British Poultry Science最新文献

1. Resveratrol (RSV) is an antioxidant and anti-inflammatory plant polyphenol that is widely used for the prevention of stress-related diseases. Chronic unpredictable mild stress (CUMS) significantly affects the immune system of layers, leading to substantial losses in growth performance and welfare. The aim of this study was to explore the effect of a multi-stress environment under CUMS conditions on the bursa of Fabricius and any therapeutic effects.2. A total of 288 healthy, one-day-old layer chicks were divided into three groups: a healthy control, challenged with CUMS or CUMS+RSV. At 42 d of age, bursa of Fabricius samples were collected and analysed. Transmission electron microscopy (TEM), haematoxylin and eosin (H&E) staining, RNA-seq technology, qRT-PCR, Western blots, immunofluorescence and immunohistochemical staining were used to assess tissue damage and mRNA expression and enrichment pathways.3. The tissue damage under CUMS challenge was observed and RSV alleviated the degree of injury from the results of H&E staining and TEM. Transcriptome analysis identified a total of 631, 293 and 598 differentially expressed genes (DEG; log2 fold change > 1, p < 0.05) in the control vs. CUMS, CUMS vs. CUMS+RSV and control vs. CUMS+RSV group, respectively.4. Genes related to neuroactive ligand-receptor interaction were NTSR1 and GZMA down-regulated while KNG1, OPRL1 and P2RY8 were up-regulated and calcium signalling pathway genes CXCR4, PLCG2, PRKCB and CAMK2A were up-regulated in the CUMS group compared to control group. However, CXCR4, PLCG2 and CAMK2A were down-regulated, whereas NTSR1 and GZMA were up-regulated genes in CUMS+RSV group compared to the CUMS group. Analyses of DEG was conducted based on the KEGG pathway and verified using qRT PCR and Western blots.

1. Pendulous crop is a metabolic illness causing irreversible distension of the crop muscles due to weakened supporting ligaments. The present study assessed the physical, haematological and biochemical features of broiler chickens afflicted by pendulous crop (PC).2. Fifty-six broiler chickens, male and female Cobb 500, were used. Forty-two-day old animals were chosen from the batch by verifying the volume of the organ and 28 healthy and 28 animals with PC were selected. The birds were weighed, assessed and 4 ml of blood was collected for cell count and serum biochemistry analysis.3. Birds with PC had lack of co-ordination, difficulty in locomotion and regurgitation of the contents of the crop. Body weight was similar in PC and healthy birds (p > 0.05), however the absolute and relative crop weight in affected birds was higher than in healthy birds (p < 0.05).4. When analysing the blood count, the mean corpuscular haemoglobin concentration (MCHC) in afflicted birds was lower than in healthy birds (p < 0.05). Serum biochemistry analysis showed that creatine kinase (CK) was higher in afflicted birds, and uric acid (UA) and triglycerides (TC) were lower in birds with PC (p < 0.05).5. This disease compromises the physical state, behaviour and crop weight of birds, but did not cause significant haematological changes. However, it modified creatine kinase, which suggested changes in muscle metabolism and impairment of the digestion and nutrient's absorption process.

