Atrazine (ATR), a widely applied herbicide, poses health risks to animals and humans owing to its environmental persistence and bioaccumulation. Kidney is a target organ of ATR, and renal ion disturbance is a major effect of ATR-induced nephrotoxicity. Selenium-enriched yeast (Yeast-Se) is an organic selenium source with high bioavailability and antioxidant properties that protects against chemical-induced organ damage. This study aimed to explore investigate the protective effect of Yeast-Se on ATR-induced renal injury in Japanese quails. In this study, quails were randomly distributed into four groups: Control group (basal diet), ATR group (basal diet + 500 mg/kg B.W. ATR), ATR + Se group (500 mg/kg B.W. ATR + 0.3 mg/ kg of Yeast-Se), and Yeast-Se group (0.3 mg/kg of Yeast-Se). After 28 days of treatment, Yeast-Se supplementation effectively restored kidney structural and functional damage caused by ATR. Renal Na[+] and Cl[-] levels were significantly increased after the treatment of ATR, whereas K[+], Ca[2+]and Mg[2+]levels decreased. Notably, Yeast-Se could relieve ATR-induced nephrotoxicity via upregulating Na[+]-K[+]-ATPase activity, downregulating Ca[2+]/Mg[2+]-ATPase activity and controlling aquaporin (AQP) subunit expression. These findings collectively suggested that Yeast-Se has strong potential ameliorative impact against ATR induced renal ionic homeostasis disturbance by modulating AQPs expression.

Blackhead disease (Histomoniasis), caused by Histomonas meleagridis, continues to threaten turkey production by causing severe lesions in the ceca and liver, with no approved treatments currently available. A study was conducted to evaluate whether dietary pine bark (PB), a polyphenol- and tannin-rich feed additive, could mitigate disease severity and tissue damage in H. meleagridis-challenged turkey poults. A total of 432 one-day-old male turkey poults were used in a 2 × 3 factorial design with two factors: H. meleagridis challenge (HM[+]/HM[-]) and dietary PB inclusion (0, 0.2, or 0.4%), generating six treatments with six replicate cages per treatment (12 poults/replicate). Pine bark extract was fed from day 0, and HM challenge was administered on day 18 via the cloacal route. Growth performance was assessed through day 28, mortality was recorded daily, and necropsies were performed to determine infection status and lesion severity. Intestinal histomorphology was evaluated, and vascular permeability was quantified using Evans Blue Dye (EBD) across multiple organs. H. meleagridis challenge significantly reduced body weight and feed intake and increased feed conversion ratio compared with non-challenged birds (P < 0.01). Pine bark extract supplementation did not significantly alter body weight gain or feed intake; however, it reduced mortality in challenged poults from 52% in the challenged basal group to 26% and 38% in the 0.2% and 0.4% PB groups, respectively (P = 0.04). The infection rate remained high across challenged groups, with rates of 100%, 94%, and 96% in the 0%, 0.3%, and 0.4% PB groups, respectively. Cecal lesion severity was decreased by PB inclusion (P = 0.04), with the lowest lesion scores observed at 0.2% PB. Evans Blue results showed that HM challenge increased vascular permeability in the ceca, liver, and cecal tonsils (P < 0.01). Pine bark extract reduced EBD accumulation in the ceca (P = 0.04), and a PB × HM interaction was detected in the liver (P = 0.01), indicating tissue-specific effects under challenge conditions. Overall, dietary pine bark reduced mortality and improved ceca vascular integrity in H. meleagridis-infected turkey poults, with the highest survival benefit observed at 0.2% inclusion.

As demand for poultry meat continues to increase, commercial broiler production relies on increasingly large-scale facilities and higher stocking densities. In production environments, which prioritize maximum efficiency, environmental management is often overlooked and/or underprioritized. There is an increased risk of bacterial pathogen transmission, environmental contamination, and the accumulation of organic waste, allowing widespread pathogen proliferation. One of the primary sources of pathogen transmission is the improper management of bedding in these confined spaces. Once birds are introduced, bedding accumulates excreta, feed waste, feathers, broken eggs, and residual bedding as it transitions to litter. Potential pathogens include Clostridium, pathogenic Escherichia coli, Staphylococcus, Campylobacter, Enterococcus, and Salmonella. Pathogens in poultry litter can pass between generations and within flocks, as recontamination is a concurrent issue in these environments. The ability of bacterial pathogens to persist in litter, survive between production cycles, and serve as a continued source of flock reinfection will be described in this review. Poultry house and flock management strategies that may have an impact on pathogen survival and dissemination will also be discussed in this review.

