Polymelia and concurrent intestinal duplication and cloacal atresia in a broiler chick: case report and literature review.

Congenital malformations are a highly diverse group of conditions reported in both humans and animals, characterized by defects in morphogenesis observed at birth. Although most cases are idiopathic, genetic and environmental factors may be involved. The frequency of such conditions varies with species, geographic regions, and the specific malformation involved. In polymelia, supernumerary limbs are attached to different parts of the body. Gastrointestinal duplications are described less frequently and can be associated with polymelia. Cloacal atresia is among the least-reported malformations in avian species, described only once in a kiwi. Here we describe a case with these 3 malformations in a single broiler chick (Gallus gallus domesticus) and provide a literature review about the occurrence of these malformations in birds. The 3-d-old chick also had an unidentified structure projecting from the pygostyle region. We performed clinical, radiographic, and postmortem examinations. The intestinal duplication was identified only during the postmortem evaluation. Detailed descriptions of avian congenital malformations are scarce. Although similar cases have been reported, we retrieved no cases of concurrent polymelia, intestinal duplication, and cloacal atresia in broiler chickens in our literature search, suggesting that the simultaneous occurrence of these conditions has not been reported previously in this species.

Effects of Dietary Supplementation of Fumaric Acid on Growth Performance, Blood Hematological and Biochemical Profile of Broiler Chickens Exposed to Chronic Heat Stress

The aim of this study was to investigate the effects of dietary fumaric acid (FA) on the growth performance, hematological parameters and serum biochemistry in broilers under heat stress (HS) condition. A total number of 200 broilers were allocated to five treatments including the thermoneutral group, which was reared at standard ambient temperature and fed basal diet (CONT) and four heat-stressed groups, which were held at 32 ± 1ºC aged from 22 to 42 days and fed the basal diet supplemented with 0, 5, 10 and 15 g/kg FA, respectively. On day 42, body weight and feed intake were measured and feed conversion ratio was calculated. Blood was collected for the estimation of hematological and biochemical parameters. HS impaired the growth performance, but the addition of FA made a higher final body weight, average daily gain and European broiler index in comparison with HS group. The hemoglobin concentration and packed cell volume of HS broilers were significantly lower than those of the CONT birds. Birds administered 5g/kg FA diet had significantly (p 0.05) higher erythrocyte counts and hemoglobin concentration compared with birds in the HS group fed basal diet. Also, the HS group exhibited significant increase in glucose, triglyceride, total cholesterol, low-density lipoprotein cholesterol and creatinine when compared with CONT group. Dietary 5g/kg FA increased the serum total protein, albumin, globulin, total cholesterol, high-density lipoprotein cholesterol in comparison with the HS group. In conclusion, this study demonstrated the importance of using FA as feed additives to improve the growth performance of heat-stressed broilers through haematological and biochemical regulation.

Effects of Dietary Supplementation of Fumaric Acid on Growth Performance, Blood Hematological and Biochemical Profile of Broiler Chickens Exposed to Chronic Heat Stress

The aim of this study was to investigate the effects of dietary fumaric acid (FA) on the growth performance, hematological parameters and serum biochemistry in broilers under heat stress (HS) condition. A total number of 200 broilers were allocated to five treatments including the thermoneutral group, which was reared at standard ambient temperature and fed basal diet (CONT) and four heat-stressed groups, which were held at 32 ± 1ºC aged from 22 to 42 days and fed the basal diet supplemented with 0, 5, 10 and 15 g/kg FA, respectively. On day 42, body weight and feed intake were measured and feed conversion ratio was calculated. Blood was collected for the estimation of hematological and biochemical parameters. HS impaired the growth performance, but the addition of FA made a higher final body weight, average daily gain and European broiler index in comparison with HS group. The hemoglobin concentration and packed cell volume of HS broilers were significantly lower than those of the CONT birds. Birds administered 5g/kg FA diet had significantly (p 0.05) higher erythrocyte counts and hemoglobin concentration compared with birds in the HS group fed basal diet. Also, the HS group exhibited significant increase in glucose, triglyceride, total cholesterol, low-density lipoprotein cholesterol and creatinine when compared with CONT group. Dietary 5g/kg FA increased the serum total protein, albumin, globulin, total cholesterol, high-density lipoprotein cholesterol in comparison with the HS group. In conclusion, this study demonstrated the importance of using FA as feed additives to improve the growth performance of heat-stressed broilers through haematological and biochemical regulation.(AU)

