Abstract
Little information on the cholesterol content and the fatty acid composition of avian species other than chicken is available. This study was conducted to compare the yolk cholesterol content and the fatty acid profiles of some wild birds maintained in captivity on commercial grain-based chicken diets. The concentration of cholesterol/g of yolk as well as the total yolk cholesterol per egg varied among species. Yolk cholesterol concentration, expressed as mg/g of yolk, was highest in chukar, followed by pheasant, guinea fowl and quail, while total yolk cholesterol in an egg was highest in guinea fowl, followed by pheasant, chuckar and quail. An inverse relationship between yolk cholesterol concentration and egg weight was observed among species with an exception of quail. Although major fatty acids of egg yolk were oleic acid, palmitic acid, linoleic acid and stearic acid in all birds, the composition varied among species. Chukar and quail showed higher oleic acid content than pheasant and guinea fowl, while showing lower linoleic acid. Fatty acids of chukar and guinea fowl eggs were more saturated than those of pheasant and quail. Chukar and especially quail had higher monounsaturated fatty acids (MUFA) than pheasant and guinea fowl; in quail egg 51.6% of total fatty acids were MUFA. Polyunsaturated fatty acids (PUFA), essential fatty acids (EFA) and the ratio of PUFA to saturated fatty acid (P/S ratio) were higher in pheasant and guinea fowl than in chukar and quail. Differences in fatty acid profile of triglyceride (TG) among birds were largely similar to those of total lipid. In comparison to TG, phosphatidyl choline (PC) was low in MUFA while high in saturated fatty acids (SFA), PUFA, P/S ratio and EFA. PC was most saturated in guinea fowl egg yolk, followed by chukar, quail and pheasant. PUFA, P/S ratio and EFA in PC were highest in pheasant followed by chukar, guinea fowl and quail. PE was distinguished from PC by its high contents of stearic acid, eicosapentenoic acid (EPA) and docosahexenoic acid (DHA) while low in palmitic, oleic and linoleic acids. In egg yolk of all birds MUFA was significantly lower in PE than in PC except in quail. Compared to other species, quail had a considerably higher content of MUFA in PE at the expense of SFA and PUFA.