The possible application of fungal enriched substrates in ruminant nutrition. A review

Abstract

Microbial utilization of raw agro-substrates by solid-state fermentation (SSF) leads to an effective enrichment of prefermented cereal-derived substrates (PCS) with oleaginous fungi being a source of ?-linolenic acid (GLA, 18:3n-6). Such method could open up new possibilities in animal nutrition. In this review, the nutritional effects of various PCS used as components of basal diets are summarized through the integrating related studies. PCS with two oleaginous fungi (Thamnidium elegans and Cunninghamella echinulata) as GLA sources were described. Apart from fatty acids, other related fermentation parameters i.e. digestibility of dry matter, neutral detergent fibre, acid detergent fibre, methane and ammonia concentration, short-chain fatty acid profiles and protozoal counts were taken into account. The effectiveness of GLA sources in increasing ruminal GLA outputs varied, depending on the filamentous fungi used, in the order C. echinulate > T. elegans, but efficiency also depends on the cereal substrate type. However, in vivo studies are needed to determine the impact of using cereal substrates enriched with oleaginous fungi as a source of GLA on rumen metabolism as well as the quality of ruminant meat and dairy products.