Abstract in English:The factorial approach has been used to partition the energy requirements into maintenance, growth, and production. The coefficients determined for these purposes can be used to elaborate energy requirement models. These models consider the body weight, weight gain, egg production, and environmental temperature to determine the energy requirements for poultry. Predicting daily energy requirement models can help to establish better and more profitable feeding programs for poultry. Studies were conducted at UNESP-Jaboticabal to determine metabolizable energy (ME) requirement models for broiler breeders, laying hens, and broilers. These models were evaluated in performance trials and provided good adjustments. Therefore, they could be used to establish nutritional programs. This review aims to outline the results found at UNESP studies and to show the application of models in nutritional programs for broiler breeders, laying hens, and broilers.
Abstract in English:This investigation was carried out to study egg traits (weight, specific gravity and eggshell thickness), and neonatal chick parameters (weight, blood, cardiac and lung parameters) from breeder at different ages. After hatching, neonatal chicks, male and female, from broiler breeder at three different ages (30, 45 and 60 weeks) were sacrificed and blood (red blood cell number, hematocrit, mean cell volume, blood viscosity, and haemoglobin), cardiac (right ventricle and total ventricle weights, cardiac index) and lung (mean pulmonary pressure, fresh relative lung weight) parameters were measured. No significant differences in eggshell thickness or specific gravity were observed in eggs from the three different breeder age. The incubated eggs and neonatal chicks showed heavier absolute weights with increasing breeder age. Broiler breeder age did not affect blood parameters or cardiac index, but affected right ventricle and total ventricle absolute weights. Red blood cell number and hematocrit were higher and lung weight and lung weight:chick weight index were lower for female neonatal chicks. The findings of this study revealed that breeder age affects neonatal chick parameters such as body weight, heart and lung absolute weights, but not blood parameters.
Abstract in English:A study was carried out to evaluate the effect of broiler breeder age on the development of the digestive tract of embryos and chicks. Fertilized eggs Cobb from 30 and 60 week-old broiler breeder was utilized in this experiment. The results showed that eggs from older (60 weeks of age) broiler breeders were heavier (p = 0.001) than those from younger (30 weeks of age) broiler breeder. In addition, older broiler breeder had larger (p = 0.001) embryos showing a higher yolk sac (p = 0.001) and higher gastrointestinal tract relative weight (p = 0.007) than those from younger broiler breeder. The activities of pancreatic lipase and trypsin enzymes were also higher in embryos from older broiler breeder than those from younger broiler breeder (p = 0.001 and p = 0.002, respectively). Nevertheless, at the seven-day-old chick, no difference was observed in relative weight of gastrointestinal tract or pancreatic lipase and trypsin activities between older and younger broiler breeder age. However chicks from older broiler breeder were heavier than those from younger broiler breeder (p = 0.005). These data suggest that broiler breeder age is important on grower and on the development of the gastrointestinal tract and pancreatic lipase and trypsin activities of embryo. However after one week of hatching the morphophysiological difference disappear.
Abstract in English:There are many situations that involve health risks to the Brazilian rural worker, and animal production is just one of them. Inhalation of organic dust, which has many microorganisms, leads in general to respiratory allergic reactions in some individuals, "asthma-like syndrome", and mucous membrane inflammation syndrome, that is a complex of nasal, eye, and throat complaints. Furthermore, workers might have farmer's hypersensitivity pneumonia, that is a respiratory health risk along the years. The objective of this study was to evaluate the potential pulmonary health risks in poultry production workers in the region of Curitiba, PR, Brazil. Interviews using a pre-elaborated questionnaire with 40 questions were made with 37 broiler production workers, which were submitted to a pulmonary function test. Results of restrictive function with lower FEV1 (the maximum respiratory potential, the forced expiratory volume in the first second of exhalation) and FVC (forced vital capacity) represented 24.32% of the total of workers, and severe obstruction represented 2.70%. Other symptoms were found in 67.57% of the workers as well. The results showed that those who work more than 4 years and within more than one poultry house, exceeding 5 hours per day of work, presented higher pulmonary health risks. It is concluded that the activities within broiler houses may induce allergic respiratory reaction in workers. The use of IPE (individual protection equipment) besides special attention to the air quality inside the housing may be advised in a preventive way.
Abstract in English:Duodenum swabs were harvested from 80 broilers in 15 flocks of 8 broiler farms and were submitted to bacteriological evaluation. Five broiler breeders were sampled to obtain comparative data. Macro and microscopic lesions in the gut and the liver were evaluated in all birds submitted to swab harvesting and also broilers of two slaughter plants. Semiquantitative bacterial examination in duodenum swabs demonstrated higher microorganism growth in blood agar than in MacConkey medium. Staphylococcus sp, Enterococcus sp and Escherichia coli were found in some broiler flocks. An increased cellularity of the muscular mucosae of duodenum villi and/or the presence of some gametocytes or schizonts of coccidia were found in the lesioned gut in addition to high bacterial growth in blood agar. In some flocks, enlarged yellowish livers with vacuolated hepatocytes and/or increased reticuloendothelial response were seen in some birds. Liver and gut samples were collected in two slaughter plants in order to establish a pattern of response in broilers after withdrawal of growth promoters. Livers with macroscopic lesions presented microscopic lesions in the parenchyma such as increased leukocyte response in the sinusoidal space, vacuolar degeneration of hepatocytes or focal necrosis in the perilobular region, increased size or number of lymphoid nests in the perilobular region, the perivascular space and surrounding the biliary duct and increased extramedular granulocytopoiesis. Duodenum with hyperemic patches showed increased cellular response in the muscular mucosa of villi. These observations support the concept that semi-quantitative bacteriology and liver lesion evaluation could be used as a model to study gut bacterial imbalance in chickens.
