| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Animal Breeding and Genetics and
2 Department of Animal Health and Welfare, Danish Institute of Agricultural Sciences, Research Center Foulum, Tjele, Denmark
3 Farm Management Group, Wageningen University, Wageningen, The Netherlands
Corresponding author: Elise Norberg; e-mail: Elise.Norberg{at}agrsci.dk.
Electrical conductivity (EC) of milk has been introduced as an indicator trait for mastitis over the last decade, and it may be considered as a potential trait in a breeding program where selection for improved udder health is included. In this study, various EC traits were investigated for their association with udder health. In total, 322 cows with 549 lactations were included in the study. Cows were classified as healthy or clinically or subclinically infected, and EC was measured repeatedly during milking on each quarter. Four EC traits were defined; the inter-quarter ratio (IQR) between the highest and lowest quarter EC values, the maximum EC level for a cow, IQR between the highest and lowest quarter EC variation, and the maximum EC variation for a cow. Values for the traits were calculated for every milking throughout the entire lactation. All EC traits increased significantly (P < 0.001) when cows were subclinically or clinically infected. A simple threshold test and discriminant function analysis was used to validate the ability of the EC traits to distinguish between cows in different health groups. Traits reflecting the level rather than variation of EC, and in particular the IQR, performed best to classify cows correctly. By using this trait, 80.6% of clinical and 45.0% of subclinical cases were classified correctly. Of the cows classified as healthy, 74.8% were classified correctly. However, some extra information about udder health status was obtained when a combination of EC traits was used.
Key Words: electrical conductivity • milk • mastitis • indicator trait
Abbreviation key: EC = electrical conductivity, mS = milliSiemens, IQR = inter-quarter ratio
This article has been cited by other articles:
|
|
 |
|
  J. M. Lukas, J. K. Reneau, R. Wallace, D. Hawkins, and C. Munoz-Zanzi A novel method of analyzing daily milk production and electrical conductivity to predict disease onset J Dairy Sci, December 1, 2009; 92(12): 5964 - 5976. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. J. Hassan, S. Samarasinghe, and M. G. Lopez-Benavides Use of neural networks to detect minor and major pathogens that cause bovine mastitis J Dairy Sci, April 1, 2009; 92(4): 1493 - 1499. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. C. Friggens, M. G. G. Chagunda, M. Bjerring, C. Ridder, S. Hojsgaard, and T. Larsen Estimating Degree of Mastitis from Time-Series Measurements in Milk: A Test of a Model Based on Lactate Dehydrogenase Measurements J Dairy Sci, December 1, 2007; 90(12): 5415 - 5427. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. G. G. Chagunda, N. C. Friggens, M. D. Rasmussen, and T. Larsen A model for detection of individual cow mastitis based on an indicator measured in milk. J Dairy Sci, August 1, 2006; 89(8): 2980 - 2998. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Norberg, G. W. Rogers, J. Odegard, J. B. Cooper, and P. Madsen Short Communication: Genetic Correlation Between Test-Day Electrical Conductivity of Milk and Mastitis J Dairy Sci, February 1, 2006; 89(2): 779 - 781. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Norberg, G. W. Rogers, R. C. Goodling, J. B. Cooper, and P. Madsen Genetic Parameters for Test-Day Electrical Conductivity of Milk for First-Lactation Cows from Random Regression Models J Dairy Sci, June 1, 2004; 87(6): 1917 - 1924. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
