O objetivo foi avaliar como os fatores granulometria e textura do milho podem alterar os parâmetros de desempenho produtivo de poedeiras comerciais, bem como o consumo de energia elétrica para moagem dos grãos. Foram utilizadas 384 poedeiras da linhagem Isa Brown com 36 semanas de idade, alojadas em aviário de produção convencional com taxa de lotação de 562,5 cm2 ave-1. Os tratamentos foram distribuídos em delineamento inteiramente ao acaso em esquema fatorial 2 x 3 (texturas de milho: duro e dentado e graus de moagem: fino, médio e grosso), com oito repetições de oito aves por parcela. Os dados foram avaliados com o auxílio do pacote estatístico SISVAR com médias comparadas pelo teste de Tukey a 5% de probabilidade. Foi constatada diferença para o fator textura, em que a textura dura apresentou aumento nas variáveis: consumo de ração e peso dos ovos. As características de qualidade dos ovos demonstraram diferença significativa apenas quanto à cor da gema. Maiores granulometrias consumiram menos energia elétrica durante a moagem. A cultivar de milho duro teve consumo de energia elétrica 31,66% menor comparativamente à cultivar dentado.

The influence of maize corn size and texture on the performance parameters of laying hens and power consumption required for grinding maize corn were evaluated. The experiment was carried out on 384 Isa Brown hens, 36 weeks old, penned in a conventional aviary with 562.5 cm2 bird-1 stocking rate. The treatments were distributed in a completely randomized 2 x 3 factorial design (maize textures: flint and dent; and milling degree: fine, medium and coarse) with eight replicates of eight birds per plot. Data were evaluated with SISVAR and means were compared by Tukey's test at 5% probability. Difference was reported for the variable texture and flint increased the variables feed intake and egg weight. Significant difference in the characteristics of egg quality occurred only for the colorof the yolk. Larger corn sizes consumed less electricity during grinding. The maize flint cultivar had a lower 31.7% power consumption when compared to that of the dent cultivar.

O experimento foi conduzido com o objetivo de avaliar o efeito da suplementação da enzima protease sobre o desempenho produtivo e a qualidade de casca de poedeiras semipesadas. Utilizaram-se 240 poedeiras da linhagem comercial Isa Brown com 44 semanas de idade. Foi adotado um delineamento inteiramente casualizado em esquema de parcela subdividida no tempo (5 períodos de 21 dias cada) com quatro tratamentos e seis repetições (10 aves por repetição). Foram avaliados: produção de ovos, consumo de ração, conversão alimentar, peso médio dos ovos, perda de ovos, gravidade específica, porcentagem e espessura de casca. Após a coleta, os dados foram submetidos à análise pelo pacote estatístico SISVAR com as médias comparadas pelo teste de SNK a 5% de probabilidade. Para as variáveis de qualidade externa dos ovos, não houve diferença significativa (p > 0,05) dos tratamentos. Conclui-se que a suplementação de 500 g ton-1 da protease (100 U g-1), em dietas com redução dos níveis nutricionais, proporciona produção de ovos e conversão alimentar semelhantes aos obtido em poedeiras semipesadas, recebendo ração com níveis nutricionais indicados pelo manual da linhagem, porém não mostra efeito sobre a qualidade de casca dos ovos.

The experiment was conducted with the objective of evaluating the effect of protease enzyme supplementation on performance parameters and quality shell of laying hens. We used 240 Isa Brown commercial laying hens with 44 weeks of age. A completely randomized split-plot design (5 periods of 21 days) with four treatments and six replications (10 hens per replication) was used. The experimental diets were formulated according to the requirements of the breed. The following parameters were evaluated: egg production, feed intake, feed conversion, average egg weight, egg loss, specific gravity, percentage and shell thickness. After collection, the data were analyzed with SISVAR Statistical Package, and the means compared by SNK test at 5% probability. It was concluded that supplementation of diets low in nutrients with 500 g ton-1 of protease (100 U g-1), provides egg production and feed conversion rates similar to those obtained in laying hens fed diet with the nutritional level recommended for the breed. However, protease supplementation did not show effect on egg shell quality.

An experiment employing three hundred and twenty 81-week-old Lohmann LSL commercial-breed hens was conducted to compare alternative induced-molting methods with the conventional method (fasting). Induced molting lasted 28 days at most, production and quality being monitored for four periods of 28 days thereafter. A completely randomized experimental design with five treatments, eight replicates of eight birds each per plot was adopted. The following experimental treatments were applied until a loss of 26% of body weight was reached: T1 - fasting, T2 - wheat bran ad libitum, T3 - rice bran ad libitum, T4 - cracked rice ad libitum, T5 - ground alfalfa ad libitum. Birds were then fed production diet ad libitum, except for those on treatment T1 (fasting) which received 30, 60 and 100 g/bird/day and then feed ad libitum. During induced molting the birds were exposed to a natural photoperiod and at day 28 that period was increased by 30 minutes/week until reaching 16 hours of light/day. The characteristics evaluated during induced molting were: feed intake, body weight changes and laying percentage. In the post-molt period, performance (feed intake, laying percentage, egg weight, egg mass, feed conversion ratio per dozen and per egg mass and percentage of broken eggs) and egg quality (specific gravity, eggshell breaking strength, percentages of eggshell, yolk, and albumen, eggshell thickness, yolk color and Haugh unit) were evaluated. Every 28 days one egg was collected from each repetition for three consecutive days for quality assessment. The use of rice bran and wheat bran is viable as molting inducers since the birds given those treatments display performance and egg quality similar to those fasted during the induced molting and also because these ingredients promote easier handling, eliminates the need for grinding and feed-mixing equipment and, being less aggressive, provide greater bird welfare.