Practical assessment of spaghetti breast in diverse genetic strain broilers reared under different environments

Brazilian processing plants have identified the so-calledspaghetti breast myopathy characterized by muscular dystrophy of unknown etiology. This study aimed at estimating the incidence of spaghetti breast myopathyin broilers from three commercial genetic strains (Ross, Cobb, Hubbard) reared in two different housing systems (DH, Dark house, and TS, Tunnel system), presenting different controlled ventilation systems and light availability. Breast meat samples (n=5,580) were collected and macroscopically evaluated for spaghetti breast myopathy according to a 0-2 scale, as 0 = normal, 1 = intermediate or moderate, and 2 = severe. A higher number of broilers reared in DH presented normal breasts and moderate myopathy relative to TS-reared birds. Ross broilers presented a higher incidence of normal breasts compared with Cobb and Hubbard broilers. The risk of presenting spaghetti breast myopathy was higher in broilers reared in DH than those in reared in TS, indicating that the exposure to DH environmental conditions may increase the chance of myopathy incidence. Broilers reared in dark houses presented 26% higher chance and 13% higher risk of showing spaghetti-breast myopathy the than those reared in tunnel-ventilated systems.

Techniques to Minimize the Effects of Acute Heat Stress or Chronic in Broilers

High environmental temperature is limiting factor in broiler production. In order to minimize the undesirable consequences of acute or chronic heat stress, the techniques of fixed dietary electrolyte balance and early heat conditioning were evaluated. The objective of this study was to evaluate the possible interactions and effects of dietary electrolyte balance and early heat conditioning on feed intake, body weight, feed conversion ratio, mortality, energy bioeconomic index, fecal moisture, abdominal fat, and breast meat color (L*a*b*) of broilers submitted to chronic or acute heat stress. In total, 1280 chicks, were equally divided in experiment I (chronic heat stress, 6h/day at 32ºC from 35 to 39 d of age) and II (acute heat stress, 36 ºC for 6h at 38 days of age). The data of both experiments were combined and analyzed according to a 2x2x2 factorial arrangement (early heat conditioning (ETC) or not; fixed dietary electrolyte balance (EB) or not; and exposure to acute or chronic heat stress). ETC consisted of exposing 5-d-old birds to 36.0 °C for 24 hours. No interaction among the evaluated factors was detected. Birds exposed to acute heat stress presented significantly higher compared with chronic heat stress. Fixed dietary EB resulted in significantly higher fecal moisture. Lower abdominal fat percentage was obtained in birds exposed to chronic relative to acute heat stress. Higher breast meat L* and b* values were observed in birds exposed to acute heat stress than those submitted to chronic heat stress, indicating worse meat quality.

An Outbreak of Intestinal Obstruction by Ascaridia Galli in Broilers in Minas Gerais

Industrial broilers raised on helminthic medication-free feed were diagnosed with a severe disease caused by Ascaridia galli, characterized by intestinal hemorrhage and obstruction. A. galli was identified based on the morphological features of the nematode. Broilers were raised for a longer period (63 days) for weight recovery, grouped as stunted (n=500), had low body score and had fetid diarrhea. The duodenum-jejunum segment was the most severely affected with obstruction and had localized accumulation of gas. The intestinal mucosa was severely congested with petechial and suffusive hemorrhages. The outbreak resulted in morbidity of about 10% and mortality of up to 4% and was associated to the absence of preventive medication on feed and slack biosecurity. The reemergence of A. galli is discussed in view of the alternative poultry management and raising conditions for drug free and welfare.

