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Simple Summary: Salmonella poses a significant threat to poultry farming, as it can asymptomatically infect flocks, ultimately leading to foodborne illnesses when contaminated poultry products reach consumers. This review focuses on various strategies for controlling Salmonella colonization in commercial layer chickens at the pre-harvest level. The approaches discussed include enhancing farm biosecurity, using vaccines, incorporating feed additives, and improving genetic resistance to infection through selective breeding. Each of these approaches offers unique benefits, such as preventing the introduction of pathogens, enhancing immunity against Salmonella, and/or improving intestinal health to reduce Salmonella colonization. Therefore, a combined approach is essential for minimizing the risk of Salmonella, promoting food safety, and supporting sustainable poultry production. Non-typhoidal Salmonella (NTS) infections in poultry, particularly in commercial-layer chickens, pose a critical risk to food safety and public health worldwide. NTS bacteria can remain undetected in poultry flocks, contaminating products and potentially leading to gastroenteritis in humans. This review examines pre-harvest control strategies for NTS in layer chickens, including biosecurity protocols, vaccinations, feed additives, genetic selection, and environmental management. These strategies have substantially reduced Salmonella colonization and product contamination rates in the commercial layer industry. By evaluating these strategies, this review highlights the importance of integrated control measures to limit NTS colonization, reduce antimicrobial resistance, and improve poultry health. This review aims to provide producers, researchers, and policymakers with insights into effective practices to minimize Salmonella contamination and enhance both animal and human health outcomes. [ABSTRACT FROM AUTHOR]

This study examines the dietary effect of dried olive pulp (OP) on the overall performance, egg quality, health, and gut microbiota of laying hens during a 36-week trial. A total of 180 Isa Brown layers, aged 23 weeks, were assigned to 15-floor pens and divided into three feeding groups (CON, OP4, and OP6) based on the dietary level of OP. Egg quality and biochemical parameters were assessed in 39- and 59-week-old hens. Fecal samples were collected for microbiota analysis. Data were analyzed with an Analysis of Variance. The percentage of broken eggshells was found to be 15–34% lower in the OP groups compared to the CON groups. At 59 weeks of age, a significant reduction in shell thickness was observed in the CON eggs compared to the OP eggs (p < 0.05). At 39 weeks of age, OP6 eggs had the darkest yolk color of all groups (p < 0.05). Fecal microbial diversity was affected only by hens' age. However, an enrichment in bacterial species belonging to the genera Megasphaera and Megamonas was found in the OP groups at 59 weeks of age. Our results demonstrate that OP feeding beneficially affects egg quality and promotes the proliferation of bacteria involved in the degradation of complex plant compounds, potentially contributing to the overall health of the gut microbiota. [ABSTRACT FROM AUTHOR]

Objective: Infectious laryngotracheitis virus (ILTV) is responsible for causing infectious laryngotracheitis (ILT), which is a rapidly spreading and extremely transmissible disease in chickens. The current research aims to isolate and characterize ILTV from layer chickens in Bangladesh. Materials and Methods: A total of 345 samples (trachea, larynx, and lungs) were collected from ILT-suspected dead and sick layer chickens of 32 ILT-suspected farms in three different outbreak districts (Gazipur, Tangail, and Mymensingh) of Bangladesh during the outbreak year 2021-2022. Rapid detection kits examined the samples for avian influenza virus (AIV) and Newcastle disease virus (NDV). ILTV-specific primers were used to screen 72 NDV- and AIV-negative samples by polymerase chain reaction (PCR). Using chorioallantoic membrane (CAM), the study isolated the ILT virus from 9 to 10-day-old seronegative embryonated chicken eggs (ECEs) using selected PCRpositive samples. The virus was confirmed using nucleotide sequencing, agar gel immunodiffusion test (AGIDT), viral neutralization test (VNT), and pathogenicity evaluations using mortality index for chicken embryos (MICEs) and intra-tracheal pathogenicity index (ITPI). Results: The results indicated that among the PCR-positive 10 samples, only two (Alim_ILT_1001 and Alim_ILT_1,000) were found positive using ECEs. There were two field isolates of ILTVs, as shown by the amplicon size of the ICP4 gene-based PCR. A phylogenetic study of the ICP4 gene revealed that the recent isolates have a close similarity with the ILTV isolates of Turkey, Bangladesh, and Australia. AGIDT revealed strong precipitation lines due to ILTV-specific antibodies reacting with field viruses, while VNT neutralized both isolates with conventional ILTV antibodies. The pathogenicity testing indicated that Alim_ILT_1001 had MICE and ITPI values of 0.77 and 0.63, whereas Alim_ILT_1,000 had 0.71 and 0.57. Conclusion: Both the ILTV isolates have similarities with the isolates of Turkey, Bangladesh, and Australia, and they are highly virulent for chickens. [ABSTRACT FROM AUTHOR]

The incidence of colibacillosis in poultry is on the rise, significantly affecting the chicken industry. Ceftiofur sodium (CS) is frequently employed to treat this disease, resulting in lipopolysaccharide (LPS) buildup. Processing plays a vital role in traditional Chinese veterinary medicine. The potential intervention in liver injury by polysaccharides from the differently processed products of Angelica sinensis (PDPPAS) induced by combined CS and LPS remains unclear. This study aims to investigate the protective effect of PDPPAS on chicken liver injury caused by CS combined with LPS buildup and further identify the polysaccharides with the highest hepatoprotective activity in chickens. Furthermore, the study elucidates polysaccharides' intervention mechanism using tandem mass tag (TMT) proteomics and multiple reaction monitoring (MRM) methods. A total of 190 1‐day‐old layer chickens were randomly assigned into 12 groups, of which 14 chickens were in the control group and 16 in other groups, for a 10‐day trial. The screening results showed that charred A. sinensis polysaccharide (CASP) had the most effective and the best hepatoprotective effect at 48 h. TMT proteomics and MRM validation results demonstrated that the intervention mechanism of the CASP high‐dose (CASPH) intervention group was closely related to the protein expressions of FCER2, TBXAS1, CD34, AGXT, GCAT, COX7A2L, and CYP2AC1. Conclusively, the intervention mechanism of CASPH had multitarget, multicenter regulatory features. [ABSTRACT FROM AUTHOR]

Objective: Infectious laryngotracheitis virus (ILTV) is responsible for causing infectious laryngo¬tracheitis (ILT), which is a rapidly spreading and extremely transmissible disease in chickens. The current research aims to isolate and characterize ILTV from layer chickens in Bangladesh. Materials and Methods: A total of 345 samples (trachea, larynx, and lungs) were collected from ILT-suspected dead and sick layer chickens of 32 ILT-suspected farms in three different outbreak districts (Gazipur, Tangail, and Mymensingh) of Bangladesh during the outbreak year 2021-2022. Rapid detection kits examined the samples for avian influenza virus (AIV) and Newcastle disease virus (NDV). ILTV-specific primers were used to screen 72 NDV- and AIV-negative samples by poly¬merase chain reaction (PCR). Using chorioallantoic membrane (CAM), the study isolated the ILT virus from 9 to 10-day-old seronegative embryonated chicken eggs (ECEs) using selected PCR-positive samples. The virus was confirmed using nucleotide sequencing, agar gel immunodiffusion test (AGIDT), viral neutralization test (VNT), and pathogenicity evaluations using mortality index for chicken embryos (MICEs) and intra-tracheal pathogenicity index (ITPI). Results: The results indicated that among the PCR-positive 10 samples, only two (Alim_ILT_1001 and Alim_ILT_1,000) were found positive using ECEs. There were two field isolates of ILTVs, as shown by the amplicon size of the ICP4 gene-based PCR. A phylogenetic study of the ICP4 gene revealed that the recent isolates have a close similarity with the ILTV isolates of Turkey, Bangladesh, and Australia. AGIDT revealed strong precipitation lines due to ILTV-specific antibod¬ies reacting with field viruses, while VNT neutralized both isolates with conventional ILTV antibod¬ies. The pathogenicity testing indicated that Alim_ILT_1001 had MICE and ITPI values of 0.77 and 0.63, whereas Alim_ILT_1,000 had 0.71 and 0.57. Conclusion: Both the ILTV isolates have similarities with the isolates of Turkey, Bangladesh, and Australia, and they are highly virulent for chickens. [J Adv Vet Anim Res 2024; 11(2.000): 398-407]

