Resumo em Inglês:

In this review, diagnostic techniques and viral agents involved in enteric diseases affecting turkeys are described. Data from field observations and laboratory researches have been reported in turkey flocks for over 70 years, and several viruses have been identified. After a period of 30 years of inoculation experiments and neutralization studies, adequate visualization of the viruses was achieved using electronic microscopy. During the following years, several studies were then conducted to isolate and classify those viruses using cell-culture, embryo-propagation, serological tests, genome electropherotyping by polyacrylamide gel electrophoresis of double-stranded RNA viruses, and recently, nucleic acid studies. Thus, since the 1990s, the nucleic-acid technology has focused on genomic surveys and on the detection of specific segments of the genome of each virus using the polymerase-chain reaction, resulting in several prevalence studies and phylogenetic analyses of different isolates and proper classification of the viruses.

Resumo em Inglês:

This study aimed at investigating factors that contribute to changes in the quality of corn used in compound poultry feeds. Samples were collected from 6488 bulk cargos received at a feed mill located close to Brasília, Brazil. The parameters studied were divided into two groups: those related to corn chemical composition, including crude protein (% CP), ether extract (% EE), crude fiber (% CF), nitrogen-free extract (% NFE), and estimated metabolizable energy (ME), and corn physical characteristics, including density, moisture, and grain physical damage. High coefficients of determination (R²) and low coefficients of variation (CV) were determined for the chemical and physical parameters. The analysis of variance showed low to medium R². Month, year, supplier, and their interactions influenced (p <0.05) all chemical properties, as well as density, moisture, and ME. Physical characteristics were less affected by those factors, except for quantity of damaged grains. The principal component analysis separated the physical and chemical factors. The coefficients of the first component explained 54% of the total variation between variables. The first principal component showed that NFE and ME increased as humidity decreased. The second component also showed a decrease of physical problems due to reduction in humidity. Results indicate that the feed mills should take preventive measures when selecting suppliers, and diets should be formulated according to the differences in chemical and physical composition of corn supplied in different months and years.

Resumo em Inglês:

The objective of this study was to evaluate the effect of dietary energy level reduction and xylanase inclusion on the performance and on intestinal mucosa morphometry of two- to six-week-old laying hens. In total, 400 Hy-line W36 laying hens were distributed according to a completely randomized design in 2 x 2 factorial arrangement (energy level x inclusion of xylanase), totaling four treatments with 10 replicates of 10 birds per experimental unit. The following treatments were evaluated: positive control (balanced diet); positive control + xylanase; negative control (diet with of 100 kcal ME reduction /kg); negative control + xylanase. Body weight, weight gain, feed conversion ratio, uniformity and livability were not influenced by diets with metabolizable energy reduction and xylanase inclusion; however, the addition of xylanase to the diets resulted in shallower crypts depth and greater villus:crypt ratio in the ileum. The energy reduction of the diet associated with the supplementation of xylanase did not influence performance, but increased the feed intake of 2- to 6-week-old laying hens and increased villus height in the ileum of 6-wk-old hens. Xylanase reduces crypt depth in the ileum of 6-week-old hens.

Resumo em Inglês:

High environmental temperatures have a negative effect on the production efficiency of poultry reared in hot climates. This study evaluated the efficiency of electrolyte supplementation under high environmental temperature conditions by manipulating water and feed electrolyte balance (EB) on the survival and performance of European quails. In experiment 1, a completely randomized experimental design was applied in a 4 x 2 factorial arrangement. Treatments consisted in four feed EB values (0, 120, 240, 360 mEq/kg), and two environmental temperatures (25 and 34 ºC). Feed electrolyte balance was manipulated by the addition of sodium bicarbonate and ammonium chloride. In experiment 2, birds were randomly distributed according to a 5 x 2 factorial arrangement. Treatments consisted in five BE values in the drinking water (0, 30, 60, 90, 120 mEq/L) and two environmental temperatures (25 and 34 °C). Only sodium bicarbonate was added to the water to obtain the different BE values. The experiments were carried out simultaneously in environmental chambers at constant temperatures with 20- to 37-d-old quails. Most evaluated parameters were influenced by temperature in both experiments. In experiment 1, EB affected water intake and intestinal length. In experiment 2, EB values influenced (p < 0.05) water intake and heart and liver relative weights. Electrolyte balance values of 120 mEq/kg of feed and of 30 mEq/L of drinking water are recommended to increase water intake of grower European quails reared under hot temperature.

