Lian Li

This study evaluated the effects of dietary supplementation with a commercial lactoferrin–osteopontin complexes preparation (LF-OPN; LF:OPN mass ratio 8:1; 240 mg/kg body weight) on growth, immune indices, antioxidant status, intestinal barrier-related markers, fecal microbiota, short-chain fatty acids (SCFAs), peripheral lymphocyte subsets, and the whole-blood transcriptome of growing British Shorthair kittens. Sixteen kittens were randomly assigned to either a basal diet group (CON) or a group supplemented with LF-OPN complexes (LFT) for 28 days. LF-OPN supplementation did not significantly affect body weight or average daily gain. On D28, the LFT group had a higher serum immunoglobulin M concentration and a lower tumor necrosis factor-α concentration (p < 0.05). Serum superoxide dismutase and glutathione peroxidase activities and total antioxidant capacity were higher, whereas malondialdehyde was lower (p < 0.05) in the LFT group (p < 0.01). Fecal 16S rRNA gene sequencing revealed no significant difference in alpha diversity; howerer, LEfSe identified selective taxonomic difference, including higher relative abundances of Holdemanella and Erysipelotrichaceae and lower relative abundances of Enterobacteriaceae and Escherichia-Shigella in the LFT group. Fecal short-chain fatty acid concentrations were unchanged. Flow cytometry revealed a higher proportions of peripheral CD4+ lymphocytes and a higher CD4+/CD8+ ratio in the LFT group (p < 0.01), whereas the CD8+ proportion was unchanged. Whole-blood RNA sequencing identified 283 differentially expressed genes (199 upregulated and 84 downregulated), with enrichment of immune-related pathways including hematopoietic cell lineage, antigen processing and presentation, cytokine–cytokine receptor interaction, NF-κB signaling, and IL-17 signaling, but these findings were not independently validated. The tested LF-OPN preparation was well tolerated and was associated with elevated antioxidant status, altered immune indices, and selective modulation of the fecal microbiota in growing kittens. The study does not establish synergy or identify the individual contributions of either protein.

Brown adipose tissue (BAT) is essential for neonatal ruminants to maintain body temperature and survive postnatal cold stress through non-shivering thermogenesis. At birth, BAT is abundant and mainly distributed in the neck, shoulder, perirenal region, and around the heart, but declines with age (“whitening”). This review summarizes BAT developmental dynamics, physiological functions, and the nutritional regulation of BAT, focusing on how fatty acids, carnitine, vitamins, and minerals modulate thermogenic activity through effects on mitochondrial function, lipid metabolism, and key signaling pathways (e.g., UCP1, PGC-1 α, and PPAR γ). Evidence indicates that targeted nutritional strategies can enhance BAT function, improving neonatal cold tolerance, survival, and early growth performance. Finally, we highlight the use of multi-omics technologies as a promising future direction to decipher BAT regulatory networks and guide precise nutritional interventions.

Functional ingredients in companion animal nutrition offer a promising strategy for enhancing pet health and reducing disease risk through targeted dietary interventions. This review, drawing on terminology from human nutrition, establishes definitions and classification systems for functional ingredients, bioactive compounds, and dietary supplements in pets. The article systematically explores the application mechanisms, physiological effects, and related clinical evidence of bioactive ingredients such as probiotics, prebiotics, metabiotics, exogenous enzymes, omega-3 fatty acids, antioxidants, and plant extracts in commercial pet foods across eleven core dimensions: digestive health, skin and coat, musculoskeletal system, oral health, behavior and mood, immune regulation, cognitive function, obesity management, cardiovascular regulation, liver protection, and urinary and renal health. Furthermore, this article emphasizes the importance of precise nutrition and optimized dosage tailored to different life stages and physiological states. This review supports evidence-based functional nutrition as a powerful supplement or alternative to traditional drug therapy, aiming to extend the healthy lifespan of companion animals and improve their quality of life.

Previous studies have identified oxidative stress and inflammatory responses in granulosa cells (GCs) of periparturient dairy cows. However, whether non-esterified fatty acids (NEFA)-induced endoplasmic reticulum (ER) stress is involved in GC apoptosis remains unclear. In this study, treatment with NEFA (0.9 mM, 24 h) activated the ER stress pathway. This was evidenced by increased expression of both CHOP and GRP78. Furthermore, upregulation of pro-apoptotic factors BAX and Caspase-3 and downregulation of the anti-apoptotic factor Bcl-2 were observed. Pretreatment of GCs with 4-phenylbutyric acid (4-PBA, 2.5 mM, 2 h) reversed the ER stress and apoptotic effects. This suggests that NEFA-induced apoptosis is mediated through activation of the PERK pathway of ER stress, and that 4-PBA alleviates this effect. Furthermore, targeted metabolomics revealed disruptions in lipid and hormone metabolism in GCs following NEFA treatment. Analysis revealed an increase in the levels of 26 types of fatty acids, while a decrease was detected in the levels of 3 types of fatty acids. In summary, NEFA induces ER stress and disrupts intracellular fatty acid, ultimately leading to cell apoptosis. Our findings offer valuable insights for developing strategies to regulate follicular development in dairy cows and mitigate the impacts of postpartum negative energy balance (NEB).

