Avaliação de qualidade de ovos com o fornecimento de cálcio em diferentes horários para galinhas poedeiras em final de ciclo produtivo

Abstract

The purpose of this study was evaluate variables of internal and external quality of eggs, as well as mineral content in the egg shell, in laying hens in the end of the production cycle, receiving diets with different calcium supply schedules. The experiment was carried out in the experimental aviary of the Federal University of Fronteira Sul, Campus Erechim, lasting 90 days. The experiment was carried out in a completely randomized design, with 40 laying hens, divided into 12 plots with 3 hens each plot, and 4 cages held 1 bird more in case losses occurred during the experiment, distributed in four treatments, these with variations in the calcium level being respectively 4% of the two shifts (T1), 2.75% in the morning and 1.25% in the afternoon (T2), 2.0% in the morning and 2.0% in the afternoon (T3) and 1.25% in the morning and 2.75% in the afternoon (T4). Four analyzes of the eggs were carried out in the laboratory at 50, 68, 85 and 90 days after the beginning of the experiment, counting the adaptation period, analyzing egg weight, yolk and albumen, shell thickness and weight, length and height. yolk, in addition to chemical elements such as calcium, sodium and potassium in their shell. The results were evaluated with the aid of the SAS statistical program (2001), through the PROC GLM and the comparison of means by the Tukey test (5%). In general, the time of calcium supply did not affect the internal quality data of the egg, calcium content in the shell, however, it changed parameters of thickness and weight of the shell, as well as the sodium and potassium contents in it (P<0 .05). It can be concluded that the supply of Calcium at different times does not affect the internal quality of the egg, however, further studies must be carried out in relation to the effects of reducing the thickness and weight of the shell in terms of its shelf life.