British Poultry Science最新文献

1. The Ispenc chicken, a genetically undefined miniature breed in Türkiye, was analysed using mitochondrial DNA to clarify its maternal lineage and assess its distinction from European ornamental breeds (Sabelpoot and Barbu d'Anvers) as well as from the Sultan breed.2. Phylogenetic analysis of a 1508 bp mtDNA fragment spanning the D-loop identified five haplotypes (H1-H5): Ispenc individuals carried H2 and H3, Sultan chickens carried H4, while Sabelpoot and Barbu d'Anvers shared H5.3. Molecular variance analysis indicated strong population structure, with 98% of genetic variation occurring among populations (F_st = 0.98184). Two complete mitogenomes representing the H2 and H3 haplotypes of the Ispenc breed (16785 bp each) were assembled, each containing a 1232 bp D-loop and the standard set of 37 mitochondrial genes.4. Comparative mitogenome analysis identified 62 nucleotide differences among haplotypes: Ispenc differed from Sabelpoot and Barbu d'Anvers by 44-45 nucleotides, whereas these two breeds differed by only two nucleotides. Haplogroup analysis assigned Ispenc to haplogroup A and the European ornamental breeds to haplogroup E.5. These results demonstrated that the Ispenc chicken represents a distinct maternal lineage that is clearly differentiated from European miniature breeds. This underscored its value as a native genetic resource and highlighting the need to conserve both of its mtDNA lineages (H2 and H3).

1. A total of 450 male chickens were individually housed and assessed for residual feed intake (RFI) and feed conversion ratio (FCR) over a 28 d feeding trial, with subsequent phenotypic measurements and breast muscle samples collected from selected high- and low-efficiency groups for metabolomic and lipidomic profiling.2. Residual FI had significant correlations with faecal volume, behavioural activity and head temperature, while FCR showed only a negative correlation with head temperature. Meat quality analysis revealed that residual FI correlated with breast muscle shear force, while FCR was associated with thigh muscle colour parameters.3. Multi-omics profiling of breast muscle showed distinct metabolite and lipid compositions between efficiency groups, and FCR was linked to triacylglycerol content and residual feed intake (RFI) to glycerophospholipid levels.4. This trial demonstrated that feed efficiency influences both physiological processes and meat quality, providing a basis for balanced breeding strategies in slow-growing poultry.

1. This study investigated the effects of different monochromatic light-emitting diode (LED) light colours on tear production, intraocular pressure and corneal thickness in broiler chickens, and to identify any correlations among these ocular parameters.2. A total of 72 male broilers (144 eyes) were used. One-d-old chicks were randomly assigned to six experimental groups (white, blue, green, blue-green-blue, green-blue-green and white-blue-green LED light; n = 12). Lighting was provided using LED bulbs under identical environmental and management conditions.3. At 42 d of age, 12 birds per group were randomly selected for ophthalmological examination, including the Schirmer tear test I (STT I), intraocular pressure measurement (IOP) and central corneal thickness assessment. At the animal level, without distinguishing between right and left eyes, a significant difference was observed in central corneal thickness between birds in the white LED group and the other treatments.4. Monochromatic LED light colours affected only central corneal thickness, while tear production and intraocular pressure remained unaffected. The changes in corneal thickness observed under different light colours were within normal physiological limits, which indicated no adverse effect on ocular health in broiler chickens.

