8Stevens V I, Blair R, Riddell C. Dietary level of fat, calcium, and vitamins A and D3 as contributory factors to rickets in poults [J]. Poultry Science, 1983, 62(10): 2073-2082.
9Aburto A, Britton W M. Effects and interactions of dietary levels ofvitamins A and E and choleealeiferol in broiler chickens[J]. Poultry Science, 1998, 77(5):666-673.
10Veltmann J R, Jensen L S, Rowland G N. Excess dietary vitamin A in the growing chick : Effect of fat source and vitamin D[J]. Poultry Science, 1986, 65:153-163.
