Search Results (772)

Infectious Bronchitis Virus is one of several major viral infections in poultry, affecting the respiratory, reproductive, and renal systems and causing significant economic losses worldwide. Current vaccines, including the H120 strain, provide limited cross-protection against emerging variants, underscoring the need for improved vaccine strategies. In this study, the complete genome of IBV H120 was divided into 12 fragments, synthesized, and assembled using the Golden Gate Assembly (GGA) method. The recombinant virus (rH120) was successfully rescued in chicken fibroblast cells and propagated in embryonated specific-pathogen-free (SPF) chicken eggs. Growth kinetics in embryonated SPF chicken eggs revealed similar replication patterns between rH120 and the original H120 strain. In broiler chickens, rH120 replicated efficiently, as confirmed by viral RNA detection in throat and cloacal swabs, and induced a stronger antibody response by 14 days post-infection. The rH120 virus proved to be genetically stable, infectious, and immunogenic, indicating that GGA-based reverse genetics is an effective system for IBV vaccine development. Full article

Background and Objectives: This study compared the effects of rosuvastatin and chitosan on the kidneys of rabbits fed a high-fat diet. Materials and Methods: In total, 28 New Zealand White rabbits (Oryctolagus cuniculus) were randomly divided into four groups of 7 rabbits: a control group (CG) fed a regular diet; a hyperlipidic group (HG) fed the regular diet and 20 mL of egg yolk daily; and the third (RG) and fourth (ChiG) groups fed the HG diet plus rosuvastatin and chitosan, respectively. Cholesterol, triglyceride, glucose, creatinine, and urea levels were analyzed. After kidney excision, glomerular height and length were analyzed and stereological analysis was conducted. The Kruskal–Wallis and Dunn multiple comparison tests were used for statistical analysis, and a p value of <0.05 was considered significant. Results: The chicken egg yolk diet was successful in inducing a hypercholesterolemic state. Total cholesterol levels showed a significant reduction in rabbits treated with rosuvastatin, and chitosan and rosuvastatin significantly reduced triglyceride, VLDL, creatinine, and glucose levels. The size of the glomerulus was increased significantly in the HG rabbits. Stereological analysis showed a mean glomerular volumetric density of 8.27 ± 3.27, 4.14 ± 2.87, 10.03 ± 3.22, and 6.18 ± 3.50 vV% for CG, HG, RG, and ChiG, respectively. Conclusions: Chitosan reduced triglyceride, VLDL, creatinine, and glucose levels but was less effective than rosuvastatin. Kidney morphology was slightly altered in the animals fed a high-fat diet, and these changes were ameliorated by treatment with chitosan or rosuvastatin. Full article

The conventional method for detecting protein content in egg albumen is the Kjeldahl method, but this method cannot be applied in practical production due to cost limitations. Therefore, we developed albumen density (AD), which had certain potential application value in low-cost and efficient evaluation of albumen protein content. We calculated the heritability of AD in White Leghorn (WL) chickens and its correlation with average albumen protein quantity (AAP), total albumen protein quantity (TAP), albumen weight (AW), albumen volume (AV), egg weight (EW), albumen height (AH), haugh unit (HU), and yolk color (YC). It is worth noting that albumen protein content was measured in a small subset of samples. The average value of AD in eggs was 0.97 and its heritability was less than 0.1. The average value of AAP in eggs was 10.1%, and the average value of TAP in eggs was 2.95 g. There were significant positive correlations between AAP, TAP, AW, AV, AD, and EW, and there were strong positive genetic and phenotypic correlations between EW, AW, AV, and AD. The results of this study indicated that AD might have potential value as a supplementary tool for albumen protein trait selection in breeding. Full article

The widespread use of antibiotics in human medicine, veterinary care, and livestock production has resulted in their frequent detection in diverse environmental and food matrices, making continuous surveillance of antibiotic residues in food products essential for consumer protection. In this study, a sustainable analytical method based on dispersive liquid–liquid microextraction (DLLME) coupled with UHPLC–MS/MS was developed for the trace determination of sulfamethoxazole, sulfadimethoxine, and enrofloxacin in commercial cow milk and chicken eggs. A natural deep eutectic solvent (NADES) composed of anisaldehyde and octanoic acid (2:1, molar ratio) was employed as a biodegradable extraction solvent, and key extraction parameters were systematically optimized. Under optimized conditions, the method demonstrated excellent linearity (R² ≥ 0.9982), recoveries of 89.5–98.7%, and RSDs ≤ 6.04%. Application to 44 commercial samples from the Saudi market revealed sulfamethoxazole as the most frequently detected antibiotic, occurring in 90% of egg samples (2.17–13.76 µg kg⁻¹) and 70.8% of milk samples (0.26–26.67 µg L⁻¹). A comprehensive evaluation using ten metrics confirmed the method’s greenness, practicality, analytical performance, and innovation. Overall, the proposed NADES–DLLME–UHPLC–MS/MS approach offers a rapid, cost-effective, and environmentally friendly alternative for routine monitoring of antibiotic residues in food matrices. Full article