Environmental enrichment is a promising strategy to improve welfare in laying hens, particularly in aviary systems where large group sizes and complex social interactions can predispose birds to fearfulness and feather pecking. This study evaluated the effects of providing coarsely milled almond shells (AS; geometric mean diameter = 1525 µm) as an environmental enrichment on welfare indicators, egg quality, and organ development in large commercial aviary flocks. The study compared two treatments-hens receiving AS and a control group that did not receive AS-with four pens per treatment and 2,500 hens per pen. Welfare indicators, as well as external and internal egg quality traits, were assessed at peak lay (13 weeks (wk) of trial; 33 weeks of age) and post-peak lay (23 wk of trial; 43 wk of age). In addition, at 23 wk of trial, serum corticosterone and relative organ weights were measured. At peak lay, hens provided with AS enrichment showed reduced fearfulness in the novel object test (P < 0.001), a trend toward lower gentle feather pecking (P < 0.1), and fewer comb pecking wounds and lower overall pecking scores (P < 0.001). No differences were observed in free feathers in the litter or severe/aggressive pecking. At post-peak, hens provided with AS enrichment continued to show lower fear responses (P < 0.001), fewer free feathers in the litter (P < 0.05), and tendencies toward reduced plumage damage, lower overall pecking scores, and reduced serum corticosterone (7.05 vs. 11.23 ng/mL; P < 0.1). Both internal and external egg quality parameters remained unaffected at both ages. Relative weights of liver, proventriculus, gizzard, pancreas, and spleen were unchanged, while small and large intestines tended to be heavier in hens provided with AS enrichment (P < 0.1). In conclusion, milled AS could be an effective enrichment for aviary-housed laying hens, by reducing fear and stress, mitigating feather pecking, and supporting minor digestive adaptations, without compromising egg quality. These findings support the use of AS as a sustainable agricultural by-product to improve welfare in large commercial flocks.

Klebsiella pneumoniae causes pulmonary disease and production losses in poultry, while resistant strains may disseminate antimicrobial resistance. Rational antimicrobial dosing is important. This study characterized pulmonary ceftiofur exposure-response relationships and assessed dose fractionation by comparing once-daily (QD) and twice-daily (BID) regimens at matched daily doses. MIC testing against eight antimicrobials was performed on 12 chicken-derived clinical K. pneumoniae isolates to support ceftiofur selection. A strain with stable pulmonary colonization was selected for determination of ceftiofur MIC, MBC, and time-kill kinetics. A total of 312 chicks with experimentally induced K. pneumoniae pulmonary infection were used for pharmacokinetic assessment. After establishment of the pulmonary infection model, total ceftiofur equivalents in plasma and lung homogenate were determined after intramuscular ceftiofur sodium at 2, 5, 10, or 20 mg/kg. Therapeutic efficacy was evaluated in 60 infected chicks receiving 5-20 mg/kg QD or BID for 3 d. Pulmonary PK/PD data were fitted to an inhibitory sigmoid Emax model relating AUC0-24h/MIC, Cmax/MIC, and T%>MIC to baseline-referenced changes in pulmonary bacterial burden. The T%>MIC target associated with a 3-log10CFU/g reduction was used to estimate a candidate BID regimen. GZJC2922 maintained a high burden for 24 h. Its MIC and MBC were 0.5 and 2 μg/mL; ≥2×MIC reduced counts to the detection limit within 24 h. Pulmonary Cmax and AUC0-24 h increased in proportion to dose. At matched daily doses, BID produced burdens 0.29-0.54 log10CFU/g lower than QD (all adjusted P < 0.001). T%>MIC fit best (R[2] = 0.90; AIC=85.357), followed by AUC0-24h/MIC (R[2]=0.89; AIC=90.167); Cmax/MIC was weaker (R[2]=0.62; AIC=154.926). Their 3-log10CFU/g targets were 51.71%, 58.90 h, and 8.88. The T%>MIC target yielded a candidate regimen of 2.98 mg/kg every 12 h for 3 d. Thus, T%>MIC was the most informative pulmonary PK/PD index, and the candidate regimen requires prospective validation.

