Avaliação do desempenho e qualidade dos ovos de poedeiras comerciais, submetidas as dietas suplementadas com diferentes óleos vegetais

Abstract

The research was developed in the Sector of Poultry of the Department of Zootecnical Center of Agrarian Sciences of the Federal University of Ceará (UFC), objectifying to evaluate the zootecnical performance and the quality of eggs of commercial laying hens, submitted to the diets with different vegetal oils. The experimental procedure involved 224 commercial laying hens of the Hy-line W-36 line, with 23 weeks of age, divided in 5 cycles of 28 days, during which were collected data for study The experiment followed a randomized blocks, distributed in seven treatments, each experimental unit was a box with 8 hens and 4 repetitions per treatment. The treatments consisted of 7 rations, with level of energy of 2850 kcal ME/kg and protein of 18%, being: T1 - basal diet (without oil); T2 - basal diet + 2% of soy oil; T3 - basal diet + 4% of soy oil; T4 - basal diet + 2% of flax oil; T5 - basal diet + 4% of flax oil; T6 - basal diet + 2% of cotton oil and T7 - basal diet + 4% cotton oil. The inclusion of the vegetal oil in the diets did not make possible an absolute improvement (P>0,05) in the egg percentage, feed conversion, egg mass, body weight, egg weight, percentages of the yolk, egg white and shell and did not reduce cholesterol level of eggs, in relation to the basal diet (without oil). In accordance with the age of the birds, significant increase (P<0,05) of the weight of eggs and the percentage of the egg yolk was observed, and reduction in the percentage of the yolk and the coloration of the raw egg yolk, however it does not to have significant alteration (P>0,05) in the percentage of the shell. The level of 4% of addition of the vegetal oil in the diets promoted an effective improvement (P<0,05) in the coloration of the raw egg yolk. The eggs conserved in temperature of refrigeration presented (P<0,05) smaller loss of weight and better (P<0,05) percentage of the yolk, specific gravity, Haugh units and coloration of the raw egg yolk, when compared with eggs conserved in ambient temperature. It was evidenced that the quality of eggs is modified significantly (P>0,05) in function of the temperature of conservation and the period of storage, mainly for the parameters weight loss, percentages of the yolk and, specific gravity and Haugh units. In relation to the sensorial analysis, the inclusion of 4% of oil addition of flax oil in the diets effectively modified (P<0,05) the flavor and the texture of the yolk and the white egg. Economic analysis suggested that the rude edge and the effective operational profit were bigger in the diet with 2% oil of soy and smaller in the diet with 4% flax oil. The best economic reply of the egg production was gotten by the birds that consumed diet with 2% soy oil.