Avaliação do desempenho, morfometria intestinal e parâmetros de incubação de frangos de corte submetidos a nutrição in ovo

Abstract

The objective of this research was to evaluate two different techniques and 3 days of incubation for in ovo nutrition and to evaluate the effect of in ovo amino acid inoculation on the parameters of incubation, productive performance and development of organs of the gastrointestinal tract of broilers. For this, the experiment was divided into two stages. The first step consisted of testing two distinct techniques on three different incubation days. In this first experiment, 240 embryonated eggs of the COBB® lineage were selected. The eggs were distributed in a 2 × 3 factorial arrangement (two techniques and 3 days) with 4 egg weight classes. The variables analyzed were hatch rate, chick weight at birth, weight of organs of the gastrointestinal tract, evaluation of chick quality and classification of embryonic mortality trough embryonic diagnosis. In step 2, the best technique and the best observed day were selected for the execution of step 2. In this way, 720 embryonated eggs were incubated and incubated in three times, with 240 eggs at a time. There were five treatments with 144 eggs per treatment and 3 classes of eggs. The treatments consisted of control group, methionine 20mg, methionine 30mg, lysine 20mg and lysine 30mg. After hatching, these animals were housed for evaluation for 14 days. In the field, the animals remained with the same 5 incubation treatments with 9 replicates plus sex with 4 to 12 animals per replicate (due to different hatch rates per treatment). The hatch rate, birth weight and quality of the chicks were evaluated and feed conversion was measured, feed intake, weight gain at 7 and 14 days of life. Histological sections of the intestine of an animal were also performed by repetition on the 14th day, in addition to weighing the organs of the digestive tract on the same date of two animals per repetition. The results of step 1 indicate that the technique with 45 ° needle axis passing through the air chamber hinders hatchability (P <0.05). Meanwhile, incubation days (16, 17 and 18) had no influence on the analyzes evaluated. The other variables in this stage did not change for the treatments, however, it was observed that the larger eggs provided larger chicks with greater gizzard at birth (P <0.05). For stage two, the inoculation of lysine (20 and 30 mg) impaired the hatching rate (P <0.05) and at the dose 30mg the animals had lower quality score. For performance, males consumed more ration on days 7 and 14 (P <0.05) and in the second week, animals receiving methionine 20 mg consumed more ration (P <0.05) than the 30 mg treatment lysine. In the organ weighing, there was no difference between the evaluated factors. For intestinal morphometry, there was only a significant difference (P <0.05) between the dose factor for the crypt villi and crypt diameter. Thus, the technique as a 90º angle without passing through the air chamber is the most indicated and the days tested had no influence on the parameters evaluated. In addition, the inoculation of methionine (20 and 30mg) obtained data similar to the control group. However, the lysine doses used were not feasible for the embryos, because they worsened most of the analyzed parameters.