Níveis de energia metabolizável em dietas de frango de crescimento lento

• Autor(a) principal: Veríssimo, Saulo
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/001300000d311
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/10923
• topic: Desempenho; Frango caipira; Nutrição; Performance; Free-range chicken; Nutrition; CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL

The aim was to evaluate four levels of metabolizable energy (ME) in the feed of Isa Label broilers, in the first phase on productive performance, carcass composition and energy metabolism. Two experiments were conducted. In triaI I, 240 male and 240 females of the Isa Label lineage, naked neck, were fed with diets containing different levels of ME (2,725, 2,850, 2,975 and 3,100 kcal / kg). The design used was completely randomized in a 4x2 factorial scheme, the treatments was four levels of ME in the initial diet (up to 28 days) combined with two sexes, with six repetitions per treatment, of 20 birds. In the growth phase (29 to 56 days of age) all birds received the same fed. Carcass yield and performance were evaluated. A metabolism trail was carried out with total collection of excreta from 17 to 21 days, with 160 male and 160 females. The design used was completely randomized in a 4x2 factorial scheme, as well as in the first trail, with eight replicates of 10 birds each. The data were submitted to analysis of variance. Polynomial regression analysis was used to study the levels of metabolizable energy in the diet, using the SAS Statistical program. In the phase from 1 to 7 days of age, there was a difference between sexes for feed conversion. At 21 and 28 days there was a difference between sexes for live weight, weight gain and feed consumption. At 28 days there was a quadratic regression effect with a maximum point of 2915.22 for live weight and weight gain and negative linear regression for feed conversion. At 56 days of age, there was a difference between males and females for all variables analyzed and a quadratic regression effect for feed consumption with a minimum point of 2912.5, in addition to interaction between the factors studied (energy x sex) for feed conversion, females responded in a with quadratic regression with a maximum point of 2929.55, males responded in a linear regression. There was no significant regression effect for carcass and fine cuts at 56 days. There was a quadratic regression effect for nitrogen balance and nitrogen metabolizability coefficient, with a minimum point of 2912.5. There was a positive linear regression effect for ether extract balance and quadratic regression effect for the ether extract metabolizability coefficient with a maximum point of 2912.5. For the dry matter metabolizability coefficient, there was a positive linear regression effect. The variables apparent metabolizable energy and the metabolizable energy corrected by nitrogen presented positive linear regression effect. It is recommended to work with diets with levels of 2900-2930 kcal ME / kg, in initial diets from one to 28 days of age.