1. This 42 d study further examined the physiological mechanisms underlying responses to a precision biotic (PB) on growth performance and ileal amino acid digestibility. It focussed on fermentation profile, caecal soluble protein levels, gut integrity, immune modulation, intestinal lesion scores and antimicrobial resistance gene (AMR) abundance in Eimeria challenged broiler chickens.2. In total, 1012 one-d-old male chicks were assigned to one of six treatments, each with a minimum of seven replicates in a randomised incomplete block design. The treatments were: control (C) maize-soya (SBM) based diet, no challenge (C-NCH); or with challenge, without PB (C-CH-0); wheat-based (W) diet plus challenge, with 0, 300, 600, or 900 mg/kg PB (W-CH-0, W-CH-300, W-CH-600, W-CH-900). On d 12, except for C-NCH, all birds were inoculated with mixed Eimeria spp. oocysts through feed to induce enteric stress. Caecal contents, jejunal and splenic tissues were collected on d 20 and 42 to determine caecal SCFA profiles, soluble protein concentrations, relative abundance of antimicrobial resistant genes (AMR) genes, mRNA expression of gut integrity (CLDN1, OCLDN and JAM2) and immune-related genes (IL-6, IL-10, IL-1 β, IFN-γ, TGF-β1 and iNOS), respectively.3. On d 42, caecal isobutyrate, isovalerate and total branched-chain fatty acids (BCFA) were lower (p < 0.05) in W-CH-0 than in C-CH-0. No significant treatment effects were observed for caeca soluble protein concentrations. On d 20, PB linearly increased (p < 0.05) the expression of OCLDN gene, while IL-1β expression decreased quadratically (p < 0.05). However, IFN-γ expression was lower (p < 0.05) in challenged birds on d 42. Relative abundance of AMR genes (sul2, tetM, strB and blaCTX-M) showed no significant treatment effects.4. Overall, decreased caecal BCFA suggested lower protein fermentation with possible modulation of caeca microbiota. The PB supplementation increased OCLDN expression, possibly positively affecting gut integrity in the challenged birds. This could have accounted for the beneficial effect of PB on the growth performance in challenged broilers.

1. The objective of this trial was to examine the effect of Sacha inchi oil (SIO), extracted from local nut sources common to the Amazon region, in broiler diets. The oil was substituted for soybean oil (SBO) within diets of slow-growing broilers and the effects on growth performance, carcass traits, serum biochemistry, objective meat quality and meat fatty acid profile were assessed.2. A total of 400, mixed sex, 56 d old, crossbred Ho × Luong Phuong broilers were randomly allocated to one of four experimental diets: a control diet (CON) containing 4.5% SBO and three experimental diets with SIO at substitution levels of 33.3% (SI1), 66.7% (SI2) and 100% (SI3) instead of SBO for a feeding period of 56 days. Each diet was replicated in four replicated pens of 25 birds, comprising two pens of males and two pens of females.3. Growth variables were recorded every two weeks. Blood samples were collected via puncture of the brachial vein one day prior to the completion of the experiment to determine serum biochemical indices. At the end of the study, four birds per pen were humanely slaughtered to evaluate carcass traits and breast samples were collected for assessments of meat technological quality and fatty acid profile.4. The inclusion of SIO increased the proportion of n-3 PUFA, lowered the n-6/n-3 PUFA ratio and cholesterol content in breast muscle and reduced serum triglyceride and low-density lipoprotein levels, without detrimental effects on growth, carcass traits or meat quality variables.5. The results demonstrated that SIO is a promising alternative lipid source for improving the nutritional value of poultry meat without adversely affecting productive performance or carcass characteristics.

1. This study evaluated the effects of phytase superdosing in broiler chicken diets based on corn, soybean meal and meat and bone meal on performance, carcass yield, pectoral myopathies, bone mineral composition and the metabolisability of energy and nutrients.2. Two experiments were conducted: one focused on performance and the other on nutrient metabolism. In both experiments, birds were randomly assigned to a completely randomised experimental design. The performance trial included 1600 male Cobb 500 broilers, whereas the metabolism trial included 480 birds of the same strain. In the performance trial, birds were allocated to one of eight treatments with 10 replicates of 20 birds per experimental unit from 1 to 42 d of age. In the metabolism trial, each experimental unit consisted of six birds. Linear and quadratic regression analyses were performed to estimate the optimal phytase supplementation level.3. Higher phytase inclusion levels, particularly 2000 phytase units/kg feed, resulted in greater weight gain and better feed conversion ratio. Diets supplemented with 2000 and 2500 phytase units/kg caused the highest calcium and phosphorus concentrations in tibia bones.4. In the nutrient metabolisability trial, phytase supplementation promoted linear increases in metabolisability coefficients for gross energy, organic matter and zinc, along with linear reductions in excreted mineral matter and zinc.5. Overall, phytase superdosing, especially at 2000 and 2500 phytase units/kg, enhanced broiler performance, increased bone mineral deposition, improved nutrient metabolisability by 7 to 29% and reduced phosphorus excretion by up to 31.6%.6. These findings demonstrated that high-dose phytase can be an effective strategy to improve feed efficiency and nutrient utilisation in broiler diets containing mixed phosphorus sources, including animal-derived ingredients.