Salmonella Enteritidis (SE) is a major contamination concern in eggs and risk for Salmonellosis in humans. Strains of Bacillus subtilis and yeast cell wall can be used as substitutes for antibiotic substances in feed against Salmonella in poultry. The objective of this study was to assess the effect of BacPack® (Quality Technology International, Inc., Elgin, IL, USA) Q1+1 (BPQ11), a feed additive combination of a Bacillus subtilis strain and Saccharomyces cerevisiae cell wall, on SE cecal colonization in Lohmann LSL pullets. A control group (CON) and a test group (BPQ) were each randomly assigned 100-day-old chicks. CON was fed a corn–soybean meal-based vegetarian mash diet, and BPQ was fed the control diet supplemented with BPQ11 for the duration of the study. At 8 days of age, chicks were orally challenged with a nalidixic acid-resistant SE strain at a dose of 6.3 × 107 colony forming units (CFUs) per bird. At 7, 11, 15, and 19 days post-challenge (DPC), 25 birds per group were euthanized, and their cecal contents were collected and analyzed for SE. SE counts were 6.88, 7.98, 7.79, and 7.50 in CON and 7.18, 7.31, 6.35, and 6.30 log10 CFU/g in BPQ at 7, 11, 15, and 19 DPC, respectively. SE did not differ between CON and BPQ at 7 DPC; however, BPQ had lower (p < 0.0001) SE at 11 (−0.67), 15 (−1.45), and 19 (−1.20 log10 CFU/g) DPC. Results indicate that synbiotic BPQ11 may be a useful dietary pre-harvest tool for SE management in layer birds.

Salmonella Enteritidis (SE) is a major contamination concern in eggs and risk for Salmonellosis in humans. Strains of Bacillus subtilis and yeast cell wall can be used as substitutes for antibiotic substances in feed against Salmonella in poultry. The objective of this study was to assess the effect of BacPack® (Quality Technology International, Inc., Elgin, IL, USA) Q1+1 (BPQ11), a feed additive combination of a Bacillus subtilis strain and Saccharomyces cerevisiae cell wall, on SE cecal colonization in Lohmann LSL pullets. A control group (CON) and a test group (BPQ) were each randomly assigned 100-day-old chicks. CON was fed a corn–soybean meal-based vegetarian mash diet, and BPQ was fed the control diet supplemented with BPQ11 for the duration of the study. At 8 days of age, chicks were orally challenged with a nalidixic acid-resistant SE strain at a dose of 6.3 × 107 colony forming units (CFUs) per bird. At 7, 11, 15, and 19 days post-challenge (DPC), 25 birds per group were euthanized, and their cecal contents were collected and analyzed for SE. SE counts were 6.88, 7.98, 7.79, and 7.50 in CON and 7.18, 7.31, 6.35, and 6.30 log10 CFU/g in BPQ at 7, 11, 15, and 19 DPC, respectively. SE did not differ between CON and BPQ at 7 DPC; however, BPQ had lower (p < 0.0001) SE at 11 (−0.67), 15 (−1.45), and 19 (−1.20 log10 CFU/g) DPC. Results indicate that synbiotic BPQ11 may be a useful dietary pre-harvest tool for SE management in layer birds. [ABSTRACT FROM AUTHOR]

Abstract Background Supplementing poultry diets with certain natural phytogenic additives has positive impacts on performance parameters like feed intake, egg production and quality of layer hens. Objectives The study aimed to examine how supplementing papaya seed as phytogenic feed additive (PFA) to the diets of layer chickens affected their egg production, quality and blood serum biochemical parameters. Methods One hundred twenty 28‐week‐old Bovans brown laying hens were randomly assigned to one of four treatments with varying levels of papaya seed supplementation at 0 g/kg (T1), 5 g/kg (T2), 10 g/kg (T3) and 15 g/kg (T4) in a complete randomized design. Result Layer chickens supplemented with 0.5% (T2), 1% (T3) and 1.5% (T4) papaya seed as a PFA had significantly (p 0.05) in serum albumin, glucose, total cholesterol, triglyceride and aspartate aminotransferase levels among treatments laying hens. Conclusion Papaya seed can be a potential candidate as a PFA at 5–15 g/kg of the basal diet to improve egg‐laying performance and quality without deteriorating effect.

This study examines the dietary effect of dried olive pulp (OP) on the overall performance, egg quality, health, and gut microbiota of laying hens during a 36-week trial. A total of 180 Isa Brown layers, aged 23 weeks, were assigned to 15-floor pens and divided into three feeding groups (CON, OP4, and OP6) based on the dietary level of OP. Egg quality and biochemical parameters were assessed in 39- and 59-week-old hens. Fecal samples were collected for microbiota analysis. Data were analyzed with an Analysis of Variance. The percentage of broken eggshells was found to be 15–34% lower in the OP groups compared to the CON groups. At 59 weeks of age, a significant reduction in shell thickness was observed in the CON eggs compared to the OP eggs (p < 0.05). At 39 weeks of age, OP6 eggs had the darkest yolk color of all groups (p < 0.05). Fecal microbial diversity was affected only by hens’ age. However, an enrichment in bacterial species belonging to the genera Megasphaera and Megamonas was found in the OP groups at 59 weeks of age. Our results demonstrate that OP feeding beneficially affects egg quality and promotes the proliferation of bacteria involved in the degradation of complex plant compounds, potentially contributing to the overall health of the gut microbiota.

Experiments were conducted to assess the nutritive value of false yam seed meal (FYSM) when subjected to sequential processing techniques (water treatment, sodium chloride and blanching). Matured false yam (Icacina oliviformis) fruits were harvested and seeds extracted. Two different FYSM samples were prepared. (1) An untreated sample was prepared by crushing fresh false yam seed and sun-dried to about 12% moisture. (2) A treated sample was crushed and soaked in water (1:2; w/v) for 12 days with water replaced every 3 days; after 12 days the sample was re-soaked in 1 M concentration of sodium chloride (NaCl) for 24 hours, washed, blanched and sun-dried to a moisture content of about 12%. The processed false yam seed samples were ground into gritty flour using a hammer mill (2 mm screen size). Maize served as the control. The false yam seed meals replaced maize (wt./wt. bases) in layer chick mash and layer grower diets, respectively. The nutrient compositions of the untreated and treated FYSM samples were determined. The proximate composition of the FYSM revealed that the untreated and treated samples contained high levels of dry matter (91.1 and 92.0%) and nitrogen free extractive (74.1 and 82.2%) respectively. However, the NaCl treated sample contained a relatively low level of crude protein (4.3%). Processing with NaCl significantly reduced the concentrations of essential amino acids compared to the untreated sample. The NaCl processing technique reduced the concentration of saponin and terpenes by 88 and 78% respectively. Feed preference test results indicated that layer chicks preferred NaCl treated diets 40 and 50% inclusion rate over those with lower inclusion rates; however, for the untreated FYSM they did not prefer inclusion rates of over 10%. In an apparent nutrient digestibility trial untreated and treated FYSM samples were each tested at inclusion levels of 30 and 50%. There were no significant (P > 0.05) differences in DM digestibility. Crude protein improved significantly (P = 0.05) at 50% inclusion of NaCl treatment compared to 50% inclusion of untreated FYSM. Crude fiber and Nitrogen free extract digestibility were not significant (P > 0.05) in terms of treatment as well as levels of inclusion. Ash digestibility was significantly (P < 0.001) higher in diets containing untreated FYSM than in those containing NaCl treated. In a growth trial, feed intake improved (P = 0.05) as the level of NaCl treated samples was increased up to 50%. Growth performance and feed conversion efficiency of pullets fed the control diet (maize) and diets containing NaCl treated FYSM were comparable (P > 0.05). It was concluded that false yam seed meal contains high dry matter and nitrogen free extract contents but is low in crude protein content. Mineral content was high with high contents of anti-nutrients (terpenes and saponins). However, the NaCl processing induced losses in crude protein, essential amino acids, and minerals as well as anti-nutrients. The method of processing used was effective in improving feed intake of pullets and did not have any adverse effect on their growth performance. [ABSTRACT FROM AUTHOR]

