In vitro assessment of poleo and suico on fermentation and ruminal microbial populations over time.

SCORCIONE C.; CERÓN CUCCHI M.E.; GERE J. I.; ORTIZ CHURA A.; MARTINÉZ J. ; MORENO M. ; COLOMBATTO D.

Conferencia; 8th Greenhouse Gas and Animal Agriculture Conference.; 2022

Argentina has a wide diversity of botanical species that contain bioactive compounds traditionally used for medicinal purposes. To date, there is little information about their antimicrobial properties as ruminal fermentation modifiers. The objective of this study was to determine methane (CH4) production, digestibility and ruminal microbiota parameters in response to the inclusion of Lippia turbinata (poleo) and Tagetes minuta (suico), using the in vitro batch fermentation technique (at 0, 12, 24 and 48 h of incubation) using a substrate similar to a dairy diet. Fifty mg of ground plant material was added to 450 mg of substrate (excepting control). A positive control with monensin (1.87 mg /L) was also included. Three cannulated Hereford steers (518 ± 51 kg) fed alfalfa hay and ground corn grain (80:20 on a dry basis) were used as donors of ruminal fluid. In vitro CH4 production with respect to neutral detergent fiber incubated was lower than that of the control (P=0.001) at 12 h, 24 h, and 48 h incubation with poleo (33, 35 and 31%) and with suico (30, 29 and 30%). While poleo reduced CH4 production and methanogenic archaea populations (1, 3 and 7%) as compared to control (P=0.001), suico decreased CH4 without affecting these microorganisms (P=0.001). It was not possible to establish a direct relationship between the reduction in the number of methanogenic archaea and the number of protozoa. Total bacteria increased, but changes were not of biological relevance as they did not affect any of the fermentation parameters evaluated. Regarding protozoa, only monensin significantly reduced their population (39%), while both poleo and suico had no effect. In addition, poleo and suico decreased the digestibility of the substrate used, and reduced ruminal CH4 production, likely by different modes of action.