Effect of feeding isolates of anaerobic fungusNeocallimastixsp. CF 17 on growth rate and fibre digestion in buffalo calves

Abstract

In this investigation, the effects of feeding encapsulated cells (rhizomycelia and zoospores) of a fibrolytic isolate from an anaerobic fungus (Neocallimastix sp. CF 17) on nutrient digestion, ruminal fermentation, microbial populations, enzyme profile and growth performance were evaluated in buffaloes. In three in vitro studies, the true digestibility of wheat straw was increased after addition of CF 17 to buffalo rumen fluid (p < 0.05). In Exp. 1, three groups of six buffaloes each (initial BW [body weight] 148 +/- 12.0 kg) were allotted to three dosing regimes: Group 1 received 200 ml of liquid culture of Neocallimastix sp. CF 17 (about 10(6) TFU [thallus-forming units]/ml); Group 2 received an encapsulated culture of the same fungi prepared from 200 ml liquid culture; Group 3: received 200 ml of autoclaved culture (Control). The supplementations were given weekly for four weeks (on days 1,7, 14 and 21). During the dosing period, the average daily gain of Group 2 was higher than in the Control group (444 g/d compared with 264 g/d; p < 0.05). Furthermore, the digestibility of organic matter increased in Group 1 and 2 compared with the Control (64.8, 64.0 and 60.4% respectively; p < 0.05), resulting in an increase in the total digestible nutrient (TDN) percent of ration (p < 0.05). But these effects disappeared post-dosing. There were also an increase in concentration of volatile fatty acids, trichloroacetic acid precipitable N and number of fibrolytic microbes in the rumen during the dosing period (p < 0.05), but these effects declined post-dosing. Results of Exp 2., where the encapsulated culture was applied at intervals of 4 d or 8 d for 120 d, showed that a shorter dosing frequency did not improve growth performance or feed intake. However, independent of the dosing frequency the growth rate of both groups fed the encapsulated culture were about 20% higher than in the Control group (p < 0.05). The present study showed that encapsulated fungi have a high potential to be used as feed additive at the farmers' level and that weekly dosing can increase growth performance of wheat straw based diets.

Metatranscriptomic Profiling Reveals the Effect of Breed on Active Rumen Eukaryotic Composition in Beef Cattle With Varied Feed Efficiency

“…Therefore, the high abundance of active rumen fungi in low-RFI steers may provide increased energy to hosts from the fermentation of structural polysaccharides, leading to a high feed efficiency. As an indirect proof, it has been demonstrated that inclusion of cultures of anaerobic fungi in the diets of various ruminants improved feed intake, animal growth rate, feed efficiency, and milk production (Lee et al, 2000;Saxena et al, 2010;Paul et al, 2011).…”

Anaerobic fungi (phylumNeocallimastigomycota): advances in understanding their taxonomy, life cycle, ecology, role and biotechnological potential

“…The application of anaerobic fungi as a direct‐fed microbial supplement has been investigated, in both ruminant and nonruminant livestock production, as a means to improve utilisation of low‐quality forages. Inclusion of cultures of anaerobic fungi in the diets of various ruminants has been investigated and demonstrated to improve feed intake, animal growth rate, feed efficiency and milk production (Lee et al ., ; Dey et al ., ; Paul et al ., , ; Tripathi et al ., ; Samanta et al ., ; Sehgal et al ., ; Mamen et al ., ; Saxena et al ., ; Gao et al ., ). The benefits observed being even more marked in young ruminants (Theodorou et al ., ; Sehgal et al ., ) and sheep devoid of anaerobic fungi (Elliott et al ., ; Gordon & Phillips, ).…”

Development of an RNA interference (RNAi) gene knockdown protocol in the anaerobic gut fungusPecoramyces ruminantiumstrain C1A

“…The anaerobic gut fungi (AGF) represent a basal fungal phylum (Neocallimastigomycota) that resides in the herbivorous gut and plays an important role in enhancing plant biomass metabolism by the host animals ( Gruninger et al, 2014 ). The AGF have multiple potential biotechnological applications such as a source of lignocellulolytic enzymes ( Cheng et al, 2014 ; Kwon et al, 2016 ; Lee et al, 2015 ; Morrison, Elshahed & Youssef, 2016 ; Wang, Chen & Hseu, 2014 ; Wei et al, 2016a ; Wei et al, 2016b ), direct utilization of AGF strains for sugar extraction from plant biomass in enzyme-free biofuel production schemes ( Ranganathan et al, 2017 ), additives to biogas production reactors ( Nkemka et al, 2015 ; Procházka et al, 2012 ), and feed additives for livestock ( Dey et al, 2004 ; Lee, Ha & Cheng, 2000 ; Paul et al, 2011 ; Paul et al, 2004 ; Saxena et al, 2010 ; Sehgal et al, 2008 ; Tripathi et al, 2007 ). However, the strict anaerobic nature of AGF renders genetic manipulation procedures involving plating and colony selection extremely cumbersome.…”