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In recent years, the global poultry industry has been facing increasing and challenging myopathies such as the woody breast (WB) condition that has caused significant economic losses. Even though the etiological causes of WB myopathy are still unknown or partially understood, the intensive genetic selection for rapid-growth rates and high yields in broilers may be the main factor associated with the development of this abnormality. The severity of this anomaly and its incidence rates are associated with fast-growing and heavier broilers, especially with those from high breast yielding strains. Such WB myopathy is primarily characterized by a notorious hardness in broiler breast muscles, which exhibit morphometric and histopathological alterations coupled with physicochemical abnormalities that result in undesired sensory, nutritional, and technological properties. In this negative context, although scientists are trying to solve or reduce the prevalence of this meat quality problem, the poultry industry needs noncontact and rapid in-line methods for WB detection at the fillet and/or carcass level that could help to establish automated objective grading or sorting systems according to its severity. Another need is the development and selection of profitable alternatives for the utilization of WB meat once poultry carcasses or deboned fillets affected by this abnormality are objectively detected and sorted. Indeed, there is a need for studies to expand the industrial applications of WB meat in further processed products, optimizing the incorporation of this affected chicken meat based on sensorial, technological, and nutritional profile evaluations. Even though a better understanding of the contribution of genetic and nongenetic factors to the development of growth-related myopathies can be the main strategy to mitigate their negative effects, the poultry industry could benefit from meeting the aforementioned needs.

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Forty broilers maintained under natural hypobaric hypoxia (2,638 m above sea level) and 20 maintained under relative normoxia (460 m above sea level) were selected as pulmonary hypertensive (PHB) and nonpulmonary hypertensive (NPHB), to estimate the degree of the adventitial vascular thickness in lung arterioles and connective tissue growth factor (CTGF) expression in lung. In each group, the adventitial thickness (%AT) of 20 arterioles with 100 to 250 µm of external diameter was measured in lung samples of 24 and 42-day-old broilers. Also, mRNA extraction and real-time reverse transcription-PCR analysis were used to measure lung CTGF expression. The %AT was higher in PHB at 42 D as compared to NPHB at both ages and PHB at 24 D; however, the same differences were not evidenced at 24 D. In the 2 ages evaluated, differences were observed in the %AT between broilers under hypobaric hypoxia (PHB and NPHB) and under relative normoxia (P < 0.01). In broilers subjected to relative normoxia, no significant differences were found at any of the 2 ages. The expression levels of CTGF mRNA were higher in PHB compared to NPHB at the 2 ages. The %AT was higher in PHB with high levels of expression of CTGF mRNA than those NPHB with low expression of CTGF mRNA. This study showed that adventitial thickening is part of the pulmonary hypertension (PH) physiopathology in broilers exposed to hypobaric hypoxia, in which CTGF appears to be a fibrosis enhancer. Although present data suggest that adventitial engrossment could be a time-dependent process, individual susceptibility and the variable time-course of PH pathophysiology have to be considered.

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Vitamins play an essential role in broiler nutrition. They are fundamental for normal metabolic and physiological process, and their requirements for poultry are not fixed and can be affected by multiple factors. In contrast, mycotoxins are a challenging issue because they hinder performance and the immune system. Vitamin supplementation above minimum requirements would permit improvement in productive potential, health, bone and meat quality in a situation of mycotoxin challenge. The objective of this study was to determine the influence of optimum vitamin nutrition in diets contaminated with aflatoxin in broilers from 1 to 44 days of age. A total of 1800 Cobb 500 male chicks were randomized to 15 sets of eight treatment groups, each containing 15 birds using a 2 × 2 × 2 factorial design (commercial vitamin levels and high vitamin levels, two levels of aflatoxin - 0 and 0.5 ppm with binder levels of 0 and 10 000 mg/kg). The mash diets were corn and soybean meal based, formulated according to commercial practices. Feed intake, weight gain and feed conversion were analyzed for birds from 1 to 44 days of age. To determine carcass characteristics (carcass yield, breast yield and leg yield) and black bone syndrome, two birds were slaughtered from each group at 45 days. Other analyses included breast tenderness, water loss by dripping and malonaldehyde concentrations. The results demonstrated that broilers that were fed high levels of vitamins showed better weight gain, feed conversion, carcass yield and breast yield than broilers that were fed diets with commercial vitamin levels (P < 0.05); also, broilers that were fed diets containing 0.5 ppm aflatoxin had lower weight gain, carcass yield and breast yield (P < 0.05). The use of 10 000 mg/kg of binder improved (P < 0.05) feed conversion throughout the rearing period. We conclude that aflatoxin negatively affects performance and carcass yield; however, feeding optimum vitamin nutrition improved these performance traits.

