Poultry Industry Research Articles

RNA-sequencing revisited data shed new light on wooden breast myopathy

Wooden Breast (WB) abnormality represents one of the major challenges that the poultry industry has faced in the last 10 years. Despite the enormous progress in understanding the mechanisms underlying WB, the precise initial causes remain to be clarified. In this scenario, the present research is intended to characterize the gene expression profiles of broiler Pectoralis major muscles affected by WB, comparing them to the unaffected counterpart, to provide new insights into the biological mechanisms underlying this defect and potentially identifying novel genes likely involved in its occurrence. To this purpose, data obtained in a previous study through the RNA-sequencing technology have been used to identify differentially expressed genes (DEGs) between 6 affected and 5 unaffected broilers' breast muscles, by using the newest reference genome assembly for Gallus gallus (GRCg7b). Also, to deeply investigate molecular and biological pathways involved in the WB progression, pathways analyses have been performed. The results achieved through the differential gene expression analysis mainly evidenced the downregulation of glycogen metabolic processes, gluconeogenesis, and tricarboxylic acid cycle in WB muscles, thus corroborating the evidence of a dysregulated energy metabolism characterizing breasts affected by this abnormality. Also, genes related to hypertrophic muscle growth have been identified as differentially expressed (e.g., WFIKKN1). Together with that, a downregulation of genes involved in mitochondrial biogenesis and functionality has been detected. Among them, PPARGC1A and PPARGC1B chicken genes are particularly noteworthy. These genes not only have essential roles in regulating mitochondrial biogenesis but also play pivotal roles in maintaining glucose and energy homeostasis. In view of that, their downregulation in WB-affected muscle may be considered as potentially related to both the mitochondrial dysfunction and altered glucose metabolism in WB muscles, and their key involvement in the molecular alterations characterizing this muscular abnormality might be hypothesized.

Meat productivity of quail of the Pharaoh breed after drinking a biotechnologicum supplementum (Suspension of Chlorella sorokiniana)

Currently, the use of microalgae as feed additives is gaining more and more popularity in the poultry industry. Microalgae are rich in bioactive metabolites that have demonstrated powerful antioxidant, antiinflammatory, and antiviral properties. Adding a small amount of such an additive to traditional feed has a positive effect on the health and well-being of birds, as well as the quality and quantity of products. The results of the study of meat productivity of quail of the Pharaoh breed after drinking Chlorella sorokiniana suspension are given. The research was conducted on quails during the period of cultivation from 1 to 60 days. To conduct the experiment, two groups (control and experimental) of 30 heads each were formed from day-old birds. Quails were kept in vivarium conditions, in battery cages in compliance with established microclimate requirements. Poultry of both groups received combined feed, developed taking into account age and physiological characteristics. With drinking water, the birds of the experimental group received a chlorella suspension for 60 days. Counting of the quail population and their weighing was carried out weekly, starting from day-old age. The following indicators were determined: preservation, dynamics of live weight, average daily growth of live weight. Based on the results of the control slaughter, the weight of the carcass and the weight of the edible part were determined. Slaughter qualities and morphological composition of quail carcasses were determined by anatomical dissection with determination of the following parameters: pre-slaughter weight, weight of semi-carcasses, carcases of carcases, slaughter yield, weight of edible parts. Drinking chlorella suspension of young quails increased their preservation by 3,83 %, live weight, and absolute growth by 21,0 and 0,57 g (Р<0,05), respectively. Addition of Chlorella sorokiniana suspension to drinking water of quails contributed to an increase in their pre-slaughter weight by 20,0 g, and their weight by 21,0 g compared to the control group. Quail carcasses of the research group were characterized by a higher yield of edible parts compared to birds that consumed clean water. Key words: biotechnology, Chlorella sorokiniana suspension, biotechnological parameters, cultivation, photobioreactor, quails of the Pharaoh breed, body weight, growth, slaughter parameters, weight of carcass, weight of internal organs, output of edible parts.

