RESUMO
Reproductive performance was determined on Beltsville Small White hens housed 2 or 3 per cage for 10 weeks and then changed to 1 or 2 per cage for 10 additional weeks. Hens were then molted and data collected for a second production cycle of 18 weeks. Hens were fed a basal diet calculated to contain 1230 mg./kg. of choline, or supplemented with choline chloride to provide 1900, 2570 or 3240 mg. of choline per kg. of diet. Variations in production, fertility and hatch were observed between the first and second 10 week periods of the first laying cycle, but differences were affected more by two high choline levels than by number of hens per cage. When data was combined to show the effects of choline supplements for the entire 20 weeks, there were no significant differences in egg production or hatch of fertile eggs due to choline levels. However, significantly lower fertility resulted in groups fed choline at the level of 2570 or 3240 mg./kg. during this 20 wk. laying cycle. During the second production cycle (one hen per cage), choline supplements improved egg production, increased egg weight, depressed fertility and had no effect on hatch of fertile eggs. When data from the first and second production cycles were combined, there was no significant effect of choline on production or hatchability, but all groups supplemented with choline had significantly lower fertility than the basal group, indicating that 1230 mg./kg. of choline was adequate.