Egg productivity and morphological parameters of domestic laying hens eggs are an objective criterium of their wellbeing. Decreased egg production and egg defects may be the only sign of the latent course of trichomoniasis in poultry. We investigated the level of productivity and morphological indicators of eggs in the conditions of a mini poultry farm of laying hens with spontaneous trichomoniasis. It was found that 20% of hens stopped laying. Decrease in egg production by 29.16%, various defects in the texture of the shell (calcareous bumps, deformations, lack of a calcified layer) and the internal content of the egg (thinning of the protein part, presence of hemorrhages) were found in laying hens with preserved egg production. Severe forms of obstructive salpingitis and atrophic ovariitis with the absence of ovulatory follicles in the altered ovarium were diagnosed in poultry with cessation of egg production as a result of trichomoniasis infestation by post-mortem examination. [ABSTRACT FROM AUTHOR]

Background: Supplementing poultry diets with certain natural phytogenic additives has positive impacts on performance parameters like feed intake, egg production and quality of layer hens. Objectives: The study aimed to examine how supplementing papaya seed as phytogenic feed additive (PFA) to the diets of layer chickens affected their egg production, quality and blood serum biochemical parameters. Methods: One hundred twenty 28‐week‐old Bovans brown laying hens were randomly assigned to one of four treatments with varying levels of papaya seed supplementation at 0 g/kg (T1), 5 g/kg (T2), 10 g/kg (T3) and 15 g/kg (T4) in a complete randomized design. Result: Layer chickens supplemented with 0.5% (T2), 1% (T3) and 1.5% (T4) papaya seed as a PFA had significantly (p < 0.05) improved dry matter intake, egg production%, egg mass and feed conversion. On the other hand, papaya seed supplementation decreased (p < 0.05) the bodyweight gain of laying hens. Papaya seed supplementation significantly (p < 0.05) increased egg weight, length, width, yolk height and yolk colour compared to the control group. Serum total protein on T4 and liver enzyme of alkaline phosphatase on T3 were significantly greater (p < 0.05) than in the control group. However, there were no significant differences (p > 0.05) in serum albumin, glucose, total cholesterol, triglyceride and aspartate aminotransferase levels among treatments laying hens. Conclusion: Papaya seed can be a potential candidate as a PFA at 5–15 g/kg of the basal diet to improve egg‐laying performance and quality without deteriorating effect. [ABSTRACT FROM AUTHOR]

Introduction: Gut microbes like segmented filamentous bacteria (SFB) play a key role in gut maturation during early life, as demonstrated in humans and mice. Our previous study demonstrated oral inoculation of ileum-spores containing SFB to chickens after hatch increases early SFB gut colonization, which increases immune maturation and resistance to bacteria, like Salmonella, as tested in vitro; however, more studies are needed for treatment optimization and in vivo testing. The objectives of this study were to (1) test a treatment that includes both spores and filamentous SFB, (2) validate antimicrobial ability of the treatment in layer hens in vivo, and (3) elucidate its molecular mechanism. Methods: One-day-old specific pathogen-free layers (n = 12 per group) were orally treated with either PBS (CON) or SFB-based treatment (SFB). At 4 days post-inoculation (DPI), both CON and SFB groups were orally challenged with Salmonella Typhimurium. Total Enterobacteriaceae and Salmonella were examined by plating and enumeration in feces at 7,10 and 14 dpi; and in the ileum, cecum, and spleen at 16 dpi in euthanized birds. The presence and levels of SFB were determined from ilea scrapings via microscopy and qPCR, respectively. Relative gene expression of host-derived antimicrobial peptides and cytokines in the distal ileum was determined by RT-qPCR. Results: At 10 and 14 dpi, a significant decrease in total Enterobacteriaceae was observed in the feces of the SFB group. At necropsy, the level of SFB was significantly higher in the SFB group than in the CON group, while a significant decrease in total Enterobacteriaceae and Salmonella was observed in the ceca of the SFB group. RT-qPCR revealed increased expression of β-defensin 14, and cytokines IL-10 and IFNγ. Discussion: The introduction of SFB at hatch as a prophylactic treatment may benefit commercial partners as well as consumers by reducing the incidence of Enterobacteriaceae in food animals. Reduction of these bacteria in animals would, in turn, increase animal health, productivity, and safety for consumers. Studies to optimize the treatment for poultry industry applications are ongoing in our lab. [ABSTRACT FROM AUTHOR]

IntroductionGut microbes like segmented filamentous bacteria (SFB) play a key role in gut maturation during early life, as demonstrated in humans and mice. Our previous study demonstrated oral inoculation of ileum-spores containing SFB to chickens after hatch increases early SFB gut colonization, which increases immune maturation and resistance to bacteria, like Salmonella, as tested in vitro; however, more studies are needed for treatment optimization and in vivo testing. The objectives of this study were to (1) test a treatment that includes both spores and filamentous SFB, (2) validate antimicrobial ability of the treatment in layer hens in vivo, and (3) elucidate its molecular mechanism.MethodsOne-day-old specific pathogen-free layers (n = 12 per group) were orally treated with either PBS (CON) or SFB-based treatment (SFB). At 4 days post-inoculation (DPI), both CON and SFB groups were orally challenged with Salmonella Typhimurium. Total Enterobacteriaceae and Salmonella were examined by plating and enumeration in feces at 7,10 and 14 dpi; and in the ileum, cecum, and spleen at 16 dpi in euthanized birds. The presence and levels of SFB were determined from ilea scrapings via microscopy and qPCR, respectively. Relative gene expression of host-derived antimicrobial peptides and cytokines in the distal ileum was determined by RT-qPCR.ResultsAt 10 and 14 dpi, a significant decrease in total Enterobacteriaceae was observed in the feces of the SFB group. At necropsy, the level of SFB was significantly higher in the SFB group than in the CON group, while a significant decrease in total Enterobacteriaceae and Salmonella was observed in the ceca of the SFB group. RT-qPCR revealed increased expression of β-defensin 14, and cytokines IL-10 and IFNγ.DiscussionThe introduction of SFB at hatch as a prophylactic treatment may benefit commercial partners as well as consumers by reducing the incidence of Enterobacteriaceae in food animals. Reduction of these bacteria in animals would, in turn, increase animal health, productivity, and safety for consumers. Studies to optimize the treatment for poultry industry applications are ongoing in our lab.

Simple Summary: This study aimed to analyze the intervention mechanism of polysaccharides from charred Angelica sinensis (CASP) on the liver injury caused by Ceftiofur sodium and lipopolysaccharide from the perspective of the intestine. The detection of the intestinal floras and the short-chain fatty acids (SCFAs) of chicken cecal contents and their association analysis were carried out. The results showed that the structure of chicken liver in the normal control group was normal, while that in the model group was damaged. The structure of chicken liver in the CASP intervention group was similar to the normal control group. The intestinal floras in the model group were maladjusted compared to the normal control group. After the intervention of CASP, the diversity, and richness of chicken intestinal floras changed. The contents of acetic acid, butyric acid, and total SCFAs in the intervention group of CASP were significantly lower than those in the model group, and the contents of propionic acid and valeric acid in the intervention group of CASP were significantly lower than those in the model group and normal control group. The changes in the intestinal floras were correlated with the changes SCFAs in the cecum. It is confirmed that the liver-protecting effect of CASP is indeed related to the changes in intestinal floras and SCFAs content in the cecum. To analyze the intervention mechanism of polysaccharides from charred Angelica sinensis (CASP) on the liver injury caused by Ceftiofur sodium (CS) and lipopolysaccharide (LPS) from the perspective of the intestine. Ninety-four one-day-old laying chickens underwent free feeding and drinking water for three days. Then, fourteen laying chickens were randomly selected as the control group, and sixteen laying chickens were selected as the model group. Sixteen laying chickens in the rest were randomly selected as the intervention group of CASP. Chickens in the intervention group were given CASP by the oral administration (0.25 g/kg/d) for 10 days, the control and model groups were given the same amount of physiological saline. During the 8th and 10th days, laying chickens in the model and CASP intervention group were subcutaneously injected with CS at the neck. In contrast, those in the control group were subcutaneously injected with the same amount of normal saline simultaneously. Except for the control group, the layer chickens in the model and CASP intervention groups were injected with LPS after CS injection on the 10th day of the experiment. In contrast, those in the control group were injected with the same amount of normal saline at the same time. 48 h after the experiment, the liver samples of each group were collected, and the liver injury was analyzed by hematoxylin-eosin (HE) staining and transmission electron microscopy. And the cecum contents of six-layer chickens in each group were collected, and the intervention mechanism of CASP on the liver injury from the perspective of the intestine was analyzed by the 16S rDNA amplicon sequencing technology and the short-chain fatty acids (SCFAs) detection of cecal contents based on Gas Chromatography-Mass Spectrometry (GC-MS), and their association analysis was carried out. The results showed that the structure of chicken liver in the normal control group was normal, while that in the model group was damaged. The structure of chicken liver in the CASP intervention group was similar to the normal control group. The intestinal floras in the model group were maladjusted compared to the normal control group. After the intervention of CASP, the diversity, and richness of chicken intestinal floras changed significantly. It was speculated that the intervention mechanism of CASP on the chicken liver injury might be related to the abundance and proportion of Bacteroidetes and Firmicutes. Compared with the model group, the indexes of ace, chao1, observed species, and PD whole tree of chicken cecum floras in the intervention group of CASP were significantly increased (p < 0.05). The contents of acetic acid, butyric acid, and total SCFAs in the intervention group of CASP were significantly lower than those in the model group (p < 0.05), and the contents of propionic acid and valeric acid in the intervention group of CASP were significantly lower than those in the model group (p < 0.05) and normal control group (p < 0.05). The correlation analysis showed that the changes in the intestinal floras were correlated with the changes in SCFAs in the cecum. It is confirmed that the liver-protecting effect of CASP is indeed related to the changes in the intestinal floras and SCFAs content in the cecum, which provides a basis for screening liver-protecting alternative antibiotics products for poultry. [ABSTRACT FROM AUTHOR]

