| 摘要 |
PURPOSE:To obtain eggs of increased shell strength by feeding laying hens or breeding hens with a feed containing L-tryptophan or its salt. CONSTITUTION:L-Tryptophan and/or its salt, preferably free L-tryptophan, is added to a feed, preferably in an amount of 10 to 10,000ppm, and laying hens or breeding hens are given the feed to produce eggs of thick shells, thus being free from breakage of shell during laying, egg collection, washing, storage and transportation. |