Chlorinated paraffins (CPs) are a class of persistent organic pollutants that pose potential human health risks through dietary exposure. In this study, we analyzed CPs in 55 chicken egg samples collected from five regions across China. Short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) were detected using a two-dimensional gas chromatograph coupled with an electron-capture negative-ionization mass spectrometer. Dietary exposure risks were assessed using the margin of exposure (MOE) approach based on the food consumption data of Chinese residents from 2018 to 2020. The average concentrations of SCCPs and MCCPs in all samples were 28.4 ng/g wet weight (ww) and 176.5 ng/g ww, respectively. The congener profiles of SCCPs and MCCPs were similar across different regions, with C_10–11 Cl_6–7 as the dominant homologs. For MCCPs, the average contributions of C₁₄-CP, C₁₅-CP, C₁₆-CP, and C₁₇-CP were 25%, 21%, 27%, and 27%, respectively. The estimated daily intake (EDI) for the entire population was 18.3 ng/kg body weight (bw)/d for SCCPs and 118.3 ng/kg bw/d for MCCPs. In the consumer-only group, the average exposure levels of SCCPs and MCCPs were 27.8 ng/kg bw/d and 174.1 ng/kg bw/d, respectively. This preliminary risk assessment indicates that there is no health risk to the Chinese population from exposure to CP through consumption of chicken eggs. Full article

Background: Non-typhoidal Salmonella (NTS) is a major foodborne pathogen, with poultry products, especially eggs, being the primary source of human infections. Current serovar-specific poultry vaccines effectively reduce targeted Salmonella serovars but may inadvertently promote the emergence of untargeted serovars within poultry flocks. Therefore, novel vaccine candidates providing broad cross-serovar protection are needed to improve overall effectiveness of Salmonella control programs. Objectives: This study evaluated the immunogenicity of the novel subunit vaccine candidate InvG and assessed its ability to reduce Salmonella colonization in vaccinated laying hens and their progeny through maternally derived antibodies transferred via egg yolk. Methodology: Three experiments were performed. Experiment I evaluated the immunogenicity of purified recombinant InvG by (a) measuring anti-InvG antibodies using an enzyme-linked immunosorbent assay (ELISA) and (b) completing transcriptomic profiling of immune responses in vaccinated chickens. Vaccinated chickens were subsequently challenged with Salmonella Enteritidis to assess the efficacy of anti InvG antibodies in reducing intestinal colonization of Salmonella. Experiment II involved immunizing hens with InvG, to evaluate passive transfer of antibodies via egg yolk and the protective efficacy of maternally derived antibodies against Salmonella challenge. Passive transfer was assessed by measuring IgY antibodies in hen serum, egg yolk, and progeny serum, as well as secretory IgA (sIgA) antibodies in progeny intestinal washings using ELISA. Protective efficacy was evaluated by orally challenging one-day-old chicks with three different Salmonella serovars. Experiment III assessed the persistence of anti-InvG antibodies in the serum of vaccinated hens and their transfer into eggs following two doses of InvG. Results: InvG vaccination induced robust IgY antibody responses in hens, with efficient maternal antibody transfer to progeny via egg yolk. A statistically significant reduction in Salmonella colonization was observed in both vaccinated hens and their progeny. Conclusions: These findings demonstrate that InvG represents a promising subunit vaccine candidate for Salmonella control in poultry and warrants further investigation towards development as a broadly protective commercial poultry vaccine against Salmonella. Full article