Excessive lipid deposition in layer chickens due to inappropriate feeding adversely affects egg production; however, nutritional manipulation methods to deal with this issue are still limited. β-hydroxy-β-methylbutyrate (HMB), a metabolite of L-leucine, was recently reported as a lipid-lowering nutrient in mice and pigs, although its role in layers had not been investigated. Here, we employed high-fat and high-cholesterol diet (HFHCD)−challenged growing layers as an obese model to explore HMB function in the regulation of lipid metabolism and the potential mechanisms involved. We found that dietary supplementation with (0.05% or 0.10%) HMB significantly reduced HFHCD−induced bodyweight growth in layers, mainly due to reduction in abdominal fat deposition. Mechanistically, HMB supplementation enhanced hepatic bile acid synthesis from cholesterol through elevating expression of Cyp7a1, a gene coding a key enzyme in bile acid synthesis. Furthermore, 16S rRNA gene sequencing revealed that HMB supplementation remodeled the diversity and composition of the layers’ cecal microbiota, and the abundance of Bacteroidetes at the phylum level were especially affected. Correlation analysis further indicated a strong negative association between Bacteroidetes abundance and lipid metabolism−related parameters. Taken together, these data suggest that dietary HMB supplementation could improve abdominal fat deposition in layers, probably through modulating hepatic bile acid synthesis and gut microbiota function.

Very few data exist globally regarding the use of antimicrobials in the table egg industry. Antimicrobial use data from broiler chickens and turkeys cannot be used as a surrogate of layer chickens because of the fact that table eggs for human consumption are produced daily by laying hens. To avoid the possibility of antimicrobial residues in the eggs, there are very few antimicrobials approved for use in layers in the U.S. The objective of this study was to collect on-farm antimicrobial use data from the U.S. table egg industry and to have it be representative of the national layer flock. Participation was voluntary. Data were collected for the period 2016 through 2021 and are reported on a calendar year basis. Using production statistics from USDA:NASS as a denominator, the data supplied by participating companies accounted for 3,016,183,140 dozen eggs (~40% of national egg production) in 2016 and 3,556,743,270 dozen eggs (~45% of national egg production) in 2021. All of the replacement chicks placed on pullet farms during the study period were estimated to have received 0.2 mg/chick gentamicin at the hatchery. Most of the antimicrobial administration in U.S. egg production is via the feed. The ionophores monensin and salinomycin were used in the pullets, bacitracin was used in both pullets and layers (primarily for control of necrotic enteritis), and chlortetracycline was used primarily in layers for the treatment of E. coli-related disease. In the layers, between 0.10 and 0.19% of total hen-days were exposed to chlortetracycline. Only two water-soluble administrations were recorded during the entire study period, both involving lincomycin to pullet flocks for the treatment of necrotic enteritis. Overall, antimicrobial use in the U.S. layer industry was focused mainly on controlling necrotic enteritis in the pullets and treating E. coli-related disease in the laying hens.

Avian coccidiosis remains an economically important disease affecting the poultry industry worldwide. The dearth of information on haematological changes resulting from field cases of coccidiosis in commercial layer chickens necessitated this research. One hundred and twenty commercial layer chickens sampled from different farms in Zaria, diagnosed of coccidiosis at early, mid/peak and late production stages were used for this study. Results showed a significant (p < 0.05) decline in almost all haematological parameters (except for elevated MCV) of commercial layer chickens which were diagnosed of coccidiosis at the different production stages when compared to corresponding values of other apparently healthy layers that served as controls. The mean corpuscular volume (MCV) values in the layers diagnosed of coccidiosis at all production stages were significantly higher than the values obtained from the corresponding apparently healthy ones that served as control, whereas the MCHC showed significant decreases across all layer chickens diagnosed of coccidiosis at different production stages when compared to the corresponding values of the apparently healthy control layers. Thus, the erythrocytic indices of the layer chickens with coccidiosis showed the RBCs were macrocytic and hypochromic. On the basis of mean PCV, layer chickens at early production stage (PCV: 24.51 ± 3.17%) were most severely affected by coccidiosis, following closely by the layers at mid/peak production stage (PCV: 24.66 ± 1.64%). The highest mean WBC (19.15 ± 2.99 x109/L) was recorded in layers with coccidiosis at mid/peak production stage, which showed they were better in mounting inflammatory response when compared to the mean values of layers at early (14.92 ± 2.85 x109/L) and late (17.99 ± 2.70 x109/L) stages of production. In conclusion, coccidiosis in commercial layer chickens caused significant haematological alterations which could necessitate dietary supplementation to prevent occurrence of anaemia and decline in egg production. [ABSTRACT FROM AUTHOR]

Mycoplasma gallisepticum causes major health hazards in poultry birds in Bangladesh which results in huge economic losses every year. This study was carried out to estimate and analyze the prevalence of Mycoplasma gallisepticum (MG) infection in commercial layer chickens at Kishoreganj district of Bangladesh during the period from November 2018 to October 2019. A total of 505 serum samples from 94 commercial layer farms of Kishoreganj Sadar Upazila and Pakundia Upazila of Kishoreganj district were collected. Serum plate agglutination (SPA) was performed to detect the antibody against MG. Prevalence was found 73% in the Kishoreganj district by SPA test. MG was significantly (P0.05) association was not found between flock size and seroprevalence of MG. Seroprevalence was highest in flock containing above 2600 birds. MG infection is prevalent in the chicken population of Kishoreganj district, Bangladesh. Measures should be taken for successful prevention and control of this disease in Bangladesh.

Koksidiosis merupakan penyakit yang di sebabkan oleh protozoa spesies Eimeria spp. yang dapat menginfeksi ayam. Eimeria sp adalah spesies yang paling patogen dan menyebabkan diare berdarah pada ayam. Satu kendala yang dirasakan oleh peternak di sana adalah adanya penyakit berak darah pada ayam layer di Desa Sesaot kecamatan Narmada Lombok Barat. Tujuan penelitian untuk mengetahui adanya endoparasit koksidiosis pada ayam layer yang dipelihara di Sesaot kecamatan Narmada Lombok Barat sebagai langkah untuk melakukan pengendalian terhadap koksidiosis. Sejumlah 9 sampel diambil dari ayam yang menunjukkan gejala klinis terinfeksi koksidia, yaitu diare berdarah. Sampel feses diambil secara aseptis, kemudian dibawa ke Laboratorium Equine Clinical Skills Centre Universitas Pendidikan Mandalika. Sampel yang sudah ada di laboratoirum diperiksa menggunakan metode Pengapungan. Berdasarkan hasil pemeriksaan, terdapat satu sampel positif terinfeksi Eimeria spp. dari total 9 sampel yang diidentifikasi.

