INVESTIGATIONS ON RIBOFLAVIN REQUIREMENT OF FATTENING CHICKENS

The effect of riboflavin supplements of 0, 1, 2, 3, 4 and 8 mg/kg feed to a ration with 0,65 mg native riboflavin was tested in a fattening trial with 360 male day old broilers in 6 groups. The performance data weight gains, feed intake and feed efficiency (kg feed/kg weight gain ) were measured. The experiment lasted 5 weeks. Animals with 0 or 1 mg riboflavin supplementation exhibited severe deficiency symptoms. Thes e groups were excluded from the experiment after 11 or 15 days, respec tively. The mean average final weights of the other groups were 1750 g , with a daily feed intake of 81 g and 1.65 kg feed consumption/kg wei ght gain. From these results it is recommended to supplement rations i n practical broiler fattening with 3 mg riboflavin/kg feed.