The value of the biomarkers cathelicidin, milk amyloid A, and haptoglobin to diagnose and classify clinical and subclinical mastitis.
Timely and objective diagnosis and classification of mastitis is crucial to ensure adequate management and therapeutic decisions. Analyzing specific biomarkers in milk could be advantageous compared with subjective or semiquantitative criteria, such as palpation of the udder in clinical mastitis cases or evaluation of somatic cell count using cow side tests (e.g., California Mastitis Test) in subclinical mastitis quarters. The objective of this study was to investigate the diagnostic value of 3 biomarkers; cathelicidin, milk amyloid A, and haptoglobin for the diagnosis of subclinical and clinical mastitis. Furthermore, the suitability of these biomarkers to differentiate between mild, moderate, and severe clinical mastitis and the influence of different pathogens on biomarker levels was tested. A total of 67 healthy cows, 119 cows with subclinical mastitis, and 212 cows with clinical mastitis were enrolled in the study. Although cathelicidin, haptoglobin, and milk amyloid A were measured in all samples from healthy cows and those with subclinical mastitis, haptoglobin, and cathelicidin results were only available from 121 out of 212 cows with clinical mastitis. Milk amyloid A was measured in all samples. In cows with clinical mastitis, the mastitic quarter and a second healthy quarter serving as a healthy in-cow control quarter were sampled. It was possible to differentiate between healthy quarters, quarters with subclinical mastitis, and quarters with clinical mastitis using all 3 biomarkers. Concerning cathelicidin, thresholds were 0.000 [sensitivity (Se) = 0.83, specificity (Sp) = 0.97] and 0.053 (Se = 0.98, Sp = 0.99) for normalized optical density at 450 nm (NOD450) for differentiating between healthy quarters and quarters with subclinical or clinical mastitis, respectively. Thresholds of 1.28 µg/mL (Se = 0.65, Sp = 0.76) and 1.81 µg/mL (Se = 0.77, Sp = 0.83) for milk amyloid A and 3.65 µg/mL (Se = 0.92, Sp = 0.94) and 5.40 µg/mL mL (Se = 0.96, Sp = 0.99) for haptoglobin were calculated, respectively. Healthy in-cow control quarters from cows with CM showed elevated milk amyloid A and haptoglobin levels compared with healthy quarters from healthy cows. Only the level of milk amyloid A was higher in severe clinical mastitis cases compared with mild ones. In contrast to clinical mastitis, cathelicidin and haptoglobin in subclinical mastitis quarters were significantly influenced by different bacteriological results. The measurement of cathelicidin, milk amyloid A, and haptoglobin in milk proved to be a reliable method to detect quarters with subclinical or clinical mastitis.
Wollowski L
，Heuwieser W
，Kossatz A
，Addis MF
，Puggioni GMG
，Meriaux L
，Bertulat S
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Sensitivity and specificity of infrared thermography in detection of subclinical mastitis in dairy cows.
The objectives of this experiment were to determine interrelationships among mastitis indicators and evaluate the subclinical mastitis detection ability of infrared thermography (IRT) in comparison with the California Mastitis Test (CMT). Somatic cell count (SCC), CMT, and udder skin surface temperature (USST) data were compiled from 62 Brown Swiss dairy cows (days in milk=117+/-51, milk yield=14.7+/-5.2 kg; mean +/- SD). The CORR, REG, and NLIN procedures of Statistical Analysis System (SAS Institute Inc., Cary, NC) were employed to attain interrelationships among mastitis indicators. The diagnostic merit of IRT as an indirect measure of subclinical mastitis was compared with CMT using the receiver operating characteristics curves. The udder skin surface temperature was positively correlated with the CMT score (r=0.86) and SCC (r=0.73). There was an exponential increase in SCC (SCC, x10(3) cells/mL=22.35 x e(1.31 x CMT score); R(2)=0.98) and a linear increase in USST (USST, degrees C=33.45+1.08 x CMT score; R(2)=0.75) as the CMT score increased. As SCC increased, USST increased logarithmically [USST, degrees C=28.72+0.49 x ln(SCC, x10(3) cells/mL); R(2)=0.72]. The USST for healthy quarters (SCC <or=400,000 cells/mL; n=94) was different from that for subclinical mastitic quarters (SCC >400,000 cells/mL; n=135) (mean +/- SE; 33.45+/-0.09 vs. 35.80+/-0.08 degrees C). The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value, and negative predictive value were 95.6, 93.6, 14.97, 0.05, 95.0, and 93.6, respectively, for IRT and 88.9, 98.9, 83.56, 0.11, 99.2, and 86.1, respectively, for CMT. The area under the receiver operating characteristics curve for IRT and CMT was not different. In conclusion, as a noninvasive and quick tool, IRT can be employed for screening subclinical mastitis via measuring USST, with a high predictive diagnostic ability similar to CMT when microbiological culturing is unavailable. However, the reliability of IRT among cows with different characteristics and those living under various environmental conditions remains to be determined.
Polat B
，Colak A
，Cengiz M
，Yanmaz LE
，Oral H
，Bastan A
，Kaya S
，Hayirli A
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