Due to the exceptional laying performance of hens, the demand on lipid metabolism and oxidation in vivo is vigorous, resulting in excessive lipid accumulation in late-phase hens, which lowers the production performance. Bile acids regulate lipid metabolism and gut microbiota in humans and animals. However, the effect of porcine bile acids on lipid metabolism and cecal microbiota in laying hens in the late phase is still unclear. A total of 360 healthy 45-week-old laying hens were chosen for a 24-week feeding trial, where 0, 30, 60 and 90 mg/kg porcine bile acids were added to a basal diet, respectively. The results showed that dietary supplementation of 60 mg/kg bile acids increased egg production and feed conversion (P < 0.05). Also, 60 and 90 mg/kg porcine bile acids reduced abdominal fat percentage and body weight (P < 0.05). The levels of serum total cholesterol, triglyceride, and low-density lipoprotein cholesterol of hens decreased (P < 0.05) in bile acids supplement groups. As for cecal microbiota, bile acids supplementation did not affect the alpha diversity of cecal microbiota at the genus level. Moreover, dietary supplementation of 90 mg/kg bile acids resulted in an increase in the abundance of beneficial bacteria in the cecum, such as Lactobacillus, Bifidobacterium and Turicibacter. The changes in the cecal microbiota caused by bile acids supplementation correlated with serum lipid indexes. According to KEGG pathway analysis, dietary supplementation of 60 and 90 mg/kg bile acids promoted structural transformation of the cecal microbiota to down-regulate steroid biosynthesis, up-regulate fatty acid degradation and up-regulate unsaturated fatty acid biosynthesis. Meanwhile, bile acids bio-isomerization function of cecal microbiota was enhanced in 60 and 90 mg/kg bile acids treatment, and the short-chain fatty acid metabolism was also affected. In conclusion, the present study revealed dietary supplementation of porcine bile acids enriched probiotics in the gut and improved serum lipid metabolism of laying hens. These findings demonstrate that porcine bile acids can be a potential gut beneficial promoter for late-phase laying hens.

Objective: The purpose of this experiment was to investigate the effects of the Agaricus bisporus stem residue (ABSR) on the performance, nutrients digestibility, antioxidant activity of laying hens, and its effects on egg storage to determine the appropriate dosage of ABSR, so as to provide a scientific basis for the effective utilization of ABSR.Methods: A total of 384 53-wk-old Nongda III layers were randomly divided into six treatments, four replicates in each treatment and 16 birds in each replicate. The control treatment was fed with basic diet, while experimental treatments were fed with diets of 2%, 4%, 6%, 8%, and 10% ABSR respectively. The experimental period was 56 d.Results: The results showed that compared with the control treatment, ABSR had no significant effect on laying performance (p>0.05). The crude protein and total energy digestibility of experimental treatments was significantly higher than those of control treatment (p0.05). The superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) activity in the serum of the experimental treatments were significantly higher than those of the control treatment (p<0.05), and the malonaldehyde (MDA) content did not change dramatically. SOD activity in yolk of experimental treatments was significantly higher than that in control treatment (p<0.05); MDA content in yolk was markedly lower than that in control treatment (p<0.05). The activity of GSH-Px and SOD in yolk of experimental treatments was significantly higher than that of control treatment stored at 25°C for 21 d, and the content of MDA was significantly lower than that of control treatment (p<0.05).Conclusion: ABSR can be used to improve the antioxidant activity of laying hens without affecting laying performance.