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This study aimed to investigate the frequency of anti-Toxoplasma gondii antibodies in serum from 629 chickens on 39 family farms in seven municipalities in the semiarid region, Pernambuco, Brazil, and to identify risk factors associated with T. gondii infection. The risk factors were studied in 421 samples from 29 farms. Anti-T. gondii antibodies were investigated by indirect fluorescent antibody test with a 1:16 cutoff. The frequency of positive chickens was 27.9% (176/629) and 94.8% of the farms studied had chickens infected by T. gondii. Multivariate analysis showed variables significantly associated with anti-T. gondii antibodies in serum: slaughter of animals on the farm, reproductive disorders in sheep, consumption of fetal adnexa and placentas by chickens, presence of sheep in the property and birth of sheep the property. The results suggest that there is a complex relationship between general management practices for different animal species raised on the same farm and the prevalence of T. gondii infection in chickens. In addition, the results draw attention to the risk of human infection by T. gondii via consumption of infected chicken meat, because the farming conditions and the low human development indices observed in the region studied result in inappropriate meat preparation practices.

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Abstract This study aimed to investigate the frequency of anti-Toxoplasma gondii antibodies in serum from 629 chickens on 39 family farms in seven municipalities in the semiarid region, Pernambuco, Brazil, and to identify risk factors associated with T. gondii infection. The risk factors were studied in 421 samples from 29 farms. Anti-T. gondii antibodies were investigated by indirect fluorescent antibody test with a 1:16 cutoff. The frequency of positive chickens was 27.9% (176/629) and 94.8% of the farms studied had chickens infected by T. gondii. Multivariate analysis showed variables significantly associated with anti-T. gondii antibodies in serum: slaughter of animals on the farm, reproductive disorders in sheep, consumption of fetal adnexa and placentas by chickens, presence of sheep in the property and birth of sheep the property. The results suggest that there is a complex relationship between general management practices for different animal species raised on the same farm and the prevalence of T. gondii infection in chickens. In addition, the results draw attention to the risk of human infection by T. gondii via consumption of infected chicken meat, because the farming conditions and the low human development indices observed in the region studied result in inappropriate meat preparation practices.

Resumo Objetivou-se investigar a prevalência de anticorpos anti-Toxoplasma gondii em 629 soros de galinha em 39 propriedades da agricultura familiar em sete municípios de Pernambuco, Brasil e identificar os fatores de risco associados à infecção. Para a pesquisa de anticorpos anti-T. gondii empregou-se a reação de imunofluorescência indireta com ponto-de-corte 1:16. O estudo dos fatores de risco foi realizado em 29 propriedades, totalizando 421 amostras. A prevalência de aves positivas foi de 27,9% (176/629) e 94,8% das propriedades tinham galinhas infectadas por T. gondii. Na análise multivariada, obteve-se como variáveis significativas associadas com anticorpos anti-T. gondii a ocorrência de abate de animais na propriedade, relato de distúrbios reprodutivos em ovinos, ingestão de anexos fetais e placentas pelas galinhas, presença de ovinos na propriedade e nascimento de ovinos na propriedade. Os resultados sugerem relações complexas entre o manejo das espécies animais criados nas propriedades e a prevalência da infecção nas galinhas. Em adicional, chama-se atenção para o risco de infecção humana por T. gondii via consumo de carne de galinha infectada, uma vez que as condições de criação e os baixos índices de desenvolvimento observados na região resultam em inapropriada preparação da carne para consumo.

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Myopathies are gaining the attention of poultry meat producers globally. White Striping (WS) is a condition characterized by the occurrence of white striations parallel to muscle fibers on breast, thigh, and tender muscles of broilers, while Woody Breast (WB) imparts tougher consistency to raw breast fillets. Histologically, both conditions have been characterized with myodegeneration and necrosis, fibrosis, lipidosis, and regenerative changes. The occurrence of these modern myopathies has been associated with increased growth rate in birds. The severity of the myopathies can adversely affect consumer acceptance of raw cut up parts and/or quality of further processed poultry meat products, resulting in huge economic loss to the industry. Even though gross and/or histologic characteristics of modern myopathies are similar to some of the known conditions, such as hereditary muscular dystrophy, nutritional myopathy, toxic myopathies, and marbling, WS and WB could have a different etiology. As a result, there is a need for future studies to identify markers for WS and WB in live birds and genetic, nutritional, and/or management strategies to alleviate the condition.

