Objetivou-se com esta pesquisa avaliar os efeitos dos níveis de fibra em detergente neutro (FDN) das rações oferecidas para as aves entre a 7ª e 17ª semanas de idade sobre o desempenho, o desenvolvimento dos sistemas digestório e reprodutor, bem como os efeitos na maturidade sexual, no desempenho e na qualidade dos ovos na fase de postura.Foram distribuídas 1.296 aves em delineamento inteiramente casualizado em esquema fatorial 3 × 2, composto de três níveis de FDN e duas linhagens, com quatro repetições de 54 aves. Foram testados os níveis de 14,5; 16,5; e 18,5% de FDN em aves leves e semipesadas. Ao final da fase de crescimento, as aves foram transferidas para o galpão de postura, mantendo o mesmo delineamento, composto por 14 aves por parcela. Não houve interação entre os níveis de FDN e as linhagens para as variáveis avaliadas. Na fase de crescimento, o aumento do nível de FDN reduziu o ganho de peso e o peso final, piorou a conversão alimentar e aumentou o peso dos intestinos. Na fase de postura, os níveis de FDN não influenciaram o desempenho das aves nem os constituintes e a qualidade dos ovos. Na fase de crescimento, as aves semipesadas apresentaram maior consumo, ganho de peso e peso final, melhor conversão alimentar, peso maior da moela e menor do fígado e do ovário. Na fase de postura, as aves leves foram mais precoces, apresentaram menor peso e massa de ovos, pior conversão alimentar, ovos com mais gema, menos albúmen, maior densidade específica e menores unidades Haugh. Independentemente da linhagem, o aumento do nível de FDN em rações para crescimento pode influenciar o desempenho das frangas, resultando em aves menos pesadas, sem influenciar a maturidade sexual, o desempenho e a qualidade dos ovos na fase de postura.

With the objective of evaluating the effect of reducing crude protein (CP) and L-glutamic acid supplementation, Dekalb Brown laying hens with 34 weeks of age. The birds were distributed in six treatments in a completely randomized design, eight replications of eight birds. The control diet contained 17% CP. The second and third treatments had CP reduced by 1.5 and 3.0 percentage points (pp) of CP in relation to the control diet, respectively. In the fourth treatment, was added the same amount of glutamate of the control diet (2.982%), and the last two treatments was added 1 and 2 pp of glutamate in relation to control diet (3.982 and 4.98%), respectively. The treatment with 15.17% CP + 0.341% L-glutamic acid (T4) promoted higher egg production, and the control diet showed greater egg weight than others treatments. There was no significant effect on the variables on quality of eggs. The T4 presented values of excreted nitrogen similar to the others treatments, with lower concentration of uric acid than the control diet and lower cost in the production. In conclusion, it is recommended the treatment with 15.17% CP + 0.341% L-glutamic acid for Brown laying hens with 34 weeks of age.

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.

In order to evaluate the effects of chlorine levels for Japanese quails in the growing phase and its effects on the production phase, 384 quail day old were used distributed in a completely randomized design with six treatments and eight replicates of eight birds. Chlorine levels were: 0.07, 0.12, 0.17, 0.22, 0.27 and 0.32%. The variables studied in the growth phase were: feed intake (g/bird), weight gain (g/bird), feed conversion (g/g), water consumption (mL/bird/day), relative water consumption/feed intake, excreta moisture (%), digestibility of dry matter (%), nitrogen (%), gross energy (%), apparent metabolizable energy (kcal/kg DM) and corrected for apparent nitrogen balance (kcal/kg DM). According to the results the statistical analysis showed no significant effect on feed intake, weight gain, consumption ratio of water / feed intake, excreta moisture, feed conversion, water intake, digestibility of dry matter (CDMS), nitrogen (CDN) and gross energy (GEDC) and values of apparent metabolizable energy (AME) and apparent nitrogen corrected (AMEn) of feed. Although this test showed that chlorine levels received by the quails in the growing phase did not significantly affect the performance of quails. Considering the results, it can be recommended diets for Japanese quails in the growing phase containing chlorine levels up to 0.32%.