VITAMIN-D REQUIREMENT OF MULE DUCKLINGS

Three experiments were conducted to determine the dietary vitamin D re quirement of mule ducklings fed corn-soybean meal diets. Day-old mule ducklings were fed diets containing various levels of vitamin D-3 for three weeks. Weight gain, feed efficiency, tibia ash, plasma calcium a nd plasma 25-OH vitamin D-3 contents were used as parameter for the de termination of the optimum level of dietary vitamin D-3 requirement of mule ducklings. The minmum vitamin D-3 requirement were 172 and 151 I CU/kg, respectively for maximum growth and optimum tibia ash content a s determined by regression analysis on body weight gain and tibia ash content against vitamin D-3 levels in diets. The results suggest that the minmum vitamin D-3 requirement of mule ducklings fed corn-soybean meal diets is 172 ICU/kg.