Chicken colibacillosis is one of the most severe diseases in the poultry industry. Ceftiofur sodium (CS) is often used to treat it in clinical practice and lipopolysaccharide (LPS) accumulates in the chicken's body. Previous experimental studies found that CS combined with LPS could induce liver injury in layer chickens, and polysaccharides from charred Angelica sinensis(CASP) had a better hepatoprotective effect than polysaccharides from unprocessed Angelica sinensis(UASP). However, the intervention mechanism was unclear. Thus, UPLC–Q/TOF–MS/MS‐based metabonomics and transcriptomics were used in this study to clarify the hepatoprotective effect mechanism of CASP and UASP in layer chickens. Transcriptomics and enzyme‐linked immunosorbent assay were used for biological verification of some critical mutual metabolic pathways screened with metabonomics. The comprehensive analysis results showed that in a layer chicken liver injury model built with LPS and CS, 12 critical metabolic pathways were disturbed, involving 10 important differential metabolites. The hepatoprotective effect mechanism of CASP is related to the arachidonic acid metabolism and mTOR signaling pathways, involving nine important differential metabolites. In contrast, the hepatoprotective effect mechanism of UASP is related to the arachidonic acid metabolism pathway, involving six important differential metabolites. [ABSTRACT FROM AUTHOR]

ABSTRACT: Light is one of the essential environmental factors in the production process of laying hens, which can directly affect their behavior, growth and development, and production performance. The spectral sensitivity of humans is different from that of poultry, and the perceived illuminance units of human and poultry are lux and clux, respectively. If the light management of laying hen production is carried out according to human perceived illuminance, the growth and development of laying hens during pullet rearing may be adversely affected due to the discomfort of the perceived illuminance. Preliminary research has found that blue-green LED light can improve the immune function of laying hens during the brooding and rearing periods. However, the differences of the effects caused by blue-green light on the immune performance and bone development of laying hens during pullet rearing are still unclear for the 2 spectral sensitivities. A total of 120 Jinghong layer chickens were raised from 1 d to 13 wk of age in one of three groups with a white LED light (light intensity unit lux, WL) group, a blue-green LED light (light intensity unit lux, HBGL) group, and blue-green LED light (light intensity unit clux, PBGL) group, and unlimited feed and water were provided during the whole experiment. At 7 and 13 wk of age, the immune performance, bone parameters, and related gene expression were investigated. The results showed that compared with the WL groups, HBGL and PBGL increased the immunoglobulin A (IgA) content at 13 wk of age and the IgM content at 7 wk of age (P < 0.05). The bone mineral density (BMD) at 7 and 13 wk of age and tibial strength (TS) at 13 wk of age of the pullets in the WL group were significantly higher than those in the HBGL and PBGL group (P < 0.05). Osteoclastogenesis inhibitory factor gene (OPG mRNA) expression was increased in the layer chickens at the age of 7 and 13 wk for the WL group (P < 0.05). Compared with the WL group and PBGL group, the melanopsin gene (OPN4 mRNA) transcription level of hypothalamus and pineal gland of the chickens under HBGL significantly increased at 7 and 13 wk of age (P < 0.05). In conclusion, blue-green LED light with two perceived illuminance (human and poultry) can increase the Ig content and the immune performance of layer chickens, and blue-green LED light (light intensity unit lux) can promote the expression of OPN4 gene in the hypothalamus and pineal gland. In addition, white LED light can enhance bone quality by increasing tibia OPG gene expression.

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Blitar District is one of the areas that has potential in developing laying hens. However, laying hens in Blitar are still traditionally carried out and have not paid attention to aspects of effectiveness and efficiency economically. The purpose of the study was to find out the profile of farmer , test the level of farmer productivity and examine the effect of socio-economic factors (the age of farmer, education level, length of livestock raising and number of livestock) on labor productivity in laying hens in Blitar District. The study used a survey method with a sample of 22 sub-districts in Blitar District. The determination of the number of sub-districts was chosen using the purposive sampling method, so that 6 sub-districts were selected. Respondents were selected by the quota sampling method of 10 farmer in each selected region. Data collected were analyzed descriptively and statistically. To find out the social influence on productivity, classical assumption was tested and multiple linear regression tests. Based on the results of the study, the profile of laying hens in Blitar District carried out traditional farming systems with livestock ownership including high categories that had heterogeneous socio-economic status. Furthermore, labor productivity of laying hens in Blitar District is quite effective and efficient, because the value is greater than the minimum wage (UMR) of Blitar District. Age of farmers, education of farmers, and number of livestock have a significant influence on the productivity of laying hens farmers in Blitar District.

To analyze the intervention mechanism of polysaccharides from charred Angelica sinensis (CASP) on the liver injury caused by Ceftiofur sodium (CS) and lipopolysaccharide (LPS) from the perspective of the intestine. Ninety-four one-day-old laying chickens underwent free feeding and drinking water for three days. Then, fourteen laying chickens were randomly selected as the control group, and sixteen laying chickens were selected as the model group. Sixteen laying chickens in the rest were randomly selected as the intervention group of CASP. Chickens in the intervention group were given CASP by the oral administration (0.25 g/kg/d) for 10 days, the control and model groups were given the same amount of physiological saline. During the 8th and 10th days, laying chickens in the model and CASP intervention group were subcutaneously injected with CS at the neck. In contrast, those in the control group were subcutaneously injected with the same amount of normal saline simultaneously. Except for the control group, the layer chickens in the model and CASP intervention groups were injected with LPS after CS injection on the 10th day of the experiment. In contrast, those in the control group were injected with the same amount of normal saline at the same time. 48 h after the experiment, the liver samples of each group were collected, and the liver injury was analyzed by hematoxylin-eosin (HE) staining and transmission electron microscopy. And the cecum contents of six-layer chickens in each group were collected, and the intervention mechanism of CASP on the liver injury from the perspective of the intestine was analyzed by the 16S rDNA amplicon sequencing technology and the short-chain fatty acids (SCFAs) detection of cecal contents based on Gas Chromatography-Mass Spectrometry (GC-MS), and their association analysis was carried out. The results showed that the structure of chicken liver in the normal control group was normal, while that in the model group was damaged. The structure of chicken liver in the CASP intervention group was similar to the normal control group. The intestinal floras in the model group were maladjusted compared to the normal control group. After the intervention of CASP, the diversity, and richness of chicken intestinal floras changed significantly. It was speculated that the intervention mechanism of CASP on the chicken liver injury might be related to the abundance and proportion of Bacteroidetes and Firmicutes. Compared with the model group, the indexes of ace, chao1, observed species, and PD whole tree of chicken cecum floras in the intervention group of CASP were significantly increased (p < 0.05). The contents of acetic acid, butyric acid, and total SCFAs in the intervention group of CASP were significantly lower than those in the model group (p < 0.05), and the contents of propionic acid and valeric acid in the intervention group of CASP were significantly lower than those in the model group (p < 0.05) and normal control group (p < 0.05). The correlation analysis showed that the changes in the intestinal floras were correlated with the changes in SCFAs in the cecum. It is confirmed that the liver-protecting effect of CASP is indeed related to the changes in the intestinal floras and SCFAs content in the cecum, which provides a basis for screening liver-protecting alternative antibiotics products for poultry.

Poultry production in Bangladesh has been experiencing H5N1 highly pathogenic avian influenza (HPAI) and H9N2 low pathogenic avian influenza (LPAI) for the last 14 years. Vaccination of chickens against H5 HPAI is in practice since the end of 2012. Subsequently, the official reporting of HPAI outbreaks gradually decreased. However, the true extent of circulation of avian influenza virus (AIV) in commercial poultry production is not clear. To explore this, we conducted active surveillance in 422 small‐scale commercial layer farms in 20 villages of Mymensingh and Tangail districts of Bangladesh during 2017 and 2018 for the presence of diseases with respiratory signs. A total of 88 farms with respiratory disease problems were identified and investigated during the surveillance. In addition, 22 small‐scale commercial layer farms in the neighbouring areas with respiratory disease problem were also investigated on request from the farmers. Pooled samples of oropharyngeal swabs from live birds or respiratory tissues from dead birds of the farm suffering from respiratory disease problem were tested for molecular detection of avian influenza virus (AIV), Newcastle disease virus (NDV), infectious bronchitis virus (IBV), infectious laryngotracheitis virus (ILTV), Mycoplasma gallisepticum and Avibacterium paragallinarum. A total of 110 farms (88 in the surveillance site and 22 in the neighbouring region) were investigated, and one or more respiratory pathogens were detected from 89 farms. AIV was detected in 57 farms often concurrently with other pathogens. Among these 57 farms, H5, H9, both H5 and H9 or non‐H5 and non‐H9 AIV were detected in 28, 9, 13 or 7 farms, respectively. Birds of most of the H5 AIV‐positive farms did not present typical clinical signs or high mortality. Twenty such farms were observed longitudinally, which had only 1.05%–5.50% mortality but a marked drop in egg production. This widespread circulation of H5 AIV along with H9 AIV and other pathogens in small‐scale commercial layer farms, often with low mortality, reaffirms the enzootic circulation of AIV in Bangladesh, which may escape syndromic surveillance focused on unusual mortality only. To reduce public health risks, strengthening of the control programme with comprehensive vaccination, enhanced biosecurity, improved surveillance and outbreak response is suggested. [ABSTRACT FROM AUTHOR]

