British Poultry Science最新文献

1. The current study analysed Marek's Disease virus (MDV) strains, genome characteristics and associated pathology, with reference to the central nervous system, in naturally occurring field cases across India.2. A total of 179 birds, aged less than 18 weeks, with visible visceral tumours in any of the organs were collected from major poultry areas of India. The source flocks were all vaccinated against MDV. Gross, cytological and histopathological examinations were conducted, alongside PCR for detecting MDV in lymphomatous tissues and the brain. The genetic characterisation and phylogenetic analyses of meq gene were conducted.3. The liver and spleen were affected in all cases, followed by the proventriculus, kidneys, heart, lungs, pancreas and sciatic nerves. Histopathologically, infiltration of pleomorphic lymphocytes was observed in affected organs, including the brain.4. All the cases were PCR-positive for the MDV genome, including four cases involving the brain. Four representative full-length sequences of the MDV meq gene from the brain exhibited amino acid substitutions (A-E-Y-R-V-C-P-P-T-P-L) at key positions, characteristic of virulent MDV strains.5. The findings indicated the circulation of virulent strains among MDV samples from India, based on sequence analysis and pathology involving the brain. Field isolates from the sampled locations were virulent forms of MDV and under positive selection, leading to varied tissue tropism, such as brain affinity, which has been previously reported in virulent MDV.6. The study highlighted the emergence of neurotropic, virulent MDV strains in India, underscoring the need for vigilant surveillance and revised vaccination strategies. Brain involvement in naturally occurring field cases suggests expanding tissue tropism with potential implications for diagnosis and disease control.

1. Fowl cholera poses a significant challenge for poultry farms around the globe. The disease's high mortality in poultry affects economics for farmers.2. A susceptible-exposed-symptomatic-asymptomatic-treated-culled-recovered (SEIATCR) mathematical model was used to describe the dynamics of cholera transmission in poultry farms. This calculated the basic reproduction number (R_0) using a next-generation matrix; a mathematical tool used in population dynamics and epidemiology to calculate the basic reproduction number (R₀).3. The SEIATCR model was replicated using the Runge-Kutta-Fehlberg Method (RK-45) numerical process using the value of the model's parameters available from the reported literature.4. The results showed that treatment and culling had a significant effect on disease transmission. Moreover, treatment was more effective than culling. Sensitivity analysis of the model's parameters for the basic reproduction number was investigated using partial rank correlation coefficients (PRCC), which showed that transmission rate and vaccine efficacy had the greatest sensitivity index and treatment rate is more sensitive than culling. In epidemiology, a sensitivity index is a numerical value that enumerates the impact of changes in a model's parameters on the model's output, such as disease transmission.5. There will always be a need to vaccinate, treat and cull infected poultry to control cholera in poultry farms.

1. The following reports an in-vivo study to investigate the toxicity profile of the azithromycin drug in broilers.2. Ninety, 1-d-old Hubbard chicks were purchased from Dakahliah Poultry Company, Egypt and, on d 25 of age, were subdivided into three groups. Group 1 (G1, control) received only drinking water, Group 2 (G2, treatment 1) received 50 mg azithromycin/kg body weight (BW) and Group 3 (G3, treatment 2) received 300 mg azithromycin/kg BW. All treatments were administered orally. Immunological, histopathological, and immunohistochemical assays were performed to evaluate the effect of azithromycin on broiler health.3. The weights of bursa of Fabricius and spleen in azithromycin-treated broilers decreased, particularly in G3. A decrease in both the phagocytic activity and index was evident in the treated groups (G2 and G3). Prominent degenerative changes and necrosis of immune organs were observed in treated chicks. Furthermore, strong immunoreactivity to caspase-3 was observed in the G3 group, which indicated elevated apoptosis in immune organs following exposure to a high-dose of azithromycin.4. It was concluded that administering azithromycin in broilers at a dose of 300 mg/kg impaired the immune function, promoted apoptosis and induced many microscopical alterations in different organs.

