Effects of a suboptimal dietary intake of particular B-vitamins on the growth of fattening chicken

In a fattening trial of 5 weeks with 360 male day-old broiler chicks (Ross) the effect of suboptimal supply of several B-vitamins on performance was measured. Group I (the basal diet and negative control) was deficient in riboflavin, niacin, vitamin B₁₂, biotin, folic acid and choline. Group II, the positive control, was supplemented with riboflavin, niacin, pantothenic acid, vitamin B₁₂, biotin, folic acid, and choline according to the recommendations. Group III was supplemented with all these vitamins except niacin, group IV except vitamin B₁₂, group V except biotin and group VI except folic acid. Each treatment was replicated six times. After 2 weeks group I with no supplementation had to be removed from the experiment because of massive animal losses (77%). The positive control exhibited a good growth performance with 2011 g final live weight, a daily feed consumption of 87 g and a feed conversion of 1.53 kg feed/kg weight gain. The other groups were similar to group II in their performance. Only group V with no biotin supplementation showed a reduction in live weight of 5%, in feed consumption of 8%, but a slightly better feed conversion. It is concluded that the present German recommendations are high enough to produce good performance. A deficiency of only one of the tested vitamins (except biotin) could be compensated. Biotin seems to admit the smallest allowance between optimal and suboptimal supply compared to niacin, vitamin B₁₂ and folic acid.