In order to protect endangered species, many zoos adopt diverse rearing models to achieve optimal conservation outcomes. This study employed metagenomic approaches to assess differences in the fecal microbiome of captive and semi-free-ranging ring-tailed lemurs (Lemur catta). The results show that captivity significantly altered the microbial community structure. The inter-individual variability in the microbial community within the captive-bred (CB) group was lower than that in the semi-free-ranging (FR) group, yet these individuals harbored a higher abundance of potential pathogens (Treponema_D). In contrast, microbial genera associated with fiber degradation and short-chain fatty acid production in the FR group were significantly elevated (Faecalibacterium, Roseburia, and Megamonas) as compared to the CB group. Environmental variations between the two rearing systems led to distinct profiles in microbial functions and carbohydrate-active enzyme gene composition. Notably, the FR group of lemurs exhibited an increased abundance of enzyme genes associated with the degradation of complex polysaccharides (cellulose, hemicellulose, and pectin), suggesting that their diet, rich in natural plant fibers, enhances the capacity of their gut microbiota to extract essential energy and nutrients. Conversely, the CB group displayed a more homogeneous microbial community with a higher prevalence of potential pathogens, implying that a captive lifestyle may negatively impact gastrointestinal health. These findings offer valuable insights into the influence of rearing conditions on gut microbial ecology and its potential implications for the health management of ring-tailed lemurs.

Feeding raw meat to cats and dogs has become a common practice in Western countries. Many pet owners cite their pets’ wild carnivore ancestry and believe raw meat diets are healthier, citing higher nutritional value, a lack of processing, low-carbohydrate content, and/or the presence of whole ingredients. However, due to the risks associated with raw meat-based diets (e.g., microbial contamination, nutritional imbalances) and growing concerns about food sustainability, most nutritional specialists and public health stakeholders question the practice of feeding raw meat. In this context, the vast majority of owners’ claims regarding the beneficial health effects of raw meat diets lack scientific substantiation, while professional advice primarily focuses on risks, often overlooking potential positive health effects. To better understand the effects of raw meat diets on the health of cats and dogs, this review summarises the latest scientific evidence and discusses both the potential health benefits and the risks associated with these diets.

Joint health is crucial for the quality of life of companion animals, influencing their mobility, physical activity, and overall well-being. Nutritional strategies play an essential role in mitigating joint degeneration, managing inflammation, and enhancing musculoskeletal resilience across different life stages. This review explores the impact of dietary interventions, including macronutrient balance, bioactive compounds, and specialized supplementation, in maintaining joint integrity and function. Emerging evidence highlights the significance of omega-3 fatty acids, chondroprotective agents, and antioxidant-rich diets in modulating inflammatory pathways, and slowing disease progression. Additionally, tailored nutrition during growth phases is essential to prevent developmental orthopedic diseases, particularly in large-breed dogs. A lifelong, nutrition-centered approach to joint health-integrating dietary modifications with veterinary oversight offers a proactive framework for enhancing mobility, reducing disease burden, and improving the quality of life in companion animals. This review underscores the need for further research into molecular mechanisms linking diet and joint homeostasis, facilitating evidence-based dietary recommendations for veterinary practice.

Plant extracts, derived from various natural sources, encompass primary and secondary metabolites, which include plant polysaccharides, polyphenols, alkaloids, flavonoids, glycosides, terpenes, and volatile oils. These compounds exhibit a range of biological activities such as antioxidant, anti-inflammatory, and antimicrobial functions. Currently, polyphenols and other bioactive compounds are being incorporated into the diets of farm animals, fish, and pets to promote health benefits. Despite this, the application and potential of plant extracts in canine and feline nutrition have not been comprehensively explored. Many aspects of the mechanisms underlying the action of these plant metabolites remain to be analyzed and elucidated. Furthermore, leveraging natural plant extracts for the treatment of clinical conditions in dogs and cats is a crucial component of clinical nutrition. Consequently, this review aims to highlight the impact of plant extracts on overall health, gastrointestinal health, immune health, cardiovascular health, redox balance, and pathology in dogs and cats.

With the rising popularity of pet cats as companion animals, the survival of newborn kittens is often threatened by factors such as inadequate nursing, maternal behavior and blood incompatibility. These challenges require the use of milk replacers for nurturing. To investigate the effects that feeding kittens with an experimental milk replacer (EMR) have on growth and development, intestinal microbiota, immune response and nutrient metabolism, 12 British shorthair kittens were randomly divided into two groups after nursing for the first week of life. Kittens were fed queen’s milk or EMR, whereby kittens fed queen’s milk served as the control (CON) group. The findings revealed that the CON group exhibited superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC) (p < 0.01) on day 7. However, the EMR group had better growth performance during the later stage of the experiment (p < 0.05); the immunocompetence and antioxidant capacity of the EMR group were not significantly different from those of the CON group in the middle and late stages of the experiment, and the mean values of all the indexes were slightly better than those of the control group. Sequencing of the 16S rRNA gene in microbiota demonstrated that EMR increased the colonization of bacterial genera, including Lachnospiraceae, Enterococcus, Rothia and Ligilactobacillus. Compared to the CON group, acetate acid (p < 0.05), propionate acid (p < 0.01) and total SCFAs (p < 0.01) in the EMR group were significantly increased. Moreover, the intake of the EMR resulted in the production of distinct metabolites implicated in the metabolism of lipids and amino acids, among other nutrients, thus invigorating the associated metabolic pathways. These results elucidate the impact of administering a milk replacer on gastrointestinal health and nutrient assimilation in kittens. The study provides insights into the use of milk powder alternatives and sets the stage for future research on the formulation and effectiveness of kitten milk replacers.