In vitro evaluation of novel crude extracts produced by actinobacteria for modulation of ruminal fermentation

Abstract

Ruminants Full-length research article In vitro evaluation of novel crude extracts produced by actinobacteria for modulation of ruminal fermentation ABSTRACT-We evaluated the inclusion of two crude extracts produced by Streptomyces genus on in vitro dry matter and organic matter digestibility (IVDMD; IVOMD), cumulative gas production, volatile fatty acids (VFA), and methane (CH 4) and ammoniacal nitrogen (NH 3-N) concentration. The experimental design was randomized blocks with three blocks and four treatments: AMC (1.2 mg/25 mL ruminal inoculum), Caat (1.2 mg/25 mL ruminal inoculum), negative control (no inclusion of extracts), and positive control (sodium monensin, 1.7 mg/25 mL ruminal inoculum). Ruminal fluid samples were collected from three multiparous Holstein dairy cows fitted with ruminal cannula and incubated in a 24-h fermentation assay. There was no effect of crude extract inclusion in comparison with negative control on cumulative gas production in 24 h. However, cumulative gas production was lower when Caat extract was included in comparison with AMC inclusion. The Caat inclusion increased propionic acid concentration and reduced the concentration of butyric acid and acetate:propionate (A:P) ratio in relation to negative control. The CH 4 concentration was lower with Caat inclusion in relation to AMC, and the ratio of CH 4 concentration to digestible dry matter was lower in the negative control compared with all additives. Caat inclusion decreased the NH 3-N concentration, and IVDMD was not altered compared with negative control. Additionally, the inclusion of Caat crude extract increased propionic acid concentration and reduced butyric acid concentration and A:P ratio, without reducing the IVDMD and IVOMD. Caat extract modulates rumen fermentation, increasing available energy and decreasing gas production without causing changes in dry matter and organic matter digestibility.

Caracterización nutricional y producción de gas de especies vegetales con potencial alimenticio para la alimentación de rumiantes

“…Si la fermentación está enfocada en la producción de propionato se podría esperar una reducción en la producción de metano y gases (37). La fermentación de un sustrato a propionato es una reacción productora de gas debida a la neutralización del ácido; por lo que una baja producción de gas está asociada con una fermentación propiónica (38). En este sentido, los resultados obtenidos para el HUI son consistentes con lo anterior.…”