Tumbling pigeons are prone to oxidative stress and disruption of gut microbiota balance during long-term exercise training and competitions. Considering that Portulaca oleracea (P. oleracea), as a natural plant feed additive, has natural antioxidant, anti-inflammatory, and gut function improvement effects. This study investigates the effects of adding P. oleracea into health care sand on nutrient digestion and metabolism, serum parameters, and excreta microbiota metabolism in tumbler pigeons. Ninety 12-month-old tumbler pigeons were randomly assigned to three groups, with ten cages with three birds each. The CON Group received a basal diet added with 4 g of health care sand; Group TRT1 received a basal diet added with 4 g of health care sand containing 0.75% P. oleracea; and Group TRT2 received a basal diet added with 4 g of health care sand containing 1.00% Portulaca oleracea. The adaptation period lasted for 7 days, followed by a formal testing phase of 45 days. All tumbler pigeons received 1 h of flight training daily. The CON and TRT2 groups showed significantly increased dry matter (DM) apparent digestibility by 11.68% (p < 0.01) and 8.50% (p < 0.05), respectively, compared to the TRT1 group. The TRT2 group also demonstrated higher organic matter (OM) apparent digestibility (increase of 4.25%, p < 0.05) and markedly improved crude protein (CP) digestibility (16.72% higher than CON, p < 0.05; 27.12% higher than TRT1, p < 0.01). Both gross energy (GE) and metabolizable energy (ME) digestibility were significantly elevated in CON and TRT2 groups compared to TRT1 (p < 0.01). Compared to the CON group, the TRT2 group showed a 19.86% decrease in lactate (LAC) level (p < 0.05) alongside a 38.91% increase in lactate dehydrogenase (LDH) activity (p < 0.05). Serum uric acid (UA) levels increased by 33.65–36.14% in both treatment groups (p < 0.05). Antioxidant capacity markedly improved, with malondialdehyde (MDA) decreasing by up to 27.75% (p < 0.01) and key antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC) showing dose-dependent enhancements of up to 25.23% (p < 0.01). Other serum biochemical parameters showed no significant differences (p > 0.05). Microbial analysis demonstrated that Actinobacteriota, Acidothermaceae, and Nitrosotaleaceae were enriched in the TRT1 and TRT2 groups, while the relative abundance of Proteobacteria and Chitinophagaceae decreased (p > 0.05). Metabolomic analysis revealed a significant increase in beneficial metabolites, including agmatine, pyropheophorbide-a, and N-acetylmuramate (p < 0.01). In conclusion, the addition of 1.00% Portulaca oleracea in health care sand effectively enhanced apparent nutrient digestibility, improved antioxidant capacity, and modulated the intestinal microbiota and metabolic profile of tumbler.

This study investigated the effects of dietary sodium butyrate supplementation on blood gas profiles, biochemical parameters, and untargeted plasma metabolomics in tumbler pigeons. Eighty tumbler pigeons of similar age, body weight, and training intensity were randomly allocated into four groups: a control group without sodium butyrate supplementation (CON) and three sodium butyrate-supplemented groups receiving 6 mg/d (T1), 12 mg/d (T2), and 18 mg/d (T3), respectively. All birds were maintained under identical husbandry conditions and fed the same basal diet throughout a 40-day experimental period consisting of a 10-day acclimation phase and a 30-day feeding trial. Results showed that dietary sodium butyrate supplementation significantly improved dry matter digestibility, with T2 and T3 exhibiting higher values than CON (p < 0.05), while metabolizable energy utilization was significantly increased in T3 compared with CON (p < 0.05). Sodium butyrate supplementation also significantly altered several blood gas parameters associated with acid–base balance and gas exchange. In addition, antioxidant enzyme activities were enhanced, with SOD, CAT, GSH-Px, and T-AOC activities significantly increased in supplemented groups compared with CON (p < 0.01). Furthermore, sodium butyrate supplementation significantly modulated inflammatory responses, increasing IL-10 concentrations (p < 0.01) while decreasing IL-6 and IL-8 levels (p < 0.01). Untargeted metabolomic analysis revealed significant alterations in pathways related to lipid metabolism, amino acid metabolism, and inflammatory regulation. In conclusion, dietary sodium butyrate supplementation influenced nutrient utilization, blood physiological parameters, antioxidant capacity, inflammatory status, and plasma metabolic profiles in tumbler pigeons. Among the tested supplementation levels, 18 mg/d sodium butyrate was associated with the most favorable overall physiological responses. These findings provide a basis for future investigations into the physiological and metabolic effects of sodium butyrate supplementation in competitive pigeons.