Functional feed additives offer a viable strategy for producing sustainable and healthful poultry. Guanidinoacetic acid (GAA), a non-antibiotic growth stimulant, has attracted significant interest from both investors in the poultry sector and researchers due to its distinct biological properties and multiple potential applications. GAA facilitates creatine synthesis, accelerates metabolism, and boosts poultry growth. Consequently, GAA can be considered a safe and beneficial creatine substitute, as it is the sole natural precursor of creatine. GAA meets the livestock industry’s demand for safe and effective therapies because it is non-toxic, readily degradable, and leaves no residues. Additionally, GAA is more stable and economical than creatine, making it a superior feed additive. In broiler chicks, GAA can replace arginine in practical diets containing either adequate or deficient levels of arginine. Supplementation with GAA offers promising opportunities to optimize broiler production and general health by promoting energy metabolism and protein synthesis. Commercially available feed-grade GAA has a high potential for inclusion in broiler diets. Supplementing broiler chickens with GAA may be an effective approach to improve performance parameters such as body weight and feed conversion ratio. In conclusion, dietary GAA supplementation (approximately 0.6–1.2 g/kg of diet, depending on desired impacts) can improve the productive performance of poultry. This review updates current knowledge on the impacts of GAA on productive and reproductive performance, egg quality, digestibility, antioxidant indices, and gut health in poultry. Full article

The epidemiological situation in Poland for IBV GII (formerly known as D1466) has seemed stable over the years, but an increase in such infections has been recently reported. In this study, genetic characterization of the representatives of this genotype was performed in order to determine whether the new epidemic wave of GII IBV was responsible for changes in this status quo. Genotyping based on the complete S1 coding region of eight Polish IBV field strains from 2011 to 2021 confirmed that they belonged to genotype II, with two of them clustered in the two previously identified GII-1 and GII-2 lineages. In turn, the S1 coding region sequences of the next six Polish strains are very different from the previous ones and form a separate group on the phylogenetic tree. However, comprehensive analysis of all complete S1 coding regions of GII strains did not fulfill all parameters needed to create the separate GII lineage, and they all seem to belong to the GII-1 lineage. Further analysis of the partial S1 sequence of 15 IBV GII strains showed their genetic distinctiveness and indicates the ongoing evolution of this virus genotype. Considering the results of our study and the recent outbreaks of GII-2 in Western Europe, it appears that infections with GII virus strains mainly affect egg-producing, long-lived chickens, commercial layers, and breeders. Furthermore, due to the high diversity of these viruses, their circulation in the poultry population may remain undetected, and for this reason, the observed production problems in laying flocks may be attributed to other, unrelated factors. Full article

Background/Objective: The poultry industry requires extensive vaccination of chickens against IBV in an effort to prevent the disease in animals and significant economic losses. Current vaccination strategies often lack effectiveness, and the continual emergence of new IBV variants makes disease control increasingly challenging. We have developed an inactivated vaccine for poultry containing nine different antigens (Nobilis Multriva), including two IBDV strains, two ARV strains, one NDV strain, one AMPV strain, one EDSV strain and two IBV strains: M41 (genotype GI-1) and 4–91 (genotype GI-13). In this study, the IB efficacy of this novel inactivated vaccine was investigated against homologous and heterologous IBV strains. Methods: Inactivated IBV vaccine containing the M41 and 4–91 strains (Nobilis Multriva) was administered intramuscularly, either alone or following vaccine priming, in SPF and commercial chickens. Birds were challenged with homologous and heterologous IBV strains at defined ages (peak of lay, mid-lay and end of lay). Vaccine efficacy was evaluated through serological assays, clinical observations, and monitoring of egg production post-challenge. Results: This vaccine provided excellent broad protection against different IBV strains circulating in different parts of the world, including IBV M41, 4–91, QX, Q1 and Var2. Furthermore, the vaccine provided long-lasting IBV serological response against IB M41 and IB 4–91 until at least 96 weeks of age in SPF and commercial layers and breeder birds. This vaccine will allow farmers to reduce the number of vaccination moments, thereby minimizing stress to the birds, while also decreasing labor demands and the risk of human error, ultimately contributing to lower overall vaccination costs. Conclusions: Given its demonstrated broad cross-protection and sustained serological responses, this nine-valent inactivated vaccine (Nobilis Multriva) represents a key component of an effective vaccination regimen for controlling IBV infections in the poultry industry. Full article