Effects of Methionine Deficiency on the B Lymphocyte and Immunoglobulins of Cecal Tonsil in Cobb Broilers

The present study was conducted on one-day-old broilers to investigate the effects of methionine deficiency on B lymphocytes and immunoglobulins (sIgA, IgA, IgG, IgM) in the cecal tonsil of Cobb broiler chicken. Methods including immunohistochemistry (IHC), western blot (WB), quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) and Enzyme-Linked Immuno Sorbent Assay (ELISA) were used, and the study lasted for 6 weeks. It was found that the IgA+ B lymphocytes mainly existed in the diffuse lymphoid tissues and lymphoid follicles of the cecal tonsil. The data indicated that the number of IgA+ B lymphocytes was decreased in the methionine deficiency group, and the WB and qRT-PCR results suggested that the protein and mRNA expression of CD19 were reduced in the methionine deficiency group. Besides, the contents of sIgA, IgA, IgG and IgM determined by ELISA decreased in the methionine deficiency group. It could be concluded that methionine deficiency exerts significantly negative effects on the humoral immune function of the intestinal mucosal immunity.

Effects of Flammulinavelutipes Stem Base on Microflora and Volatile Fatty Acids In Caecum of Growing Layers under Heat Stress Condition

The present study was undertaken to investigate the effects of Flammulinavelutipes stem base (FVS) on growth performance, microbial flora and volatile fatty acids of growing layers under heat stress condition. A total of 72 ISA Brown hens were randomly divided into six treatments: thermoneutral temperature control group (CON), heat stress control group (HS), heat stress antibiotic group (ANT) as positive control and heat stress FVS groups (20, 40 or 60 g/kg FVS). The experimental period had a duration of 28 d (days 84-112). On day 98, daily gain average was significantly higher (p 0.05) in the FVS groups than in the HS group. The number of bands in the FVS groups were higher (p 0.05) than in the HS group on day 98. The microbial similarity between the 60 g/kg FVS group and the HS group were the lowest on day 98. FVS groups specific bacteria were mainly Coprococcus comes, [Clostridium] papyrosolvens, Butyricicoccuspullicaecorumon day 98. Whereas on day 112, the FVS groups specific bacteria were mainly Parabacteroides distasonis, Coprobacterfastidiosus, Elusimicrobiumminutum. The content of acetic acid and butyric acid were higher (p 0.05) in 20 g/kg FVS group than in the CON group on day 112. In conclusion, FVS can lighten the adverse effect of heat stress by increasing the diversity of intestinal flora in growing layers.

Techniques to Minimize the Effects of Acute Heat Stress or Chronic in Broilers

High environmental temperature is limiting factor in broiler production. In order to minimize the undesirable consequences of acute or chronic heat stress, the techniques of fixed dietary electrolyte balance and early heat conditioning were evaluated. The objective of this study was to evaluate the possible interactions and effects of dietary electrolyte balance and early heat conditioning on feed intake, body weight, feed conversion ratio, mortality, energy bioeconomic index, fecal moisture, abdominal fat, and breast meat color (L*a*b*) of broilers submitted to chronic or acute heat stress. In total, 1280 chicks, were equally divided in experiment I (chronic heat stress, 6h/day at 32ºC from 35 to 39 d of age) and II (acute heat stress, 36 ºC for 6h at 38 days of age). The data of both experiments were combined and analyzed according to a 2x2x2 factorial arrangement (early heat conditioning (ETC) or not; fixed dietary electrolyte balance (EB) or not; and exposure to acute or chronic heat stress). ETC consisted of exposing 5-d-old birds to 36.0 °C for 24 hours. No interaction among the evaluated factors was detected. Birds exposed to acute heat stress presented significantly higher compared with chronic heat stress. Fixed dietary EB resulted in significantly higher fecal moisture. Lower abdominal fat percentage was obtained in birds exposed to chronic relative to acute heat stress. Higher breast meat L* and b* values were observed in birds exposed to acute heat stress than those submitted to chronic heat stress, indicating worse meat quality.(AU)

