Meeting Abstract

P1.42  Jan. 4  Experimental manipulation of egg quality in chickens: Influence of albumen volume and protein content on body size and organ mass in embryos and hatchlings. FINKLER, M.S.*; BURGGREN, W.W.; Indiana Univ., Kokomo; Univ. North Texas, Denton mfinkler@iuk.edu

Although variation in hatchling size has been shown to correlate with variation in total albumen content in birds, the relative contributions of the two major constituents of albumen (protein and water) on tissue growth and development in avian embryos is unclear. Herein, we conducted an experiment in which we removed ~10% of the albumen content from one group of chicken eggs to manipulate total content volume, replaced ~10% of the albumen content with Ringers solution in a second group, and sham-manipulated a third group. Yolk-free embryo mass was measured on Days 5, 10, 14, 18, and 21 (post-hatching), and the masses of the heart, intestine, and liver were measured on Days 18 and 21 (post-hatching). At Day 5, both wet and dry yolk-free embryo masses were significantly lower in the albumen-removed and albumen-replaced treatments than in sham-manipulated controls, but there was no difference among the treatments in either wet or dry embryo mass at any other interval prior to hatching. At Day 21, wet yolk-free hatchling mass was smaller in the albumen-removed group than in the other two groups at hatching, but dry yolk-free hatchling mass did not differ among the treatments. There was no difference in either wet or dry heart mass, wet intestine mass, or dry liver mass among the treatments in either Day 18 embryos or Day 21 hatchlings. However, both dry intestine mass and wet liver mass were significantly lower in the albumen-replacement treatment than in the other two groups in Day 21 hatchlings. These findings suggest that the water content of albumen may be the primary determinant in overall size at hatching. In addition, the concentration of protein in the albumen may influence proliferation of the small intestine between internal pipping and hatching, when avian embryos imbibe much of the remaining albumen.