Abstract in English:Avian influenza (AI) is considered an exotic disease in the Brazilian poultry industry, according to the National Avian Health Program (PNSA), with permanent monitoring of domestic, exotic and native avian species. Brazil presents privileged environmental conditions of reduced risk. In addition, all commercial poultry and conservation holdings are registered in state or national inventories and geographically located (GPS) for health control. Poultry health standards are adopted for the conformity to the international market, mostly for the intensified poultry destined for exportation, but also for companion exotic and native conservation facilities. Guidelines for monitoring and the diagnosis of AI are published by the PNSA and follow the standards proposed by the international health code (World Organization for Animal Health, Organization International des Epizooties - OIE) and insure the free of status for avian influenza virus (AIV) of LPAIV-low pathogenicity AIV and HPAIV-high pathogenicity AIV. In addition, the infections by mesogenic and velogenic Newcastle disease virus, Mycoplasma gallisepticum, M. synoviae and M. meleagridis, Salmonella enteric subspecies enterica serovar Gallinarum biovars Gallinarum and Pullorum are eradicated from reproduction. Controlled infections by S.enterica subspecies enterica serovars Enteritidis and Typhimurium are monitored for breeders. The vaccination of chickens in ovo or at hatch against Marek's disease is mandatory. Broiler production is an indoor activity, confinement which insures biosecurity, with safe distances from the potential AIV reservoir avian species. Worldwide HPAIV H5N1 notifications to the OIE, in March 2011, included 51 countries.
Abstract in English:This study was carried out to verify if Saccharomyces cerevisiae cell wall (SCCW) dietary supplementation (0.2%) was capable of protecting the intestinal mucosa of broiler chickens vaccinated against coccidiosis. Body weight gain, feed intake, feed conversion and intestinal mucosa morphometric parameters and epithelial loss were evaluated. In the experiment,400 day-old male chicks were distributed according to a completely randomized design in a 2x2 factorial arrangement. The following treatments were applied: T1 - no vaccination/ no SCCW supplementation; T2 - no vaccination/SCCW supplementation; T3 - vaccination/no SCCW supplementation; and T4 - vaccination/SCCW supplementation to four replicates of 25 birds each. Birds were vaccinated on the first day of age using a spray vaccine (Coccivac B®, Coopers), containing E. acervulina, E. maxima, E. mivati and E. tenella. S. cerevisiae cell wall was supplied from the first day of age. Live performance, intestinal morphometric parameters and epithelial loss were evaluated at 14, 21 and 28 days of age. Performance was affected by vaccination only at 21-days of age, when body weight gain was reduced in the vaccinated birds, but no body weight difference was observed on day 28. Vaccine also increased the crypt depth (p<0.05) in the duodenum and jejunum, suggesting a high cell activity in the crypt:villus transition area to maintain the epithelial cell turnover. Villi number/area (103,269 µm²) was not affected (p>0.05) by vaccine or cell wall supplementation, and epithelial loss was more pronounced in the duodenum and jejunum. In conclusion, the findings of this study suggest that S. cerevisiae cell wall supplementation may be an useful management tool to maintain the intestinal integrity of broilers vaccinated against coccidiosis.
Abstract in English: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.
Abstract in English:This study was designed to investigate the effects of a probiotic plus an immunomodulatory product on the growth performance, immune response and net economic returns of broiler chicks vaccinated against Infectious bursal diseases virus (IBDV). A flock of 350 day-old chicks were equally and randomly distributed in seven groups, each comprising 50 birds. A mixture of microorganisms (¹Probiotic) or Cyclophosphamide (immune suppressor) was offered through feed supplementation to different groups. The Probiotic, consisting of Lactobacillus species, Bifidobacterium, Streptococcus salivarius and Enterococcus faecium, in addition to Aspergillus oryza and Candida pintolopessii. Compared with control treatment group, the probiotic-supplemented chicks had better feed conversion ratio (FCR) (1.938 and 1.959), with significantly heavier live body weight 2141.0±34.2 and 2120.3±33.2, respectively. Similarly, their antibody titers against IBDV were significantly higher (941 and 832) on day 35. No morbidity and mortality were observed in these groups. This study suggests that a product composed of a probiotic and cyclophosphamide enhanced the growth rate as well as the immunity against infectious bursal disease virus of broilers chicks.