1. This study used the Chinese local breed, Gushi chicken, as the model to investigate the ankyrin repeat domain 9 (ANKRD9) gene. This focussed on its biological function in muscle development and regulation of inosine monophosphate (IMP), a key flavour metabolite in chicken meat.2. The dynamic expression of ANKRD9 in breast muscle tissue was analysed using qRT-PCR. Combined with transcriptomic and metabolomic technologies, the regulatory network of ANKRD9 in chicken primary myoblasts (CPM) was elucidated.3. The results indicated that ANKRD9 likely affected cellular adhesion and IMP accumulation. The ELISA assays in CPM confirmed that overexpression of ANKRD9 significantly inhibited IMP metabolism in myoblasts. This suggested this gene has a key role in the negative regulation of IMP.4. These results highlighted the critical role of ANKRD9 in regulating the flavour metabolite IMP. This provides a potential molecular target and theoretical foundation for the breeding of high-quality broilers.

1. Light wavelength is a key environmental factor influencing broiler growth, feed efficiency and meat quality. This study evaluated the effects of monochromatic (white, blue, green) and combined (white-blue-green, blue-green-blue, green-blue-green) LED lighting regimens on growth performance, carcase yield and breast meat characteristics in Ross 308 broilers. White (400-770 nm), blue (450-470 nm) and green (520-570 nm) LED lamps were used throughout the 42-d trial. Light intensity was standardised at 20 lux photopic illuminance at bird-head level and verified daily using a calibrated digital luxmeter.2. A total of 216 male chicks were allocated to 6 treatments (three replicates; 12 birds/pen). Growth traits were monitored across the starter, grower and finisher phases; carcase yield and meat quality (pH, colour, cooking loss and water-holding capacity) were assessed post-slaughter.3. Sequential green-blue lighting regimens (GBG and BGB) significantly improved body weight and FCR compared with monochromatic white light (p < 0.001). Although breast yield decreased under blue light alone, this effect was not observed under combined regimens. Meat quality traits were largely unaffected, although redness increased and cooking loss decreased under green-blue combinations.4. Phase-specific green-blue LED lighting programmes can enhance broiler productivity and energy efficiency without compromising carcase yield or meat quality, representing a practical and welfare-compatible strategy for sustainable poultry production.

1. This study examined the impact of perch-based enrichment on the growth performance, welfare and behavioural parameters of broilers. A total of 180, one-day-old male Ross 308 broilers were used in this study. The experiment was conducted using six pens in a commercial broiler house, each with three deep litter systems and three perch-based enriched systems.2. Both rearing systems had similar effects on final body weight, final body weight gain, cumulative feed consumption, feed conversion ratio and mortality rate (p > 0.05).3. The broilers in the deep litter system had worse hock burn (p = 0.000) and gait score (p = 0.052) than the enriched system.4. Plumage cleanliness, body wounds, toe damage, foot pad and bumble foot lesions and tonic immobility reaction had similar effects on both systems (p > 0.05). The investigated behaviours were similar in both systems (p > 0.05).5. In conclusion, perch-based enrichment had no significant effects on broiler growth performance, behaviour or most welfare indicators. However, perch-based enrichment improved hock burn and tended to improve gait.

1. This study evaluated the potential of visible-near infrared (Vis-NIR) hyperspectral imaging (HSI) combined with machine learning and explainable artificial intelligence (AI) to non-destructively predict chick embryo mortality before incubation and at 4 d of incubation.2. The partial least squares discriminant analysis (PLS-DA), random forest (RF) and categorical boosting (CatBoost) calibration models were developed and independent validation and test sets evaluated the performance of the calibration models. In addition to raw figures, synthetic data was utilised for classification model development. Various spectral pre-processing and feature selection methods were evaluated to enhance predictive robustness. The best model was interpreted using Shapley additive explanations (SHAP) for AI.3. At full wavelength (501-921 nm), the PLS-DA model demonstrated the best performance for chick embryo mortality classification, achieving an accuracy of 91.3% for calibration, 88% for validation and 86.7% for the test set for pre-incubation. At d 4 of incubation (ED4), the model showed 97.3% accuracy for calibration, 96% for validation and 97.3% for the test set, highlighting its robustness across different data sets.4. The PLS-DA models, using a reduced set of important spectral features, demonstrated strong predictive performance, offering computational efficiency, robustness and enhanced interpretability.5. The SHAP explainable AI revealed that wavelengths associated with embryo hydration status, blood formation and metabolic differences between live and dead embryos are critical for classifying chick embryo mortality during early incubation.