Effects of monensin and cashew nut-shell extract on bacterial community composition in a dual-flow continuous culture system

Efstathios Sarmikasoglou; Phussorn Sumadong; Luiz Fernando Roesch; Sultana Halima; Chie Hikita; Tomonori Watanabe; Antonio P Faciola

doi:10.1093/tas/txad148

Effects of monensin and cashew nut-shell extract on bacterial community composition in a dual-flow continuous culture system

Transl Anim Sci. 2023 Dec 23:8:txad148. doi: 10.1093/tas/txad148. eCollection 2024.

Authors

Efstathios Sarmikasoglou^{1

2}, Phussorn Sumadong^{2

3}, Luiz Fernando Roesch⁴, Sultana Halima², Chie Hikita⁵, Tomonori Watanabe⁵, Antonio P Faciola²

Affiliations

¹ Department of Animal Science, Michigan State University, East Lansing, MI 48824, USA.
² Department of Animal Sciences, University of Florida, Gainesville, 32611 FL, USA.
³ Department of Animal Science, Khon Kaen University, Khon Kaen 40002, Thailand.
⁴ Department of Microbiology and Cell Science, University of Florida, Gainesville, 32603 FL, USA.
⁵ Product Development Department, SDS Biotech K.K., Tokyo 101-0022, Japan.

Abstract

The objective of this study was to evaluate the effects of including monensin and two doses of CNSE in a high producing dairy cow diet on ruminal bacterial communities. A dual-flow continuous culture system was used in a replicated 4 × 4 Latin Square design. A basal diet was formulated to meet the requirements of a cow producing 45 kg of milk per d (17% crude protein and 27% starch). There were four experimental treatments: the basal diet without any feed additive (CON), 2.5 μM monensin (MON), 100 ppm CNSE granule (CNSE100), and 200 ppm CNSE granule (CNSE200). Samples were collected from the fluid and solid effluents at 3, 6, and 9 h after feeding; a composite of all time points was made for each fermenter within their respective fractions. Bacterial community composition was analyzed by sequencing the V4 region of the 16S rRNA gene using the Illumina MiSeq platform. Treatment responses for bacterial community structure were analyzed with the PERMANOVA test run with the R Vegan package. Treatment responses for correlations were analyzed with the CORR procedure of SAS. Orthogonal contrasts were used to test the effects of (1) ADD (CON vs. MON, CNSE100, and CNSE200); (2) MCN (MON vs. CNSE100 and CNSE200); and (3) DOSE (CNSE100 vs. CNSE200). Significance was declared at P ≤ 0.05. We observed that the relative abundance of Sharpea (P < 0.01), Mailhella (P = 0.05), Ruminococcus (P = 0.03), Eubacterium (P = 0.01), and Coprococcus (P < 0.01) from the liquid fraction and the relative abundance of Ruminococcus (P = 0.03) and Catonella (P = 0.02) from the solid fraction decreased, while the relative abundance of Syntrophococcus (P = 0.02) increased in response to MON when compared to CNSE treatments. Our results demonstrate that CNSE and monensin have similar effects on the major ruminal bacterial genera, while some differences were observed in some minor genera. Overall, the tested additives would affect the ruminal fermentation in a similar pattern.

Keywords: anacardic acid; cardol; monensin; rumen bacteria.