Effect of different metabolizable energy and soybean oil levels in the diet of laying hens on the egg chemical composition and lipid profile

Abstract

This study was carried out to evaluate the effects of increasing metabolizable energy and soybean oil levels on the egg chemical composition, total lipids and cholesterol contents and fatty acids profile in the egg yolk. Three hundred and sixty 29 week-old Bovans Goldline semi-heavy commercial layers were used during three periods of 28 days. A completely randomized design were used in a 3 × 3 double factorial arrangement with three soybean oil levels (1, 2 and 3%) and three metabolizable energy levels in the diet (2,600, 2,750 and 2,900 kcal/kg), totalizing nine diets with five replicates of eight birds. No interaction soybean oil × metabolizable energy levels was observed. The metabolizable energy levels did not affect any of the determined characteristics. The moisture, ash and protein contents in the egg yolk and albumen and the lipid and cholesterol contents in the yolk were not affected by the soybean oil levels in the diet, while linoleic acid (C18:3) and linolenic acid (C18:2) levels responded linearly. The use of 2,600 kcal ME/kg and 3% of soybean oil in the diet of laying hens with consumption of 120 g/bird/day is justifiable, since this feeding strategy improves the fatty acids profile of the egg.