Modern problems of preclinical studying feed additives for animals and ways to solve them

Resource-saving technology in agriculture is the use of stimulating additives in animal feeding rations that promote better absorption of feed. One of the measures to prevent toxicosis in industrial livestock and poultry farming is to determine the toxicity of feed. The variety of existing methods makes it possible to determine the level and class of drug toxicity at the initial stage. In the developed classification for veterinary drugs, the cumulation coefficient, therapeutic breadth index and dose level of toxic effect are used, which makes it possible to predict the nature and degree of their danger at the stage of preclinical study of feed additives. To determine the listed indicators, it is necessary to establish LD50and the cumulation coefficient. Since feed additives are introduced into the body through the digestive tract, during preclinical studies they are studied and classified according to their hepatotoxic effect. Bilirubin, albumin, and enzyme activity contained in the blood (glutamate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and the ratio of alanine aminotransferase to alkaline phosphatase) are used as markers. It is necessary to determine the de Ritis, Schmidt coefficient and the R index. This will minimize the intake of toxic feed additives into the animals’ bodies and will contribute to an increase in their productivity.

Review: Myopathies in broilers: supply chain approach to provide solutions to challenges related to raising fast growing birds

This review is a summary of a Poultry Science Association symposium addressing myopathies in broilers’ breast meat, focusing on the interactions between genetics, nutrition, husbandry, and meat processing. The Pectoralis major myopathies (WB = woody breast; WS = white striping; SM = spaghetti meat) and Pectoralis minor (“feathering”) are described, followed by discussing their prevalence, potential causes, current and future ways to mitigate, as well as detection methods (in live birds and meat) and ways to utilize affected meat. Overall, breast myopathies remain an important focus across the poultry industry and whilst a lot of data and knowledge has been gathered, it is clear that there is still a lot to understand. As there are multiple factors impacting the occurrence of breast myopathies, their reduction relies on a holistic approach. Ongoing balanced breeding strategies by poultry breeders is targeting the longer-term genetic component but comprehending the significant influence from non-genetic factors (short-term solutions such as nutrition) remains a key area of opportunity. Consequently, understanding the physiology and biological needs of the muscle through the life of the bird is critical to reduce the myopathies (e.g., minimizing oxidative stress) and gain more insight into their aetiology.

A novel highly virulent nephropathogenic QX-like infectious bronchitis virus originating from recombination of GI-13 and GI-19 genotype strains in China

Infectious bronchitis virus (IBV) is one of the most widely spread RNA viruses, causing respiratory, renal, and intestinal damage, as well as decreased reproductive performance in hens, leading to significant economic losses in the poultry industry. In this study, a new IBV strain designated as CK/CH/GX/LA/071423 was successfully isolated from the 60-day-old Three-Yellow chicken vaccinated with H120 and QXL87 vaccines. The complete genome sequence analysis revealed that the CK/CH/GX/LA/071423 strain shared a high similarity of 96.7% with the YX10 strain belonging to the GI-19 genotype. Genetic evolution analysis based on the IBV S1 gene showed that the CK/CH/GX/LA/071423 isolate belonged to the GI-19 genotype. Recombination analysis of the virus genome using RDP and Simplot software indicated that CK/CH/GX/LA/071423 was derived from recombination events between the YX10 and 4/91 vaccine strains, which was supported by phylogenetic analysis using gene sequences from the 3 regions. Furthermore, the S1 protein tertiary structure differences were observed between the CK/CH/GX/LA/071423 and the QXL87 and H120 vaccine strains. Pathogenicity studies revealed that the CK/CH/GX/LA/071423 caused death and led to pale and enlarged kidneys with abundant urate deposits, indicative of a nephropathogenic IBV strain. High virus titers were detected in the trachea, kidneys, and cecal tonsils, demonstrating broad tissue tropism. Throughout the experimental period, the virus positive rate in throat swabs of the infected group reached to 100%. These findings highlight the continued predominance of the QX genotype IBV in Guangxi of China and the ongoing evolution of different genotypes through genetic recombination, raising concerns about the efficacy of current IBV vaccines in providing effective protection to poultry.

