Symbiosis exists between probiotics and exogenous fibrolytic enzymes in ruminant nutrition: A review

Abstract

The ultimate goal of any nutritionist is to optimize the productive potential of the animal. Addition of Exogenous Fibrolytic Enzymes (EFE) to the ruminant diet altered rumen fermentation pattern positively by the production of SCFA resulting in improved performance. EFE has a major role in the fibre digestibility since the fibre-based forages are the staple feed for the ruminants. It was reported that when calves were fed with EFE, it showed a positive effect on the microbial enzymes like carboxymethyl cellulase, cellobiose, xylanase, pectinase and others’ activities in the rumen especially after weaning. On the other hand, probiotics are said to increase the population of beneficial micro-organisms including Lactobacilli and Bifidobacteria which then inhibit the growth of pathogenic organisms by producing inhibiting substances like bacteriocins and/or organic acids. These are said to have an improved feed intake, growth rate and nutrient digestibility. Supplementation of probiotics like Saccharomyces cerevisiae promote the growth and metabolism of lactate-utilizing bacteria in the rumen and then support the conversion of lactate to propionate, allowing calves to obtain more energy from their diet. Both EFE and probiotics, have the potential to modulate rumen fermentation and improve fibre digestibility, animal performance, and feed conversion efficiency. A good example of symbiotic relationship between EFE and probiotics is that fibrolytic enzymes degrades the fibre fractions whereas probiotics maintain the rumen microbial balance. Live yeast culture (Saccharomyces cerevisiae) checks the decrease in rumen pH while EFE functions more efficiently in the pH levels higher than 6.0 leading to more cellulolysis. Fibrolytic enzymes are gaining importance because they improve the nutrient digestibility and performance of animals without affecting the animals’ health. Probiotics (bacteria and/or yeast) are also important feed additives that can support ruminal microbial activity and enhance gut health and ecology through microbial establishment. Exogenous fibrolytic enzymes increases the fibre digestion there by increased available energy to ruminants which results in increased nutrient digestibility, growth rate and rumen fibrolytic bacteria activity. Further, supplementation of yeast had shown that yeast cell wall products mannooligosaccharides, β-glucans have positive impact on growth of animals and absorb the pathogens and improves the immune response. However, the symbiotic relation between these two is not consistent as it depends on many factors like source of origin, dosage, period of supply, mode of application and other related factors. It was concluded that the symbiotic relation ship between these two feed additives was not harmful though not beneficial with more inclination towards a positive side.