An Outbreak of Intestinal Obstruction by Ascaridia Galli in Broilers in Minas Gerais

Industrial broilers raised on helminthic medication-free feed were diagnosed with a severe disease caused by Ascaridia galli, characterized by intestinal hemorrhage and obstruction. A. galli was identified based on the morphological features of the nematode. Broilers were raised for a longer period (63 days) for weight recovery, grouped as stunted (n=500), had low body score and had fetid diarrhea. The duodenum-jejunum segment was the most severely affected with obstruction and had localized accumulation of gas. The intestinal mucosa was severely congested with petechial and suffusive hemorrhages. The outbreak resulted in morbidity of about 10% and mortality of up to 4% and was associated to the absence of preventive medication on feed and slack biosecurity. The reemergence of A. galli is discussed in view of the alternative poultry management and raising conditions for drug free and welfare.(AU)

Effects of Flammulinavelutipes Stem Base on Microflora and Volatile Fatty Acids In Caecum of Growing Layers under Heat Stress Condition

The present study was undertaken to investigate the effects of Flammulinavelutipes stem base (FVS) on growth performance, microbial flora and volatile fatty acids of growing layers under heat stress condition. A total of 72 ISA Brown hens were randomly divided into six treatments: thermoneutral temperature control group (CON), heat stress control group (HS), heat stress antibiotic group (ANT) as positive control and heat stress FVS groups (20, 40 or 60 g/kg FVS). The experimental period had a duration of 28 d (days 84-112). On day 98, daily gain average was significantly higher (p 0.05) in the FVS groups than in the HS group. The number of bands in the FVS groups were higher (p 0.05) than in the HS group on day 98. The microbial similarity between the 60 g/kg FVS group and the HS group were the lowest on day 98. FVS groups specific bacteria were mainly Coprococcus comes, [Clostridium] papyrosolvens, Butyricicoccuspullicaecorumon day 98. Whereas on day 112, the FVS groups specific bacteria were mainly Parabacteroides distasonis, Coprobacterfastidiosus, Elusimicrobiumminutum. The content of acetic acid and butyric acid were higher (p 0.05) in 20 g/kg FVS group than in the CON group on day 112. In conclusion, FVS can lighten the adverse effect of heat stress by increasing the diversity of intestinal flora in growing layers.(AU)

Effects of Methionine Deficiency on the B Lymphocyte and Immunoglobulins of Cecal Tonsil in Cobb Broilers

The present study was conducted on one-day-old broilers to investigate the effects of methionine deficiency on B lymphocytes and immunoglobulins (sIgA, IgA, IgG, IgM) in the cecal tonsil of Cobb broiler chicken. Methods including immunohistochemistry (IHC), western blot (WB), quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) and Enzyme-Linked Immuno Sorbent Assay (ELISA) were used, and the study lasted for 6 weeks. It was found that the IgA+ B lymphocytes mainly existed in the diffuse lymphoid tissues and lymphoid follicles of the cecal tonsil. The data indicated that the number of IgA+ B lymphocytes was decreased in the methionine deficiency group, and the WB and qRT-PCR results suggested that the protein and mRNA expression of CD19 were reduced in the methionine deficiency group. Besides, the contents of sIgA, IgA, IgG and IgM determined by ELISA decreased in the methionine deficiency group. It could be concluded that methionine deficiency exerts significantly negative effects on the humoral immune function of the intestinal mucosal immunity.(AU)

Esophageal squamous cell carcinoma in a backyard rooster

Squamous cell carcinoma, a malignant epithelial neoplasm originating from the epidermis squamous cells or the digestive mucosa epithelium, was diagnosed in an adult rooster. The rooster was lethargic and presented difficulties in swallowing. Physical examination revealed a large deep mass in the cranial cervical region. Due to poor prognosis, the bird was euthanized and then post mortem examined. Grossly, in the oral portion of the esophagus, there was a mass invading and partially occluding the lumen. Microscopically, the mass had neoplastic cells interconnected by evident desmosomes junctions and keratin pearl formations. Microscopic findings confirmed the diagnosis of squamous cell carcinoma. This neoplasia is an important differential diagnosis for esophageal lesions in birds. There are various carcinogens for squamous cell carcinoma such as sunlight, virus, some chemicals and chronic wounds, the last one being a possible cause of the squamous cell carcinoma in this rooster as no evidence of other etiologies were found.(AU)