Salmonella pathogenicity island-14 is a critical virulence factor responsible for systemic infection in chickens caused by Salmonella gallinarum

Salmonella enterica serovar Gallinarum (S. gallinarum) is an important host-specific pathogen that causes fowl typhoid, a severe systemic, septicemic, and fatal infection, in chickens. S. gallinarum causes high morbidity and mortality in chickens and poses a significant burden and economic losses to the poultry industry in many developing countries. However, the virulence factors and mechanisms of S. gallinarum-induced systemic infection in chickens remain poorly understood. In this study, we constructed a Salmonella pathogenicity island-14 (SPI-14) mutant strain (mSPI-14) of S. gallinarum and evaluated the pathogenicity of mSPI-14 in the chicken systemic infection model. The mSPI-14 exhibited the same level of bacterial growth and morphological characteristics but significantly reduced resistance to bile acids compared with the wild-type (WT) strain in vitro. The virulence of mSPI-14 was significantly attenuated in the chicken oral infection model in vivo. Chickens infected with WT showed typical clinical symptoms of fowl typhoid, with all birds succumbing to the infection within 6 to 9 days post-inoculation, and substantial increases in bacterial counts and significant pathological changes in the liver and spleen were observed. In contrast, all mSPI-14-infected chickens survived, the bacterial counts in the organs were significantly lower, and no significant pathological changes were observed in the liver and spleen. The expression of interleukin (IL)-1β, IL-12, CXCLi1, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ in the liver of mSPI-14-infected chickens were significantly lower than those in the WT-infected chickens. These results indicate that SPI-14 is a crucial virulence factor in systemic infection of chickens, and avirulent mSPI-14 could be used to develop a new attenuated live vaccine to prevent S. gallinarum infection in chickens.

Dried crickets (Gryllus sigillatus) or black soldier fly (Hermetia illucens) larvae meal for broiler chickens: nutrient composition and digestibility

Abstract This study explores the potential of cricket meal and black soldier fly larvae meal (BSFLM) as alternative protein sources in broiler chicken diets. With the use of the substitution method, using diatomaceous earth as an external marker, we investigated the nutrient availability and apparent metabilizeable energy content of oven-dried full-fat cricket meal (OD-CM), freeze-dried full-fat cricket meal (FD-CM), and defatted BSFLM in a feeding trial involving 320 Ross 308 broilers housed in 32 pens (8 replicates / treatment; 8 birds / pen). Feed intake, daily weight gain, and feed conversion ratio were measured between days 15 and 21. Excreta collected on days 19, 20, and 21 were analyzed for nutrient content. Both cricket treatments were high in crude protein. Additionally, FD-CM demonstrated the highest fat content, surpassing OD-CM. OD-CM displayed a significantly higher apparent digestibility coefficient for crude protein compared to BSFLM (). FD-CM had the highest apparent digestibility coefficient for gross energy (). The nitrogen-corrected apparent metabolizable energy of OD-CM and FD-CM were significantly higher than that of BSFLM (). Furthermore, OD-CM exhibited a significantly higher available crude protein content compared to BSFLM and FD-CM (). This research sheds light on the potential of OD-CM and FD-CM as valuable alternative protein sources for broiler chickens, providing critical insights for the poultry industry’s sustainable future. This research is important as the apparent digestibility coefficients, as well as available nutrients calculated for the three ingredients may be used to accurately formulate poultry diets on an available nutrient basis.

A novel subunit vaccine based on Fiber1/2 knob domain provides full protection against fowl adenovirus serotype 4 and induces stronger immune responses than a Fiber2 subunit vaccine

Outbreaks of hepatitis-hydropericardium syndrome (HHS) caused by fowl adenovirus serotype 4 (FAdV-4) have resulted in huge economic losses to the poultry industry in China since 2015. However, commercially available vaccines against the FAdV-4 infection remain scarce. In our study, subunit vaccine candidates derived from the bacterially expressed recombinant Fiber1 knob domain and Fiber2 knob domain fusion protein (termed as Fiber1/2 knob subunit vaccine) and Fiber2 protein (termed as Fiber2 subunit vaccine) of the FAdV-4 SDSX strain were developed. Immunogenicity evaluation showed that the Fiber1/2 knob subunit vaccine induced the production of antibodies at 7 d postvaccination (dpv), earlier than the Fiber2 subunit vaccine. Moreover, the neutralizing antibody level of the Fiber1/2 subunit vaccine group was higher than the Fiber2 subunit vaccine group, showing significant differences at 14, 21, and 28 dpv. Immune protection test results revealed that both Fiber1/2 knob subunit and Fiber2 subunit vaccines could protect chickens from death against FAdV-4 challenge, although the weight of chickens in the Fiber1/2 knob subunit vaccine group decreased less. Furthermore, analysis of plasma Glutamic oxaloacetic transaminase (AST) and blood glutamic pyruvic transaminase (ALT) levels suggested that the Fiber1/2 subunit vaccine can significantly inhibit liver damage caused by FAdV-4 infection and is more effective in blocking the pathogenicity of FAdV-4 in target organs. In addition, the Fiber1/2 knob subunit vaccine further reduced the viral load in different tissues and virus shedding in chickens than the Fiber2 subunit vaccine. Overall, the Fiber1/2 knob subunit vaccine was more effective than the Fiber2 subunit vaccine. These findings lay the foundation for the development of more effective FAdV-4 subunit vaccines.

