5Ovesen L, Brot C, Jakobsen J. Food contents and biological activity of 25-hydroxyvitamin D: a vitamin D metabolite to be reckoned with[J]. Ann Nutr Metab, 2003, 47:107-113.
6Heaney R P, Barger-Lux M J, Dowell M S, et al. Calcium absorptive effects of vitamin D and its major metabolites [J]. J Clin Endocr Met,1997, 82:4 111-4 116.
7Barger-Lux M J, Heaney R P, Lanspa S J, et al. An investigation of sources of variation in calcium absorption efficiency[J]. J Clin Endocr Met, 1995, 80:406-411.
8Yarger J G, Quar!es C L, Hollis B W, et al. Safety of 25-hydroxycholecalciferol as a source of cholecalciferol in poultry rations[J]. Poult Sci, 1995, 74:1 437-1 446,.
9Morrissey R L, Cohn R M, Enpson Jr R N, et al. Relative toxicity and metabolic effects of cholecalciferol and 25-hydroxycholecalciferol in chicks[J]. J Nutr, 1977, 107:1 027-1 034.
10Edwards Jr H M. Studies on the efficacy of cholecalciferol and derivatives for stimulating phytate utilization in broilers[J]. Pouh Sci, 2002, 81:1 026-1 031.
4Wawek S S.Effect of vatamin D3 supplementation of beef Steers on longissmus muscle tenderness[J].Jounrnal of Animal Science,1998,76(2):13.
5Yarger,Quarles,Hollis,et al.Safety of 25-Hy-Droxycholecalciferol as a Source of Cholecalciferol in Poultry Rations.Poultry Science,1995,74(9):1437-1446.
6Yarger,Saunders,McNaughton,et al.Commparison of dietary 25-Hydroxychole calciferol and cholecalci ferol in Broiler Chickens.Poultry Scicnce,1995,74(7):1159-1167.
