Hulong Lei

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.

Copper supplements are prominent antibiotic alternatives in livestock production, but their excessive use poses environmental risks, necessitating safer substitutes. Potassium diformate (KDF), an organic acid salt, has shown potential as a feed additive, yet its effectiveness in copper-unsupplemented diets remains unclear. This study compared the effects of copper glycinate (Cu_Gly) and KDF on weaned piglets fed a copper-unsupplemented basal diet. Forty-five Meishan piglets were allocated to a control group (basal diet), a Cu_Gly group (basal diet + 60 mg/kg Cu_Gly), or a KDF group (basal diet + 10 g/kg KDF). The KDF group exhibited a lower feed conversion ratio (FCR) than the control group. Although no significant differences in average daily gain were observed, KDF supplementation significantly enhanced immune function by increasing plasma IgG and decreasing IgM, IL-6, and IL-1 levels compared to the control. 16S rRNA sequencing analysis revealed that the Control group was enriched with pathogenic genera (Staphylococcus, Escherichia-Shigella, Brevibacterium) in the ileum and cecum. Cu_Gly supplementation enriched Bacillus, Longispora, and Terrisporobacterin the ileum, while KDF increased the abundance of beneficial taxa (TM7, Nesterenkoniain the ileum; Lachnospiraceae_UCG-007 in the cecum). Correlation analysis showed that the abundances of Escherichia-Shigella and Staphylococcus were negatively correlated with IgG but positively correlated with IgM and IL-6. Cecal Lachnospiraceae_UCG-007 (enriched in the KDF group) was negatively correlated with IL-1. In summary, KDF improved feed efficiency and demonstrates superior immunomodulatory effects compared to Cu_Gly. The enrichment of bacteria linked to metal resistance in the Cu_Gly group suggested a potential drawback not associated with KDF. Therefore, KDF represented a viable and sustainable alternative to copper supplements, offering a combination of improved gut health, enhanced immunity, and a reduced environmental risk profile.

Dairy cattle are a substantial contributor to global agricultural greenhouse gas emissions, primarily producing enteric methane through the ruminal anaerobic fermentation of dietary fiber. As China formally pledges to achieve carbon neutrality before 2060, accurately quantifying these emissions and developing localized mitigation strategies within the livestock sector has become a critical priority. Enteric methane emissions in dairy cattle are not a static physiological baseline; rather, they represent a highly dynamic phenotype profoundly influenced by an intricate network of physiological and environmental parameters. These include the animal’s age, anatomical and ruminal development, parity, lactation stage, and the precise stoichiometric balance of dietary carbohydrates. This review synthesizes extensive experimental data to construct a robust, scientifically logical framework elucidating the profound physiological mechanisms that govern apparent methane emission parameters. Accordingly, this paper reviews our recent research on methane emissions from Holstein dairy cattle across various ages and lactation stages, including heifers, lactating cows, and dry cows. Furthermore, it extensively evaluates the modulation of methanogenesis under diets with varying neutral detergent fiber to non-fibrous carbohydrate (NDF/NFC) ratios, demonstrating that an increased NDF/NFC ratio is positively correlated with higher enteric methane production, yield, and intensity due to the promotion of acetate-type ruminal fermentation. Ultimately, this review aims to provide robust theoretical support for the accurate quantification of enteric methane emissions and the formulation of precision mitigation strategies tailored to specific physiological states.

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.

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 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.

The health status of weaned pigs is crucial for their subsequent growth performance. Supplementation with fermented feedstuff is able to improve the feed intake and growth of weaned pigs; however, the exact mechanism behind this is not clear. Hence, in the present study a total of 320 Duroc × Landrace × Yorkshire weaned pigs were selected and allocated to the following two groups: unfermented diet group (UFD) and fermented diet group (FD). The experimental period lasted 21 days. At the end of the experiment, feces, blood, and gastrointestinal tissue samples (including the stomach, jejunum, and ileum) were collected and used for further analysis. The results of growth performance suggested that the FD group had significantly increased (p < 0.05) average daily feed intake (ADFI) and average daily gain (ADG) during the first week, during the last two weeks, and over the entire three-week period compared with the UFD group. The results of the apparent nutrient digestibility of pigs showed that, compared with the UFD group, the FD group showed increased phosphorus (p < 0.05) and CP (p < 0.1) digestibility. There were no significant differences in the serum biochemical parameters between the UFD and FD groups. Moreover, our results showed that the FD group showed significantly increased gene expression of SGLT1 and PepT1 in the jejunum (p < 0.05). Compared with the UFD group, the FD group showed an increased (p < 0.05) serum orexin level and prepro-orexin (PPOX) expression in the gastric fundus, jejunum, and ileum mucosa and increased IGF-1 and IGFR expression in the jejunum. Collectively, these results indicated that supplementation with fermented feedstuff in the diet effectively enhanced the feed intake and growth of weaned pigs and that this may have been caused by the increased orexin, IGF-1, and IGFR serum levels.

Decabrominated diphenyl ether (BDE-209) is widely used as a flame retardant and is detected at high levels in the environment. Its toxicities have been reported and have attracted attention. In the present study, broilers were used to determine the response in growth performance, carcass traits, meat quality, blood profiles and antioxidant system to BDE-209 exposure at doses of 0, 0.02, 0.4 and 4 mg/kg. The results showed that BDE-209 exposure at levels of 0.02 or 0.4 mg/kg increased feed intake and decreased feed efficiency. BDE-209 altered the blood profiles, such as reducing the numbers of white blood cells, lymphocytes and neutrophilic granulocytes. As compared with the control, BDE-209 exposure significantly increased abdominal fat percentages of broilers at 64.9–159.5% and adversely affected the selected biochemical indicators, including alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine (CRE), which indicated its toxicity to liver and kidney functions. Moreover, BDE-209 exposure significantly increased plasma malondialdehyde (MDA) concentrations and decreased the activities of glutathione peroxidase (GSH-px) and superoxide dismutase (SOD), which implied aggravating oxidant stress and decline of antioxidant capacity in broilers. In conclusion, our data demonstrated that the environmental pollutant BDE-209 adversely influenced growth performance, increased the deposition of abdominal fat, impaired antioxidant capacity and the immune system and had potential toxicity to the liver and kidney of broilers.