1. Inclusion body hepatitis (IBH), hepatitis-hydropericardium syndrome (HHS) and adenoviral gizzard erosion (AGE) are poultry diseases that are caused by fowl aviadenovirus (FAdV). Identifying serotypes is crucial for differentiation.2. Between September 2020 and May 2021, 58 FAdV strains were isolated from 278 potentially infected commercial chicken flocks in Turkey, specifically from broiler and breeder flocks located in Balıkesir, İzmir, Manisa, Çanakkale, Afyonkarahisar, Bursa and Elazığ.3. Viruses were isolated from pooled internal organs and propagated using primary chicken embryo kidney cell cultures (CEKC) and SPF embryonated chicken eggs. Amplification by PCR of the Hexon gene, followed by Sanger sequencing, revealed three FAdV-D (serotype 11) and 55 FAdV-E (serotype 8b) genotypes.4. For next-generation sequencing (NGS), two representative serotypes, TR/FAdV/1 (FAdV-8b) and TR/FAdV/2 (FAdV-11) were chosen. Whole-genome sequencing performed on the Illumina MiSeq platform identified both as FAdV-8b. The TR/FAdV/1 genome, measuring 44 061 bp with a G/C content of 57.9%, showed 98.1% identity with the U.S. FAdV-E strain (GB624-U.S.A.). Meanwhile, the TR/FAdV/2 genome, consisting of 43 891 bp with a G/C content of 57.88%, displayed 99.90% similarity to the Spanish FAdV-E strain (11 -16 629). Both genomes contained 36 open reading frames (ORFs).5. Severe IBH outbreaks linked to FAdV-D and FAdV-E were marked by enlarged, pale yellow livers with petechial haemorrhages. At present, no commercial vaccines for FAdV are available locally. Understanding and characterising emerging FAdV strains is needed for vaccine development and control strategies.

1. The presence of fractures or cracks in eggshells represent a significant risk in terms of food safety. Bacteria and viruses are likely to enter through these cracks, which increases the risk of food poisoning. Furthermore, deformations in the shell can compromise the integrity of the protective shell, rendering the egg more susceptible to environmental damage and accelerating deterioration.2. In order to mitigate these risks, a convolutional neural network (CNN) integrated into an acoustic signal to image conversion was developed as a crack detection system. Mechanical and electronic sub-systems were designed to generate non-destructive acoustic excitation on the eggshell and capture the resulting sound with a high-sensitivity microphone.3. The recorded 1 × 731-sample signals from 120 intact or cracked eggs were subjected to variational mode decomposition (VMD) to extract intrinsic mode functions (IMF). Subsequently, IMF were converted to greyscale images and classified using the proposed acoustic signal-to-image conversion and the lightweight CNN.4. The proposed model showed the capability (100%) to distinguish between intact and cracked eggs, including invisible micro-cracks.

1. Heat stress negatively affects animal growth. This study examined the impact of heat stress on a modern broiler (Ross 708) chicken compared to a heritage meat-type chicken line (UIUC).2. To mimic the effects of a heat wave, birds were exposed to daily, cyclic high ambient temperatures between post-hatch d 21-42, while control birds were maintained at thermoneutral temperature throughout this period.3. On d 28 and 42 post-hatch, eight heat-stressed and eight control birds from both lines were weighed, necropsied and total organ masses were determined for the brain, breast muscle, liver, small intestine, and spleen.4. Normalised tissue mass at d 42 under thermoneutral conditions for the Ross 708 breast muscle was 2.4-fold larger than that of the UIUC chickens. The cross-sectional area of the Ross 708 breast muscle cells was also twofold larger than that of the UIUC birds. In contrast, UIUC birds had larger heart, spleen, duodenum, jejunum, ileum and brain masses than the Ross 708 chickens when raised at the thermoneutral temperature.5. These results indicated that heat-stress shifted growth resources away from immune, skeletal muscle, neuronal and hepatic systems to maintain the heart and small intestine.

1. The aim of this study was a comparative analysis of three goose genotypes (Rypińska, Suwalska, Kartuska) after a four-year laying period at the National Research Institute of Animal Production, Waterfowl Genetic Resources Station in Dworzyska. It examined carcase composition as well as morphometric parameters of their digestive system and leg bones.2. In total, 42 goose carcases comprised of seven females and seven males from each genotype were analysed. The traits investigated included those of carcase weight, breast and leg muscle and giblet weight (heart, stomach, forestomach, liver and spleen). The length and diameter of each intestinal segment were then measured, as well as the weight and measurements of the femur and tibia bones. The percentage of the length of the intestinal segments in the whole intestine was calculated.3. The genotype of the birds significantly affected (p < 0.05) the weight of the breast muscle, leg muscle, proventriculus and diameter of the terminal intestine. In contrast, the sex of the birds affected the weight of the carcase, pectoral muscles, leg muscles, heart and liver. Gender influenced the length of the duodenum, entire intestine, diameter of the terminal intestine and certain dimensions of the femur and tibia.4. The results showed the differences between genotypes and sexes in carcase weight, muscle and giblets, individual length of gut sections, femur and tibia dimensions.