Abstract in English:IBDV Gm 11 (Simbios eleven-molecular group) has been detected since 1997 in many farms of commercial broilers and layers causing high mortality (2 to 15%) and severe macro and microscopic damage in cloacal bursae, spleen, thymus, kidney and liver. Five serial passages of 2050/97-Gm 11 IBDV sample by CAM route in SPF chicken's embryonated eggs did not elicit increased embryo mortality. High mortality (100%) of 21 day-old SPF leghorn chickens and severe bursal and splenic lesions were seen from 24 up to 48 hours after eye-drop inoculation of 2050/97 strain (50 mL of 10-2 dilution of 10% bursae homogenate). Mortality was not detected when vaccinated SPF and broiler chickens were inoculated. One dead bird was found among ten challenged unvaccinated broilers. Variations in the intensity of cloacal bursae injury and spleen response were found between unvaccinated and vaccinated broiler chickens. IBDV antibodies were detected by ELISA test in almost all vaccinated SPF chickens before challenge while low number of commercial vaccinated and unvaccinated broilers were serologically positive (0 to 3 birds in 18). Increasing IBDV antibody titers were detected after challenge with 2050/97 strain and highest GMTs were found in broilers. It was concluded that 2050/97 strain is a highly virulent IBDV and SPF leghorn chickens immunized with BV8 intermediate vaccine strain were resistant to the challenge. Increasing susceptibility was found from experimental groups of unvaccinated broilers to vaccinated broilers and to unvaccinated SPF birds. It is discussed that passive immunity was involved in the rate of protection of challenged unvaccinated broiler and in the immune response impairment after vaccination of broilers chicks. The use of a constant virus suspension with known potency to challenge the experimental birds was suitable to evaluate vaccination efficacy. Evaluation of bursal and splenic responses at early and delayed time after challenge were useful to estimate vaccination efficacy and field interactions.
Abstract in English:The traditional method of total excreta collection was applied, using 30 to 40 day old male Ross 308 broiler chickens. One hundred and eight broiler chickens were used, randomly assigned to a 3x3 factorial experimental design. The room temperatures were 14 C (cold), 25 °C (thermoneutral) and 32 °C (hot) and the three diets were 100% maize, 100% sorghum with tannin and 100% sorghum without tannin, with four replicates of each. The digestibility coefficients for the dry matter, crude protein, crude fibre, neutral detergent fibre, acid detergent fibre, ether extract, mineral matter and nitrogen-free extract were determined. It was observed that all the digestibility coefficients were higher in the hot chamber and lower in the cold chamber, and that these values tended to be higher for maize.
Abstract in English:An experiment was carried out to evaluate different formulated feeds for broilers from 43 to 49 days of age. Six hundred male Cobb broilers were distributed in a completely at random experimental design with 3 treatments (3 different criteria of feed formulation) and 4 repetitions per treatment, with 50 birds each. Diets were formulated with different criteria of digestible amino acid inclusion (methionine, methionine+cystine, lysine and threonine), according to the profiles recommended by Baker and Chung (1992), Degussa (1997) and Rostagno (2000) Live performance and carcass yield were evaluated in birds fed the different diets from 43 to 49 days of age). The profile established by Degussa (1997) resulted in best live performance. All profiles supplied the nutritional requirements of the birds for adequate carcass yield, but Degussa (1997) profile resulted in highest breast yield.
Abstract in English:Susceptibility of chicken embryo related cells (CER) to non-classical IBDV was compared with Vero cells for the same purpose. It was used 20 bursal samples collected from clinical cases of IBDV, positive by histopathological evaluation. After three times infection of CER and Vero cells monolayers, at 6, 12, 18, 24, 48, 60 and 72h post-infection (PI), extra-cellular and intracelluar IBDV was measured. The extra-cellular amount of IBDV particles was quantified by DAS-ELISA from 6h PI, and increased for both cells studied until 72h PI. The IBDV re-isolation performed by infecting chicken embryos showed positive results at all PI studied. The intracellular IBDV RNA was shown by RT-PCR, where all tested samples were positive. However, the cytopathic effect (CPE) caused by IBDV infection was pronounced at 18h for Vero and 36h for CER cells. The RT-PCR was done to detect IBDV RNA from the bursa samples, where all were positive. Regarding to IBDV isolation, 20% of samples tested were negative in Vero cells, where all were positive in CER cells infection. The findings allow concluding that CER cell can be a new and appropriated tool for IBDV isolation.