Practical assessment of spaghetti breast in diverse genetic strain broilers reared under different environments

Brazilian processing plants have identified the so-calledspaghetti breast myopathy characterized by muscular dystrophy of unknown etiology. This study aimed at estimating the incidence of spaghetti breast myopathyin broilers from three commercial genetic strains (Ross, Cobb, Hubbard) reared in two different housing systems (DH, Dark house, and TS, Tunnel system), presenting different controlled ventilation systems and light availability. Breast meat samples (n=5,580) were collected and macroscopically evaluated for spaghetti breast myopathy according to a 0-2 scale, as 0 = normal, 1 = intermediate or moderate, and 2 = severe. A higher number of broilers reared in DH presented normal breasts and moderate myopathy relative to TS-reared birds. Ross broilers presented a higher incidence of normal breasts compared with Cobb and Hubbard broilers. The risk of presenting spaghetti breast myopathy was higher in broilers reared in DH than those in reared in TS, indicating that the exposure to DH environmental conditions may increase the chance of myopathy incidence. Broilers reared in dark houses presented 26% higher chance and 13% higher risk of showing spaghetti-breast myopathy the than those reared in tunnel-ventilated systems.(AU)

Esophageal squamous cell carcinoma in a backyard rooster

Squamous cell carcinoma, a malignant epithelial neoplasm originating from the epidermis squamous cells or the digestive mucosa epithelium, was diagnosed in an adult rooster. The rooster was lethargic and presented difficulties in swallowing. Physical examination revealed a large deep mass in the cranial cervical region. Due to poor prognosis, the bird was euthanized and then post mortem examined. Grossly, in the oral portion of the esophagus, there was a mass invading and partially occluding the lumen. Microscopically, the mass had neoplastic cells interconnected by evident desmosomes junctions and keratin pearl formations. Microscopic findings confirmed the diagnosis of squamous cell carcinoma. This neoplasia is an important differential diagnosis for esophageal lesions in birds. There are various carcinogens for squamous cell carcinoma such as sunlight, virus, some chemicals and chronic wounds, the last one being a possible cause of the squamous cell carcinoma in this rooster as no evidence of other etiologies were found.

Influence of rearing temperature and feed format in the development of the pendulous crop in broilers.

The pendulous crop is characterized by excessive distension of the crop musculature, compromising the bird's productivity and welfare. The etiology is still unknown, but it is believed that factors related to the birds' handling might be related to its incidence. The study was conducted in 2 environmental chambers. One was maintained at a comfortable temperature, while the other was set at a much lower temperature. In each chamber, animals were divided into 16 experimental pens (8 received mash feed and the others received pelletized feed) with a density of 12 birds/m2 (an expected stocking density of 32-36 kg/m2 after 42 d). The effects of rearing temperatures were evaluated in terms of broiler performance, specifically weight gain (kg), feed intake (kg), weekly feed intake (kg/wk), and feed conversion (kgfeed/kggrowth). The occurrences of pendulous crop were quantified every 2 d after the 14th day of rearing. Birds grown in thermal comfort and fed a pelletized ration were most susceptible (12%) to pendulous crop, followed by birds fed pelletized feed and reared in cold conditions (6.8%), and birds given mashed feed and reared at either temperature (about 3%). We concluded that feeding pelleted feed combined with warmer rearing temperatures may have caused some alteration of the gastrointestinal system of birds, which caused pendulous crop to be more prevalent.

