British Poultry Science最新文献

1. Liver-enriched antimicrobial peptide 2 (LEAP2), ghrelin and growth hormone secretagogue receptor (GHSR) are critical components of the appetite regulation system. This study analysed changes in LEAP2-ghrelin-GHSR expression across diverse feeding conditions and body weights in adult broilers and investigated the effects of intraperitoneally injected LEAP2 and ghrelin peptides on the feed intake of chicks.2. In adult broilers, the expression of LEAP2 in the liver and intestine exhibited significant variations under different feeding conditions (fed, fasting and refeeding), with a notable reduction observed during fasting. Compared to the fed group, proventriculus ghrelin and hypothalamus GHSR gene expression doubled, but was not statistically significant. Serum analyses revealed that fasting significantly decreased LEAP2 levels relative to the fed state and a significant negative correlation was identified between LEAP2 levels and body weight in fasting chickens. Conversely, ghrelin levels remained stable irrespective of feeding states and showed no correlation with body weight.3. Intraperitoneal injection of LEAP2 mature peptide, comprising the N-terminal 14 amino acids significantly reduced feed intake of chicks within the initial 4 h. In contrast, ghrelin injection resulted in a decrease in feed intake during the first 30 min. However, prior administration of ghrelin followed by LEAP2 mitigated the suppressive effect of ghrelin on feed intake within this timeframe.4. This study demonstrated that chicken LEAP2 gives a more sensitive feedback factor than ghrelin under different feeding conditions in adult broilers. It revealed that LEAP2 in a chick model modulated feed intake. These findings provide a theoretical basis for exploring the underlying mechanisms of LEAP2-mediated feed intake regulation in poultry.

1. This study determined the presence of Salmonella spp. on the shell of Japanese quail eggs of different colour and to examine effects of eggshell colour on the internal and external quality characteristics and chemical composition of eggs. A total of 360 Japanese quail eggs derived from the same farm (near Belgrade, Serbia) were divided into two groups based on shell colour: brown-spotted (n = 180) and blue (n = 180) eggs.2. Out of 360 Japanese quail eggs examined, Salmonella spp. was found on the shells of 12 samples (3.33%), all of which originated from blue quail eggs (6.67%).3. Blue quail eggs had higher egg weight, dirty eggs, egg width and E_{whole egg} value, but lower eggshell dirtiness score, percentage of normal-shaped eggs and eggshell thickness. Brown-spotted quail eggs had a higher albumen percentage and height, Haugh units, albumen index, yolk height, index and L* and b* value. Contrarily, blue quail eggs had higher albumen pH and width, yolk weight, percentage and width and a* value.4. A higher occurrence of meat and blood spots was detected in blue quail eggs. Blue quail eggs had higher content of proteins, fats, dry matter, ash, oleic acid, linoleic acid, polyunsaturated fatty acids (PUFAs), monounsaturated fatty acids (MUFAs) and Σn-6. They had higher nutritive value index, hypocholesterolaemia/hypercholesterolemic index, n-6/n-3 ratio and PUFA/SFA ratio. Contrarily, brown-spotted quail eggs had higher content of moisture, palmitic acid, palmitoleic acid, stearic acid, elaidic acid and saturated fatty acids (SFAs), as well as higher atherogenic and thrombogenic index.5. In conclusion, brown-spotted quail eggs are safer for consumption and have higher internal and external quality characteristics, whereas blue quail eggs have more favourable chemical composition, fatty acid profile and lipid indexes.

1. Follicular development involves a series of critical processes, including the recruitment and selection of follicles, regulated by complex mechanisms. However, the specific genes and molecular mechanisms involved in follicular development in pigeons during the egg-laying interval (LI) are still unknown.2. To identify key genes that regulate follicular development in pigeons, the largest follicles (F1) and the second-largest follicles (F2) were collected on the third (LI3), fifth (LI5) and seventh (LI7) days of the LI for RNA sequencing and bioinformatics analyses.3. In F1 follicle granulosa cells (F1GC), 7,743 and 2,791 differentially expressed genes (DEG) were identified in the LI3 vs. LI5 group and the LI5 vs. LI7 group, respectively. In F2 follicle granulosa cells (F2GC), 3,072 DEG were detected in the LI5 vs. LI7 group.4. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) analyses were performed and a protein-protein network for the DEG was constructed. This allowed the identification of hub genes (FKBP4, RAF1, CTNNB1, ENO1, FST and PHB) associated with hierarchical follicular development in pigeons.