The present study was carried out to analyze the complete genome sequences of infectious bursal disease virus (IBDV) isolates obtained from field outbreaks in the southern regions of India. Bursal tissue samples were collected and screened by RT-PCR, targeting the VP2 gene. Positive samples were subjected to serological identification via AGID. Following this, eight samples (BGE14, BGE15, MDI14, THI14, EDE14, RPM14, VCN14, and NKL14) were subjected to virus isolation in 9 to 11-day-old embryonated chicken eggs, and their complete genomes were sequenced. Analysis of the VP2 hypervariable region (HVR) revealed that all eight isolates had five unique and highly conserved amino acids (A222, I242, Q249, I256, and S299). However, all the isolates reveal a substitution of Isoleucine by Valine at residue 294 (I294V). Furthermore, analysis of segment B from all Indian IBDV sequences revealed that the triplet amino acid pattern was NEG (residues 145–147) and the amino acid at position 242 was consistently D across all isolates. These findings suggest that segment B of the isolates in this study resembled that of vaccine strains and non-vvIBDV strains. Additionally, the presence of the signature D242 in all Indian isolates, characteristic of non-vvIBDV strains, implies a potential attenuation. Moreover, in the phylogenetic analysis of VP2-HVR, all isolates clustered with very virulent reference strains, while segment B clustered with classical attenuated strains. Notably, the phylogenetic analysis of VP2-HVR and VP1 of these viruses demonstrated genetic variances, suggesting evolutionary changes in segment B across all eight Indian isolates, likely indicative of natural genome reassortment resulting in these specific outbreaks in the flocks. Full article

The epithelial egg tooth is used by birds to open the eggshell for hatching. This ectodermal structure consists of a multilayered periderm and a hard cornified portion, the caruncle or actual egg tooth. Here, we determined the protein composition of the egg tooth of the chicken and compared the proteins to markers of other epithelia identified in previous studies. The egg tooth and the upper beak of chicken embryos of Hamburger and Hamilton (HH) stage 44 were subjected to mass spectrometry-based proteomics. We found that scaffoldin, a marker of the embryonic periderm and the feather sheath, was enriched in the egg tooth relative to the beak. Likewise, Epidermal Differentiation protein containing DPCC Motifs (EDDM) and Epidermal Differentiation protein starting with a MTF motif and rich in Histidine (EDMTFH), which had previously been characterized as markers of the subperiderm on embryonic scutate scales and the barbs of feathers, were also enriched in the egg tooth. The expression of EDDM and EDMTFH was confirmed RT-PCR analysis. Our data suggest that the epithelial egg tooth is related to the subperiderm and feathers, a hypothesis with potentially important implications for the evolution of the avian integument. Full article

Soybean meal has traditionally dominated poultry diets as the protein source. However, its widespread use raises concerns regarding economic costs, environmental impact and social sustainability. As a result, there is growing interest in alternative protein sources, such as canola meal, which may reduce feed costs while sustaining productivity. This review evaluates the potential of canola meal as a sustainable protein source in modern poultry production systems, focusing on nutritional, economic and environmental advantages, as well as the potential implications of canola meal inclusion in reduced-protein diets. Evidence from scientific studies indicates that canola meal’s nutritional profile supports bird growth and production, although higher fiber content and anti-nutritional compounds reduce metabolizable energy, making it more suitable for laying hens than broiler chickens. Processing techniques, enzyme supplementation, fermentation, and modern cultivars have improved both nutritional value and practical utility of canola meal. Performance outcomes differ by species. Broilers exhibit variable growth at high inclusion levels, whereas laying hens are estimated to tolerate up to 20% without affecting laying performance or egg quality; however, data is severely lacking, particularly under the context of modern reduced-protein diets. Economically, canola meal is cost-competitive with soybean meal. From an environmental perspective, substituting imported soybean meal with local canola reduces greenhouse gas emissions, enhances resource efficiency, and supports pollinators. Nevertheless, trade-offs exist, including increased land use, variable digestibility, and potential eutrophication. Incorporating canola meal into reduced-protein diets offers both economic and ecological benefits, though effectiveness depends on the extent of protein reduction and the precision of amino acid formulation. Overall, canola meal offers a sustainable, economically viable, and environmentally responsible protein source for modern poultry production, provided that inclusion levels are adjusted to species-specific requirements and regional conditions. Full article

Eggs from ten Slovenian chicken genotypes—four layer-type purebreds, three meat-type purebreds, and three commercial F₁ crossbreds—were analysed at 50 weeks of age (n = 118). All hens were reared indoors in identical floor-barn systems and fed the same complete layer diet, with feed intake restricted only in meat-type hens. Cholesterol was determined spectrophotometrically, and results included cholesterol per yolk dry matter and fresh yolk, per whole egg and egg content, total cholesterol per egg, and the yolk-to-albumen ratio. Production type significantly affected all traits (p < 0.0001): meat-type hens had the highest cholesterol concentrations and totals, layer-type purebreds were intermediate, and crossbreds the lowest. The yolk-to-albumen ratio showed the same gradient (≈0.44 in crossbreds, ≈0.46 in layer purebreds, ≈0.50 in meat types; p = 0.004), indicating that a larger yolk fraction contributes to higher total cholesterol. Reciprocal crossbreds did not differ in cholesterol levels (p > 0.05), suggesting negligible maternal or sex-linked effects. Under standardised conditions, genotype and production orientation were the main determinants of egg cholesterol and yolk proportion. These results provide reference values for Slovenian breeding and conservation populations and confirm exploitable genetic variability for future selection aimed at improving egg composition. Full article

