25-hydroxy-cholecalciferol

The research progress of 25- hydroxycholecalciferol (25-OH D) in animal nutrition, especially poultry, was reviewed. 25-OH DJ can improve the growth performance of broilers, but its effect is affected by the basal dietary calcium, phosphorus and vitamin D levels. 25-OH D can improve bone quality and reduce the incidence of tibial chondroplasia (TD), but this effect is affected by the genetic background of birds. 25-OH D: Increases distal ileum phytate-phosphorus digestibility without affecting intestinal (endogenous) phytase activity. 25-OH Ds regulates intestinal structure and immunity. 25-hydroxyD can improve eggshell quality of older laying hens. Based on bone mineralization and eggshell quality, 25-OH D was 1 to 2.5 times more effective than vitamin D. 25-OH D is 5 to 10 times more toxic than vitamin D in terms of kidney calcification.