ABSTRACT. An experiment was carried out to evaluate the requirement of digestible methionine for growing pullets at growth phase (7 to 12 weeks of age). A completely randomized design was distributed in five treatments, six replicates, and 15 pullets per experimental unit. 450 Dekalb White pullets from the 7th weeks of age, with an average initial weight of 313.14 ± 12.49 g were used. Dietary treatments consisted in five diets supplemented with DL-Methionine which resulted in five levels of digestible methionine (0.266, 0.294, 0.322, 0.350, and 0.378 %). Performance, serological blood, histopathology and histomorphometry data were evaluated. Quadratic responses were observed for final live weight (p < 0.0143), weight gain (p < 0.0073), feed conversion ratio (p < 0.0058), glycogen deposition in the liver (p < 0.0001), gamma-glutamyl transferase enzyme activity (p < 0.0008), and villus height (p < 0.0024) with digestible dMet levels. In conclusion, the use of 0.343 % dMet, corresponding to a dMet:dLys ratio 55, is recommended for white-egg pullets from 7 to 12 weeks of age.

Com o objetivo de avaliar o efeito da redução da proteína bruta (PB) e suplementação de L-glutamato em poedeiras da linhagem Dekalb Brown com 34 semanas de idade, as aves foram distribuídas em seis tratamentos em um delineamento experimental inteiramente casualizado com oito repetições. A dieta controle continha 17% PB. Os segundo e terceiro tratamentos tinham redução de 1,5 e 3,0 pontos percentuais (pp) de PB em relação à dieta controle, respectivamente. No quarto tratamento, foi adicionada a mesma quantidade de glutamato da dieta controle (2,982%), e nos dois últimos tratamentos foram adicionados 1 e 2 pp de glutamato em relação à dieta controle (3,982 e 4,98%), respectivamente. O tratamento com 15,17% CP + 0,341% L-glutâmico (T4) promoveu maior produção de ovos, e a ração controle apresentou maior peso de ovos do que os outros tratamentos. Não houve efeito significativo sobre as variáveis relativas à qualidade dos ovos. O T4 apresentou valores de nitrogênio excretado semelhante aos demais tratamentos, com menor concentração de ácido úrico que a dieta controle e menor custo na produção. Em conclusão, recomenda-se o tratamento com 15,17% PB + 0,341% de ácido L-glutâmico para poedeiras semipesadas com 34 semanas de idade.

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.

The objective of this study was to determine the chlorine nutritional requirement of Japanese Quails during the laying phase, based on performance and egg quality parameters. A total of 240 Japanese quails were distributed according to a randomized block design, with five treatments and six replicates, with 8 birds each. The experiment lasted 84 days, divided in four cycles of 21 days each. Treatments consisted of a basal diet formulated to meet the nutritional requirements, except for chlorine, and four supplementation levels with ammonium chloride, generating the levels 0.8; 1.6; 2.4; 3.2 and 4.0 g/kg. The parameters evaluated were: feed intake (g/bird/day), egg production (egg/bird/day), egg weight (g), egg mass (g), egg mass conversion (g/g), conversion per dozen eggs (kg/dz), weight of yolk (g/100 g of egg), albumen (g/100g of egg) and shell (g/100 g of egg), specific gravity (g/cm³) and shell thickness (mm). As a result of this study, feed intake, egg weight, weights of albumen, yolk, shell and specific gravity were not affected by treatments. There was a quadratic behavior for egg production, egg mass, egg mass conversion, conversion per dozen eggs and shell thickness according to the chlorine levels in the diets, with the requirements for those parameters established at 1.54; 1.37; 1.39 and 2.78 g/kg, respectively. The recommendation is 1.39 g/kg of chlorine and 244.22 mEq/kg of electrolyte balance in diets for Japanese quails.