Effect of ultra-fine traditional Chinese medicine compounds on regulation of lipid metabolism and reduction in egg cholesterol of aying hens

This study has the objective of investigating the effects of traditional Chinese medicine prescriptions (TCM) on serum lipid, abdominal and hepatic fat percentage, cholesterol content in eggs, and mRNA expression of genes apoA I and apoB100. One hundred and thirty five healthy (300-day-old) layers were randomly assigned to three treatments. The hens in control group were fed with the basal diet. The hens in the experimental groups (TCM 1 and TCM 2) were fed with the basal diet supplemented with 1% TCM 1 and 1% TCM 2 respectively over a period of 60 days. Laying performance and the serum parameters relevant to fat metabolism were measured. The results showed that no significant differences were found in average daily feed intake and egg weight among three treatments. Average daily laying rate in TCM treatments was increased, and the cholesterol content in eggs was decreased. The serum triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels in experimental treatments were decreased (p<0.05), while the serum high-density lipoprotein cholesterol (HDL-C) level was increased (p<0.05) compared to the control group. Additionally, abdominal fat percentage decreased in TCM 1 treatment (p<0.05), and hepatic fat percentage decreased in both TCM treatments (p<0.05). The expression of apolipoproteinA I (apoA I) and apolipoproteinB100 (apoB100) mRNA in the liver increased in both TCM treatments (p<0.05). These results suggest that the diet supplemented with TCM could increase the expression of apoA I and apoB100 mRNA in the liver, and decrease lipid content in the serum, and reduce egg cholesterol in layers.

Effect of ultra-fine traditional Chinese medicine compounds on regulation of lipid metabolism and reduction in egg cholesterol of aying hens

This study has the objective of investigating the effects of traditional Chinese medicine prescriptions (TCM) on serum lipid, abdominal and hepatic fat percentage, cholesterol content in eggs, and mRNA expression of genes apoA I and apoB100. One hundred and thirty five healthy (300-day-old) layers were randomly assigned to three treatments. The hens in control group were fed with the basal diet. The hens in the experimental groups (TCM 1 and TCM 2) were fed with the basal diet supplemented with 1% TCM 1 and 1% TCM 2 respectively over a period of 60 days. Laying performance and the serum parameters relevant to fat metabolism were measured. The results showed that no significant differences were found in average daily feed intake and egg weight among three treatments. Average daily laying rate in TCM treatments was increased, and the cholesterol content in eggs was decreased. The serum triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels in experimental treatments were decreased (p<0.05), while the serum high-density lipoprotein cholesterol (HDL-C) level was increased (p<0.05) compared to the control group. Additionally, abdominal fat percentage decreased in TCM 1 treatment (p<0.05), and hepatic fat percentage decreased in both TCM treatments (p<0.05). The expression of apolipoproteinA I (apoA I) and apolipoproteinB100 (apoB100) mRNA in the liver increased in both TCM treatments (p<0.05). These results suggest that the diet supplemented with TCM could increase the expression of apoA I and apoB100 mRNA in the liver, and decrease lipid content in the serum, and reduce egg cholesterol in layers.(AU)

Broilers thermal comfort and performance utilizing two differentwood-burning heating systems / Conforto térmico e desempenho zootécnico de frangos de corte utilizando dois sistemas de aquecimento distintos

The objective of this study was to evaluate the thermal comfort and performance of broilers in their initial stage of development utilizing two different heating systems. The experiment was conducted in two sheds placed on a commercial farm. The heating systems were: indirect heating furnace and radiation heating drums. At the beginning of the heating phase the birds were confined in an area corresponding to 360 m² in shed 1 and 180 m² in shed 2, delimited by polyurethane curtains, allowing a density of 58.8 birds m-². The variables: dry bulb temperature (Tdb), relative humidity (RH%) and temperature and humidity index (THI) were calculated. Measurements were performed using continuous reading data loggers at 15-minute intervals throughout the experimental period, which was a complete productive cycle for males. Differences were detected in the environmental variables during the period evaluated, as well as differences in performance were found as a function of the two heating systems. The heating system of the furnace presented UR ranging from 47-59% in relation to the drum system (51-57%), besides providing a more constant temperature and providing a greater distribution of heating. On the other hand, the drum system provided greater weight gain in the animals.