Enrofloxacin is a broad-spectrum antimicrobial agent, but the study of its pharmacokinetics/pharmacodynamics (PKs/PDs) in donkeys is rarely reported. The present study aimed to investigate the pharmacokinetics of enrofloxacin administered intragastrically, and to study the pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in plasma, urine, and feces, and the PK/PD parameters were investigated to provide a rationale for enrofloxacin treatment in donkeys. A total of five healthy donkeys were selected for intragastric administration of 7.5 mg·kg⁻¹ BW of enrofloxacin by gavage, and blood, urine, and fecal samples were collected. The results showed that the elimination half-life of plasma enrofloxacin was 11.40 ± 6.40 h, T_max was 0.55 ± 0.12 h, C_max was 2.46 ± 0.14 mg·L⁻¹, AUC_0–∞ was 10.30 ± 3.37 mg·L⁻¹·h, and mean residence time (MRT) was 7.88 ± 1.26 h. The T_max of plasma ciprofloxacin was 0.52 ± 0.08 h, C_max was 0.14 ± 0.03 mg·L⁻¹, and AUC_0–∞ was 0.24 ± 0.16 mg·L⁻¹·h. Urinary C_max was 38.18 ± 8.56 mg·L⁻¹ for enrofloxacin and 15.94 ± 4.15 mg·L⁻¹ for ciprofloxacin. The total enrofloxacin and ciprofloxacin recovered amount in urine was 7.09 ± 2.55% of the dose for 144 h after dosing. The total enrofloxacin and ciprofloxacin recovered amount in feces was 25.73 ± 10.34% of the dose for 144 h after dosing. PK/PD parameters were also examined in this study, based on published MICs. In conclusion, 7.5 mg/kg BW of enrofloxacin administered intragastrically to donkeys was rapidly absorbed, widely distributed, and slowly eliminated in their bodies, and was predicted to be effective against bacteria with MICs < 0.25 mg·L⁻¹.

This study aimed to investigate the effects of a compound probiotic on production performance and antioxidant capacity in post-molting broiler breeders. A total of 6800 healthy 69-week-old Arbor Acres breeders were randomly allocated to 2 treatment groups (4 replicates of 850 birds each). Both groups were fed an identical basal diet, whereas the drinking water was supplemented with 75 g/t of the compound probiotic for the Experimental group only. The trial included a 7-day adaptation followed by a 49-day experimental period. Results demonstrated that drinking water supplementation with dietary compound probiotic preparation improved the laying performance rate, fertilization rate, and hatchability compared to the control (p < 0.05). The serum total antioxidant capacity was significantly enhanced (p < 0.05), while a concurrent trend of reduction in MDA content was also noted (p = 0.086). Significant decreases in serum total protein and globulin levels were observed (p < 0.05). Antioxidant profiles in reproductive tissues were also improved, with increased superoxide dismutase activity in the liver and oviduct, enhanced total antioxidant capacity in the ovary and oviduct, and a concurrent decrease in malondialdehyde content in the oviduct (p < 0.05). Furthermore, serum immunoglobulin M, and cecal butyric acid and isobutyric acid contents were higher in the compound probiotic preparation group (p < 0.05). In conclusion, supplementing drinking water with the compound probiotic during the post-molting period enhanced production performance, antioxidant status, and immune and gut health in aging broiler breeders, supporting the preservation of valuable poultry genetic resources.

In this study, the effects of pediocin (PP) on intestinal barrier function, renal injury, and immune regulation were evaluated in Salmonella pullorum-infected chickens. Forty-five 7-day-old specific-pathogen-free (SPF) chickens were randomly assigned to three groups: control (CON), S. pullorum infection (SP), and S. pullorum infection + PP treatment (SPA). The results showed that S. pullorum infection significantly elevated (p < 0.05) the renal (CREA, UREA), hepatic (ALT, AST), immunological (IgG, IgM), and inflammatory (TNF-α, IL-6, SAA, CRP) parameters, as well as the expression of trefoil factor 3, Toll-like receptor 2, TNF-α, IL-1β, and IL-6. In contrast, the jejunal villus height and the villus-to-crypt ratio, and the expression of intestinal tight junction proteins (occludin, claudin-1, and Zonula occludens-1), mucin-2, and transforming growth factor-β1 were significantly decreased in both the SP and SPA groups. In the SP group, the parameter alterations observed at 6 DPI compared to the CON group persisted until 12 DPI. In contrast, in the SPA group, these parameters returned to levels comparable to those of the CON group after 6 days of PP treatment. Moreover, S. pullorum infection markedly reduced the α-diversity of the gut microbiota, and this reduction could be partially restored following PP treatment. At the phylum level, S. pullorum infection significantly reduced the relative abundances of Proteobacteria and Verrucomicrobia. PP treatment increased the abundances of Firmicutes and Actinobacteria, while also restoring the abundances of Proteobacteria and Verrucomicrobia to some extent. At the genus level, PP treatment significantly increased the abundance of Faecalibacterium and Lactobacillus. Additionally, Faecalibacterium and Butyricicoccus were significantly more abundant in the SPA group. Thus, PP could alleviate S. pullorum infection induced intestinal barrier damage, reduce immune stress responses, and exert a protective effect by modulating the composition of the intestinal microbiota of chickens.