Evaluation of cellulolytic exogenous enzyme-containing microbial inoculants as feed additives for ruminant rations composed of low-quality roughage

Abstract

The supplementation of ruminant diets with exogenous cellulolytic enzymes can improve their digestibility and feeding value. The objective of this study was to determine the effect of supplementing roughage (rice straw) and concentrate with inoculants containing four fungal strains (Pleurotus ostreatus, Phanerochaete chrysosporium, Trichoderma reesei and Trichoderma viride) and four bacterial strains (Paenibacillus polymyxa, Bacillus megaterium, Bacillus circulans and Bacillus subtilis), given separately or as a mixture, as a source of exogenous cellulolytic enzymes, on basic rumen parameters in vitro, including digestibility and methane production. A batch culture trial was used to select the best supplements, and a long-term rumen simulation technique (RUSITEC) was used to evaluate the effects of P. chrysosporium, B. subtilis, and a 1 : 1 mixture of these two on dietary component digestibility and fermentation parameters. In the batch culture evaluation, there were significant increases in the organic matter (OM) digestibility, the total gas production expressed as ml/g of dry matter, the OM, the neutral detergent fibre (NDF) and the acid detergent fibre (ADF) of the supplemented rations, as compared to the control, excluding the rations supplemented with T. viride and B. circulans. In the RUSITEC, the ration supplemented with mixed inoculants showed significantly higher digestibility of crude protein, ether extract, NDF and ADF than did the ration supplemented with the P. chrysosporium and B. subtilis inoculants. It can be concluded that the simultaneous use of fungal and bacterial exogenous cellulases on rice straw roughage improves its digestibility, without negative effects on other rumen parameters.

Role of Live Microbes for Fermentation and Enhancement of Feeding Value of Wheat Straw as Animal Fodder

“…These results agree with that reported by Zayed [23]. Different material sources indicated that the abilities of microorganisms made a significant change in the physical structure of straw depending on the species of microorganism and the growth condition of microbes [28].…”

The effects of compound treatment of Aspergillus oryzae and fibrolytic enzyme on in vitro degradation, gas production and fermentative profile of maize silage and sugarcane silage

“…Furthermore, Zayed et al . (2020) in an in vitro study reported that the simultaneous use of inoculants containing fungal and bacterial strains, as a source of exogenous cellulolytic enzymes, increased the fibre digestibility of rice straw.…”

“…Feed additive strategies have been evaluated to improve fibre digestibility and feed efficiency. Exogenous fibrolytic enzyme increases the dry matter (DM) and neutral detergent fibre (NDF) in vitro degradation (Gandra et al ., 2017; Zayed et al ., 2020), fermentative kinetics (Elghandour et al ., 2016) and beef cattle average daily gain (Tirado-González et al ., 2018). However, the efficiency of exogenous enzyme is highly variable (Meale et al ., 2014; Abid et al ., 2019).…”

The Impact of Anthropogenic Climate Change on Egyptian Livestock Production

“…Other possibilities include environmental modification through the use of technology to prevent solar heat loads and increasing opportunities for animal heat loss through using shelter and cooling systems; also, nutritional options, such as fibrolytic enzyme supplementation, could be used. Supplementation with exogenous cellulolytic enzymes in ruminant diets can improve the digestibility and feeding value [ 92 ]. Ruminants could be supplemented with rice straw and grains inoculated with fungal and bacterial strains to improve digestibility and to reduce methane production.…”