ABSTRACT The objective was to examine the effects of supplementing different levels of zeolite in the diet of laying hens during the laying phase, at 54 weeks of age, on production performance, egg quality, ammonia volatilization, excreta pH, blood parameters, weight, and organ morphometry. The treatments consisted of a control diet free of zeolite and five diets including increasing levels of zeolite (0.7, 1.4, 2.1, 2.8, and 3.5%). A completely randomized design was adopted with eight replicates of five birds per plot, totaling 240 laying hens, for four 28-day periods. Results were subjected to ANOVA, Dunnett’s test, and regression analysis at 5% probability. The zeolite levels had no significant effect on production performance, egg quality, and blood parameters. The zeolite levels have a significant effect on ammonia volatilization, excreta pH, liver weight, and organ morphometry specifically on the intestinal length. Ammonia and pH reached a linear plateau. Ammoniacal nitrogen levels in the excreta differed from that observed in the control group at all zeolite levels, whereas the pH was lowest at the zeolite inclusion levels of 0.7 and 1.4%. Ammonia volatilization and the pH value of the excreta decreased by 46.9% and 4.6%, when the laying hens consumed diets with 0.93% and 1.19% zeolite, respectively. There was an effect on the relative weight of the organs, with higher liver yield and intestinal length provided by zeolite inclusion. Therefore, zeolite can be included in the diet of commercial layers at up to 0.93% without affecting their production performance or egg quality.

ABSTRACT This study aimed at evaluating beak-trimming methods and intensities on the performance, beak length and uniformity, and egg parameters of commercial layers. During the rearing period, birds were distributed in randomized blocks, with a 2x3 factorial design + two treatments, consisting of beak trimming with infrared (IR) radiation (moderate or severe); three IR intensities (low: 42 nm, intermediate: 46 nm, or high: 52 nm); and two control hot blade (HB) beak trimming treatments (moderate or severe) with eight treatments and five replicates of 21 chicks each, totaling 840 birds. During the growing phase (second experiment) the factorial design was modified to 2 x 3 x 2 + 4, comprising two IR beak-trimming intensities (moderate or severe); three IR radiation intensities (low, moderate and high), second beak trimming at 11 weeks of age or not, and four additional HB beak-trimming treatments (moderate or severe) beak-trimming intensities, and second beak trimming at 11 weeks of age or not. There were 16 treatments with six replicates of seven birds each, totaling 672 laying hens, out of which 576 were selected for evaluation during the production period, with the same number of treatments and replicates of the previous phase. Weight gain (g), body weight (g), body weight uniformity (%), beak length (mm) and uniformity (%), absence of cannibalism (%), livability (%), egg production (%), feed intake (g), feed conversion per eggmass, eggmass, specific gravity, eggshell strength, Haugh unit, % yolk were evaluated. Beak trimming by infra-red radiation may be employed in commercial laying hens.

ABSTRACT The objective of this study was to evaluate the effect of diets formulated with corn plus soybean meal (CSM) or with 21% autoclaved castor meal (ACM), with the addition of two enzyme complexes (EC1 and EC2), on the performance and egg quality of laying quail. Two hundred and sixteen quails were selected by egg production and weight uniformity and distributed in a completely randomized design with six treatments (in a 2 × 3 cross-factorial arrangement) and six replicates with six birds each. Three CSM and three ACM diets supplemented withEC1, EC2, or unsupplemented were established. The trial lasted three cycles of 21 days. Feed intake, laying rate, egg mass, feed conversion per egg mass, and feed conversion per dozen eggs did not differ. The use of ACM diet reduced egg (EW), yolk (YW), and eggshell (SW) weights, egg specific gravity and increased yolk color. However, EW and YW were similar among quails fed diets containing CSM and ACM when supplemented with CE1.The use of enzyme complex containing xylanase, b-glucanase, and phytase is recommended when 21% autoclaved castor mealis included in the diet of laying quails.

ABSTRACT These experiments were performed to determine the chemical composition, coefficients of nutrient and energy metabolizability, amino acid composition, and cytotoxicity of different castor oil meals subjected to different detoxification processes and added to the diet of Japanese quails. In the trial, 180 46-d-old female Japanese quails were distributed according to a completely randomized design into five treatments and with replicates of six bird each. The treatments consisted of following detoxification methods of castor oil meal: Castor oil meal A (CMA) - recovery in alcohol at 80 °C for 20 minutes and drying at 80 °C; castor oil meal B (CMB) and C (CMC) - recovery in alcohol at 80 °C for 6 minutes, neutralization with 5% NaOH, and drying under direct sunlight sun for two days (CMB) or pelleted (CMC); castor oil meal D (CMD) - recovery in alcohol at 110 °C for 15 minutes and drying at 110 °C. Castor oil meal was added replacing 20% of the reference diet. There was slight chemical composition variation (1.21% in crude protein, 6% in dry matter, 2.2% in ether extract and 64 kcal/kg in gross energy) among the castor oil meals submitted to the different treatments. The castor oil meal submitted to treatment C showed the highest amino acid values. In the cytotoxicity test, treatment D presented lower ricin activity. Castor oil meals A, C, and D may be included in Japanese quail diets; however, castor oil meal D is recommended due to the simplicity its industrial process, its low toxicity, and metabolizability coefficients obtained.