1. Scaly leg, caused by Cnemidocoptes mutans, is occasionally observed in backyard poultry farms in Greece. In Greece, infestations with C. mutans typically result in mild lesions and occasional scratching behaviour.2. This study evaluated the therapeutic efficacy and safety of two antiparasitic treatments - Phoxim (via foot baths and barn spraying) and Ivermectin (in feed) - in 36 backyard poultry farms in southern Greece, in groups of 15-82 chickens.3. All treatment protocols were found to be effective and safe for clinical use. A single application of either treatment was as effective as two applications administered 11 d apart. Barn spraying with Phoxim solution did not enhance the efficacy of the Phoxim foot bath. For Ivermectin administered via medicated feed, it was observed that providing the drug for only 1 d may result in some birds not consuming the necessary dose. Therefore, it is recommended to administer the medicated feed over at least two consecutive days to ensure adequate drug intake.4. The study investigated the impact of scaly leg on egg production, the potential effects of Ivermectin on egg production and the role of cohabiting Muscovy ducks in an additional 10 backyard poultry farms. The results indicated that (i) scaly leg disease was associated with a reduction in egg production, (ii) Ivermectin had no adverse effects on egg production in laying hens and (iii) Muscovy ducks were not affected by Cnemidocoptes mutans and did not contribute to its transmission or epidemiology.5. These findings provide practical recommendations for managing scaly leg in backyard flocks and contribute to improved poultry health and productivity in small-scale farming systems.

1. This study investigated the effects of Aronia melanocarpa pomace (AP) supplementation on serum variables, egg quality, laying performance, nutrient utilisation and gut microflora in late-stage laying hens.2. A total of 288 Hy-Line Brown hens (60 weeks old) were randomly allocated to one of four groups: a control (basal) or the basal diet supplemented with either 1% AP (APL), 2% AP (APM), or 3% AP (APH) for 20 weeks. Each group contained six replicates of 12 hens.3. Egg production, egg mass and shell thickness increased with AP supplementation, peaking in the 3% AP group (p < 0.05). The AP supplementation significantly reduced serum total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and aspartate aminotransferase (ALT) concentrations, with the greatest reductions observed in the 3% AP group (p < 0.05). Linear decreases in TG, TC and LDL-C were more pronounced in the 2% and 3% AP groups (p < 0.05). Linear improvements in calcium metabolism were observed in AP groups compared to the control group (p < 0.05).4. Crypt depth decreased in the duodenum, jejunum and ileum (p < 0.05), while the villus height-to-crypt depth ratio increased in the duodenum and ileum (p < 0.05), with a similar trend for the jejunal samples (p = 0.092). The AP supplementation increased beta diversity of caecal microbiota. At the genus level, Megamonas and Olsenella spp. abundance rose (p < 0.05), while Barnesiella spp. decreased (p < 0.05).5. Supplementation with 3% AP enhanced laying performance and egg quality in late-stage hens by improving lipid metabolism, calcium utilisation and gut microbiota composition. These findings highlighted AP as a functional feed additive for sustainable poultry production.

1. Chlorella vulgaris, a microalga rich in bioactive compounds, has antioxidant, anti-inflammatory and prebiotic properties. This study investigated the effects of 2% inclusion of autotrophic and heterotrophic C. vulgaris, both with and without pulsed electric field (PEF) processing, on the performance, intestinal health, and meat quality of broilers under a coccidiosis vaccine challenge.2. A total of 1008 Ross 308 male broilers were randomly divided into five treatment groups and fed diets containing either autotrophic or heterotrophic C. vulgaris, with or without PEF-processing, or a control diet without algae. The birds were subjected to a coccidiosis challenge through a high-dose times Eimeria vaccine. Performance variables and meat quality were recorded and intestinal health was assessed through ileal ovotransferrin levels as a marker of gut permeability, histological parameters and antioxidant capacity of blood plasma.3. Inclusion of C. vulgaris did not affect most performance parameters. However, a trend to an increased feed conversion ratio (FCR) was seen. Ovotransferrin concentrations and antioxidant capacity were higher for broilers fed with heterotrophic algae than with autotrophic algae. No significant differences in intestinal morphology were observed.4. Meat quality variables revealed that heterotrophic algae-fed broilers had darker, redder and more yellow breast meat. This was likely due to pigment uptake, but showed abnormalities like wooden breast and white striping.5. Supplementing with C. vulgaris can act as a functional feed additive in broiler production, particularly under conditions that simulate commercial stressors such as coccidiosis.

