Open Access Open Access  Restricted Access Subscription Access
Open Access Open Access Open Access  Restricted Access Restricted Access Subscription Access

Receiver Operating Characteristic Analysis of Milk Lactose for Identification of Mastitis in Buffaloes


Affiliations
1 College of Veterinary Science & Animal Husbandry, Junagadh Agricultural University (JAU), Junagadh-362001, Gujarat, India
2 College of Veterinary Science and A.H., Junagadh Agricultural University (JAU), Junagadh-362 001, India
3 College of Agriculture and Research Station, Janjgir-Champa-495668, C.G., India
4 Cattle Breeding Farm, Junagadh Agricultural University (JAU), Junagadh-362001, Gujarat, India
5 National Dairy Research Institute, Karnal-132001, Haryana, India
     

   Subscribe/Renew Journal


Receiver operating characteristic (ROC) analysis is a simple statistical tool used to classify a diagnostic indicator in terms of area under a ROC curve (AUC) and to develop potential threshold values of a diagnostic indicator. Milk lactose was analyzed by ROC analysis to see its accuracy to discriminate infected and healthy udder quarters, and to develope an optimum threshold value along with corresponding sensitivity (Se), specificity (Sp) and positive likelihood ratio (LR+) value. Data for the present study comprised of 1516 milk samples collected from Jaffrabadi buffaloes. Milk lactose was estimated by milk analyzer 'LACTOSCAN' and further samples were checked for sub-clinical mastitis by California mastitis test (CMT). The threshold values of milk lactose for identification of moderate and severe infection were found to be 5.31g% (Se, 58.82%; Sp, 58.28%) and 5.23g% (Se, 70.97%; Sp, 64.41%), respectively by ROC analysis. Milk samples with lactose content below 5.31g% were 1.41 times more likely come from moderately infected quarters (LR+ = 1.41); whereas, below 5.23g% were 1.99 times more likely come from severely infected quarters (LR+ = 1.99). The overall accuracy of milk lactose for discrimination of normal quarters from moderately infected quarters was 64% (AUC=0.64) and from severely infected quarters was 72% (AUC=0.72) (P<0.001). Thus, the present study indicated that milk lactose classified mastitic and healthy udder quarters in Jaffrabadi buffaloes with moderate accuracy.

Keywords

Buffaloes, Milk Lactose, ROC Analysis, Mastitis.
Subscription Login to verify subscription
User
Notifications
Font Size


Abstract Views: 115

PDF Views: 0




  • Receiver Operating Characteristic Analysis of Milk Lactose for Identification of Mastitis in Buffaloes

Abstract Views: 115  |  PDF Views: 0

Authors

T. K. Patbandha
College of Veterinary Science & Animal Husbandry, Junagadh Agricultural University (JAU), Junagadh-362001, Gujarat, India
K. Ravikala
College of Veterinary Science and A.H., Junagadh Agricultural University (JAU), Junagadh-362 001, India
B. R. Maharana
College of Veterinary Science and A.H., Junagadh Agricultural University (JAU), Junagadh-362 001, India
Rupal Pathak
College of Agriculture and Research Station, Janjgir-Champa-495668, C.G., India
S. Marandi
College of Veterinary Science and A.H., Junagadh Agricultural University (JAU), Junagadh-362 001, India
P. U. Gajbhiye
Cattle Breeding Farm, Junagadh Agricultural University (JAU), Junagadh-362001, Gujarat, India
T. K. Mohanty
National Dairy Research Institute, Karnal-132001, Haryana, India
R. Malhotra
National Dairy Research Institute, Karnal-132001, Haryana, India

Abstract


Receiver operating characteristic (ROC) analysis is a simple statistical tool used to classify a diagnostic indicator in terms of area under a ROC curve (AUC) and to develop potential threshold values of a diagnostic indicator. Milk lactose was analyzed by ROC analysis to see its accuracy to discriminate infected and healthy udder quarters, and to develope an optimum threshold value along with corresponding sensitivity (Se), specificity (Sp) and positive likelihood ratio (LR+) value. Data for the present study comprised of 1516 milk samples collected from Jaffrabadi buffaloes. Milk lactose was estimated by milk analyzer 'LACTOSCAN' and further samples were checked for sub-clinical mastitis by California mastitis test (CMT). The threshold values of milk lactose for identification of moderate and severe infection were found to be 5.31g% (Se, 58.82%; Sp, 58.28%) and 5.23g% (Se, 70.97%; Sp, 64.41%), respectively by ROC analysis. Milk samples with lactose content below 5.31g% were 1.41 times more likely come from moderately infected quarters (LR+ = 1.41); whereas, below 5.23g% were 1.99 times more likely come from severely infected quarters (LR+ = 1.99). The overall accuracy of milk lactose for discrimination of normal quarters from moderately infected quarters was 64% (AUC=0.64) and from severely infected quarters was 72% (AUC=0.72) (P<0.001). Thus, the present study indicated that milk lactose classified mastitic and healthy udder quarters in Jaffrabadi buffaloes with moderate accuracy.

Keywords


Buffaloes, Milk Lactose, ROC Analysis, Mastitis.