Sesame seed (SS) and sesame oil (SO) are rich sources of unsaturated fatty acids, lignans, and natural antioxidants that have been reported to improve poultry performance and health. However, their relative biological efficacy under identical experimental conditions has not been directly compared. This study evaluated the comparative effects of dietary sesame seed (20 g/kg) and sesame oil (1.5 mL/kg) supplementation on production performance, egg quality, serum biochemical profile, antioxidant status, intestinal microflora, and intestinal morphology in Rhode Island Red laying hens. A total of 180 laying hens were randomly assigned to three dietary treatments: a control diet, control supplemented with sesame seed (20 g/kg), and control supplemented with sesame oil (1.5 mL/kg). Neither sesame seed nor sesame oil affected feed intake or egg quality (P > 0.05). Both dietary supplements significantly increased egg production, hen-day production, and feed conversion efficiency while improving serum lipid profile by reducing low-density lipoprotein and total cholesterol and increasing high-density lipoprotein (P < 0.05). Antioxidant capacity was enhanced through increased superoxide dismutase, glutathione peroxidase, and total antioxidant status, whereas malondialdehyde remained unchanged (P > 0.05). Both treatments reduced fecal E. coli and Salmonella populations and improved intestinal morphology by increasing villus height and villus height-to-crypt depth ratio while reducing crypt depth (P < 0.05). Across most measured parameters, sesame oil produced significantly greater improvements than sesame seed. Both sesame seed and sesame oil improved productive performance, metabolic health, antioxidant status, gut health, and intestinal morphology without compromising egg quality. Sesame oil consistently exhibited superior biological efficacy, indicating that it is a more effective sesame-derived functional feed additive for enhancing the productivity and physiological health of laying hens.

Based on previously observed eggshell defects of translucent eggs and sand-shelled eggs, this study systematically elucidates their formation mechanisms and key physiological differences in laying hens through multi-omics approaches. Sand-shelled eggs were characterized by altered serum calcium-regulating hormones profiles, lower tibial strength, downregulated uterine calcium-phosphorus transport genes, and impaired mammillary layer formation. Translucent eggs exhibited distinct phenotypic traits, including significantly fewer eggshell pores and greater shell weight, along with markedly downregulated uterine calcium-phosphorus transport genes and compensatory upregulation of the corresponding genes in the duodenum and kidney. Transcriptomic analysis further revealed that PPAR signaling and peroxisome pathways were activated in the duodenum of hens laying translucent eggs, with heat shock protein HSPH1 consistently upregulated across three tissues, indicating energy-lipid metabolic reprogramming and modest cellular stress. In conclusion, the formation of translucent eggs primarily resulted from localized uterine calcium-phosphorus secretion dysfunction and its consequent systemic metabolic adaptation and stress response, whereas sand-shelled eggs resulted from systemic calcium deficiency and more severe uterine functional impairment. This study provides novel insights into the regulatory network of eggshell biomineralization and offers a theoretical basis for improving eggshell quality.