An experiment was carried out to evaluate the effect of environmental enrichment in a free-range chicken production system on live performance as a function of microclimate, physiological parameters, and performance parameters. Four production modules were divided into four pens with 10 birds each, totaling 60 birds. The following treatments were applied: access to a paddock (TEST), access to a paddock with perches (PER), access to a paddock with artificial shade (SHA), and access to the paddock with perches and artificial shade (PESH). The PESH production module presented the best globe temperature (Tbg,ºC) and enthalpy (h, kJ/kg), and thereby, the best thermal environmental conditions, which ensured the longest permanence time of the birds in the paddock. The SHA and PESH modules promoted the lowest respiratory rate and shank and comb temperatures. Live performance was influenced by the presence of environmental enrichment (modules SHA and PESH), with the highest live weight (LW) and weight gain (WG) and the lowest feed conversion ratio (FCR) and metabolizable energy intake (MEI). Parts yield, such as giblets, were not influenced by production modules, except for PESH, which promoted higher offal weight. In general, chickens reared in enriched production modules presented greatest performance and comfort results and were considered close to optimal rearing conditions.

An experiment was carried out to determine the chemical composition, metabolizable energy values, and coefficients of nutrient digestibility of corn germ meal for layers. The chemical composition of corn germ meal was determined, and then a metabolism assay was performed to determine its apparent metabolizable energy (AME) and apparent metabolizable energy corrected for nitrogen (AMEn) values and its dry matter and gross energy apparent metabolizability coefficients (CAMDM and CAMGE, respectively). In the 8-day assay (four days of adaptation and four days of total excreta collection), 60 29-week-old white Lohman LSL layers were used. A completely randomized experimental design, with three treatments with five replicates of four birds each, was applied. Treatments consisted of a reference diet and two test diets, containing 20 or 30% corn germ meal. Results were submitted to analysis of variance and means were compared by the Tukey tests at 5% probability level. The chemical composition of corn germ meal was: 96.39% dry matter, 49.48% ether extract, 1.87% ashes, 7243 kcal gross energy/kg, 11.48% protein, 0.19% methionine, 0.21% cystine, 0.48% lysine, 0.40% threonine, 0.72% arginine, 0.35% isoleucine, 0.83% leucine, 0.57% valine, and 0.37% histidine, on as-fed basis. There were no statistical differences in AME, AMEn, CAMDM, and CAMGE values with the inclusion of 20 and 30% corn germ meal in the diets. On dry matter basis, AME, AMEn, CAMDM, and CAMGE values of corn germ meal were: 4,578 and 4,548 kcal/kg, 4,723 and 4,372 kcal/kg, 64.95 and 61.86%, respectively.

The aim of this study was to determine the chemical composition, amino acid content and energy values, as well as to quantify the passage rate in the digestive tract of three different poultry offal meals (POM), in two experiments carried out with broilers. In the first experiment, metabolizable energy values were determined (AMEn and TMEn) using the method of total excreta collection. In this experiment, 150 15-d-old male and female broilers were distributed according to a completely randomized experimental design with 5 treatments of 5 replicates of 6 birds each. The following treatments were applied: a reference diet, three test diets consisting of 250 g/kg of the tested ingredient (POM) + 750 g/kg of the reference diet, and one group of birds fasted for excreta collection to determine endogenous and metabolic losses. In the second experiment, POM passage rate results were obtained using 90 26-d-old broilers distributed according a completely randomized design with three treatments of 5 replicates of 6 birds each. POM passage rate was correlated (r = -99.86%) with its EE content. The evaluated POMs presented the following ME values: 16,727; 15,781 and 17,443 MJ AMEn /kg and 17,877; 15,882 and 17,527 MJ TMEn /kg for samples A, B and C, respectively.

A fibrolytic enzyme complex was added to the pre-starter diet. Broiler chicks were randomly distributed into five treatments, consisting of a diet with no enzyme addition and four test diets supplemented with 100, 200, 300 and 400g/T of an enzyme complex. The dietary inclusion of the enzyme complex increased weight gain, and the dose of 300g/T improved weight gain and worsened feed conversion ratio.

The use of probiotics in animal and human feeding has been a subject of increasing interest both for the academia and the industry, mostly due to their potential positive effects on health and profitability. However, the knowledge on the composition of bacterial gastrointestinal communities in humans and animals, as well as its respective nutritional requirements, is far from being elucidated. Due to the ban of the use of antibiotic growth promoters in animal feeds, there has been an increasing interest on the utilization of probiotics to improve animal intestinal health under commercial settings. However, the possibility of horizontal transference of antibiotic-resistant genes between probiotic bacteria and pathogenic species has become a concern of poultry farmers and consumers around the world. Innovative ideas have emerged, such as the addition of essential oils, spices, and other plant extracts to feeds of monogastric animals to promote intestinal health. These natural compounds are considered ecologically adequate and safe for feeding purposes. This new reality will probably change the direction of research and of the use of additives in poultry production.