Resumo em Inglês:

Due to the constant evolution of industrial poultry production and the global emergence of bacterial resistance to antibiotics there has been an increasing interest in alternatives for the treatment of poultry salmonellosis, such as phage therapy and probiotics. The present study evaluated the effects of the oral administration of the bacteriophage P22 and of a probiotic, consisting of four Lactobacillus species, on the level of circulating heterophils containing a superoxide anion of one-day-old broilers challenged with Salmonella Typhimurium for seven days. It was concluded that the treatment with a probiotic with lactobacilli of broilers experimentally infected with Salmonella spp eliminates this pathogen by increasing the circulating levels of reactive heterophils. When chicks are treated with a probiotic and a bacteriophage, the agent is eliminated with no changes in circulating reactive heterophil counts. It is also concluded that the heterophils of day-old chicks are not capable of producing superoxide anion. However, this capacity is detected after 48 h of life, indicating that heterophils mature as birds age.

Resumo em Inglês:

The objective of this study was to determine thermal comfort ranges, as evaluated by air temperature and black-glove temperature and humidity index (BGTHI), for starter meat-type quails. Nine hundred quails were randomly distributed into five environmental chambers. Each chamber was programmed to provide different temperatures weekly. The following thermal environments were provided: SC - severe cold, MC - moderate cold, TC - recommended comfort environment, MH - moderate heat, and SH - severe heat. The best live performance was obtained when quails were submitted to temperatures of 36-39 ºC and BGTHI of 87.1 ± 0.4 and 91.4 ± 0.6 during the first week of rearing. Temperatures of 27-30 ºC and BGTHI of 75.8 ± 0.4 and 79.9 ± 0.6, during the second week, and temperature of 24 ºC and BGTHI of 70.8 ± 0.5 during the third week of rearing.

Resumo em Inglês:

An experiment was conducted to determine the chemical composition and apparent metabolizable energy (AME) and apparent metabolizable energy corrected for nitrogen balance (AMEn) values of corn, soybean meal (SBM), soybean oil (SO) and sugarcane yeast (SY) (Saccharomyces cerevisiae). A metabolism trial was performed with 120 Dekalb White laying hens at 65 weeks of age, using the method of total excreta collection. Birds were housed in metabolism cages and distributed according to a completely randomized design into five treatments with, six replicates of four birds each. The experimental period consisted of four days of adaptation and four days of excreta collection. The experimental diets included: a reference diet based on corn and SBM and four test diets containing 40% corn, 30% SBM, 10% SO or 30 % SY. The chemical compositions of the tested ingredients, expressed on "as-is" basis were: 86.9, 87.29, 87.32 and 99.5% dry matter; and 3.51, 2.08, 99.31 and 0.03 ether extract for corn, SBM, SO and SY, respectively. Corn, SBM, and SO presented 7.33, 43.61 and 24.64% crude protein, and 0.58, 5.07 and 6.77% ash, respectively; and crude fiber contents of corn and SBM were, respectively, 2.24% and 3.56%. The following AME and AMEn (kcal/kg dry matter) values were obtained: 3,801 and 3,760 kcal/kg for corn, 2,640 and 2,557 kcal/kg for SBM, 8,952 and 8,866 kcal/kg for SO, and 1,023 and 925 kcal/kg for sugarcane yeast, respectively.

Resumo em Inglês:

This study aimed to evaluate diets supplemented with prebiotic, probiotic and symbiotic as an alternative to antibiotics on the performance and immune response against the virus of Newcastle disease in broiler chickens. 1,400 one-day old male Cobb 500 chicks were raised until 42 days old in a completely randomized design with 2x2+1 factorial scheme with seven replications. The treatments were: diet without supplementation (base diet - BD), BD + prebiotic, BD + probiotic, BD + symbiotic (prebiotic + probiotic), and BD + antibiotic. The parameters evaluated were performance and antibody serum titers against Newcastle disease. No antibiotic effect was observed on performance. The symbiotic provided better results for weight gain and feed:gain ratio until 21 days old than isolated additives. At 28 days old, the broilers fed diets with prebiotic presented better feed: gain ratio. In the same period (28 d-old), there was an antibody production increase against the Newcastle disease virus in the group supplemented with prebiotic. It can be concluded that the utilization of symbiotic in broiler chickens' diets can substitute performance enhancing antibiotics. The inclusion of prebiotic in the diet improves feed: gain ratio at 1-28 days old. The chickens' immune response increases at 28 days against the Newcastle disease virus in the group supplemented with prebiotic.