1. Apoptosis is suppressed in the formation of goose fatty liver, which may be a protective mechanism. The objective of this study was to elucidate the mechanism by which apoptosis is inhibited in goose fatty liver.2. Twenty, male, Landes geese were selected and randomly divided into a control group and an overfed treatment. Additionally, the primary hepatocytes were isolated from the goose embryos and treated with glucose.3. The geese in the overfed group had higher liver weight, body weight and liver:body weight ratio than that in the control (p < 0.05). No significant difference on inflammation, fibrillation, or apoptosis level was observed from the staining of liver sections between the control and overfed group.4. Neither the protein level of B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X (Bax) in liver nor the malondialdehyde concentration and manganese superoxide dismutase activity in liver mitochondria was altered in these two treatments (p < 0.05). Compared with the control group, the overfed treatment had decreased reduced glutathione (GSH) and increased glutathione reductase activity in liver mitochondria (p < 0.05).5. There was no significant difference in apoptosis level, Bcl-2 and Bax protein level and Bcl-2/Bax ratio was found in hepatocytes treated with 20, 40 or 60 mM glucose when compared with the control group (p < 0.05). However, treatment with 40 or 60 mM glucose tended to increase the MDA concentration in hepatocytes (p = 0.055 and p = 0.091, respectively). The hepatocytes in 40 or 60 mM glucose treatment had decreased GSH concentration in comparison to the control (p < 0.05).6. These findings suggested that apoptosis inhibition in goose fatty liver may be mediated through maintenance of Bcl-2/Bax ratio. Additionally, the increased antioxidant ability in tissue and mitochondria of goose fatty liver may contribute to resistance of apoptosis.

1. Transport under thermoneutral conditions may affect body weight, physiological and biochemical variables, electrolyte balance, acid-base status and renal function in broilers. Therefore, this study investigated how different transport distances affect body weight loss, physiological changes, oxidative stress, electrolyte levels and renal responses in broilers.2. Fifty broilers were randomly divided into five groups and transported over distances of 0, 50, 100, 150 or 200 km. Body weight, physiological and biochemical variables, blood electrolytes, acid-base balance and renal changes were measured.3. Broilers transported for 200 km had significantly more body weight loss than those transported for 0 and 50 km (p  <  0.05). Respiratory rate significantly increased at 50 km (p  <  0.05) and blood sodium was higher at 150 and 200 km than at 0 km (p  <  0.05). Blood pH was lowest at 0 km, while bicarbonate was lowest at 200 km (p  <  0.05).4. Kidney congestion score increased with distance, with the highest score at 200 km (p  <  0.05). Scores for 0 and 50 km transport were significantly lower than those at 100, 150 and 200 km (p  <  0.05). Renal tubular dilation scores were significantly higher at 50 and 150 km than at 0, 100 and 200 km (p  <  0.05).5. These results demonstrated that transportation, even under thermoneutral conditions, can still induce alterations in physiological and renal functions in broilers. Longer transport distances exacerbate these effects, underscoring the need for improved methods to reduce stress and support broiler welfare.

1. This study assessed the impact of varied stressors on blood leukocyte dynamics and biochemical parameters in broiler chickens. Sixty male broiler chickens (28-30 d old; 1.4-1.5 kg) were divided into four groups (A-D). Group A (control) was reared under optimal conditions. Group B underwent transport stress via a 2-h journey before slaughter. Group C was reared under high stocking density (SD) throughout the rearing period. Group D was exposed to heat stress (37 ± 2°C) for 4 h daily during rearing.2. Exposure to transport and heat stress resulted in a significant increase in circulating heterophils (H), a reduction in lymphocyte (L) counts, and a decrease in serum corticosterone concentrations (p < 0.01), thereby leading to a significantly elevated H:L ratio (p < 0.05). In contrast, serum levels of total protein, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine level remained unaffected under conditions of transport and stocking density stress.3. Heat stress increased ALT and creatinine while decreasing AST and serum total protein, and reduced triglycerides (TG) levels significantly (p < 0.05) without affecting low density lipoprotein cholesterol (LDL-c), high density lipoprotein cholesterol (HDL-c) or total cholesterol. In contrast, heat stress increased LDL-c, and total cholesterol (p < 0.05), with decreased HDL-c values.4. This study reveals the comparative effects of diverse stressors on blood leukocytes and biochemical parameters in broiler chickens. Understanding these physiological responses is crucial for enhancing poultry management strategies and promoting animal welfare in the context of commercial poultry production.