The objective of this study was to evaluate the requirement of digestible tryptophan for white laying hens in the production stage fed diets of different digestible tryptophan:digestible lysine ratios, as well as animal performance and histological alterations in their reproductive and digestive systems. A total of 280 white laying hens at 29 weeks of age were distributed in a completely randomized design with five treatments and seven replications with eight birds in each. The treatments consisted of a base feed, formulated with corn, soybean meal and corn gluten meal, and supplemented with the synthetic amino acids L-lysine, DL-methionine, L-threonine, L-isoleucine, L-arginine, and L-valine, so as to meet the nutritional requirements for laying hens, except for digestible tryptophan. The basal diet was supplemented with 0.00; 0.017; 0.035; 0.052; and 0.069 g/kg of L-tryptophan in substitution for corn starch with the objective of reaching the levels of 0.151; 0.167; 0.183; 0.199; and 0.215 g/kg of digestible tryptophan in the feed. For the ratio between digestible amino acids and lysine, the recommendation of Brazilian Tables for Poultry and Swine was followed, except for the digestible tryptophan:digestible lysine ratios, which were 19, 21, 23, 25 and 27 for each treatment. The variation in the digestible tryptophan:digestible lysine ratio promoted changes in performance and in the histological characteristics, improving the results. The digestible tryptophan:digestible lysine ratio of 24.5% in the feed of white laying hens in production stage promotes better animal performance and histological results.

The objective of this study was to evaluate the reduction of protein, the formulation of diets and supplementation of an enzyme complex for laying hens. The layers were distributed in a completely randomized 2 × 2 × 2 factorial arrangement, with two levels of crude protein reduction (0.0 and 4.0 g/kg), two kinds of diet formulation (without and with reformulation, considering 75 kcal of metabolizable energy) and two enzyme supplementations (without and with enzyme complex supplementation), totalizing 8 treatments of 8 layers each, with 7 replications, in a total of 448 laying hens at 30 weeks of age. After data analysis, it was found that the enzyme complex supplementation in the diet of layers improves performance, promotes a similar egg quality and improves the bone and intestinal health of the layers.

Objetivou-se avaliar os efeitos da redução dos níveis nutricionais de dietas para poedeiras marrons em pico de postura sobre o desempenho das aves, a qualidade dos ovos e os parâmetros ósseos. No total foram avaliadas oito dietas, cada uma com cinco repetições de oito aves: 1. controle: formulada para suprir as exigências das aves; 2) controle + 0,03% ou 600 FTU; 3) 15% PB; 2.800 kcal de EM; 3,8% Ca e 0,28% Pd; 4) dieta 3 + 0,03% ou 600 FTU; 5) 14% PB; 2.750 kcal de EM; 3,4% Ca e 0,23% Pd; 6) dieta 5 + 0,03% ou 600 FTU; 7) 13% PB; 2.700 kcal de EM; 3,0% Ca e 0,18% Pd; e 8) dieta 7 + 0,03% ou 600 FTU. A redução dos níveis nutricionais prejudicou o desempenho das aves, principalmente a produção e massa de ovos, que melhorou com a inclusão de fitase nas dietas. Os parâmetros de qualidade dos ovos, no entanto, não se alteraram com a redução até o nível de 15% de PB; 2.800 kcal de EM/kg; 3,80% Ca e 0,280% Pd, o que não se repetiu nos níveis com menor densidade nutricional. Não houve efeito da redução dos níveis nutricionais sobre os parâmetros ósseos avaliados, exceto a resistência, que melhorou com a suplementação de fitase no nível de 600 FTU. A redução nos níveis nutricionais da dieta para 15% de PB, 2.800 kcal/kg de EM, 3,8% de Ca e 0,280% de Pd com a adição de 600 FTU não prejudica a produção nem a massa de ovos e melhora a saúde óssea das aves.

