Comparison of rumen bacteria distribution in original rumen digesta, rumen liquid and solid fractions in lactating Holstein cows

Background： Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fractions vary from each other and need to be better established.Methods： To compare bacterial profiles in each fraction, samples of rumen digesta from six cows fed either a high fiber diet（HFD） or a high energy diet（HED） were collected via rumen fistulas. Rumen digesta was then squeezed through four layers of cheesecloth to separate liquid and solid fractions. The bacterial profiles of rumen original digesta, liquid and solid fractions were analyzed with High-throughput sequencing technique.Results： Rumen bacterial diversity was mainly affected by diet and individual cow（P 〉 0.05） rather than rumen fraction. Bias distributed bacteria were observed in solid and liquid fractions of rumen content using Venn diagram and LEf Se analysis. Fifteen out of 16 detected biomarkers（using LEf Se analysis） were found in liquid fraction, and these 15 biomarkers contributed the most to the bacterial differences among rumen content fractions.Conclusions： Similar results were found when using samples of original rumen digesta, rumen liquid or solid fractions to assess diversity of rumen bacteria; however, more attention should be draw onto bias distributed bacteria in different ruminal fractions, especially when liquid fraction has been used as a representative sample for rumen bacterial study.

The verbiage in variable message signs and traffic diversion during crash incidents

Purpose–WIth limited research on the effects of variable message sign(VMS)message content and verbiage on revealed driver behavior,this study aims to investigate how different verbiage of crash-related messages are related to the diversion rate.Design/methodology/approach–Using ordered logit models,the associations of message verbiage with diversion rates during crash incidents were assessed using five years of VMS message history within a section of I-15 in the state of Utah.Findings–A significant impact of message verbiage on the diversion rate was observed.Based on the analysis results,the crash message verbiage with the highest diversion was found to be miles to crash 1“prepare to stop,”followed by crash location 1 delay information,miles to crash 1“use caution”1 lane of the crash,etc.In addition,the diversion rate was found to be correlated to some roadway characteristics(e.g.occupancy in mainline,weather condition and light condition)along with the temporal variations.Research limitations/implications–These findings could be used by transportation agencies(e.g.state department of transportation[DOTs])to make informed decisions about choosing the message verbiage during future crash incidents.This study also revealed that higher diversion rates are associated with a shorter distance between the crash location and VMS device location,recommending increasing the number of VMS devices,particularly in crash-prone areas.