Resumo em Inglês:

Incubation represents around 1/3 of the life cycle of broilers of modern strains; therefore, the appropriate management of this period is crucial to ensure the quality of the neonate. An experiment evaluated the effect of carbon dioxide concentrations during incubation on the live performance, heart morphology, and differential leukocyte count in the blood of broilers submitted to fluctuating temperatures between 35 and 42 days of age. In total, 2,520 fertile eggs were distributed according to a completely randomized design with four CO2 concentrations (4,000; 6,000; 8,000 and 10,000 ppm) during the first ten days of incubation, after which all eggs were incubated at the same CO2 level (4,000 ppm). After hatching, male chicks were placed in the experimental broiler houses, and at 35 days of age, 25 birds from each level of CO2 were separated and placed in cages to study the effect of cyclic temperature variations up to 42 days of age on their live performance, heterophil:lymphocyte ratio, and heart morphology. At 42 days of age, blood was collected for hematology and two birds per replicate were sacrificed and evaluated for ascites score and heart and liver relative weights. Heart morphology was assessed by analyzing digital images. In this experiment, hypercapnia during incubation and fluctuating temperatures during the growout did not affect mortality, ascites score, heart and liver relative weights, or heart characteristics (p>0.05). However, heterophill:lymphocyte ratio increased (p<0.05) with increasing carbon dioxide concentrations during incubation. It was concluded that high CO2 levels during incubation did not influence the resistance of broilers to fluctuating temperatures during the last week of age.

Resumo em Inglês:

The aim of this study was to evaluate the incidence of footpad dermatitis and quality of broilers litter fed with sorghum grain and diets based in corn. It was used 544 male and female chicks, distributed in a completely randomized design with two treatments and eight replications. The chicken feed was formulated and produced from corn, soybean meal and sorghum grain. In the formulation were kept constant levels of energy and protein in accordance with the following treatments: A. Control (diet based on corn and soybean meal); B. Grain sorghum (Whole Sorghum + soybean meal). At 35 and 42 days were evaluated mineral matter (A %), calcium (Ca%), phosphorus (P%), pH and dry matter (DM %) of the poultry litter. To evaluate the footpad dermatitis were evaluated eight feet per treatment by visual analysis. At 35 and 42 days of age DM % MM (%), Ca (%) P (%) and pH of poultry litter no difference (p>0.05) was found between the treatments and the type of ingredient in the birds' diet is not related (p>0.05) with the incidence of footpad dermatitis. The incidence of footpad dermatitis and the quality of the litter weren't influenced by the type of the ingredient used in diet.

Resumo em Inglês:

Scientific information on the welfare of broilers reared in alternative systems is scarce. The objective of this study was to assess the welfare of free-range broilers using the Welfare Quality® protocol. Free-range broilers reared in ten farms were observed, and measures were made in broilers of five of these farms. The collected data were transformed into scores (0-100), with higher scores indicating better welfare, except for emotional states. Prevalence percentages were calculated for the remaining data. Median (min-max) scores were 81 (63-98) for lameness, 93 (83-99) for hock burn on the farm, 100 (95-100) for plumage cleanliness, 35 (8-70) for podermatitis on the farm, 56 (26-88) for density, 53 (20-53) for dust, 34 (14-67) for litter quality, 93 (41-100) for drinkers, and 100 (100-100) for birds panting or huddling on the farm. The following average (min-max) prevalence percentages were obtained: total mortality 2.0% (1.4-7.2%), culling 0.0% (0.0-2.2%), feed withdrawal time 875 min (715-945 min), water withdrawal time 220 min (170-275 min), dead on arrival at the processing plant 0.00% (0.00-0.01%), broken wings 0%, (0-0%), inefficient stunning 3.9% (1.3-6.7%), pre-stun shock 49.3% (26.7-56.8%), hepatitis 4.5% (1.8-11.0%), bruising 9.3% (6.7-16.7%), and ascites 0% (0-0%). The negative broiler welfare points detected were pododermatitis, litter quality, density, dust, culling, feed withdrawal time, inefficient stunning, pre-stun shock, and hepatitis. The positive points identified were the absence of birds panting or huddling on the farm; low prevalence of lameness, hock lesions, dead on arrival, broken wings, and ascites; good plumage cleanliness scores, and short water withdrawal time.

Resumo em Inglês:

The aim of the present work was to study the in-vitro cytotoxic effects of different concentrations of aflatoxin B1 (AFB1) on broiler lymphocytes. Lymphocyte-rich mononuclear cells were separated by Ficoll-Histopaque density and cultured in 96-wellplates containing the evaluated AFB1 concentrations in 5% CO2 atmosphere at 39°C. Thereafter, MTT, PicoGreen, and reactive oxygen species assays were performed. Cell viability decreased in the presence of 10 µg/mL AFB1 at 48 h (p < 0.05) and of 10 and 20 µg/mL AFB1 at 72 h (p < 0.01 and p < 0.001, respectively) when compared to the control (0 µg/mL). However, a dose-dependent increase in the cell-free DNA at 24 h was observed at 1, 10 and 20 µg/mL (p < 0.001). ROS formation significantly increased at 24 h at all concentrations (p < 0.001). The in-vitro results demonstrate that AFB1 is cytotoxic and causes biomolecular oxidative damage in broiler lymphocytes.

