## 2 Endophytes-Current State of the Art
### Endophytes as a Feeding Niche for Animals  
Endophytes have shown potential to influence various aspects of animal health and performance. Their effects on animals are often indirect, mediated through the plants that host them. Figure 2: Factors impacting plant endophytes and beneficials of their presence in plant tissues, according to [PERSON] et al. [28]. NGS has provided new insights into the importance of host genetics on the bovine microbiota sustainable development [113; 114]. Also, aspects connected to how the microbiome is influenced by diets/dietary additives has been studied [115; 116]. Microbiota and metabolites that are significantly influenced by human diet were also identified [117]. Plants are complex food sources, and contain many diverse nutrients, some of which are already known to interact with the microbiome [117]. When animals graze on more productive plants, they benefit from higher nutrient intake. For example, endophytic fungi produce secondary metabolites that increase N availability, improving the quality of the plants that animals consume, which in turn boosts their growth rates [118]. Endophyte-infected plants may have a higher protein content or improved digestibility, further supporting the growth of herbivores like cattle, sheep, and horses [119]. What is more, endophytes help plants resist various forms of stress, which in turn benefits animals feeding on those plants. It has been reported that endophyte-infected plants are often more resistant to drought conditions due to improved water-use efficiency and root structure [118]. This ensures more consistent forage availability for animals during dry seasons. Similarly, endophytes can help plants grow in soils containing increased concentrations of salts or trace elements [119]. This allows animals access to forage in otherwise suboptimal environments, reducing the risk of malnutrition or stress. Moreover, some endophytes produce secondary metabolites (e.g., alkaloids) that deter insects and herbivores from damaging plants. Such protection can improve the yield and quality of forage crops, reducing the impact of pests on the feed supply [118]. Endophytes can also act as biocontrol agents by producing antimicrobial compounds or inducing systemic resistance in plants [119]. Healthier, disease-resistant plants offer more reliable nutrition, which supports better animal health. The metabolites of endophytes may also explain the effect of medicinal plants in improving immunity of mammals [120]. Saponins and secondary extracts derived from endophyte fungal have the potential to be immunostimulant, and they can be implicated as medicine for improving immune diseases [120]. Also, the lipoproteins of endophytic bacteria can stimulate receptors associated with their recognition and immunity, and could consequently regulate the immune responses [121]. Thus, the endophytes with specific metabolic compositions were the potential reason for explaining the mechanisms of medical plants in improving human immunity [120]. Endophytes can have a direct or indirect role in enhancing the resistance of animals to pathogens [118]. Some endophytes produce compounds with antimicrobial properties that can help reduce the presence of harmful pathogens in plants and, potentially, in the digestive tracts of animals [5]. For example, fungal endophytes in grasses have been shown to produce alkaloids that deter fungal pathogens, insects and even parasitic nematodes [118; 119]. Symbiotic relationships between the host and the microbiome, and optimal functioning of the holobiont, are dependent on the environment [122]. Endophyte-enriched plants can influence the gut microbiome of animals, promoting beneficial microbes and limiting harmful ones [119]. A balanced gut microbiome is crucial for healthy digestion and immune function, which helps animals in resisting infections and diseases [5]. Finally, what the animal is exposed to, as a result of toxic tall rescue grazing, will influence host physiology, and what that animal excretes [52].