Experimental studies on bovine Hyena disease induced by administration of excessive vitamin AD3E premix, vitamin A, or vitamin D3.

The effects of the excessive administration of the vitamin AD3E(V-AD3E) premix, vitamin A (V-A) or vitamin D3 (V-D3) on experimental development of Hyena disease in the calves were examined. Hyena disease was recognized in 4 calves, both of the 2 calves administered a high dose of V-AD3E premix (V-A 3,000,000, V-D3 300,000, and V-E 1,200 IU/day, V-AD3E group), 1 of the 2 calves administered a half dose of the V-AD3E premix, and 1 of the 2 calves administered only V-A (V-A 3,000,000 IU/day, V-A group) when each vitamin was administered orally for 10 days from 1 week after birth. Both of 2 calves administered only V-D3 (V-D3 300,000 IU/day) did not developed. In the 4 calves with Hyena disease (Hyena calves), the plasma retinylpalmitate showed high values which was suggesting the hypervitaminosis A, and the epiphysial growth plate was narrow and destroyed structure of column. Compared with the Hyena calf in the V-A group, the Hyena calves in the V-AD3E group showed earlier appearance time of Hyena disease, lower growth rate and shorter lengths of fore and hind limb bones. In conclusion, the present findings suggested that excessive V-A administration to suckling calves might cause Hyena disease by V-A effects to the epiphysial growth plate, moreover such effects may be promoted by the V-D3.