Abstract in English:New vaccine design techniques have allowed the development of effective vaccine strains against Salmonella infections inwhich the risks of reversion to the wild type and virulence is null. The mutant strain Salmonella Gallinarum ΔcobSΔcbiA was previously shown to be avirulent in chickens. In this study, this strain was tested as a vaccine against Salmonella Gallinarum (SG) and S. Enteritidis (SE) infections, and its protection levels, safety and possible risks of reversion to virulence after vaccination of layers were evaluated. Birds were vaccinated at five days of age or at five and 25 days of age. At 45 days of age, brown and white layers were challenged with SG and SE wild strains, respectively. Two assays to test the possibility of reversion to virulence were performed. Five successive bacterial passages in brown layers were carried out in the first assay. In the second assay, brown layers received a ten-fold concentrated inoculum of the SGΔcobSΔcbiA strain and were evaluated for clinical signs and mortality. In both experiments, no birds that received the inoculation of the attenuated strain died. Additionally, the use of the mutant strain as a vaccine provided good protection levels against both challenge strains.
Abstract in English:Broiler chicken production is widely dispersed across the globe, and one important issue for growers is the selection of adequate bedding material, as the availability and price of substrates varies among countries and regions within a same country. This study aimed at applying a multiple criteria analysis approach for the selection of the most appropriate bedding material for broiler production. Based on field research data and growers' experience, the most desirable characteristics of a litter material were chosen as the main criteria. The selected materials were wood shavings, rice husks, chopped Napier grass (Pennisetum pupureum), 50% sugar cane bagasse (Saccharum L.) plus 50% wood shavings, 50% sugar cane bagasse (Saccharum L.) plus 50% rice husks, and pure sugar cane bagasse (Saccharum L.). The analytical hierarchy process (AHP) was applied for selecting the most suitable bedding material. Validation was performed using data from previous studies carried out in central-western Brazil on the effects of different types of bedding material on broiler carcass quality. Considering the selected criteria, several bedding materials were tested and ranked, and the results showed that wood-shavings litter was the best option (weight = 0.28), followed by rice husks (weight = 0.24). All other tested alternatives presented lower scores and were, therefore, not considered for use. The AHP approach was found to be an efficient tool to select the most appropriate litter material under specific scenarios.
Abstract in English:This study aimed at developing radiographic techniques for the early detection of dyschondroplastic lesions in the tibia of broilers. The experiment was carried out at the facilities of UNIFOR/MG and Formiga and UNIFENAS/ Alfenas with 420 one-day-old male Cobb broilers. At 20 days of age, all birds were radiographed and identified with an alpha-numeric metal ring in the right leg. At 40 days of age, 42 broilers previously selected as a function of bone mineral density and lesion thickness scores were again radiographed and scored, and then sacrificed. Their right tibia was removed for gross and histological examination of the growth plate. The results showed that radiographic techniques are correlated with gross and histological examination and that there was no significant differences among techniques (P>0.05). it was concluded that the use of radiographic examination to identify tibial dyschondroplasia in broilers precludes the use of bone mineral density to diagnose this condition. The non-parametric statistical Chi-square test at 5% significance level was used to analyze the results.
