Egg Flavor Quality as Affected by Fish Meals or Fish Oils in Laying Rations

Abstract

Several types of fish meals or fish oils were included at various levels as a protein source in laying rations for hens. The eggs produced were evaluated organoleptically using both descriptive analysis and an acceptability rating scale. Certain fish meals in the diet caused musty, stale, rancid, “chemical” and fishy flavors in the eggs. These undesirable characteristics were intensified when the eggs were stored for 4 weeks at 10°C. Eggs produced early in the laying cycle were superior in flavor to those laid 5 months later. Eggs from birds fed hake meal were generally rated lower in flavor acceptability than eggs produced with equal levels of British Columbia (B.C.) herring meal in the ration. Use of Canadian Atlantic herring meal (Nova Scotia, Newfoundland) resulted in eggs which were lower (P = 0.05) in flavor rating than B.C. herring meal. Ten percent fish meal resulted in undesirable egg flavor except when Peruvian anchovy meal was fed early in the laying cycle in Series II-A. Comparisons of effects of 5% levels of some fish meals, and their oils at the levels found in the meals, indicated that the cause of objectionable flavor is not contained specifically in the fish oil. A higher level (1.5%) of oil, however, resulted in off-flavored eggs, especially when Peruvian anchovy oil was fed. Except in one trial, use of soybean meal or soybean oil produced eggs of good flavor.