This study aims to compare the fecal microbiome-metabolome response to copper sulfate (CuSO₄) and copper glycinate (Cu-Gly) in pigs. Twelve Meishan gilts were allocated into the CuSO₄ group and the Cu-Gly group (fed on a basal diet supplemented with 60 mg/kg copper from CuSO₄ or Cu-Gly) paired in litter and body weight. After a two-week feeding trial, the Cu-Gly group had a higher copper digestibility, blood hemoglobin, and platelet volume and higher levels of plasma iron and insulin-like growth factor-1 than the CuSO₄ group. The Cu-Gly treatment increased the abundance of the Lachnospiraceae family and the genera Lachnospiraceae XPB1014, Corprococcus_3, Anaerorhabdus_furcosa_group, Lachnospiraceae_FCS020_group, and Lachnospiraceae_NK4B4_group and decreased the abundance of the Synergistetes phylum and Peptostreptococcaceae family compared to the CuSO₄ treatment. Moreover, the Cu-Gly group had a lower concentration of 20-Oxo-leukotriene E4 and higher concentrations of butyric acid, pentanoic acid, isopentanoic acid, coumarin, and Nb-p-Coumaroyl-tryptamine than the CuSO₄ group. The abundance of Synergistetes was positively correlated with the fecal copper content and negatively correlated with the fecal butyric acid content. The abundance of the Lachnospiraceae_XPB1014_group genus was positively correlated with the plasma iron level and fecal contents of coumarin and butyric acid. In conclusion, Cu-Gly and CuSO₄ could differentially affect fecal microbiota and metabolites, which partially contributes to the intestinal health of pigs in different manners.

Previous studies have demonstrated that melatonin (MLT) enhances boar sperm motility by modulating energy metabolism status, yet the underlying mechanisms remain incompletely understood. This study aims to investigate whether sirtuin 3 (SIRT3), a key mitochondrial deacetylase, mediates MLT’s effects. Herein, the semen of six Landrace boars (16–18 months of age) was treated with 1.0 μM MLT with/without the SIRT3 inhibitor 3-TYP, preserved at 17 °C for 3 days, and subsequently maintained at 37 °C for a duration of 10 min. We demonstrated that MLT upregulated SIRT3 protein expression and reduced the acetylation level in mitochondrial proteins. MLT significantly increased glucose uptake and suppressed lactate release in the sperm, while elevating levels of pyruvate and acetyl-CoA, the substrates of pyruvate dehydrogenase (PDH) and the tricarboxylic acid (TCA) cycle, respectively, and the protein expression of PDH, indicating enhanced metabolic flux. Notably, inhibition of SIRT3 reversed MLT’s effects: it blocked the increases in SIRT3 expression, glucose consumption, PDH expression, complex I activity, ATP content, and superoxide dismutase (SOD) activity, and prevented the decreases in the levels of acetylation and lactate, as well as pyruvate kinase (PK) activity, confirming the essential role of SIRT3. Functionally, the MLT-induced improvements in sperm motility parameters (total, progressive, fast motility, immotile) were also reversed by 3-TYP. Collectively, these findings demonstrate that the SIRT3-mediated pathway is essential for MLT to enhance boar sperm energy metabolism and antioxidant defense, thereby increasing ATP production and enhancing sperm motility. Targeting SIRT3 represents a promising therapeutic strategy for improving boar fertility and may also provide insights for research into human male infertility.

The physiological functions of mammalian sperm, such as motility, hyperactivation, and capacitation, require substantial energy. This study investigates the effects of two classic cryopreservation extenders—TCG (tris-citrate-glucose) and LEY (lactose-egg yolk)—on the energy metabolism of frozen–thawed boar semen. By comparing the quality indicators, key metabolite levels, and the activities of critical enzymes involved in glycolysis and the tricarboxylic acid cycle, we aim to understand how these different semen extenders influence the spermatozoa vitality of frozen–thawed boar semen. Following thawing, the LEY-cryopreserved sperm demonstrated significantly elevated motility parameters (viability, VCL, VSL, and VAP) and enhanced plasma membrane and acrosomal integrity compared with the TCG group (p < 0.05), though both cryopreserved groups exhibited significantly reduced performance relative to fresh semen controls. Cryopreservation markedly reduced intracellular adenosine triphosphate (ATP), pyruvate, and acetyl coenzyme A (A-CoA) levels (fresh > LEY > TCG; p < 0.05). The LEY-preserved spermatozoa retained higher activities of glycolysis-related enzymes (phosphofructokinase, PFK; pyruvate kinase, PK) compared with the TCG group, which, in turn, showed elevated lactate dehydrogenase (LDH) activity. Critically, TCG-suppressed pyruvate dehydrogenase (PDH) activity (p < 0.05) coincided with diminished A-CoA, indicating impaired mitochondrial oxidative phosphorylation. These results demonstrate LEY’s superior preservation of motility and membrane stability but highlight cryodamage-induced energy metabolism dysregulation, particularly TCG’s disruption of the glycolysis–TCA cycle coordination essential for spermatozoa function. In conclusion, the choice of semen extender has a significant impact on the energy metabolism and overall quality of frozen–thawed semen, highlighting the importance of optimizing cryopreservation protocols for improved spermatozoa viability and functionality.

