Threshold somatic cell count for delineation of subclinical mastitis cases

Vet World Vol.11 June-2018 Article-9

Research Article

Veterinary World, 11(6): 789-793

https://doi.org/10.14202/vetworld.2018.789-793

P. V. Jadhav¹, D. N. Das², K. P. Suresh³, and B. R. Shome³

1. Department of Animal Genetics and Breeding, College of Veterinary and Animal Sciences, Udgir - 413 517, Latur, Maharashtra, India.
2. Principal Scientist, South Regional Station of National Dairy Research Institute, Bengaluru - 560 030, Karnataka, India.
3. Principal Scientist, ICAR-National Institute of Veterinary Epidemiology and Disease Informatics, Yelahanka - 560 064, Bengaluru, Karnataka, India.

Background and Aim: Somatic cell count (SCC) is the most widely used single reliable indicator of udder health. The present study was carried out with an objective to find the exact threshold of SCC.

Materials and Methods: Milk samples collected from a total of 214 Holstein Friesian crossbred dairy animals were subjected to bacterial DNA extraction and SCC estimation by digital PortaCheck. California Mastitis Test and polymerase chain reaction based on amplification of organism using reported primers were performed to diagnose subclinical mastitis. Receiver's operating characteristic (ROC) curve analysis and discriminate function analyses were performed using SPSS 18 software.

Results: ROC curve analysis represented that the area under the curve was 0.930 with the standard error of 0.02. Results indicated that 93% of the case could be correctly predicted as mastitis infected using SCC as a marker (p<0.001). At cut score level of 282 000 cells/ml, 285,000 cells/ml and 288,000 cells/ml, sensitivity remained 92.6% and specificity augmented as 86.3%, 87.2%, and 88%, respectively. At SCC value of 310,000 cells/ml of milk, sensitivity and specificity were optimal, namely, 92.6% and 91.5%, respectively. The function fitted demonstrated 89.2% accuracy with p<0.001. The functions at group centroids were -0.982 and 1.209, respectively, for normal and mastitis-infected animals and log_SCC value was the most important factor contributing 38.30% of the total distance measured.

Conclusion: Our study supports that the threshold value to delineate subclinical mastitis case from the normal is 310,000 somatic cells/ml of milk and a model so fitted using the variable SCC can be successfully used in field for the diagnosis of subclinical cases of mastitis which otherwise would be difficult to differentiate based on clinical signs. Keywords: discriminate function, mastitis, receiver's operating characteristic curve, somatic cell count, threshold.

Keywords: discriminate function, mastitis, receiver's operating characteristic curve, somatic cell count, threshold.

How to cite this article: Jadhav PV, Das DN, Suresh KP, Shome BR (2018) Threshold somatic cell count for delineation of subclinical mastitis cases, Veterinary World, 11(6): 789-793.

Received: 17-01-2018 Accepted: 07-05-2018 Published online: 12-06-2018

Corresponding author: P. V. Jadhav E-mail: drprajaktavet@gmail.com

DOI: 10.14202/vetworld.2018.789-793

Copyright: Jadhav, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.