1. This study evaluated the effectiveness of different concentrations of arginine (Arg) in the diet on reproductive performance, body weight loss and plasma biochemical indices of breeding pigeons as well as on growth performance, carcass characteristics and plasma biochemical indices of squabs.2. In total, 360 pairs of 12-16-month-old European Mimas breeding pigeons were randomly divided into six groups (10 replicates of 6 pairs each). They were fed different pelleted diets with Arg levels of 0.58, 0.73, 0.88, 1.03%, 1.18 or 1.33%, respectively, for an experimental period of 45 d.3. The highest body weight gain during the incubation period occurred in the 1.03% Arg group. Feed intake increased curvilinearly throughout the trial in line with the increase in Arg levels, the highest being observed in the 1.18% Arg group.4. Body weight of squabs increased curvilinearly with an increase in Arg levels, with the highest occurring in the 1.18% Arg group. The FCR decreased curvilinearly with an increase in Arg levels. The lowest FCR occurred in the 1.03% and 1.18% Arg groups. Slaughter weights, eviscerated weight and pectoral muscle weights of 21 d squabs increased curvilinearly with increasing Arg levels and the best slaughter yield was observed in the 1.18% group.5. In addition, the highest plasma activities of total superoxide dismutase (T-SOD) and catalase (CAT) and the lowest malondialdehyde (MDA), aspartate transaminase (AST) and uric acid (UA) levels were observed in the 1.18% group. Using binary regression modelling in SPSS, the optimal dietary Arg level for breeding pigeons, based on the slaughter performance and FCR of squabs was 1.01-1.07%. Additionally, based on the full-term weight loss and oxidative stress of breeding pigeons as evaluation indexes, 0.96-1.01% Arg was optimal.6. In conclusion, the optimal dietary Arg for the best reproductive of breeding pigeons and growth performance of squabs in a 2+4 lactation pattern was 0.96%-1.07%.

1. This study evaluated the biomechanical properties of quail bones using standard guidelines. The femur and tibiotarsus bones were used from 56 healthy quails.2. Computed tomography was used for cross-sectional data. The diameters were measured and cortical indices were calculated. Three-point bending and shear tests were performed. The maximum bending, shear forces and load-displacement curves were recorded. Bone stiffness, bending strength, shear strength and elastic modulus were calculated. Statistical comparisons were performed between sexes.3. Females had higher bone weights than males. Cortical indices were similar between sexes in the femur (51-58%) but higher in the tibiotarsus of females (53-66%).4. In shear tests, the femur fractured between 62 and 88 N and the tibiotarsus between 93 and 139 N, with females demonstrating consistently higher maximum shear force. Shear strength ranged from 5 to 7 MPa in the femur and 8-12 MPa in the tibiotarsus, the latter being significantly greater in females.5. In three-point bending tests, all parameters were higher in females: the femur fractured between 37 and 51 N and the tibiotarsus between 47 and 62 N, with bending strength ranging from 32 to 65 MPa and 41 to 65 MPa and elastic modulus between 1665 and 3135 MPa and 3244 and 5818 MPa, respectively.

1. This study investigated the maternal lineage and genetic diversity of indigenous Indonesian chickens using mitochondrial DNA (mtDNA) D-loop sequences to assess population structure and maternal origins.2. Fifty-two samples from eight chicken populations were sequenced for the 1231 bp mtDNA D-loop region. A total of 26 haplotypes were identified, with high diversity observed across all populations (Hd = 0.700-0.933). Most chickens, including Tukong, clustered in haplogroup D1, which suggested a shared maternal lineage common to Southeast Asian domesticated chickens. Two individuals (KUB2 and TK2) were positioned in sub-haplogroup D2, indicating sequence divergence. Merawang and Nunukan chickens were grouped into haplogroups A and B, respectively, consistent with haplotypes shared with Chinese and Japanese chickens, pointing to historical maternal introgression, likely via trade or migration. Analysis of molecular variance (AMOVA) revealed that 28.45% of genetic variation existed among populations (Fst = 0.284, p < 0.001), which indicated a moderate but statistically significant population structure.3. Multiple haplogroups in Indonesian chickens reflect complex maternal origins and past gene flow from outside populations. These findings highlighted the importance of understanding genetic structure to inform the management and characterisation of native breeds. The distinct maternal lineages in Merawang and Nunukan showed historical introductions, while the close relationship among Tukong and Kampung chickens implied interbreeding under extensive rearing systems.