Objetivou-se comeste estudo avaliar o conforto térmico e desempenho zootécnico de frangos de corte em seu estágio inicial de desenvolvimento em função utilizando dois sistemas de aquecimento distintos. O experimento foi conduzido em dois galpões localizados numa propriedade comercial. Os sistemas de aquecimento foram: fornalha de aquecimento indireto e tambores de aquecimento por radiação. No início da fase de aquecimento as aves foram confinadas numa área correspondente a 360 m2 no galpão 1 e 180 m2 no galpão 2, delimitada por cortinas de poliuretano, possibilitando uma densidade de 58,8 aves m-2. Foram avaliadas as variáveis Temperatura de bulbo seco (Tbs), umidade relativa do ar (UR%) e calculado o índice de temperatura e umidade (ITU). As medições foram realizadas com o uso de dataloggers de leitura contínua da marca Hobbo em intervalos de 15 minutos, durante todo o período experimental, que foi de um ciclo produtivo completo para machos. Foram detectadas diferenças nas variáveis ambientais durante o período avaliado como também foram encontradas diferenças no desempenho zootécnico em função dos dois sistemas de aquecimento. O sistema de aquecimento por fornalha apresentou UR variando de 47-59% em relação ao sistema de tambores (51-57%), além de proporcionar temperatura mais constante e proporcionar maior distribuição de aquecimento. Por outro lado, o sistema de tambores proporcionou maior ganho de peso nos animais.

Broilers thermal comfort and performance utilizing two differentwood-burning heating systems / Conforto térmico e desempenho zootécnico de frangos de corte utilizando dois sistemas de aquecimento distintos

The objective of this study was to evaluate the thermal comfort and performance of broilers in their initial stage of development utilizing two different heating systems. The experiment was conducted in two sheds placed on a commercial farm. The heating systems were: indirect heating furnace and radiation heating drums. At the beginning of the heating phase the birds were confined in an area corresponding to 360 m² in shed 1 and 180 m² in shed 2, delimited by polyurethane curtains, allowing a density of 58.8 birds m-². The variables: dry bulb temperature (Tdb), relative humidity (RH%) and temperature and humidity index (THI) were calculated. Measurements were performed using continuous reading data loggers at 15-minute intervals throughout the experimental period, which was a complete productive cycle for males. Differences were detected in the environmental variables during the period evaluated, as well as differences in performance were found as a function of the two heating systems. The heating system of the furnace presented UR ranging from 47-59% in relation to the drum system (51-57%), besides providing a more constant temperature and providing a greater distribution of heating. On the other hand, the drum system provided greater weight gain in the animals.(AU)

Objetivou-se comeste estudo avaliar o conforto térmico e desempenho zootécnico de frangos de corte em seu estágio inicial de desenvolvimento em função utilizando dois sistemas de aquecimento distintos. O experimento foi conduzido em dois galpões localizados numa propriedade comercial. Os sistemas de aquecimento foram: fornalha de aquecimento indireto e tambores de aquecimento por radiação. No início da fase de aquecimento as aves foram confinadas numa área correspondente a 360 m2 no galpão 1 e 180 m2 no galpão 2, delimitada por cortinas de poliuretano, possibilitando uma densidade de 58,8 aves m-2. Foram avaliadas as variáveis Temperatura de bulbo seco (Tbs), umidade relativa do ar (UR%) e calculado o índice de temperatura e umidade (ITU). As medições foram realizadas com o uso de dataloggers de leitura contínua da marca Hobbo em intervalos de 15 minutos, durante todo o período experimental, que foi de um ciclo produtivo completo para machos. Foram detectadas diferenças nas variáveis ambientais durante o período avaliado como também foram encontradas diferenças no desempenho zootécnico em função dos dois sistemas de aquecimento. O sistema de aquecimento por fornalha apresentou UR variando de 47-59% em relação ao sistema de tambores (51-57%), além de proporcionar temperatura mais constante e proporcionar maior distribuição de aquecimento. Por outro lado, o sistema de tambores proporcionou maior ganho de peso nos animais.(AU)