Pathogenicity and transmission of novel highly pathogenic H7N2 variants originating from H7N9 avian influenza viruses in chickens

The H7 subtype avian influenza viruses are circulating widely worldwide, causing significant economic losses to the poultry industry and posing a serious threat to human health. In 2019, H7N2 and H7N9 co-circulated in Chinese poultry, yet the risk of H7N2 remained unclear. We isolated and sequenced four H7N2 viruses from chickens, revealing them as novel reassortants with H7N9-derived HA, M, NS genes and H9N2-derived PB2, PB1, PA,NP, NA genes. To further explore the key segment of pathogenicity, H7N2-H7N9NA and H7N2-H9N2HA single-substitution were constructed. Pathogenicity study showed H7N2 isolates to be highly pathogenic in chickens, with H7N2-H7N9NA slightly weaker than H7N2-Wild type. Transcriptomic analysis suggested that H7N9-derived HA genes primarily drove the high pathogenicity of H7N2 isolates, eliciting a strong inflammatory response. These findings underscored the increased threat posed by reassorted H7N2 viruses to chickens, emphasizing the necessity of long-term monitoring of H7 subtype avian influenza viruses.

Identifying Dietary Timing of Organic Trace Minerals to Reduce the Incidence of Osteomyelitis Lameness in Broiler Chickens Using the Aerosol Transmission Model.

Our prior research demonstrated a 20% to 25% reduction in bacterial chondronecrosis with osteomyelitis (BCO) lameness in broilers with organic Zn, Mn, and Cu (Availa® ZMC) supplementation. Expanding on this, we investigated the optimal timing for Availa® ZMC feeding to mitigate BCO lameness and reduce feed additive costs in the poultry industry. In this study, we compared the application of 0.15% Availa® ZMC for 56 days, the first 28 days, and the last 28 days. The experimental design was a randomized block design involving 1560 one-day-old chicks distributed across two wire-floor pens as BCO source infection and four treatment groups with six replicates. The source of BCO infection exhibited a cumulative lameness incidence of 83%, whereas the negative control group showed a 77% cumulative incidence of lameness (p = 0.125). Administering 0.15% of Availa® ZMC during the initial 28 d resulted in a 41.3% reduction in BCO incidence, significantly different from the supplementation during the last 28 d (p < 0.05). However, this reduction did not differ substantially (p > 0.05) from the 56d application period. Hence, administering 0.15% Availa® ZMC during the first four weeks emerges as the optimal timing protocol, providing a defense against lameness comparable to the continuous supplementation throughout the complete production duration. Implementing this feeding approach reduces the cost of feed additive, promotes the health of skeletal bones, and effectively protects against BCO lameness in broilers, offering a valuable consideration for producers seeking optimal outcomes in the poultry industry.