This study evaluated the effects of dietary supplementation with 25-hydroxyvitamin D3 (25-OH-D3) on reproductive performance and lipid metabolism in late-laying duck breeders, as well as hepatic lipid metabolism of their offspring. Forty healthy duck breeders at 64 wk of age, with comparable body weight and laying performance, were randomly distributed between a basal-diet control and the same diet providing 1000 IU/kg 25-OH-D3 for 15 wk. Relative to the controls, egg production, plasma and ovarian follicle-stimulating hormone concentrations, and ovarian estradiol concentration were higher in the 25-OH-D3 group than in the control group (P < 0.05). Plasma, hepatic, and egg yolk TG concentrations, as well as hepatic total fat content, were higher in the 25-OH-D3 group than in the control group, whereas plasma CHOL, HDL-C, and LDL-C concentrations and hepatic LDL-C concentration were lower (P < 0.05). Hepatic transcriptome profiling revealed that the differentially expressed genes were mainly related to fatty acid metabolism and PPAR-related signaling. Expression of FABP1, FABP3, FASN, ELOVL2, FADS1, FADS2, and ACSBG2 was higher in the 25-OH-D3 group than in the control group, and these genes are involved in fatty acid transport, synthesis, elongation, desaturation, and activation. Conversely, APOA4, LCAT, and CETP, genes associated with lipoprotein handling and lipid transport, were expressed at lower levels. Embryonic liver weight and liver index at embryonic day 20 were higher in offspring from the 25-OH-D3 group than in those from the control group (P < 0.05). In 1-d-old offspring, plasma CHOL and HDL-C concentrations and hepatic HDL-C concentration were lower in offspring from the 25-OH-D3 group than in those from the control group (P < 0.05). Furthermore, offspring hepatic RNA-seq revealed enrichment of PPAR signaling and lipid-associated pathways among the differentially expressed genes, together with lower expression of PCK1, ACSL5, NR4A1, NR4A2, and NR4A3 in the 25-OH-D3 group than in the control group. In conclusion, laying performance was higher in the 25-OH-D3 group than in the control group, accompanied by higher TG concentrations in maternal plasma, liver, and yolk and lower circulating CHOL and HDL-C concentrations in breeders and their 1-d-old progeny. Embryonic liver weight and liver index at E20 were also higher in offspring from the 25-OH-D3 group than in those from the control group.

Two experiments were conducted to determine phosphorus (P) digestibility or bioavailability in dehulled solvent-extracted soybean meals (SBM) varying in particle sizes. Experiment 1 was a 4 × 2 factorial treatment arrangement of 4 mean SBM particle sizes (466, 809, 1,174, and 1,577 μm) and 2 dietary calcium (Ca) levels (0.20 and 0.75%) and was conducted with Ross 308 broiler chicks to determine ileal P digestibility and total tract P retention at 20 d of age. Ileal P digestibility values (86 to 90%) were not affected by SBM particle size when dietary Ca was 0.2%. However, at 0.75% dietary Ca, 1,577 μm SBM yielded highest ileal P digestibility and was different (P < 0.05) from other SBM particle sizes. Chicks fed diets containing 0.20% Ca had higher (P < 0.05) ileal P digestibility and total tract P retention values when compared with chicks fed diets containing 0.75% Ca. Experiment 2 was conducted to determine relative P bioavailability in the 4 SBM relative to potassium phosphate (KH2PO4) using a tibia bone ash assay. Crossbred chicks (New Hampshire x Columbian) were fed one of 11 experimental diets from 8 to 22 d of age. Diet 1 was a P-deficient cornstarch-dextrose-SBM diet (0.14% nonphytate P). Remaining 10 diets were Diet 1 supplemented with 0.05 or 0.10% P from KH2PO4 or 12.5 or 25% SBM that had a mean particle size of 466, 809, 1,174, or 1,577 μm. Bioavailability of SBM P relative to KH2PO4 was estimated using the slope ratio method for multiple regression of tibia ash regressed on supplemental P intake. The 1,577 μm SBM yielded highest relative bioavailability values (30-36%) based on bone ash which were higher (P < 0.05) than the values for 466 μm SBM (20-25%). Results of this study indicate that increased particle size may increase digestibility and relative bioavailability of P in SBM and that dietary Ca level greatly affected SBM ileal P digestibility values.

