The effect of a foreign object in the shell gland on egg production of hens on a calcium‐deficient diet

Synopsis

When fed a calcium‐deficient diet normal hens stopped laying within 10 days, but hens with a thread in the shell gland continued to lay soft‐shelled eggs for about 9 weeks. This finding supports the hypothesis that calcium loss is an important factor in the regulation of reproductive activity in the domestic fowl.