Transcriptome analysis of sexual dimorphism in dorsal down coloration in goslings

BackgroundIn day-old Hungarian white goose goslings, there is a noticeable difference in dorsal down coloration between males and females, with females having darker dorsal plumage and males having lighter plumage. The ability to autosex day-old goslings based on their dorsal down coloration is important for managing them efficiently and planning their nutrition in the poultry industry. The aim of this study was to determine the biological and genetic factors underlying this difference in dorsal down colorationthrough histological analysis, biochemical assays, transcriptomic profiling, and q‒PCR analysis.ResultsTissue analysis and biochemical assays revealed that compared with males, 17-day-old embryos and day-old goslings of female geese exhibited a greater density of melanin-containing feather follicles and a greater melanin concentration in these follicles during development. Both female and male goslings had lower melanin concentrations in their dorsal skin compared to 17-day-old embryos. Transcriptome analysis identified a set of differentially expressed genes (DEGs) (MC1R, TYR, TYRP1, DCT and MITF) associated with melanogenesis pathways that were downregulated or silenced specifically in the dorsal skin of day-old goslings compared to 17-day-old embryos, affecting melanin synthesis in feather follicles. Additionally, two key genes (MC1R and MITF) associated with feather coloration showed differences between males and females, with females having higher expression levels correlated with increased melanin synthesis and darker plumage.ConclusionThe expression of multiple melanogenesis genes determines melanin synthesis in goose feather follicles. The dorsal down coloration of day-old Hungarian white goose goslings shows sexual dimorphism, likely due to differences in the expression of the MC1R and MITF genes between males and females. These results could help us better understand why male and female goslings exhibit different plumage patterns.

The effect of Limosilactobacillus fermentum 2i3 and 0.6% addition of humic substances on production parameters and the immune system of broilers

The widespread use of antibiotics in the poultry industry as growth promoters has led to the emergence of bacterial resistance, which poses a significant health risk to humans and animals. Substances of natural origin, such as probiotic bacteria and humic substances, can be a promising solution. The aim of this experiment was to study the effect of the administration of a probiotic strain of Limosilactobacillus fermentum 2i3 and/or a new formula of humic substances specifically designed for detoxification on the production parameters, including gene expression of myogenic growth factors and selected parameters of the immune response. We found that production parameters such as feed conversion ratio and weekly weight gain, as well as gene expression of mucin-2 and immunoglobulin A, were positively influenced mainly by the administration of L. fermentum 2i3. Similarly, the percentage of active phagocytes and their absorption capacity as well as the proportions of CD8+ and CD4+CD8+ T-lymphocyte subpopulations were significantly increased. The addition of humic substances, either alone or in combination with probiotics, significantly reduced the aforementioned parameters compared to the control. On the other hand, the relative gene expression for all myogenic growth factors was the highest in the humic group alone. Based on the results obtained, we can confirm the immunostimulating effect of L. fermentum 2i3 administered in drinking water, which also had an impact on important production parameters of broiler meat. On the other hand, in the combined group there was no expected potentiation of the positive effects on the observed parameters.

Benefits of Mushroom-Based Supplements on Growth Performance, Immunocompetence, and Meat Quality in Poultry.

The restriction on the use of antibiotics in poultry has led to an increase in the use of natural products that could serve as alternatives to antibiotics. Mushrooms contain bioactive compounds that exhibit antifungal, antiparasitic, antibacterial, antioxidant, antiviral, anti-inflammatory, and cytotoxic properties. Hence, they are being tested, revealing as performance-enhancing natural feed additives for livestock. This review focused on the role of different species of mushrooms commonly used in poultry on the performance, immunomodulatory actions, cholesterolemic properties, and meat quality of poultry birds. Different studies reviewed show that mushrooms could positively impact poultry production, improve growth performance, modulate immune response, exert tissue antioxidant activity, influence intestinal morphology, enhance gut microbiome, and improve lipid profile. The variations in their efficacy could be attributed to the variations in physicochemical properties of different species and dosage levels applied in the experiments. However, the use of mushrooms as a natural product supplement is in its infancy, and more basic, pilot and large-scale research is required to make it a viable approach for improving immune responses in the poultry industry.