Abstract in English:This experiment was conducted to determine the effects of an in-ovo injection of glucose on hatchability, weight and subsequent performances of newly-hatched chickens. The 720 fertile eggs used in this experiment were obtained from a Cobb-500 broiler breeder flock of 28 weeks of age. Treatments were the following: 1) control group (withou- injection), 2) group injected with 0.5 ml deionized water (sham group), 3) group injected with 0.5 ml glucose 15% in deionized water, 4) group injected with 0.5 ml glucose 20% in deionized water and 5) group injected with 0.5 ml glucose 25% in deionized water. There werh four replicates per treatment and 36 eggs per replicate. The experimental design was a completely randomized design. Upon hatch, hatchability and weight of newly-hatched chicks were measured, and 20 chicks per replicate were transferred to an experimental house and reared for 42 days. Live weight and feed intakeswere measured for each experimental unit at 21 and 42 days of age and then weight gai, and feed conversion ratio were calculated. The results of the study indicate that group that received glucose at 15%, 20% and 25% had significantly higher hatching weight as compared with the control and the sham groups,tbut,eggs injected in ovo had significantly lower hatchability than the controls (p < 0.01). Also, there were no significant treatment effects on feed intake between 0 and 21 days post-hatch. Chicks that received in-ovo injection of glucose haddbetter feed intake, weight gain and feed conversion ratio compared with chicks hatched from the control and the sham groups. The obtained Data suggest that in-ovo injection may increase weight and improve the performancs of newly-hatched chickens.
Abstract in English:A study was conducted to evaluate the combined effects of garlic, oyster mushroom and propolis extract on the growth performance, organ weights, antibody response to Newcastle Disease Virus (NDV), serum lipid concentrations and nutrient digestibility of male broilers. A total of 192 day old chicks (Ross 308) were randomly assigned to 3 treatments with 4 replications (16 birds per replication). Experimental treatments were a maize- soybean based diet as control, control diet supplemented with a combination of garlic (30 g/kg), oyster mushroom (2 g/kg) and propolis extract (0.2 g/kg) known as GMP, and control diet supplemented with Virginamycin (0.25 g/kg) as antibiotic. The inclusion of GMP decreased (p < 0.05) live body weight, average daily gain and feed intake but had no effect on feed conversion ratio when compared to control diet. GMP and antibiotic had no effects on relative weight of organs. Antibiotic decreased (p < 0.05) the relative weight of small intestine segments. GMP decreased total cholesterol but did not affect other serum lipids when compared to control group. Antibiotic increased (p < 0.05) cholesterol concentration in serum. The inclusion of GMP to the diet improved antibody response to NDV when compared to control and antibiotic diets. In conclusion, the results showed that GMP decreased growth performance but improved immunity of broiler chickens. More studies should be performed to confirm the action modes of such combinations.
Abstract in English:An experiment was conducted to determine the effects of different levels of methionine, protein and tallow on productive performance and egg quality of laying hens in the late phase of production. A completely randomized design with a 3×2×2 factorial arrangement, with three levels (0.34, 0.31, and 0.27%) of methionine (MET), two levels (12.8 and 14.7%) of protein (PRO) and two levels (1 and 3%) of tallow (TAL) with constant level of linoleic acid (1.55 ± 0.02%), was used. A number of 144 Hi-Line W-36 layers from 70 to 76 wk of age was randomly distributed into 12 treatment groups with 4 replicates of 3 hens each. Egg production and egg weight were daily recorded and feed intake and egg quality traits were recorded every 2 wk. There was a significant interaction between PRO levels and TAL for egg weight. Low levels of TAL and PRO decreased egg weight throughout the experiment. High levels of MET and TAL with concomitant reduced PRO, increased eggshell thickness, and a significant interaction between levels of MET, PRO and TAL was observed during the experiment (70 to 76 wk). Low level of protein (12.8%) significantly decreased albumen weight in the third 2-wk period. Yolk color increased when hens were fed low levels of PRO and TAL. Results of this experiment indicated that the simultaneous reduction of dietary PRO and MET in diets of Hi-Line W-36 laying hens in the late phase of production, reduced egg weight (P<0.05). Productive performance and egg quality were not affected by 12 and 20% reduction of PRO and MET, respectively. It seems that decreasing the levels of MET and PRO to lower than the recommended values can decrease egg weight without negative effects on productive performance and egg quality of laying hens in the late phase of production.