Proper motility enhances rumen fermentation and microbial protein synthesis with decreased saturation of dissolved gases in rumen simulation technique

Abstract

The physiological function of the reticulorumen plays an essential role in ruminant nutrition, and detailed knowledge of rumen motility can further advance understanding of ruminant nutrition and physiology. Rumen motility was simulated by setting different stirrer rotation speeds in a rumen simulation technique (RUSITEC) system. The aim of this study was to investigate the effects of rotation speeds on rumen fermentation, saturation factor of dissolved gases, hydrogen (H 2 ) and methane (CH 4 ) emissions, microbial protein synthesis, and selected microbial population using RUSITEC. The experiment was performed according to a balanced 3 × 3 Latin square design, and each period included 7 d for adaptation and 3 d for sampling. Three motility treatments included 5, 15, and 25 rpm rotation speeds. Daily total gas and H 2 and CH 4 emissions had quadratic responses to the increasing rotation speed and were highest at 15 rpm. Quadratic and linear responses (highest at 5 rpm) to increasing rotation speed were observed for saturation factors of H 2 and CH 4 , liquid-dissolved H 2 and CH 4 concentrations, and headspace concentration of H 2 in the gas phase, whereas increasing rotation speed linearly decreased saturation factors of CO 2 and liquid-dissolved CO 2 concentration. Quadratic and linear responses to increasing rotation speed were observed for molar percentages of acetate, ammonia, and microbial protein concentration, whereas increasing rotation speed quadratically increased pH and decreased total volatile fatty acid concentration and acetate-to-propionate ratio. The 15-rpm rotation speed had the highest values of total volatile fatty acids, acetate molar percentage, and microbial protein concentration. Quadratic and linear responses to increasing rotation speed were observed for copy numbers of solid-associated fungi and fluid-associated bacteria, fungi, and protozoa, while increasing rotation speed linearly increased copy numbers of solid-associated protozoa. Rotation at 15 rpm increased populations of fungi and protozoa in the solid rumen contents and the population of bacteria and fungi in the liquid rumen contents. In summary, this study provides insights on the biofunction of proper rumen motility (i.e., at a rotation speed of 15 rpm), such as improving feed fermentation, increasing gas emissions with decreased dissolved gas concentrations and saturation factors, and promoting microbial colonization and microbial protein synthesis, although further increase in rotation speed (i.e., to 25 rpm) decreases feed fermentation and microbial protein synthesis.

Dietary Administration of L-Carnitine During the Fattening Period of Early Feed Restricted Lambs Modifies Ruminal Fermentation but Does Not Improve Feed Efficiency

“…Although this effect is counteracted by water flux from the bloodstream (through saliva or directly entering across rumen wall) L-Carnitine, a compound with osmoprotectant properties, may have allowed more susceptible bacteria to overcome osmotic stress ( Meadows and Wargo, 2015 ), whereas it is plausible that microbiota of the control lambs had to use some nutrients to synthesize L-Carnitine or other osmoprotectants to be adapted against changes in osmotic pressure, thus modifying ruminal fermentation parameters. Likewise, it has been reported that carnitine supplementation can modulate gut motility ( Meyer et al, 2020 ) and transit time, which is another factor that affects gut microbiota composition and fermentation ( Tottey et al, 2017 ; Adebayo Arowolo et al, 2022 ).…”

Effects of different protein sources on nutrient disappearance, rumen fermentation parameters and microbiota in dual-flow continuous culture system

“…We used a dual-flow continuous culture fermentation system because continuous culture fermenters run continuously for longer periods than in the Daisy II , batch culture and the Ankon Gas Production System, furthermore, the continuous culture can mimic in vivo ruminal conditions and allows for natural stratification of feed particles, anaerobiosis, controlled temperature, and salivary buffering, similar to what occurs in the rumen (Alende et al 2018 ). A dual-flow continuous culture system (Adebayo Arowolo et al 2021 ) was used in this study. This system contains six fermentation units, each unit consisting of a fermentation apparatus, outflow device, liquid supply component, data detection module and controlling computer.…”

Copresent microbiome and short-chain fatty acids profiles of plant biomass utilization in rumen simulation technique system

“…Each round experiment included two cow rumen contents (cow group), two goat rumen contents (goat group), and two mixed contents of cow and goat rumen (co-inoculum group). A modification was made based on the previously described method of diluting inoculum 12 , which takes the total biomass as a consideration. Two rounds of cow rumen inocula (DNA concentration: 28.93 ± 2.91 μg/mL; 23.65 ± 0.27 μg/mL) were diluted 1.18 and 1.28-fold respectively with McDougall buffer solution, while the goat rumen inocula (DNA concentration: 24.48 ± 0.15 μg/mL; 18.42 ± 0.69 μg/mL) were diluted 0.84 and 0.77-fold respectively.…”