Technology transfer model oriented to industry 4.0

Goal: This study aimed to propose a Technology Transfer Model oriented to Industry 4.0 (TTM4.0). Design/methodology/approach. Initially, a systematic literature review was conducted to identify existing gaps in Technology Transfer models: Another focus of the review was to determine the requirements for technological implementations in Industry 4.0. Thus, a specific TT model was built. Then, the model was validated through case studies in Brazilian companies (slaughterhouses). The methods employed to measure data and support decisions in the context of TT4.0 were AHP, Likert scale, and Fuzzy-TOPSIS. Results: Focusing on similar results between Companies A and B, thinking about adopting Industry 4.0, the central strategic needs were product quality, reducing human error, and reducing waste. Among the main factors inhibiting the maximum interest and availability of Industry 4.0 for both companies were high investment, lack of knowledge (procedures or in general), and uncertainties in results. Results indicate Big Data Analytics and artificial intelligence technologies. Originality/value: The Poultry Industry strengthens the economy and significantly impacts the country's socioeconomic indices. Despite this, the sector has a low level of technological maturity compared to others. Regarding the TTM4.0, while other models start by recognizing opportunities and then select technologies in the market, this model prioritizes phases of organizational self-knowledge for decision-making support. A primary difference between a maturity model and a Technology Transfer model is in their scope, with the latter being broader. It encompasses technology definition, implementation, and management, rather than being limited to diagnosis.

Laying Hens: Why Smothering and Not Surviving?-A Literature Review.

The proliferation of rearing systems providing opportunities for birds to engage in natural behaviors can trigger behavioral repertoires that when not manageable compromise animal welfare and the economic viability of the flock. Smothering in laying hens has long been perceived as "natural" or the result of hysteria among birds in the flock. However, the current literature has recognized smothering as an abnormal outcome with the potential to result in significant losses in cage-free poultry systems. Recent studies have specifically aimed to categorize the organization of smothering behavior and highlight its potential causes and consequences. In this study, literature review and bibliographic mapping, drawing on published articles and engagement with poultry farmers through extension and rural technical assistance, were employed. The findings indicate that smothering is a behavior triggered by factors related to the environment in which the laying hens are kept. This study concludes that there is a critical need for more rigorous and detailed research to elucidate the nuances of avian behavioral physiology and assess the impact of production systems on animal welfare and the economic impacts on the flock. This research contributes to a deeper understanding of bird behavior in high-production environments and provides practical insights for the poultry industry.

Probiotic Abilities of Lactobacillus spp. Isolated from Algerian Fermented Wheat ‘Hamoum’ intended to Use in Broiler Production

Background: The use of probiotics has become popular in the broiler poultry industry due to its positive results on the health of animals, as well as the safety of consumers. In general, probiotics are isolated and selected In vitro from several sources. Despite this, only a few studies focused on isolating probiotics from cereals, which are the main natural food source for poultry. This study aimed to evaluate and identify an autochthonous Lactobacillus spp. isolated from Algerian fermented wheat “Hamoum” as potential probiotics for use in broiler feed. Methods: This research was conducted over the period between 2019-2022. Five bacterial isolates of the genus Lactobacillus were tested for their hemolysis activity, exopolysaccharides production, the ability to withstand the simulated hostile conditions of the chicken’s gut and their capacity to acidify the concentrate feed beverage. Finally, molecular identification was performed using the REP-PCR technique. Result: These isolates were found to produce exopolysaccharides and have no hemolytic activity. Also, could tolerate simulated gastric acidity. However, only three isolates were able to survive in the presence of bile salts and were found to have a high capacity for acidifying medium in a relatively short time. These isolates were identified as Lactobacillus acidophilus and Lactobacillus plantarum subsp plantarum. Those strains can be considered safe candidate probiotics for use in broiler feeds feed. Further studies are needed to investigate and evaluate the effectiveness of these isolates through an in vivo experiment on broiler chickens.

Infectious bronchitis virus: an overview of the "chicken coronavirus".

Infectious bronchitis virus (IBV) is a highly contagious avian Gammacoronavirus that affects mainly chickens (Gallus gallus) but can circulate in other avian species. IBV constitutes a significant threat to the poultry industry, causing reduced egg yield, growth and mortality levels that can vary in impact. The virus can be transmitted horizontally by inhalation or direct/indirect contact with infected birds or contaminated fomites, vehicles, farm personnel and litter (Figure 1). The error-prone viral polymerase and recombination mechanisms mean diverse viral population results, with multiple genotypes, serotypes, pathotypes and protectotypes. This significantly complicates control and mitigation strategies based on vigilance in biosecurity and the deployment of vaccination.

Biodegradation of Keratin Waste by Bacillus velezensis HFS_F2 through Optimized Keratinase Production Medium.