Day length is a critical environmental factor for regulating animal growth and development. This study aimed to investigate the effects of different day lengths on the developmental changes of growth parameters, testicular sizes, testosterone secretion in Meishan male pigs, and steroidogenesis proteins and melatonin receptors. Fourteen Meishan male pigs (10 weeks (wks) of age) with the same parity, paired in litter and body weight (BW), were evenly allocated into a short-day-length group (SDL, 10 light/14 dark) and long-day-length group (LDL, 14 light/10 dark). After 12 wks of the experiment, the LDL-treated boars had more lying time and less exploring time. The LDL treatment led to significant increases in body height, chest circumference, testicular length, testicular weight, crude protein digestibility, and fecal testosterone at the 10th and 12th wks of the experiment, and cortisol at the 10th wk, compared to the SDL treatment, with no differences in the final BW, testicular width, and epididymis weight. Furthermore, the LDL treatment significantly increased the protein levels of melatonin receptor 1b (MT2), aromatase (CYP19), and steroidogenic factor 1 (SF1) in the testis, with no differences in the protein levels of melatonin receptor 1a (MT1), steroidogenic acute regulatory (StAR), 3β-hydroxysteroid dehydrogenase (3β-HSD), and cholesterol side-chain cleavage enzyme (P450scc). The present study suggests that day length has an effect on the growth and gonadal development in male pigs maybe via MT2 and influences steroid synthesis and secretion in the testis. Therefore, proper day length should be considered in male pig breeding.

This study aimed to evaluate the effects of dietary supplementation with polyphenol-rich lettuce extract (PRLE) derived from the high-polyphenol lettuce cultivar Binfen-1 (BF-1) on production performance, antioxidant capacity, immune function, and cecal microbiota composition of Hyline Brown laying hens. A total of 140 healthy pre-laying hens (15 days before egg production) were randomly assigned to 4 groups: a control group fed a corn-soybean basal diet, and three experimental groups (TR1, TR2, TR3) fed the basal diet supplemented with 0.05%, 0.1%, and 0.15% PRLE, respectively. Diets were fed for 12 wk, afterwards 10 bird per group were euthanized for sampling blood and cecal digesta. Production performance monitoring showed that compared with the control group, 0.05% and 0.15% PRLE supplementation significantly increased the laying rate during Weeks 1-4 (p < 0.05), but no significant effects on laying rate were observed in Weeks 5-8 or 9-12 (p > 0.05). For serum antioxidant indices, PRLE supplementation significantly reduced malondialdehyde (MDA) content and increased glutathione peroxidase (GSH-Px) activity across all experimental groups (p < 0.05). In terms of immunity, 0.1% PRLE significantly elevated serum immunoglobulin (Ig) G and IgM concentrations (p < 0.05). 16S rRNA gene sequencing revealed that PRLE supplementation increased the relative abundances of Firmicutes, Desulfobacterota, and Actinobacteriota while decreasing Proteobacteria at the phylum level(p < 0.05). At the genus level, it reduced the abundance of the conditional pathogen Peptococcus and increased the abundances of beneficial bacteria (e.g., Bacteroides, Lachnospiraceae, Butyricicoccus, Romboutsia) (p < 0.05). PICRUSt2 functional prediction indicated that PRLE enriched pathways related to infectious bacterial diseases, cell motility, and the immune system, while reducing pathways associated with drug resistance and glycan metabolism. Non-targeted metabolomics showed that PRLE significantly altered the cecal metabolite profile and modulated key pathways including arachidonic acid metabolism, bile secretion, and steroid hormone biosynthesis. In conclusion, dietary PRLE supplementation enhances the antioxidant capacity and immune function of Hyline Brown laying hens, improves cecal microbiota composition and metabolic profiles, but exerts only transient (Weeks 1-4) positive effects on laying rate under the tested conditions. This study provides a scientific basis for the application of PRLE in commercial laying hen production, with future research needed to optimize its dosage, supplementation duration, and age-specific efficacy.

Minerals serve as central regulators of livestock physiology, mediating fundamental processes including bone mineralization, enzymatic cofactor assembly, electrolyte balance, immune cell signaling and intracellular antioxidant defense. Dietary minerals are divided into macrominerals and microminerals. Macrominerals include calcium, phosphorus, magnesium and sulfur, while microminerals encompass zinc, iron, copper, manganese, selenium and iodine. These minerals require species-specific supplementation to maintain metabolic homeostasis and animal health. Commercial feeds deliver minerals via inorganic salts (e.g., calcium carbonate, ferrous sulfate) or well-defined organic complexes (e.g., zinc methionine, copper glycinate, selenium-enriched yeast). Selection relies on mineral concentration as well as interactive behavior within the gastrointestinal environment. Mineral uptake follows transporter-mediated kinetics and is modulated by luminal pH, competitive cation antagonism and antinutritional components such as phytate and fiber. Modern nutritional strategies shift from general supplementation to precision mineral feeding. Optimizing mineral speciation adapts to intestinal physiology, improves mineral retention and reduces excretion. This advancement combines mineral kinetics, host–microbiota crosstalk and environmental impact mitigation, making mineral nutrition fundamental to sustainable, evidence-based livestock production.