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The pathogens Plasmodium juxtanucleare and chicken anaemia virus (CAV) are easily transmitted and potentially harmful to chickens. In this study, we established an experimental model to investigate the effects of avian malaria caused by P. juxtanucleare in white leghorn specific-pathogen-free (SPF) chicks previously immunosuppressed with CAV. Parasitaemia, haematological variables and clinical and pathological parameters were determined in four different experimental groups: chicks coinfected by CAV and P. juxtanucleare strain (Coinfected group), chicks exclusively infected by CAV (CAV group) or P. juxtanucleare (Malaria group) and uninfected chicks (Control group). Our data demonstrated that P. juxtanucleare parasitaemia was significantly higher in the Coinfected group. Furthermore, haematological parameters, including the RBC, haematocrit and haemoglobin concentration were significantly reduced in coinfected chicks. In agreement with the changes observed in haematological features, the mortality among coinfected chicks was higher compared with animals with single infections. Clinical analysis indicated moderate changes related to different organs size (bursa of Fabricius, heart and liver) in coinfected birds. The experimental coinfection of SPF chickens with P. juxtanucleare and CAV may represent a research tool for the study of avian malaria after CAV immunosuppression, enabling measurement of the impacts caused by different pathogens during malarial infection.

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1. The objectives of this study were to evaluate the residual effects of two windrow composting methods for reused litter on its quality (pH, moisture, ammonia), ammonia (NH3) volatilisation and the prevalence (scores 0-4) of foot pad dermatitis (FPD) and hock burn (HB) on d 1, 7, 14 and 21 of age in broilers. Litter was allowed to compost for 8 d within a 14-d interval between flocks. 2. The composting methods studied were with or without a PVC plastic sheet. The same procedures were applied for three consecutive flocks, with litter initially having been used for 12 flocks. Data were analysed with a mixed model of repeated measures of day, with main effects and interactions of day, composting method, litter age (block) and house nested within method. 3. At d 1, litter NH3 and NH3 volatilisation were higher in the covered litter method. Litter moisture increased to 45.3% as broilers aged. The incidence of FPD also increased with age. No signs of HB were found in any bird throughout the trials. 4. There was no effect of litter composting methods on the prevalence of FPD or body weight at any age. 5. Litter moisture should be controlled to avoid NH3 volatilisation reaching critical levels. Windrow composting of litter with a PVC plastic sheet may not be required when considering the broiler housing environment.

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Infectious bronchitis is caused by a coronavirus, infectious bronchitis virus (IBV). Infectious bronchitis is an acute and highly contagious disease of economic importance due to the reduction in weight gain observed with infected broilers and the drop in egg quality and production associated with infected laying hens. The presence of deep pectoral myopathy has been associated with IBV variants. This lesion is detected at slaughterhouses and is characterized by paleness and atrophy of the deep pectoral muscle, including necrosis of the region, leading to condemnations of the breast muscle, a valuable meat cut in the market. This work aimed to study the relationship between deep pectoral myopathy and IBV by describing tracheal and muscle lesions and comparing the frequency of IBV detection via reverse-transcription (RT) PCR in muscle, tracheal, and cecal tonsil samples from broilers with and without myopathy. A case-control study was conducted in 40 broiler flocks vaccinated with the Massachusetts strain. The case group consisted of 23 flocks that presented myopathic lesions under sanitary inspection and a control group of 17 flocks without myopathic lesions. The tracheal, cecal tonsil, and supracoracoid muscle (with and without lesions) samples from the 40 broiler flocks were screened by RT-PCR to detect IBV. Histopathology of muscle and tracheal tissue was carried out. Upon microscopic examination, the muscle samples from the case group presented extensive necrosis, intense mononuclear inflammatory infiltration, muscle fiber fragmentation, and fibrotic tissue, confirming myopathy, whereas muscles from the control group showed no alterations. The tracheal samples presented a large number of infiltrated mononuclear inflammatory cells that in some areas formed submucosal nodules. A total of 25 flocks tested IBV positive by RT-PCR: 14 from the case group and 11 from the control group. The IBV was detected by RT-PCR directly in muscle samples. Despite that, the relationship between deep pectoral myopathy and IBV was not established. The higher positive IBV RT-PCR percentage noted in the cecal tonsil samples demonstrates how important the choice of organs is for diagnostic purposes.

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Recently, in some Brazilian poultry companies, a dorsal cranial muscular lesion has been increasingly detected in broilers, causing heavy economic losses due to carcass downgrading. The observed gross lesions located in the anterior latissimus dorsi (ALD) muscle are characterized by yellowish discoloration of the skin and swelling on the dorsal cranial region of that muscle. When the ALD muscle is cut, subcutaneous edema, muscular superficial hemorrhage, pallor, adherence, and increased thickness and density are observed. Microscopically, findings indicate degenerative and polyphasic features, variation in fiber size and splitting, presence of hyaline, necrotic and regenerative myofibers, extensive fibrosis, and adipose tissue with lymphohistiocytic infiltration in all ALD muscles affected. The etiology of the lesion is unknown, and no detailed report was found in literature. The highest frequency of carcass downgrading due to this lesion was found in the heaviest and the oldest males of high-yield broiler strains (P < 0.01). This study is the first to describe the pathologic and some epidemiologic aspects of this new myopathy.

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