Objectives: Fibroblast growth factor 9 (FGF9), a crucial member of the FGF family, functions as an intercellular signaling molecule involved in angiogenesis, embryogenesis, and tissue repair. Our previous study demonstrated that FGF9 expression in chicken hierarchical granulosa cells (Post-GCs) is regulated by LSD1 Ser54 phosphorylation and that FGF9 promotes cell proliferation. This study aims to analyze the expression and regulation of the FGF9 gene in chicken ovarian follicles and its genetic effect on laying traits in hens. Methods: Chicken FGF9 mRNA expression patterns were examined by real-time quantitative PCR (RT-qPCR). Detection of single nucleotide polymorphisms (SNPs) was performed using PCR amplification and Sanger sequencing. Transcription activity was compared using dual-luciferase reporter assay. Results: Following follicle selection, chicken FGF9 expression significantly decreased in granulosa cells (p < 0.05) while it increased in theca cells (p < 0.05). Hormonal treatments revealed differential regulation; estradiol and FSH downregulated FGF9 in both pre-hierarchical and hierarchical granulosa cells (p < 0.05), whereas progesterone exhibited opposing effects, suppressing expression in pre-hierarchical granulosa cells (Pre-GCs) but stimulating its expression in Post-GCs (p < 0.05). In theca cells, estradiol consistently inhibited FGF9 expression (p < 0.05), while FSH only affected FGF9 expression in pre-hierarchical follicles. Six SNPs in the promoter region (g.−1965G>A, g.−2177G>A, g.−2289G>A, g.−3669A>G, g.−3770A>G, g.−3906G>A) were identified, five of which (g.−1965G>A, g.−2177G>A, g.−2289G>A, g.−3669A>G, g.−3906G>A) showed significant associations with egg production traits. Notably, alleles A (g.−2289), G (g.−3669), and A (g.−3906) enhanced the transcription activity of chicken FGF9 in Pre-GCs. Conclusions: These findings provide novel insights into the expression pattern and regulatory mechanisms of chicken FGF9 during follicular development and identify some genetic markers for egg-laying traits in chickens. Full article

Objectives: The aim of this experiment was to explore how the addition of Schizochytrium powder to the feeding ration affected the production performance, egg quality, and antioxidant function of chickens. Schizochytrium powder is a unicellular spherical marine microalga that can be cultivated through heterotrophic fermentation, with characteristics including rapid cell growth, stable composition, and ease of large-scale production. Experimental design: Three hundred and twenty 33-week-old chickens with similar egg production rates and body weights were selected and randomly divided into four groups, with five replicates each and 16 hens in each replicate. The control group (Group I) was fed a corn–soybean meal basal diet, while the test groups were supplemented with 0.5% (Group II), 1.0% (Group III), and 2.0% (Group IV) Schizochytrium powder on top of this basal diet, respectively. The pretest period was 1 week, and the main test period was 8 weeks. The results revealed the following: (1) Compared with Group I, the average daily feed intake (ADFI) and laying rate (LR) were significantly lower (p < 0.05) in Group IV, and there was no significant difference (p > 0.05) in the ADFI and LR between Groups II and III. (2) Compared with Group I, the eggshell strength (ES) and docosahexaenoic acid (DHA) content of Groups II, III, and IV were significantly higher (p < 0.05). (3) Compared with Group I, serum triglyceride (TG) content was significantly decreased (p < 0.05), and serum low-density lipoprotein (LDL) content was significantly increased (p < 0.05) in Groups II, III, and IV. Serum total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and peroxidase (PO) activities were significantly higher (p < 0.05) and serum malondialdehyde (MDA) content was significantly lower (p < 0.05) in Groups II, III, and IV compared to Group I. In conclusion, adding Schizochytrium powder to the feeding ration could affect chickens’ production performance, increase egg DHA content, and improve the antioxidant capacity of the organism. Based on the results of this study, we recommend a ratio of 1.0% Schizochytrium powder addition. Full article