Mastitis in dairy cows is an important factor restricting the healthy development of dairy industry. Natural extracts have become a research hotspot to alleviate and prevent diseases because of their unique properties. The purpose of this study was to investigate the effects of resveratrol (RES) on the mitochondrial biosynthesis, antioxidation, and anti-inflammatory in bovine mammary epithelial cells (BMECs) and its mechanism involved. Blood samples were collected from six healthy cows and six mastitis affected cows, respectively, and lipopolysaccharide (LPS) was used to treat BMECs to construct inflammation models, gene interference is achieved by transfection. The results showed that messenger RNA (mRNA) expression of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) was down-regulated and mitochondrial biogenesis-related gene expression was disrupted in the blood of mastitis cows and LPS-induced BMECs. RES is the best active substance to activate PGC-1α. The addition of RES can effectively alleviate the production of BMECs reactive oxygen species (ROS) and mitochondrial damage induced by LPS, and improve the antioxidation and anti-inflammatory ability, while the alleviation effect of RES is inhibited after interfering with protein kinase AMP-activated catalytic subunit α 1 (PRKAA1). In summary, our study emphasizes that PRKAA1 is a key gene mediating the activation of PGC-1α by RES, which regulates mitochondrial biosynthesis, inhibits ROS release, attenuates mitochondrial damage, and improves mitochondrial antioxidant capacity through the activation of PGC-1α by PRKAA1, thus attenuating the inflammatory response in BMECs.

This study evaluated the effects of dietary yeast culture (YC) supplementation on rumen microbiota and lactation performance in dairy goats. Twenty mid-lactation dairy goats were selected and divided into two groups: the control (CON) group was fed a basal diet; the YC group was supplemented with 10 g of YC in 1 kg of basal diet. The administration of YC was associated with a significant increase in dry matter intake, milk yield, milk protein yield, and milk lactose yield in dairy goats (P < 0.05). Additionally, serum total protein, albumin, creatinine, glucose, superoxide dismutase, and catalase levels were increased (P < 0.05). Furthermore, there was an increase in rumen pH and NH3-N levels (P < 0.05), while volatile fatty acid levels were observed to decrease (P < 0.05). The study found no significant difference in the α-diversity of bacteria and fungi between the YC and CON groups (P > 0.05). However, 15 bacterial genera and 13 fungal genera were upregulated (P < 0.05), while 4 bacterial genera and 11 fungal genera were downregulated (P < 0.05) in the YC group. The relative abundance of pathogenic fungi Dipodascus and Gibberella decreased (P < 0.05). Correlation analysis revealed that the bacterial genera were not significantly correlated with lactation performance (P > 0.05), whereas fungal genera Dipodascus and Gibberella were significantly (P < 0.05) correlated with lactation performance. In conclusion, the study demonstrated that YC can influence the rumen microbial composition, reduce the abundance of harmful fungi in the rumen, and improve lactation performance in dairy goats, suggesting that the addition of YC to dairy goat diets has good application prospects.

Feed intake, a critical factor for dairy cows during the postpartum period, is intricately linked to the rumen microbiome. However, the specific roles of rumen metagenome and metabolome in modulating feed intake in postpartum dairy cows remain unclear. In the current study, 20 postpartum dairy cows were divided into low feed intake (n = 5) and high feed intake (HFI, n = 5) groups to investigate the role of ruminal microbial composition, function, and metabolism on feed intake using a combined approach of metagenomics and metabolomics. Our analysis revealed a significant enrichment of Bacteroides and Fibrobacter in HFI cows (p < 0.05), contributing to enhanced protein and energy metabolism. Metabolomic analysis disclosed that HFI cows exhibited a higher relative concentration of rumen metabolites, such as alpha-tocopheryl acetate (fold change = 9.2, p = 0.008), linoleic acid (fold change = 5.96, p = 0.007), and leucine (fold change = 4.14, p = 0.004). Spearman correlation analysis pinpointed a positive correlation between specific microbiota (Succinivibrionaceae and Prevotellaceae) and metabolites involved in amino acid and peptide metabolism, fatty acid metabolism, and conjugates. Furthermore, co-occurrence network analysis showed that the unclassified_f_Succinivibrionaceae, Succinatimonas, and Ruminobacte were significantly associated with dry matter intake-associated metabotypes, including rumen metabolites involved in fatty acids and conjugates, favonoids, and gycerophosphocholines. The feed intake variation explained by the rumen microbiome, functions, and metabolites were 29.63%, 27.30%, and 33.50%, respectively. These findings provide comprehensive insights into rumen metagenomics at different feed intake levels in postpartum dairy cows, potentially guiding strategies to manipulate the rumen microbiome for feed intake and production improvement.

One hundred and thirteen mid-lactation cows fed same diets and supplemented with 20 g/d rumen-protected methionine (RPM) for 8 weeks were used to investigate the individual responses of dairy cows to RPM in terms of lactation performance, amino acids (AA) metabolism, and milk metabolites. Among the cows, 10 cows exhibited positive responses (PR) and 10 cows showed limited responses (LR) in energy-corrected milk yield to RPM were used for further analysis. The lactation performance changed from gradual decline to steady increase in PR cows, while kept downward trend in LR cows following RPM supplementation. In PR cows, the AA metabolism was notably enhanced after RPM supplementation, evidenced by increased mammary blood flow (69.4%, P = 0.05), mammary uptake and clearance rate and uptake-to-output ratio (U:O) of essential AA. The improved AA metabolism could be attributed to the enrichment of pyrimidine (P = 0.06) and pyruvate (P = 0.07) metabolism pathways, which may have stimulated mammary cell proliferation and enhanced AA uptake. Additionally, the upregulation of milk biotin (fold change > 2, variable importance projection > 1), known to support milk yield, likely contributed to the PR observed in PR cows. Conversely, in LR cows, RPM supplementation did not improve AA metabolism, decrease was observed in mammary uptake, mammary clearance rate, and U:O of cysteine, potentially due to cysteine being irreversibly converted from methionine. Moreover, the enrichment of central carbon metabolism in cancer pathway (P = 0.06), which also utilize methionine, along with the lysine degradation pathway (P = 0.04), suggests that methionine in the mammary glands may have been diverted toward non-lactational metabolic processes, resulting in absence of PR in LR cows. Our results indicate that the responses to RPM in dairy cows are individualized, with variation in lactation performance likely driven by differential AA metabolism.