1. Limited starch digestibility in broiler diets, associated with granule structure and ingredient variability, can reduce energy utilisation and impair performance. Thus, this study aimed to evaluate the effects of alpha-amylase supplementation on performance, carcase yield, nutrient digestibility, intestinal morphology and short-chain fatty acid production.2. A total of 640 male broiler chickens (Cobb 500) were distributed in a completely randomised design with four treatments and eight repetitions of 20 birds each. The treatments: PC: positive control, formulated to meet the nutritional requirements of the birds; NC: negative control with a reduction of 0.25 MJ of metabolisable energy (ME) per kg of diet; NCA100: NC + 100 g alpha-amylase per kg of diet; NCA200; NC + 200 g alpha-amylase per kg of diet.3. At 21 and 42 d, performance was evaluated and, at 42 d, carcase yield and cuts, nutrient digestibility, intestinal morphology and short-chain fatty acid production were assessed in broiler chickens.4. At 21 and 42 d of age, broiler chickens supplemented with NCA200 exhibited improved metabolisable energy (ME) utilisation compared to the PC and NC groups. At 42 d, NCA200 supplementation increased ileal nutrient digestibility, as indicated by both digestible ash and the ash digestibility coefficient. At the same age, broiler chickens supplemented with NCA200 showed enhanced duodenal morphology, with greater villus height and villus-to-crypt ratio, as well as elevated caecal short-chain fatty acid concentrations, including acetic, propanoic and butyric acids, compared to the PC and NC groups.5. In conclusion, supplementation with NCA200 in reduced-energy diets increased mineral digestibility, promoted beneficial changes in intestinal morphology and elevated short-chain fatty acid production, demonstrating its efficacy in broiler diets without affecting performance.

1. This study investigated the transcriptomic expression of the pigeon retina and pineal gland when exposed to red light (RL). Light is a crucial environmental factor influencing poultry production, physiology and behaviour. Different wavelengths of light have distinct effects on photoreceptors, including those in the retina and pineal gland, ultimately regulating various production benefits.2. Using transcriptome sequencing, this trial examined the gene expression profiles of the retina and pineal gland of White King pigeons exposed to either red light (RL; 660 nm) or White light (WL; 400-760 nm) for 6 months. In total, 12 RNA-seq libraries were constructed and sequenced on an Illumina Novaseq 6000 platform. This identified 2305 and 635 differentially expressed genes (DEG) in the retinal and pineal gland, respectively. Gene Ontology (GO) analysis showed a total of 466 and 235 GO terms were identified in retina and pineal gland (p < 0.05).3. In these two tissues, three common GO terms were identified, including nervous system development, glutamatergic synapse and structural constituent of ribosome. Functional enrichment analysis revealed that DEG in retina were enriched in pathways related to metabolism, genetic information processing and environmental information processing. However, DEG in the pineal gland were enriched for hormone metabolism and retinol binding.4. Through integrated analysis of a protein-protein interaction (PPI) network and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway maps, four DEG (optic protein-related genes OPN5 and EGR1 in retina, melatonin-related genes SNAT and ASMT in pineal gland) were identified, which play crucial roles and affected breed performance between RL and WL. These findings provide insights into the molecular mechanisms by which RL modulates the transcriptome of pigeon retina and pineal gland, potentially influencing poultry production and physiology.

