Vitamin D requirement of mule ducklings

Three experiments were conducted to determine the dietary vitamin D requirement 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 and plasma 25-OH vitamin D-3 contents were used as parameter for the determination of the optimum level of dietary vitamin D-3 requirement of mule ducklings. The minmum vitamin D-3 requirement were 172 and 151 ICU/kg, respectively for maximum growth and optimum tibia ash content as 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.