970. Official Methods of Analysis, Eleventh ed., Washington, D.C.
2. Multiple range and multiple F test;Duncan;Biometrics,1955
3. Fractionation of a chick growth depressing factor from rye;Fernandez;Poultry Sci.,1973
4. The effect of adding procaine penicillin to diets with different levels of vitamin D3 on the performance of turkey poults;MacAuliffe;Poultry Sci.,1976
5. National Academy of Sciences, National Research Council, 1971. Nutrient Requirements of Poultry. Sixth revised ed., Washington, D.C.