The aim of this work was to evaluate the effects of the reduction on nutritional levels of diets for semi-heavy hens during the laying peak on performance, egg quality and bone parameters. A total of eight diets were evaluated, each one with five repetitions of eight birds: 1) control: formulated to supply requirements by the birds; 2) control + 0.03% or 600 FTU; 3) 15% crude protein; 2,800 kcal ME; 3.8% Ca and 0.28% aP; 4) diet 3 + 0.03% or 600 FTU; 5) 14% crude protein; 2,750 kcal ME; 3.4% Ca and 0.23% aP; 6) diet 5 + 0.03% or 600 FTU; 7) 13% crude protein; 2,700 kcal ME; 3.0% Ca and 0.18% aP; and 8) diet 7 + 600 FTU. The reduction of the nutritional levels harmed the performance of the birds, particularly egg production and egg mass, which improved by the inclusion of phytase in the diets. However, the parameters for egg quality did not change as the level was reduced down to 15% crude protein; 2,800 kcal ME/kg; 3.80% Ca and 0.280% aP, which was not repeated in the levels with lower nutritional density. Reduction of nutritional levels did not affect the evaluated bone parameters, except for resistance, which improved as phytase was added at the level 600 FTU. Reduction on the diet nutritional levels to 15% crude protein; 2,800 kcal ME/kg; 3.80% Ca and 0.280% aP with the addition of 600 FTU of phytase does not impair egg production neither egg mass and improve the bone health of birds.

Avaliou-se o efeito de diferentes relações metionina + cistina (Met+Cis):lisina (Lis) total sobre o desempenho e a qualidade de ovos para poedeiras semipesadas. Foram utilizadas 120 aves da linhagem Lohmann Brown com 44 semanas de idade, alimentadas com rações isonutritivas (17% PB, 2.774 kcal EMAn, 4,28% de Ca e 0,375% Pd) e distribuídas em um delineamento inteiramente casualizado, com cinco repetições e quatro tratamentos, constituídos da seguinte forma: T1 = relação 0,76 ou 0,70% de Met+Cis e 0,92% de Lis total; T2 = relação 0,83 ou 0,71% de Met+Cis e 0,85% de Lis total; T3 = relação 0,85 ou 0,64% Met+Cis e 0,75% de Lis total; T4 = relação 0,86 ou 0,70% de Met+Cis e 0,81% de Lis total. As variáveis de desempenho e o resultado da análise econômica foram estudadas no período de 44 a 56 semanas de idade das poedeiras. Ao término do experimento, dez ovos por tratamento foram coletados e armazenados por 28 dias para avaliação da qualidade interna e externa dos ovos antes e após a armazenagem. À exceção da massa de ovos, os tratamentos não afetaram o consumo de ração, a produção, o peso, a conversão por massa e por dúzia de ovos e a gravidade específica da casca. A relação Met+Cis: Lis de 0,76 ou a estimativa de 0,70% de Met+Cis total e 0,92% de Lis total podem ser recomendadas para alimentação de poedeiras semipesadas. Concluiu-se que o armazenamento afeta a qualidade interna dos ovos.

The effect of different methionine + cystine (Met+Cis):total lysine (Lis) ratios on performance and egg quality for semi-heavily laying hens was evaluated. One hundred and twenty Lohmann Brown hens with 44 weeks old were allotted to a completely randomized design with with five replicates and four treatments, as follows: T1= 0.76 Met+Cys:total Lys ratio or 0.70% of Met+Cys and 0.92% of total Lys; T2 = 0.83 Met+Cys: total Lis ratio or 0.71% of Met+Cys and 0.85% of total Lys; T3 = 0.85 Met+Cys: total Lys ratio or 0.64% of Met+Cys and 0.75% of total Lys; T4 = 0.86 Met+Cys: total Lys ratio or 0.70% of Met+Cys and 0.81% of total Lys. The performance variables and economical analysis were evaluated from 44 to 56 weeks old. At the end of trial, ten eggs per treatment were collected ad stored during 28 days for evaluation of internal/external egg quality before and after storage. With the exception of egg mass, no treatment effect on feed intake, egg production, egg weight and egg:mass ratio and egg:dozen ratio and egg shell specific quality was observed. The Met+Cys:Lys ratio of 0.76 or the estimate of 0.70% of total Met+Cys and 0.92% of total Lys can be recommended for the feeding of semiheavily laying hens. It was concluded that the storage affect internal egg quality.