J. Appl. Anim. Res. 10 (1996) : 155-162
The Relationship Between Age and Egg Production, Egg Components and Lipoprotein, Lipids and Fatty Acids of the Plasma and Eggs of Laying Hens
Department of Animal Production, College of Agriculture, King Saud University, PO Box 2460, Riyadh 11451, Saudi Arabia
(Received May 13, 1996; accepted November 23, 1996)
Shafey, T.M. 1996. The relationship between age and egg production, egg components and lipoprotein, lipids and fatty acids of the plasma and eggs of laying hens. J. Appl. Anim. Res., 10: 155-162.
The relationship was studied between the age of hens from 27 to 51 weeks and production, size and components of their eggs, the lipid and fatty acid content of the yolks and the lipid composition of very low density lipoproteins (VLDL) and that of total plasma. Age of the hen was positively correlated with the production of extra large eggs and linoleic acid contents of plasma VLDL, but was negatively correlated with egg yolk lipid and the production of large, medium and small eggs. Extra large eggs had a significantly lower adjusted yolk percentage and higher adjusted albumen percentage than those of medium and large size eggs. Egg size did not significantly affect lipid or fatty acid concentration of egg yolks. It was concluded that older hens laid larger eggs, with a greater proportion of albumen, a higher concentration of the polyunsaturated fatty acid, LA, but less saturated fatty acids and total lipid than eggs from younger hens.
Key words : Age, egg components, yolk lipid, yolk fatty acids, plasma lipoproteins.