- Zanru Guo (1)
- K. Hees-Huijps van (1)
- R.G. Hu (1)
- K.A. Kline (1)
- A.T.M. Knegsel van (1)
- Peng Li (1)
- Mya Mya Khin (1)
- M. Nielen (1)
- B.H.L. Oh (1)
- O.C. Sampimon (1)
- A. Vanhoudt (1)
- J.C.M. Vernooij (1)
- Y.S. Vikhe (1)
- Jing Wang (1)
- Yilei Wang (1)
- T. Werven van (1)
Effects of reduced intramammary antimicrobial use during the dry period on udder health in Dutch dairy herds
Vanhoudt, A. ; Hees-Huijps, K. van; Knegsel, A.T.M. van; Sampimon, O.C. ; Vernooij, J.C.M. ; Nielen, M. ; Werven, T. van - \ 2018
Journal of Dairy Science 101 (2018)4. - ISSN 0022-0302 - p. 3248 - 3260.
antimicrobial - dairy cow - dry period - selective dry cow therapy - udder health
Dry cow therapy (DCT) in the Netherlands changedfrom mainly blanket to selective antimicrobial DCT.This transition was supported by a national guideline,with the individual somatic cell count (SCC) at thelast milk recording before dry-off as the main selectioncriterion for antimicrobial DCT. The aim of this retrospectiveobservational study is to evaluate the SCCdynamics during the dry period at the herd and individualdry period level following the national transitionfrom mainly blanket to selective antimicrobial DCT.At the herd level, we used 2 data sets to evaluate theSCC dynamics during the dry period: (1) a nationaldata set containing 3,493 herds with data availablefrom 2011 through 2015 and (2) a veterinary practicedata set containing 280 herds with data available from2013 through 2015. The herd level analysis was carriedout using key performance indicators provided via milkrecording (CRV, Arnhem, the Netherlands): the percentageof cows that developed a new intramammaryinfection (IMI) during the dry period and the percentageof cows cured of an IMI during the dry period.The effect of DCT at individual dry period level wasanalyzed with a mixed-effects logistic regression modelbased on 4,404 dry periods from 2,638 cows in 20 herdswithin the veterinary practice data set. For these 20herds, individual SCC data from milk recordings andindividual cow DCT were available from 2013 through2015. No significant changes were observed to the SCCdynamics during the dry period at the herd level. Thepercentage of cows that developed a new IMI duringthe dry period ranged between 16 and 18%, and thepercentage of cows cured from an IMI during the dryperiod ranged between 74 and 76%. At the individual dry period level, a low SCC at the first milk recordingfollowing a dry period was associated with the use ofintramammary antimicrobial DCT with or without theconcurrent use of an intramammary teat sealer [oddsratio (OR) = 2.16 and OR = 2.07, respectively], the useof DCT with an intramammary teat sealer only (OR =1.35), and a low SCC at the last milk recording beforedry-off (OR = 1.78). This study demonstrates that theselection of cows for DCT without antimicrobials basedon SCC thresholds at the last milk recording is possiblewithout significant changes to udder health andreduced the use of antimicrobials.
High-Performance Capacitive Deionization Disinfection of Water with Graphene Oxide-graft-Quaternized Chitosan Nanohybrid Electrode Coating
Wang, Yilei ; El-Deen, A.G. ; Li, Peng ; Oh, B.H.L. ; Guo, Zanru ; Khin, Mya Mya ; Vikhe, Y.S. ; Wang, Jing ; Hu, R.G. ; Boom, R.M. ; Kline, K.A. ; Becker, D.L. ; Duan, Hongwei ; Chan-Park, M.B. - \ 2015
ACS Nano 9 (2015)10. - ISSN 1936-0851 - p. 10142 - 10157.
antimicrobial - capacitive deionization - cationic - contact-active - graphene oxide - quaternary chitosan - water disinfection
Water disinfection materials should ideally be broad-spectrum-active, nonleachable, and noncontaminating to the liquid needing sterilization. Herein, we demonstrate a high-performance capacitive deionization disinfection (CDID) electrode made by coating an activated carbon (AC) electrode with cationic nanohybrids of graphene oxide-graft-quaternized chitosan (GO-QC). Our GO-QC/AC CDID electrode can achieve at least 99.9999% killing (i.e., 6 log reduction) of Escherichia coli in water flowing continuously through the CDID cell. Without the GO-QC coating, the AC electrode alone cannot kill the bacteria and adsorbs a much smaller fraction (4 CFU mL-1 bacteria), the GO-QC/AC electrodes can kill 99.99% of the E. coli in water for 5 h. The disinfecting GO-QC is securely attached on the AC electrode surface, so that it is noncontaminating to water, unlike many other chemicals used today. The GO-QC nanohybrids have excellent intrinsic antimicrobial properties in suspension form. Further, the GO component contributes toward the needed surface conductivity of the CDID electrode. This CDID process offers an economical method toward ultrafast, contaminant-free, and continuous killing of bacteria in biocontaminated water. The proposed strategy introduces a green in situ disinfectant approach for water purification.