1. Chlorella vulgaris (C. vulgaris) is a highly nutritious and sustainable feed ingredient, but its rigid cell wall limits nutrient availability and digestibility.2. To evaluate the effects of incorporating C. vulgaris at 15% dietary inclusion in broiler diets during a three-week finishing period (days 14-35), four experimental diets were tested: a control maize-soybean meal diet (CON), a 15% C. vulgaris diet (CHL), a 15% C. vulgaris plus 0.30% pancreatin diet (CHLENZ) and a 15% extruded C. vulgaris diet (CHLEXT).3. Growth performance, haematological variables, blood biochemistry, hepatic lipid, pigment and mineral contents were analysed. To date, no study has explored the effects of C. vulgaris at this inclusion level on broiler plasma metabolites and hepatic lipid composition, either extruded or supplemented with super-dosing pancreatin, both aimed at enhancing nutrient utilisation.4. All C. vulgaris diets maintained or improved growth performance, with CHLEXT significantly enhancing final body weight, body weight gain and feed conversion ratio. Most haematological markers were unaffected, although extrusion lowered granulocyte and elevated lymphocyte counts relative to CHL and CHLENZ. Biochemical changes included reduced triacylglycerol levels and elevated glucose in all microalga-fed groups. Additionally, creatine levels were reduced in the CHL and CHLENZ groups compared to the CON group. Hepatic fatty acid profile showed reduced n-6/n-3 polyunsaturated fatty acid ratio in all C. vulgaris-fed groups. Mineral content showed a decrease in hepatic magnesium in the CHLEXT group compared to the CON group.5. A 15% dietary inclusion of C. vulgaris is nutritionally viable and metabolically beneficial for broilers.

1. This study identified the most effective indicator for assessing the duration of fertility (DF) in chickens by comparing six potential indicators; number of fertilised eggs (NFE), maximum number of fertilised eggs continuously produced (MNFE), effective duration of fertility (EDF), fertility duration day (FDD), maximum duration of fertility conditional (MDFC) and maximum duration of fertility (MDF).2. This study used 1162 Xinhua chickens in two groups: 764 parental (unselected) and 398 selected (first-generation obtained from the parent MNFE > 6) groups, with three lines (B, C and D) in each group. Data from two artificial insemination cycles (17 d) in 60-week-old birds were used to calculate the indicator value. Subsequently, a comparative analysis of the indicators, heritability, selection response and repeatability was conducted within and between groups to assess genetic and environmental influences. Correlation analysis was performed to evaluate the relationship between the indicators and egg production status (unfertilised egg production (UEP), total egg production number (TEP) and individual fertility rate (IFR)).3. Comparing the two groups, there were significant (p < 0.001) differences in all indicators except MDFC and MDF. Among the indicators, NFE exhibited the highest heritability (h²  = 0.23), the strongest selection response (R = 0.80) and the highest repeatability in both groups. Analysis showed that NFE was significantly (p < 0.001) correlated with all indicators and highly correlated with TEP(r = 0.73), IFR (r = 0.74) and negatively moderately correlated with UEP (r = -0.49).4. The data suggested that NFE was the most reliable DF indicator, offering consistency and comparatively higher genetic influence.

1. This study determined the pre-caecal digestibility of crude protein (CP), amino acids (AA), gross energy, phosphorus (P) and pre-caecal phytate (InsP₆) disappearance of a dehulled and ethanol-extracted rapeseed kernel meal (RKM) without and with exogenous phytase in broiler chickens.2. The experiment utilised a 3 × 2 factorial design with the factors RKM inclusion (0, 12.5 or 25%) and phytase supplementation (0 or 1500 FTU/kg). Diets were fed to Ross 308 broiler chickens from 16 to 21 d of age raised in floor pens (seven per diet).3. The RKM inclusion decreased the digestibility of certain AA (p < 0.05) and phytase increased the digestibility of CP and all AA in the diets (p < 0.05). CP digestibility in RKM, calculated by linear regression, was 75% without and 80% with phytase and Lys digestibility was 81% without and 85% with phytase. There was no significant phytase effect on the slopes of regression lines.4. With increasing RKM inclusion, pre-caecal InsP₆ disappearance decreased without phytase and increased with phytase (RKM × phytase: p < 0.010). Increased RKM inclusion reduced the amount of digestible P without phytase, whereas with phytase, the amount of digestible P increased with RKM inclusion (RKM × phytase: p < 0.001).5. Pre-caecal gross energy digestibility decreased with RKM inclusion (p < 0.001) and increased with phytase supplementation (p < 0.05). Crude protein and AA digestibility of the RKM was high and increased with phytase supplementation. The P from RKM was not digestible without phytase.