Intramuscular fat (IMF) content is a major determinant of meat quality, yet the regulatory mechanisms underlying its deposition remain poorly understood, particularly in indigenous chicken breeds. In this study, an extreme phenotype grouping strategy was adopted. IMF content was measured in 200 Danzhou chickens, from which individuals with low (LIMF, n = 20) and high (HIMF, n = 20) IMF content were selected. Differences between the two groups were compared in terms of phenotypic traits, meat quality, serum biochemical parameters, breast muscle fatty acid (FA) content, cecal microbiota, serum metabolome, and breast muscle transcriptome. The results showed that the HIMF group had significantly increased IMF content, IMF area percentage, and significantly lower shear force (SF) than the LIMF group (P < 0.05). Serum levels of glucose (GLU), free fatty acids (FFA), low‑density lipoprotein cholesterol (LDL‑C), and triglycerides (TG) were significantly elevated (P < 0.05), while high‑density lipoprotein cholesterol (HDL‑C) was reduced in the HIMF group (P < 0.05). Additionally, the contents of monounsaturated fatty acids (MUFA), saturated fatty acids (SFA), and total FA in the breast muscle were significantly increased in the HIMF group (P < 0.05). Cecal microbiota analysis revealed that the HIMF group had a higher Firmicutes/Bacteroidota (F/B) ratio (P < 0.05) and this group was enriched with p__Bacillota, c__Clostridia, and s__unclassified Megamonas. These microorganisms were positively correlated with the IMF content. The metabolome‑transcriptome integrative analysis identified succinic acid, (4E)‑2‑oxohexenoic acid, and palmiticamide as key metabolites elevated in the HIMF group, which consistently showed positive correlations with the lipid metabolism‑related genes VNN1 and HSD17B12. Furthermore, the relative mRNA expression of intestinal genes involved in fatty acid uptake (CD36, FABP1, and FABP4), fatty acid synthesis (FASN and ACC), and lipid metabolism regulation (PPARβ) was upregulated in the HIMF group (P < 0.05). These results reveal cross-level associations among the microbiota, metabolites, and genes, providing candidate targets for improving the meat quality of native chicken breeds through microbiota-oriented interventions.

Pigeon adenovirus type 1 (PiAdV-1) is a causative pathogen of juvenile pigeon diarrhea disease, leading to huge economic losses to the global pigeon industry. Rapid detection on the poultry farm is helpful for the disease control. In this study, the Hexon and Fiber-2 proteins of PiAdV-1 were recombinantly expressed in a prokaryotic expression system using vector pET-28a and used for the immunization of the BALB/c mice. Two monoclonal antibodies (mAbs), 1H2 and 2F1, targeting the Hexon and Fiber-2 proteins respectively were successfully screened by the traditional method of hybridoma fusion. An immunochromatography test strip (ICS) was developed by using colloidal gold-labeled 1H2 and used for the rapid detection of PiAdV-1. The characteristic analysis revealed that the ICS displayed excellent sensitivity and specificity with a detection limit of 5.76 × 10[3] copies/μL and showed no cross-reactivity with common pigeon viruses including PiAdV-2, pigeon paramyxovirus, pigeon circovirus, and pigeon rotavirus. In addition, the ICS was validated by comparison with a polymerase chain reaction (PCR) for the 300 samples detection. The diagnostic positive rates of ICS and PCR were 22.67% (68/300) and 25.33 (76/300) respectively. The agreement rate was 97.34% between results obtained with ICS and PCR on 300 field fecal samples. Therefore, the ICS will be helpful for the rapid and effective detection of PiAdV-1 in clinical fecal samples.

This study evaluated the effects of dietary supplementation with live yeast and bacterial culture preparations on growth performance, carcass and meat quality, blood biochemical indices, antioxidant-related gene expression, and cecal microbiota in Arbor Acres broilers. A total of 336 one-day-old broilers were randomly assigned to 4 groups (n = 84/group) and fed a basal diet (F1, control) or the basal diet supplemented with 2 mL/kg of a 3-strain yeast preparation (F2), 2 mL/kg of a 4-strain bacterial preparation (F3), or 1 + 1 mL/kg of a combined yeast-bacterial preparation (F4). The experiment lasted 31 d. Dietary supplementation improved overall growth performance compared with the control (P < 0.05), with F2 producing the highest final body weight, weight gain, and production index, whereas F3 showed favorable feed utilization. F3 also produced the greatest modulation of cecal microbiota, characterized by increased Lactobacillus and decreased E. coli, total bacterial count, and Pseudomonas. Hepatic SOD1 and CAT1 expression and GPx and GST activities increased, whereas MDA decreased in F3 (P < 0.05). Serum ALT, AST, urea, creatinine, cholesterol, triglycerides, and LDL decreased, whereas HDL, IgG, IgM, and total protein increased, with the most pronounced responses generally observed in F3. Carcass yield and relative breast yield were highest in F2 and F4, whereas F4 reduced meat pH without adversely affecting other measured meat-quality traits. Overall, the responses differed among preparations, with the yeast preparation primarily supporting growth performance and the bacterial preparation producing broader antioxidant, metabolic, immune, and microbiota-related responses.