• Bisphenol A decreased the number and diameter of preovulatory follicles. • Bisphenol A and bisphenol S altered the expression of genes related to oogenesis, immune function, and ovarian cancer. • Bisphenol S produced similar ovarian toxicities as bisphenol A by inducing inflammation. Both bisphenol A (BPA) and its analog bisphenol S (BPS) are industrial chemicals that have been used to make certain plastic products applied in chicken farms, including food and water containers. They are endocrine disrupting chemicals (EDCs) with xenoestrogenic activities and affect reproductive success in many ways. It was hypothesized that BPA and BPS could adversely affect the folliculogenesis in chickens due to their disruption of the estrogen responses, using either genomic or non-genomic mechanisms. This study investigated the deleterious effects of BPA and BPS on the ovaries when adult layer chickens were orally treated with these EDCs at 50 μg/kg body weight, the reference dose for chronic oral exposure of BPA established by the U.S. EPA. The chickens in both BPA and BPS-treated groups showed a decreased number of the preovulatory follicles. BPA-treated chickens showed a significant decrease in the diameter of F1. Additionally, both BPA and BPS treatments increased the infiltrations of lymphocytes and plasma cells in ovaries. Moreover, it was found that the ovaries of BPS-treated chickens weighed the most among the groups. RNA sequencing and subsequent pathway enrichment analysis of differentially expressed genes revealed that both BPA- and BPS-treatment groups showed significant changes in gene expression and pathways related to reproduction, immune function and carcinogenesis. Taken together, both BPA and BPS are potentially carcinogenic and have deleterious effects on the fertility of laying chickens by inducing inflammation, suggesting that BPS may not be a safe replacement for BPA. [ABSTRACT FROM AUTHOR]

Abstract Background Avian hepatitis E virus (aHEV) has been associated with hepatitis-splenomegaly syndrome (HSS) in chickens along with asymptomatic subclinical infection in many cases. So far, four genotypes have been described, which cause infection in chickens, specifically in broiler breeders and layer chickens. In the present study, we isolated and identified two novel aHEV strains from the bile of layer chickens in Pakistan evincing clinical symptoms related to HSS. Methodology Histology of liver and spleen tissues was carried out to observe histopathological changes in these tissues. Bile fluid and fecal suspensions were used for viral RNA isolation through MegNA pure and Trizol method which was further used for viral genome detection and characterization by cDNA synthesis and amplification of partial open reading frame (ORF) 1, ORF2 and complete ORF3. The bioinformatics tools; Molecular Evolutionary Genetics Analysis version 6.0 (MEGA 6), Mfold and ProtScale were used for phylogenic analysis, RNA secondary structure prediction and protein hydropathy analysis, respectively. Results Sequencing and phylogenetic analysis on the basis of partial methyltranferase (MeT), helicase (Hel) domain, ORF2 and complete ORF3 sequence suggests these Pakistani aHEV (Pak aHEV) isolates may belong to a Pakistani specific clade. The overall sequence similarity between the Pak aHEV sequences was 98–100%. The ORF1/ORF3 intergenic region contains a conserved cis-reactive element (CRE) and stem-loop structure (SLS). Analysis of the amino acid sequence of ORF3 indicated two hydrophobic domains (HD) and single conserved proline-rich domain (PRD) PREPSAPP (PXXPXXPP) with a single PSAP motif found in C-terminal. Amino acid changes S15 T, A31T, Q35H and G46D unique to the Pak aHEV sequences were found in the N-terminal region of ORF3. Conclusions Our data suggests that Pak aHEV isolates may represent a novel Pakistani clade and high sequence homology to each other support the supposition they may belong to a monophyletic clade circulating in the region around Pakistan. The data presented in this study provide further information for aHEV genetic diversity, genotype mapping, global distribution and epidemiology.

In the present study, a trail to evaluate of Newcastle Disease (ND) antibodies levels after different vaccination programs was conducted on layer chickens. A total of 200 one day-old layer chicks (White Lohmann) were divided into five groups A, B, C, D and E. Birds in groups A, B and C were vaccinated with live vaccine by intraocular, intranasal and drinking water methods , respectively. On the other hand, groups D and E were kept as unvaccinated control groups. Vaccination performed at days 5, 18 and 28 by different routes for mentioned groups. Hemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA) methods were used for assessment of antibodies titer at days 15, 25, 37 and 45. Results of HI and ELISA tests indicated that, the intranasal and the intraocular method have highest antibodies titers compared with the drinking water method. In this study, maternally derived antibodies specific to Newcastle Disease Virus (NDV) (IgY) were extracted by dextran sulfate method from collected eggs of vaccinated laying chickens . Antibodies specific to NDV (IgY) were detected in the egg yolk using HI test . Data revealed that antibodies specific to NDV (IgY) were presented in high titers that confer protection during early weeks of life for hatching chicks. Data concluded that extraction of maternally derived specific antibodies from egg yolk will facilitate accurate monitoring of ND vaccination programmes.

Objective. We aimed to evaluate the use of visual assessment scale of internal egg quality and its relationship with other quality variables during storage time. Materials and methods. The analyses were carried out in the Egg Quality Laboratory of Promitec Santander. To the study, 527 commercial table eggs from five regions of Colombia were used. Eggs were stored between 28 and 30°C. On days 3, 6, 8, 12, and 17 of storage, front and top view photographic records were made for visual scale scoring, and physicochemical measurements were performed. ANOVA and TUKEY test were used to compare means for each variable between the different measurement times. The correlations between the internal quality variables were analysed using correlation coefficient and linear regression. Results. Albumin and yolk pH increased and the visual scale and the yolk index decreased through the storage time (p>0.05). A negative correlation was observed between the pH of albumin with the yolk index and the visual scale. On the other hand, a positive correlation between the yolk index and the visual scale was found (p<0.05). Conclusions. Storage time at room temperature affects the physicochemical variables measured for quality, and also decreases the score on the visual evaluation scale; which allowed to identify and score observable physical chemical changes in the internal components of the egg. [ABSTRACT FROM AUTHOR]

Granuloma disease in a flock of free range productive layers in the Netherlands in 2017 is described. The disease resembled granuloma outbreaks in layers caused by Tetratrichomonas gallinarum in 2013 and occurred in the same area in which the rearing farm considered as the source of the 2013 outbreaks was located. Between 55 and 84 weeks of age mortality was 20.3% (breeder’s norm 3.9%). All dead hens examined (n = 20) showed granulomas especially in liver and ceca. Nine hens with or without liver and/or ceca granulomas were examined for trichomonads in mentioned organs by in situ hybridization (ISH), nested PCR, and cloning and sequencing. Ceca were also examined by culture. T. gallinarum ISH was positive in all livers and ceca with granulomas and negative in case granulomas were absent. T. gallinarum strain 13/16632, which caused the 2013 outbreaks was found in 4/8 hens with granulomas. Moreover, other trichomonads were detected: a T. gallinarum strain GPO-like and a Simplicimonas sp. strain GABC1-like. Mixed infections also occurred. Infectious causes of granuloma disease other than the afore-mentioned trichomonads could be excluded. Trichomonad DNA was not detected in environmental samples and wild ducks originating from the farm of concern, except for one duck in which the same Simplicimonas sp. as in hens was detected, leaving the source of the T. gallinarum infection in hens unknown. It is concluded that the herein described granuloma disease likely was caused by T. gallinarum strain 13/16632. However, the pathogenicity of the other trichomonads found remains to be clarified.

