The main purpose of yeast supplementation is to treat rumen microbial dysbiosis which may enhance the nutrient utilization leading to enhanced animal growth and productivity. Yeast improves rumen ecosystem by two ways: by direct production of digestive enzymes and growth stimulator and by promoting the growth and function of beneficial microbiota. Yeasts have potential to produce metabolites, which stimulate the growth, like rumen acetogens and antimicrobial compounds which inhibit potential pathogens. The yeast probiotic impact on animals depend on different interacting factors including animal breed, supplemented dose, type, diet, strain, physiological stage and feeding system. In the situation of a high feed cost all over the world, probiotic yeast gives a useful nutritional strategy which allows increasing diet digestibility and consequently enhances the performance in ruminants in cost-effective manner. Many yeast culture-based products are commercially available worldwide, but their effectiveness as probiotic dietary supplement in a particular breed is mostly questionable. Therefore, exploration of the new indigenous probiotic strain is of great interest in this context. The probiotic strains of same ecological origin may be more compatible with rumen microbiome giving maximum outputs. Moreover, the breed specific probiotic yeast is an economical and viable option for farmers to overcome the effects of malnutrition.
Part of the book: Yeast
Probiotic yeast enhanced the ruminal gut microbial balance by producing intercellular effectors and important metabolites. The impact of yeast addition on animal health is influenced by different interlinked factors including animal genomics, its gut microbiota, and environment. Therefore, all factors should be considered regarding achieving the maximum outputs from animal probiotic yeast. In the situation of a high feeding cost, microbial feed supplements provide a suitable nutritional approach, which allows increased nutrient digestion rate and accordingly improves animal performance. Many yeast products are commercially available, but their efficiency as probiotic dietary addition in a particular breed is mostly questionable. Therefore, identification of ideal probiotic yeast strain is of great interest in this context. Innovative methods in relation to develop new probiotic are mainly focused on the exploring novel microbial strains from indigenous sources. It has been noted that for the identification of best probiotic strain for the host, a linkage between culture-independent and culture-dependent methods is a functional step. In this chapter, we will discuss the mode of action of probiotic yeast on animal lower gut microbiota and identification of ideal probiotic yeast by using advanced molecular methods.
Part of the book: Yeasts in Biotechnology