Evaluation of reticuloruminal pH measurements from individual cattle: sampling strategies for the assessment of herd status

Jonsson, N. N. , Kleen, J. L., Wallace, R. J., Andonovic, I., Michie, C., Farish, M., Mitchell, M., Duthie, C.-A., Jensen, D. B. and Denwood, M. J. (2019) Evaluation of reticuloruminal pH measurements from individual cattle: sampling strategies for the assessment of herd status. Veterinary Journal, 243, pp. 26-32. (doi:10.1016/j.tvjl.2018.11.006) (PMID:30606436)

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Abstract

The application of pH observations to clinical practice in dairy cattle is based on criteria derived primarily from single time-point observations more than 20 years ago. The aims of this study were to evaluate these criteria using data collected using continuous recording methods; to make recommendations that might improve their interpretation; and to determine the relationship between the number of devices deployed in a herd and the accuracy of the resulting estimate of the herd-mean reticuloruminal pH. The study made use of 815,475 observations of reticuloruminal pH values obtained from 75 cattle in three herds (one beef and two twice-daily milking herds) to assess sampling strategies for the diagnosis of sub-acute rumen acidosis (SARA), and to evaluate the ability of different numbers of bolus devices to accurately estimate the true herd-mean reticuloruminal pH value at any time. The traditional criteria for SARA provide low diagnostic utility, the probability of detection of animals with pH values below specified thresholds being affected by a strong effect of time of day and herd. The analysis suggests that regardless of time of feeding, sampling should be carried out in the late afternoon or evening to obtain a reasonable probability of detection of animals with pH values below the threshold level. The among-cow variation varied strongly between herds, but for a typical herd, if using reticuloruminal pH boluses to detect a predisposition to fermentation disorders while feeding a diet that is high in rapidly fermentable carbohydrates, it is recommended to use a minimum of nine boluses.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Jonsson, Professor Nicholas and Denwood, Dr Matthew
Authors: Jonsson, N. N., Kleen, J. L., Wallace, R. J., Andonovic, I., Michie, C., Farish, M., Mitchell, M., Duthie, C.-A., Jensen, D. B., and Denwood, M. J.
College/School:College of Medical Veterinary and Life Sciences > Institute of Biodiversity Animal Health and Comparative Medicine
College of Medical Veterinary and Life Sciences > School of Veterinary Medicine
Journal Name:Veterinary Journal
Publisher:Elsevier
ISSN:1090-0233
ISSN (Online):1532-2971
Published Online:14 November 2018
Copyright Holders:Copyright © 2018 The Authors
First Published:First published in Veterinary Journal 243: 26-32
Publisher Policy:Reproduced under a Creative Commons License

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
591951Sub-acute and acute ruminal acidosis; an interdisciplinary approach to understand and prevent a multifactorial disease.Nicholas JonssonBiotechnology and Biological Sciences Research Council (BBSRC)BB/J018120/1VET - PATHOLOGY, PUBLIC H & DISEASE INV