Enormous aggregates of keratinous wastes are produced annually by the poultry and leather industries which cause environmental degradation globally. To combat this issue, microbially synthesized extracellular proteases known as keratinase are used widely which is effective in degrading keratin found in hair and feathers. In the present work, keratinolytic bacteria were isolated from poultry farm soil and feather waste, and various cultural conditions were optimized to provide the highest enzyme production for efficient keratin waste degradation. Based on the primary and secondary screening methods, the potent keratinolytic strain (HFS_F2T) with the highest enzyme activity 32.65 ± 0.16 U/mL was genotypically characterized by 16S rRNA sequencing and was confirmed as Bacillus velezensis HFS_F2T ON556508. Through one-variable-at-a-time approach (OVAT), the keratinase production medium was optimized with sucrose (carbon source), beef extract (nitrogen source) pH-7, inoculum size (5%), and incubation at 37 °C). The degree of degradation (%DD) of keratin wastes was evaluated after 35days of degradation in the optimized keratinase production medium devoid of feather meal under submerged fermentation conditions. Further, the deteriorated keratin wastes were visually examined and the hydrolysed bovine hair with 77.32 ± 0.32% degradation was morphologically analysed through Field Emission Scanning Electron Microscopy (FESEM) to confirm the structural disintegration of the cuticle. Therefore, the current study would be a convincing strategy for reducing the detrimental impact of pollutants from the poultry and leather industries by efficient keratin waste degradation through the production of microbial keratinase.

Potential non-invasive detection of lesions in broiler femur heads: application of the DXA imaging system.

Leg health is a significant economic and welfare concern for the poultry industry. Current methods of detection rely on visual assessment of the legs and gait scores and bone scoring during necropsy for full characterization. Additionally, the current scoring of femurs only examines the external surface of the femoral head. Through the use of the dual-energy X-ray absorptiometry (DXA) imaging system, we show the presence of a necrotic region in the femurs that would otherwise be considered healthy based on the current evaluation procedures. Importantly, these lesions were present in almost 60% (22 of 37) of femurs that scored normal for femoral head necrosis (FHN). Additionally, these femurs showed greater bone mineral content (BMC) relative to weight compared to their counterparts with no lucent lesions (6.95% ± 0.20% vs. 6.26% ± 0.25; p = 0.038). Identification of these lesions presents both a challenge and an opportunity. These subclinical lesions are likely to be missed in routine scoring procedures for FHN and can inadvertently impact the characterization of the disease and genetic selection programs. Furthermore, this imaging system can be used for in vivo, ex vivo, and embryonic (egg) studies and, therefore, constitutes a potential non-invasive method for early detection of bone lesions in chickens and other avian species.

Characterisation of the tracheal transcriptional response of chickens to chronic infection with Mycoplasma synoviae

Mycoplasma synoviae causes infectious synovitis and respiratory tract infections in chickens and is responsible for significant economic losses in the poultry industry. Effective attachment and colonisation of the trachea is critical for the persistence of the organism and progression of the disease it causes. The respiratory tract infection is usually sub-clinical, but concurrent infection with infectious bronchitis virus (IBV) is known to enhance the pathogenicity of M. synoviae. This study aimed to explore differentially expressed genes in the tracheal mucosa, and their functional categories, during chronic infection with M. synoviae, using a M. synoviae-IBV infection model. The transcriptional profiles of the trachea were assessed 2 weeks after infection using RNA sequencing. In chickens infected with M. synoviae or IBV, only 1 or 8 genes were differentially expressed compared to uninfected chickens, respectively. In contrast, the M. synoviae-IBV infected chickens had 621 upregulated and 206 downregulated genes compared to uninfected chickens. Upregulated genes and their functional categories were suggestive of uncontrolled lymphoid cell proliferation and an ongoing pro-inflammatory response. Genes associated with anti-inflammatory effects, pathogen removal, apoptosis, regulation of the immune response, airway homoeostasis, cell adhesion and tissue regeneration were downregulated. Overall, transcriptional changes in the trachea, 2 weeks after infection with M. synoviae and IBV, indicate immune dysregulation, robust inflammation and a lack of cytotoxic damage during chronic infection. This model provides insights into the pathogenesis of chronic infection with M. synoviae.