Effects of dietary borate and aluminate on riboflavin metabolism in the breeding hen.

Breeding hens were used to investigate the effects of aluminate and borate ingestion on riboflavin metabolism. Groups of six hens were fed on either a control diet, or the control diet plus 15 g kg-1 of either sodium metaborate or sodium meta-aluminate. All diets contained 6 mg kg-1 riboflavin. Daily egg production per hen in the borate group had mean values of 0.71, 0.21 and 0.02 for the three weeks of the study. The values were 0.91, 0.91, 0.86 and 0.86, 0.74, 0.89 for the control and aluminate groups, respectively. Fertility (fertile eggs per 100 set) and hatchability (live chicks per 100 fertile eggs) were both nil in the borate-treated hens, compared with 57 and 95 and 59 and 100 for the control and aluminate-treated hens, respectively. Fluorimetric analysis of blood plasma, egg yolk and albumen showed that the riboflavin contents of all tissues were greatly reduced in the borate-treated hens. Borate ingestion can therefore induce a severe riboflavin deficiency in the hen, but aluminium, a more universal contaminant of food or water, did not impair riboflavin metabolism when fed as aluminate.