Response of hens to various dietary levels of tannic acid.

One-hundred-twenty Babcock B-300 ehns, 17 months of age, were placed one bird per cage with six replicates of five birds each per treatment. Four levels (0, 1, 2, and 4%) of technical grade tannic acid were added to a standard corn-soy layer diet. With the exception of feed comsumption during the second and third week, there were no significant differences for feed consumption, egg production, feed efficiency, fertility, or hatchability amond the control birds and those receiving tannic acid at the 1% level. The addition of tannic acid at levels of 2 and 4% resulted in significantly decreased feed consumption and egg production during the six-week experimental period. Fertility and hatchability were not significantly affected by dietary tannic acid.