Fiber level for laying hens during the growing phase

• Published in: Ciência e agrotecnologia 2014-04, Vol.38 (2), p.188-198
• Main Authors: Freitas, Ednardo Rodrigues, Braz, Nádia de Melo, Watanabe, Pedro Henrique, Cruz, Carlos Eduardo Braga, Nascimento, Germano Augusto Jerônimo do, Bezerra, Roseane Madeira
• Format: Article
• Language: English
• Subjects: AGRICULTURE, MULTIDISCIPLINARY; Crescimento; fibra em detergente neutro; fibra insolúvel; linhagem
• ISSN: 1413-7054; 1981-1829; 1413-7054
• DOI: 10.1590/S1413-70542014000200010

Feeding management of laying hens has been focused on the direct influence of nutrient intake on weight gain, especially at growing phase. This study evaluates nutrient digestibility, performance, development of the digestive tract, body composition, and bone quality of two strains of laying hens fed with different levels of neutral detergent fiber (NDF) during the growing phase from the 7th to the 12th week of age. A total of 1,296 birds were distributed in a completely randomized design in a 2 x 3 factorial arrangement (two strains x three levels of NDF) with four replicates of 54 birds per treatment. Semi-heavy (Hy Line Brown) and light-strain (Lohman LSL) pullets were allotted to dietary treatments consisting of 14.50, 16.50, and 18.50% NDF. An interaction between strains and NDF levels was observed only for feed/gain ratio and light-strain pullets had lower performance with 18.50% NDF. The increasing levels of NDF in the diet reduced the coefficients of digestibility of dry matter, nitrogen and gross energy, and the values of metabolizable energy. Higher levels of NDF in the diet increased the relative weight of liver and intestines and reduced gizzard weight. It was also observed differences between bone quality and composition of the femur and tibia of light and semi-heavy hens. The increase in NDF level in ration for growing phase laying hens above 14.50% decreases the nutrient digestibility and the metabolizable energy of the diet; however, it does not affect the carcass composition, bone quality, feed intake, and weight gain, although it may impair feed conversion of light-strain pullets. O manejo alimentar de poedeiras tem sido avaliado quanto à influência direta da ingestão de nutrientes no ganho de peso, principalmente na fase de crescimento. No estudo, objetivou-se avaliar os efeitos dos níveis de fibra em detergente neutro (FDN) das rações de recria (7ª e 12ª semanas de idade) sobre a digestibilidade dos nutrientes da ração, desempenho, desenvolvimento do trato digestório, composição corporal e qualidade óssea das aves de duas linhagens de poedeiras comerciais. Foram utilizadas 1.296 aves distribuídas em um delineamento experimental inteiramente casualizado em esquema fatorial dois x três (duas linhagens x três níveis de FDN) com quatro repetições de 54 aves por tratamento. Foram avaliadas aves de uma linhagem de poedeira semipesada (Hy Line Brown) e leve (Lohman LSL) e testados os níveis de 14,50; 16,50 e 18,50% de FDN. Houve interação sign