1. This study identified the pathogen Brachyspira intermedia and B. pilosicoli in laying hens from conventional and organic production systems and investigated their effects on the transcriptional regulation of intestinal immune markers.2. Molecular identification of B. intermedia and B. pilosicoli was performed by qPCR in faecal and egg samples of both production systems. The relative gene expression of nine intestinal immune response markers in caecal tissue was investigated using RT-qPCR.3. Brachyspira spp. was detected in 33% (13/40) of faecal samples but not in eggs. In conventional hens, detection was 25% (5/20) and in organic hens 40% (8/20). Laying hens harbouring Brachyspira spp. showed upregulation of IL-4, important for cytokines regulating antibody production, haematopoiesis and inflammation.4. Overall, identifying B. intermedia and B. pilosicoli in poultry helps implement preventive measures to minimise economic losses in poultry farms and reduce the risk of zoonotic transmission.

1. Ophthalmological examinations in poultry are essential for monitoring overall health and welfare. These are commonly assessed using intraocular pressure (IOP) and corneal thickness (CT). This study examined the effects of 0.5% proparacaine HCl topical anaesthetics on IOP and CT across various corneal regions in broiler chickens.2. Ninety male broilers were housed under controlled conditions and underwent ophthalmic examinations, including CT and IOP. Baseline measurements were recorded for both eyes, after which 0.5% proparacaine HCl drops were instilled in the right eyes, while the left eyes received physiological saline solution (PSS) drops as controls.3. Significant differences were observed between proparacaine HCI and PSS groups in nasal, temporal, inferior, superior and central CT measurements post-treatment, with proparacaine HCI leading to decreased CT values across various corneal areas compared to PSS. Correlations between IOP and CT measurements varied, which suggested potential disruptions in ocular dynamics following topical intervention.4. The findings emphasised the necessity of accounting for the influence of topical anaesthetics on ocular assessments to ensure accurate diagnosis and treatment.

1. This study evaluated the effectiveness of different concentrations of tryptophan in the diet on reproductive performance, body weight loss and plasma biochemical indices of breeding pigeons. It included growth performance, carcass characteristics, meat quality and plasma biochemical indices of squabs.2. In this study, 360 pairs of Mimas breeding pigeons were randomly divided into six experimental groups based on the dietary tryptophan content. The pigeons with four squabs were fed diets containing 0.10%, 0.14%, 0.18%, 0.22%, 0.26% and 0.30% tryptophan (Trp) for 50 d.3. The results showed that dietary Trp supplementation increased egg-laying rate of breeding pigeons curvilinearly, with the highest rate occurring in the 0.18-0.30% group. The FCR of squabs showed a linear and quadratic trend and the 0.26% Trp group was the lowest. The increase in semi-eviscerated and eviscerated weight of squabs showed a curvilinear trend and the best slaughter performance of squabs was observed in the 0.26% Trp group.4. The 0.22-0.30% Trp supplementation resulted in an improvement in meat colour. Plasma biochemical index results showed that Trp supplementation significantly improved metabolic function in squabs and the best indices were observed in the 0.22-0.30% Trp group.5. A regression model was established using reproductive and growth performance indexes. Laying rate of breeding pigeons was highest during incubation and lactation periods at 0.210-0.272% Trp supplementation. At this rate, the level of oxidative stress in squabs was reduced, which improved growth.

1. Although the anti-inflammatory drug Ketoprofen has been used in ducks, there has been no research on its pharmacokinetics. This study examined the disposition kinetics and bioavailability of Ketoprofen in Pekin ducks after intravenous (IV), intramuscular (IM) and oral administration for the first time.2. A total of 18 ducks were split into three equal groups (n = 6) and were given a single dose of Ketoprofen (5 mg/kg) via IV, IM or oral routes. Blood samples were collected at 16 different time points up to 24 h post-administration to determine the change in Ketoprofen plasma concentration over time by high-performance liquid chromatography with ultraviolet detection.3. Following IV injection, total clearance, volume of distribution at steady state and elimination half-life were 0.31 l/h/kg, 0.32 l/kg and 0.95 h, respectively. Following IM and oral administrations, peak plasma concentrations of 13.82 and 6.76 μg/ml were attained at 0.34 and 0.48 h, respectively. Bioavailability was 106 and 63% for IM and oral route, respectively, and average plasma protein binding was 98.8 ± 2.4%.4. Ketoprofen showed small volume of distribution and rapid elimination in Pekin ducks. The IM injection resulted in higher plasma concentration and bioavailability than oral administration. This information contributes to the use of Ketoprofen in ducks in an appropriate dosage regimen, but efficacy needs to be demonstrated in experimental inflammation models.