Oxidative stress is closely linked to inflammation and contributes to the onset of different diseases in farm animals, thereby affecting their health, performance, welfare and productivity. Oxidative damage occurs as a result of the accumulation of free radicals and pro-oxidants that overwhelm the animal’s antioxidant defense system. This imbalance impairs growth and reproductive performance, health and welfare, leading to disease susceptibility and reduced productivity. This review highlights the relationship between oxidative stress and inflammation, the production of free radicals, their effect on animal health and welfare, as well as combating oxidative stress with bioactive compounds, minerals and vitamins. Oxidative stress can be prevented through the use of naturally occurring bioactive compounds, vitamins, minerals, appropriate management and production systems. Bioactive compounds and vitamins act by scavenging free radicals through neutralization or by activating the nuclear factor erythroid 2-related factor 2 pathway, which upregulates antioxidant genes and promotes the production of antioxidant enzymes that convert free radicals into less reactive forms. Minerals, on the other hand, serve as co-factors for antioxidant enzymes, thereby enhancing their activity. Additionally, environmental enrichment, animal housing and proper handling can reduce the occurrence of oxidative stress, leading to improved animal health and welfare. In conclusion, oxidative stress can cause significant losses in animal production; however, its prevention through effective management practices and dietary interventions can significantly improve animal health, performance, welfare and productivity.

The intestinal microbiota plays a critical role in broiler health, nutrient metabolism, immune function, and overall productivity. Its composition is influenced by multiple factors, with diet being the primary driver alongside genetics, digesta passage rate, and rearing environment. Amid growing restrictions on antimicrobial growth promoters and increasing emphasis on sustainable production, fermented diets have emerged as a viable nutritional strategy in broiler nutrition. Furthermore, fermentation serves as a valuable tool for valorizing agricultural by-products and developing alternative broiler feed ingredients. Research has shown that fermented feed enhances growth performance, improves gut health, and beneficially modulates the intestinal microbiota, and hence microbiome. This review synthesizes current research on how fermented feeds, including fermented cereals, brans, legumes, pulses, pomaces, and complete rations, influence the composition, diversity, and functional dynamics of the broiler intestinal microbiota. We discuss the chicken gastrointestinal tract, microbiota, fermentation of broiler feed, the mechanisms through which fermented diets interact with the gastrointestinal environment, emphasizing their role in improving gut barrier integrity, immune responses, and nutrient absorption. By integrating recent findings, this paper highlights the potential of fermented feeds as a viable, microbiome-targeted intervention to support sustainable broiler production while addressing contemporary challenges in poultry health and nutrition.

Poultry coccidiosis remains a major parasitic disease causing significant economic losses worldwide. Although previous studies have reported its occurrence in Vietnam, there is a lack of region-specific epidemiological and clinicopathological data under distinct agro-ecological and production conditions in Thai Nguyen Province. This study determined the prevalence, associated risk factors, and clinicopathological alterations of coccidiosis in chickens in this region. A cross-sectional survey was conducted from January to December 2024 in six communes of Phu Binh District, with 300 faecal samples examined using the flotation technique for Eimeria oocysts. Infection intensity was semi-quantitatively assessed, while clinical signs, gross lesions (n = 75), and haematological parameters (10 infected vs. 10 healthy chickens) were evaluated. Prevalence differences were analysed using the Chi-square test, and haematological parameters were compared using independent-samples t-tests (P < 0.05). The overall prevalence was 49.00%, with significantly higher rates in chickens aged 1-3 months (67.05%) and in free-range systems (86.90%). Seasonal variation showed higher prevalence in summer (63.04%) and spring (53.57%) compared to winter (33.82%). Infected chickens exhibited diarrhoea, ruffled feathers, lethargy, and anorexia. Haematological analysis revealed reduced red blood cell counts and haemoglobin levels, alongside increased white blood cell counts, heterophils, and eosinophils (P < 0.05). Gross lesions included haemorrhagic enteritis, intestinal ballooning, and mucosal thickening. These findings highlight the high prevalence of coccidiosis in Thai Nguyen Province and provide region-specific evidence to support targeted control strategies and improved biosecurity measures.