This study aimed to characterize hepatic molecular features associated with residual feed intake (RFI) during the late growth stage of slow-growing yellow-feathered broilers through integrated transcriptomic and metabolomic analyzes. RFI was measured in 478 individually caged male Langya chickens from 96 to 133 days of age. After the feeding trial, the chickens were ranked in ascending order of RFI and classified into low-RFI (LRFI) and high-RFI (HRFI) subpopulations using the population mean RFI as the cutoff. Eight healthy chickens were then randomly selected from each subpopulation to form the LRFI and HRFI groups (n = 8 per group). Following slaughter and tissue collection at 133 days of age, hepatic transcriptomic and LC-MS-based untargeted metabolomic analyzes were conducted. Differentially expressed genes (DEGs) and differentially abundant metabolites (DAMs) were subsequently subjected to enrichment and correlation analyzes. Compared with HRFI chickens, LRFI chickens had lower feed intake (FI) and higher eviscerated carcass yield and breast muscle yield. They also had lower abdominal fat percentage and muscle fat width, whereas BWG and metabolic body weight were similar between groups. Liver profiling identified 850 DEGs and 282 DAMs. Integrated KEGG analysis identified 15 pathways significantly enriched in both datasets. The amino acid metabolism-related pathways among these shared pathways collectively pointed to aromatic amino acid (AAA)-related metabolism, including biosynthesis of amino acids, phenylalanine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, and tryptophan metabolism. A total of 16 DEGs and 29 DAMs were mapped to these pathways and showed widespread significant correlations. Among them, IL4I1, AFMID, ASS1, PHGDH, MAOB, IDO2, HAAO, and PAH were identified as candidate genes associated with RFI. These results characterized hepatic molecular features associated with RFI during the late growth stage of slow-growing yellow-feathered broilers. These findings indicate that hepatic AAA-related metabolism may play a potential role in RFI divergence during the late growth stage in slow-growing yellow-feathered broilers. The identified AAA metabolism-related pathways provide a focused set of candidate genes, metabolites, and pathways for further investigation of their roles in RFI and feed efficiency, and provide a theoretical basis for molecular breeding and breed conservation of slow-growing broilers.

Internal quality of chicken eggs changes during storage, but the corresponding biochemical changes in albumen and yolk remain insufficiently characterized. This study evaluated internal quality traits and metabolomic profiles of chicken eggs stored at 25.0 to 25.5 °C for 0, 7, 14, 21, and 28 days. A total of 216 eggs were included, comprising 116 eggs for measurements of egg weight, albumen height, Haugh unit, and yolk color (n = 24, 22, 20, 23, and 27, respectively) and an independent subset of 100 eggs for untargeted liquid chromatography-tandem mass spectrometry metabolomics (n = 20 per time point). Paired albumen and yolk samples were collected from each egg used for metabolomic analysis. Day 7 was the earliest sampled time point at which albumen height and Haugh unit decreased significantly relative to day 0. By day 21, these traits had decreased further, accompanied by lower egg weight and more evident changes in yolk color. After data preprocessing and QC-based filtering, 919 and 1,104 annotated metabolites were retained in albumen and yolk, respectively. Using the combined criteria of VIP ≥ 1 and P < 0.05, 267 and 286 candidate differential metabolites were screened in albumen and yolk, respectively. In albumen, changes observed by day 7 mainly involved nucleotide- and cofactor-related metabolism, whereas changes by day 21 were characterized by more pronounced glycation-, amino acid-, sulfur-containing compound-, and biogenic amine-related alterations. In yolk, changes at day 21 mainly involved unsaturated fatty acids, lipid oxidation-related metabolites, and sphingolipid-related compounds. Pathway analysis further indicated distinct metabolic responses in albumen and yolk. These findings demonstrate distinct time-dependent metabolic responses in albumen and yolk during egg storage and provide a biochemical basis for interpreting storage-related changes in internal egg quality.