This study aimed to investigate the effects of thymol supplementation in health care sand on growth performance, serum biochemical parameters, fecal microbial diversity, and fecal metabolites in Grey King squabs. A total of 160 healthy 28-day-old Grey King squabs were selected and randomly assigned to four treatment groups: the CON, 2%Thy, 3%Thy, and 4%Thy groups. Each group consisted of 10 replicates with four squabs per replicate, resulting in a total of 40 squabs per group. Under identical feeding management conditions and dietary nutrient levels, squabs in the CON group received the basal diet plus 5 g of health care sand; those in the 2%Thy group received the basal diet plus 5 g of health care sand containing 2% thymol; those in the 3%Thy group received the basal diet plus 5 g of health care sand containing 3% thymol; and those in the 4%Thy group received the basal diet plus 5 g of health care sand containing 4% thymol. The experiment lasted for 30 days. During the experimental period, the pigeons were housed in cages measuring 45 cm × 50 cm × 60 cm. Each pigeon was provided with 40 g of diet and 5 g of health care sand daily and had free access to water. After Benjamini–Hochberg false discovery rate correction, no significant differences were observed in growth performance, body measurements, apparent nutrient retention, or energy metabolizability among treatments (q > 0.05). However, thymol-supplemented groups exhibited significantly increased serum total antioxidant capacity and superoxide dismutase, glutathione peroxidase, and catalase activities, together with decreased malondialdehyde levels (q < 0.05). Fecal microbiome and metabolomic analyses were restricted to the CON and 3%Thy groups, with the 3%Thy group selected after evaluation of the phenotypic and physiological responses rather than being prespecified before the experiment. These omics comparisons were therefore considered exploratory. No statistically significant difference in overall fecal microbial community composition was detected between the two groups, whereas 17 candidate differential fecal metabolite features were observed. These features were mainly putatively annotated as lipids and lipid-like molecules, organic acids and derivatives, organoheterocyclic compounds, and benzenoids. Among the supplementation levels evaluated, the 3%Thy group showed comparatively favorable numerical responses in several measured parameters and may be considered a candidate level for further investigation. However, the present findings do not establish an optimal thymol supplementation level, and the biological significance of the exploratory fecal omics results requires further validation.

Sea buckthorn polysaccharide (SP) has antioxidant and anti-inflammatory activities, but its effects in tumbler pigeons remain unclear. Eighty-four male tumbler pigeons were assigned to four treatments receiving diets containing 0, 100, 200, or 400 mg/kg effective SP for 60 days, with seven replicate cages per treatment. SP supplementation enhanced serum antioxidant capacity and modulated inflammatory cytokine profiles, with the most pronounced overall responses observed at 200 mg/kg. The SP200 and SP400 groups also had lower serum lactate, total cholesterol, and triglyceride concentrations than the control group, whereas most blood gas, electrolyte, and acid–base variables were unaffected. Because SP200 produced the strongest antioxidant and cytokine responses, the CON and SP200 groups were selected for untargeted serum metabolomics. This analysis identified 68 and 79 differential metabolites in positive- and negative-ion modes, respectively. KEGG enrichment analysis ranked purine metabolism, phenylalanine metabolism, primary bile acid biosynthesis, and the citrate cycle among the leading pathways; however, none remained significant after Benjamini–Hochberg correction. Exploratory Spearman analysis revealed associations between selected metabolites and phenotypic indicators. Taken together, these findings indicate that 200 mg/kg SP may be an effective dietary supplementation level for improving antioxidant and inflammatory status in tumbler pigeons, while the associated metabolomic changes warrant further targeted validation.