Abstract Background The main goal of selection is to achieve genetic gain for a population by choosing the best breeders among a set of selection candidates. Since 2013, the use of a high density genotyping chip (600K Affymetrix® Axiom® HD genotyping array) for chicken has enabled the implementation of genomic selection in layer and broiler breeding, but the genotyping costs remain high for a routine use on a large number of selection candidates. It has thus been deemed interesting to develop a low density genotyping chip that would induce lower costs. In this perspective, various simulation studies have been conducted to find the best way to select a set of SNPs for low density genotyping of two laying hen lines. Results To design low density SNP chips, two methodologies, based on equidistance (EQ) or on linkage disequilibrium (LD) were compared. Imputation accuracy was assessed as the mean correlation between true and imputed genotypes. The results showed correlations more sensitive to false imputation of SNPs having low Minor Allele Frequency (MAF) when the EQ methodology was used. An increase in imputation accuracy was obtained when SNP density was increased, either through an increase in the number of selected windows on a chromosome or through the rise of the LD threshold. Moreover, the results varied depending on the type of chromosome (macro or micro-chromosome). The LD methodology enabled to optimize the number of SNPs, by reducing the SNP density on macro-chromosomes and by increasing it on micro-chromosomes. Imputation accuracy also increased when the size of the reference population was increased. Conversely, imputation accuracy decreased when the degree of kinship between reference and candidate populations was reduced. Finally, adding selection candidates’ dams in the reference population, in addition to their sire, enabled to get better imputation results. Conclusions Whichever the SNP chip, the methodology, and the scenario studied, highly accurate imputations were obtained, with mean correlations higher than 0.83. The key point to achieve good imputation results is to take into account chicken lines’ LD when designing a low density SNP chip, and to include the candidates’ direct parents in the reference population.

Background: Gastrointestinal (GIT) parasites can affect poultry productivity by compromising its health. It is well studied in other countries, but the documented reports in the Philippines have been limited. Aim: The aim of the present study was to evaluate the presence of GIT parasites in selected small-scale poultry layer farms in Leyte, Philippines. Materials and Methods: A total of 243 stool samples from eight small-scale poultry layer farms in Leyte, Philippines, were examined for GIT parasites using floatation and sedimentation technique. Profile parameters were also obtained. Fecal samples were collected and analyzed using floatation and sedimentation techniques. Statistical significance between GIT parasite positivity and profile parameters was determined using Chi-square test. Results: GIT parasites were detected in 92.2% of the samples (24.7% with single infection, 42.0% with 2-3 parasites, and 25.5% with three or more parasites). The common parasites detected were Ascaridia spp. (41.2%), Heterakis spp. (59.3%), Capillaria spp. (10.7%), Eimeria spp. (43.2%), and Strongyloides spp. (74.1%). Some profile parameters, including farm location, years in business, number of workers, nearby water system, the practice of fecal cleaning, and presence of other animals, were found to be significantly associated with GIT positivity. Conclusion: GIT parasites were detected in the poultry of small-scale layer farms in selected areas in Leyte, Philippines. This finding calls for the importance of routine GIT parasite monitoring and the implied need for regular deworming or dewormer rotation in the area.

Nigeria poultry industry is fast growing to meet the demand of the increasing population with overdependence on antibiotics for production leading to consumer safety and public health concerns. The antibiotic use in poultry farms and presence of gentamicin residues in chicken eggs from city markets of Southwest Nigeria were investigated. A semi-structured questionnaire was administered to 45 poultry farmers to determine the patterns of antibiotic use, knowledge of withdrawal periods and food safety implications. Furthermore, 270 egg samples from six retail markets in Oyo and Lagos states were analyzed with ELISA for gentamicin residues. Residue concentrations were compared with Student’s t test and ANOVA (p

Avian hepatitis E virus (aHEV) is the major etiological agent of hepatitis-splenomegaly syndrome (HSS), big liver and spleen disease (BLSD), and hepatic rupture hemorrhage syndrome (HRHS) in chickens. Infections with aHEV cause a significant decrease in egg production and increased mortality in chickens worldwide. However, studies on the prevalence of aHEV in Nigeria are scarce. In this study, serum (n = 88) and fecal samples (n = 110) obtained from apparently healthy layer chickens from three states in southwestern Nigeria were analyzed by nested reverse transcription-polymerase chain reaction (nRT-PCR) targeting the helicase and capsid gene for the presence of aHEV. Avian HEV was detected in 12.5% (n = 11/88) of serum samples and 9.1% (n = 10/110) of fecal samples tested. Phylogenetic analysis showed that five of the twelve identified aHEV sequences belonged to genotype 2. The remaining seven sequences were only distantly related to other known aHEV isolates. After amplification of the near-complete ORF2 fragment (1618 bp) and part of the ORF1 (582 bp) of isolate YF40_aHEV_NG phylogenetic analysis revealed a nucleotide sequence identity between 79.0 and 82.6% and 80.1 and 83.5%, respectively, to other known aHEV strains, indicating that the Nigerian isolate YF40_aHEV_NG belongs to a novel aHEV genotype. This is the first report of co-circulation of aHEV genotypes in chickens in Nigeria.

Avian Hepatitis E Virus (aHEV) is a single-stranded positive-sense RNA virus causing hepatitissplenomegaly syndrome (HSS) in chickens. To the best of our knowledge the circulation of aHEV in chicken has not been studied in Pakistan so far. Therefore, in the present study, we aimed to isolate and identify aHEV from layer chickens of Pakistan. The bile fluids, liver and spleen tissues were collected from overnight dead layer chickens (n = 8) from Pattoki region of Punjab province, Pakistan, during July to August 2016. The RT-PCR showed the amplifications of selected regions of helicase (186 bps, 2769- 2954 nt) and capsid (280 bps, 5461-5741 nt) domain in the bile fluids of two birds. The histological data demonstrated pathological changes in liver and spleen tissues of layer chickens positive for viral RNA. The extensive phylogenetic analysis on the basis of partial helicase domain (ORF1) and capsid protein (ORF2) revealed clustering of Pakistani aHEV (Pak aHEV) strains with members of Orthohepevirus B species. However, Pak aHEV strains were highly divergent from other known members within Orthohepevirus B suggesting as novel aHEV strains circulating in the population of layer chickens in the country. Detection of HEV in layer chickens may pose public health risk in context of zoonosis and food borne transmission if aHEV emerges as zoonotic HEV. [ABSTRACT FROM AUTHOR]

Thymoquinone (TQ) is the major constituent of Nigella sativa and known to possess a variety of pharmacological effects. This study was designed to evaluate the pharmacokinetic profile of TQ following oral (PO) and intravenous (IV) administration in layer chickens. The layer chickens were equally divided into two groups (six chickens in each group, total 12 chickens), and TQ was administered via PO and IV routes. For PO route, the dose was 20 mg/kg b.w. and for IV route, 5 mg/kg b.w. was administered, respectively. A sensitive and accurate High‐Performance Liquid Chromatography (HPLC) technique was validated for the quantification of TQ from plasma. The limit of detection (LOD) and limit of quantification (LOQ) were 0.02 µg/ml and 0.05 µg/ml, respectively with >80% recovery. Maximum plasma concentration (Cmax) following PO and IV administration was 8.805 and 4.497 µg/ml, respectively, while time to reach at maximum concentration (Tmax) was 1 and 0.1 hr, respectively. The elimination half‐lives were recorded as 1.02 and 0.978 hr, whereas the mean residence times were 1.79 and 1.036 hr following both PO and IV administration, respectively. The 85% PO bioavailability was indicative that TQ could be used for various therapeutic purposes in layer chickens. [ABSTRACT FROM AUTHOR]

Objective. Evaluate the effect of crude palm oil (CPO) on quality traits of eggs stored various days at different temperatures. Material and Methods. A total of 240 hens, 28 weeks of age were fed diets with 30 g/kg of soybean oil (SO) or CPO. After 12 weeks, sample of eggs were stored during 0, 4, 8 and 12 days at 4, 12 and 24 °C. Egg quality traits were evaluated. Results. Egg and albumen from hens in CPO diet were heavier than those in SO (p<0.05). High storage temperature reduced egg, albumen and yolk weights, Haugh units (HU), albumen and yolk heights, pH and color (p<0.05), but increased albumen and yolk widths and albumen length (p<0.05). As storage time increased, egg weight, albumen weight and height, and yolk height, pH and colour were reduced (p<0.05). However, yolk weight and width, albumen width and length increased (p<0.05). Oil x storage time interaction (p<0.05) indicated that albumen height, HU and yellowness of yolk from hens in CPO diets were better at 12 days of storage than for hens fed SO. Conclusions. Hens in CPO diet had heavier eggs and albumen than those in SO diet. Egg quality traits decreased as temperature and days of storage increased, but, eggs from hens supplemented CPO had better quality in some traits at 12 days of storage. [ABSTRACT FROM AUTHOR]

