Abstract
The present experiments were conducted to elucidate time courses of amino acid (AA) contents in the yolk of hatching eggs and newly hatched chicks over time during incubation (Days 0, 7, 14, and 19 of incubation), and newly hatched period (0, 1, and 3 days post-hatching). AA contents in the yolk decreased with advancing days of incubation from Day 0 to 14, and increased on Day 19 of incubation, and then again decreased When AA patterns of yolks were expressed as ratios to lysine contents, ratios of total aspartic acid, glutamic acid, alanine, cystine, isoleucine, leucine, and phenylalanine in the yolk increased with advancing incubation time from Day 0 to 19 of incubation. In contrast after Day 19 of incubation, when albumen was absorbed into yolk sac, AA pattern remained constant.