Resumo em Inglês:

A uniform design (UD) was used to construct models to explain the growth response of Japanese quails to dietary metabolizable energy (ME), and digestible methionine (dMet) and lysine (dLys) under tropical condition. In total, 100 floor pens with seven birds each were fed 25 UD different diets containing 25 ME (2808-3092 kcal/kg), dMet (0.31-0.49% of diet), and dLys (0.91-1.39% of diet) levels from 7 to 14 d of age. A platform of artificial neural network based on UD (ANN-UD) was generated to describe the growth response of the birds to dietary inputs using random search. Artificial neural networks of body weight gain (BWG) and feed conversion ratio (FCR) were optimized using random search algorithm. The optimization the ANN-UD results showed that maximum BWG may be achieved with 2995 kcal ME/kg, 0.45% dMet, and 1.18% dLys of diet; and minimum FCR may be obtained with 3000 kcal ME/kg, 0.45% dMet, and 1.17% dLys of diet. The result of this study showed that a ANN and UD hybrid model can be used successfully to optimize the nutritional requirements of quail chicks.

Resumo em Inglês:

The objectives of the present study were to determine the parameters of Gompertz equations and to determine curves and growth rate, feed intake and body component deposition, as well as allometric coefficients of body water, protein, and fat relative to live weight of male and female broilers of intermediate performance (C44) and high performance (Cobb-500) genetic strains. In total, 384 one-d-old chicks were distributed into four treatments: male Cobb 500, male C44, female Cobb 500, and female C44, with six replicates of 16 birds, according to a completely randomized experimental design. Average body weight, weight gain, and feed intake were weekly determined, and six birds, representing the average weight of each treatment, were sacrificed to determine body composition. Growth curves were built applying Gompertz function, with excellent fit, and growth, feed intake, and tissue deposition rates were obtained by its derivatives. Superior growth rate was obtained for Cobb 500 male broilers. This genetic strain has higher feed intake capacity, which is achieved earlier than in the C44 strain. Protein and fat deposition maturity was reached earlier in males than in females in Cobb 500. The allometric coefficients showed earlier maturity for body water in C44 and females. In terms of body protein, male Cobb 500 broilers reached maturity earlier than females and C44. Body fat deposition maturity was reached earlier in Cobb 500 than in C44. The Gompertz equations obtained in the present study efficiently described body growth, feed intake, and deposition of body components, with a coefficient of determination higher than 0.99.

Resumo em Inglês:

Serum is widely used for the purpose of monitoring and diagnosis support for most of poultry diseases. In the case of the serum plate agglutination test (SPA), commonly used to detect antibodies for Salmonella Pullorum (SP), Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS), serum cannot be frozen because it may result in false positive. Without freezing, serum can last only for a few days. In this experiment, glycerin was evaluated as a serum preservering agent. About 50 samples for each disease and analyzed by SPA test previously were separated. Glycerin was added to serum from commercial chickens, with and without antibodies for SP, MG and MS, in the proportion of 1:1 (serum:glycerin) and kept at refrigerated conditions (2 to 8 ºC). For four years they were tested by the SPA, initially weekly, afterward monthly and then annually. The results show that serum with glycerin give consistent and valid results according to the kind of antibodies present for the period tested. Sera that glycerin was not added to, the results were valid only for the first week. From the second week on, microbial growth affected the test results of the sera without glycerin. Our investigation shows that glycerin can be used to preserve chicken serum for SPA under refrigerated conditions. It is an easy, simple and cheap procedure that can extend serum shelf life, useful mainly for control sera.

Resumo em Inglês:

This study aimed at evaluating the total replacement of corn by white or red sorghum and the inclusion or not of pigment in the diet on the performance and yolk color of Japanese quail eggs. In the trial, 210 Japanese quails were distributed according to a completely randomized experimental design consisting of five treatments with six replicates of seven birds each. Treatments consisted of Corn-based diet (C), white sorghum-based diet (WS), white sorghum-based diet + pigment (WSP), red sorghum-based diet (RS), and red sorghum-based diet + pigment (RSP). Feed intake, feed conversion ratio, egg production, and egg mass were no influenced by the treatments. However, paler egg yolks were produced when corn was replaced by sorghum. When red and white sorghum varieties were compared, there were no differences in yolk color or response to pigment dietary inclusion. It was concluded that the total replacement of corn by sorghum in the feed did not influence the performance of Japanese quails and that yolk color response is not affected by the inclusion of pigments in diets containing sorghum, independently of its variety.