This case report describes a series of gizzard erosion outbreaks in two farms of commercial layers flocks at the age of 19, 25, 30 and 73 weeks observed in the period between 2012 and 2015. The clinical signs, course of disease and mortality in all cases were similar. The post-mortem examinations revealed dark-brownish contents in crops, esophagus, proventriculus, gizzards, and duodenums, as well as haemorrhagic changes in provetriculus and ablations of the overlaying keratinoid layers in the gizzards. Histopathology showed the presence of intranuclear inclusion bodies in gizzard epithelial cells and molecular findings confirmed the presence of fowl adenoviruses A. It seems that the virus persisted on the farm during this fouryear period and temperature fluctuations were to be the probable factors predisposing the clinical course of disease. [ABSTRACT FROM AUTHOR]

In the present study, a trail to evaluate of Newcastle Disease (ND) antibodies levels after different vaccination programs was conducted on layer chickens. A total of 200 one day-old layer chicks (White Lohmann) were divided into five groups A, B, C, D and E. Birds in groups A, B and C were vaccinated with live vaccine by intraocular, intranasal and drinking water methods , respectively. On the other hand, groups D and E were kept as unvaccinated control groups. Vaccination performed at days 5, 18 and 28 by different routes for mentioned groups. Hemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA) methods were used for assessment of antibodies titer at days 15, 25, 37 and 45. Results of HI and ELISA tests indicated that, the intranasal and the intraocular method have highest antibodies titers compared with the drinking water method. In this study, maternally derived antibodies specific to Newcastle Disease Virus (NDV) (IgY) were extracted by dextran sulfate method from collected eggs of vaccinated laying chickens . Antibodies specific to NDV (IgY) were detected in the egg yolk using HI test . Data revealed that antibodies specific to NDV (IgY) were presented in high titers that confer protection during early weeks of life for hatching chicks. Data concluded that extraction of maternally derived specific antibodies from egg yolk will facilitate accurate monitoring of ND vaccination programmes. [ABSTRACT FROM AUTHOR]

Background: Gastrointestinal (GIT) parasites can affect poultry productivity by compromising its health. It is well studied in other countries, but the documented reports in the Philippines have been limited. Aim: The aim of the present study was to evaluate the presence of GIT parasites in selected small-scale poultry layer farms in Leyte, Philippines. Materials and Methods: A total of 243 stool samples from eight small-scale poultry layer farms in Leyte, Philippines, were examined for GIT parasites using floatation and sedimentation technique. Profile parameters were also obtained. Fecal samples were collected and analyzed using floatation and sedimentation techniques. Statistical significance between GIT parasite positivity and profile parameters was determined using Chi-square test. Results: GIT parasites were detected in 92.2% of the samples (24.7% with single infection, 42.0% with 2-3 parasites, and 25.5% with three or more parasites). The common parasites detected were Ascaridia spp. (41.2%), Heterakis spp. (59.3%), Capillaria spp. (10.7%), Eimeria spp. (43.2%), and Strongyloides spp. (74.1%). Some profile parameters, including farm location, years in business, number of workers, nearby water system, the practice of fecal cleaning, and presence of other animals, were found to be significantly associated with GIT positivity. Conclusion: GIT parasites were detected in the poultry of small-scale layer farms in selected areas in Leyte, Philippines. This finding calls for the importance of routine GIT parasite monitoring and the implied need for regular deworming or dewormer rotation in the area. [ABSTRACT FROM AUTHOR]

Aim: Mycoplasma gallisepticum (MG) is important avian pathogen responsible for chronic respiratory disease of chicken and turkeys, which result in large economic loss for the poultry industry. The objectives of this study were determination of seroprevalence of MG antibody of commercial layer chicken at laying period in selected areas of Bangladesh. Materials and Methods: A total of 563 blood samples were collected randomly from selected commercial layer chickens at laying period during the period from July to December, 2013. Indirect enzyme linked immunosorbent assay (iELISA) and serum plate agglutination (SPA) test were performed to detect the presence of antibodies against MG. Results: Of 563 samples, 64.47% and 56.13% showed an overall prevalence of MG antibodies in iELISA and SPA test respectively. Prevalence of MG was recorded the highest (69.63%) at 50-55 weeks of age compared with lowest (53.26%) at 56-61 weeks of age (p

Objetive. To determine the effects of high temperature, the high humidity and the index on production performance in layer chickens supplemented with vitamins C and E. Materials and methods. The experiment was carried out from July 14th to August 15th. A total of 720 L33 layer chickens, 39 weeks old, were divided at random into four groups (180 birds/group), by replicates (n=4): Control Group) was fed with a basal diet and treatment groups were fed with the basal diet supplemented with either 150 mg of l-ascorbic acid/g of diet (Group Vit. C) or 150 mg of dl-α-tocopherol acetate /kg, of diet (Group Vit. E), and 150 mg of l-ascorbic acid /kg of diet plus 150 mg of dl-α-tocopherol acetate/kg of diet (Group Vit C + E). Results. Egg/bird were higher (p0.05). However, feed consumption and conversion were different (p

The effects of vitamins C and E on layer chickens transported by road for 6 h during the hot dry season were investigated. Two experimental groups consisting of thirty Shika Brown layers were separately administered vitamins C and E orally just before transportation, while another 30 layers, which were only given sterile water, served as control. Blood samples analyzed before and after transportation in the control layers showed a decrease (p0.05) from those obtained before transportation. Heterophil/lymphocyte values were highest in the control group. The result showed that transportation was stressful for the control layers. Post-transportation egg production was not signifcantly (p>0.05) different in the vitamin E treated group, but values recorded for the vitamin C and control groups were signifcantly (p

Objective In Australia, Salmonella serovar Typhimurium (S. Typhimurium) is the predominant zoonotic serovar in humans and is frequently isolated from layer hens. Vaccination against this serovar has been previously shown to be effective in broilers and the aim of this current study was to assess and determine the best vaccination strategy (live or inactivated) to minimise caecal colonisation by S. Typhimurium. Methods A long-term experiment (56 weeks) was conducted on ISABROWN pullets using a commercial live aroA deleted mutant S. Typhimurium vaccine and an autogenous inactivated multivalent Salmonella vaccine (containing serovars Typhimurium, Infantis, Montevideo and Zanzibar). These vaccines were administered PO or by SC or IM injection, either alone or in combination. Pullets were vaccinated throughout rearing (to 18 weeks of age) and sequentially bled for antibody titre levels. The birds, vaccinated and controls, were challenged orally with a field isolate of S. Typhimurium at different ages, held for 21 days post-challenge, then euthanased and their caeca cultured for the presence of Salmonella. Results None of the oral live-vaccinated groups exhibited lasting protection. When administered twice, the inactivated vaccine gave significant protection at 17 weeks of age and the live vaccine given by SC injection given twice produced significant protection at 17, 25 and 34 weeks. Conclusions Vaccination regimens that included parenteral administration of live or inactivated vaccines and thus achieved positive serum antibody levels were able to provide protection against challenge. Hence, vaccination may play a useful role in a management strategy for Salmonella carriage in layer flocks. [ABSTRACT FROM AUTHOR]

In 2013, seven outbreaks of granuloma disease occurred in Dutch flocks of productive layers housed on different farms. These outbreaks were characterized by increased mortality and high incidence of granulomas, mainly in caeca (340/408 hens =83%) and livers (69/408 hens = 17%). Mortality started to increase between 21 and 35 weeks of age and reached 3.7% to 11.0% exceeding the breeder's norm in periods ranging from 9 to 48 weeks. Some flocks also showed decreased egg production and/or loss of mean egg weight. All affected flocks were linked to one rearing farm, which therefore seemed to be the source of the disease. However, no signs of disease had been observed at this rearing farm. Sentinel hens placed in one of the affected flocks to determine whether the disease had an infectious nature developed granulomas identical to those seen in the outbreaks. Next, by fulfilling Koch's postulates it was shown that Tetratrichomonas gallinarum was the aetiological agent of the granuloma disease. The condition was reproduced in mature specified pathogen free White Leghorn hens (GD - Animal Health, Deventer, the Netherlands) by inoculation via both an artificial and a natural route with a well-defined axenic T. gallinarum isolate obtained from one of the affected flocks. Other causes of granuloma disease were excluded. [ABSTRACT FROM AUTHOR]