Publication Database

Novel approaches to diagnose, classify, and treat subclinical and clinical mastitis in dairy cows (2022)

Art

Hochschulschrift

Autor

Wollowski, Luise (WE 19)

Quelle

Berlin: Mensch & Buch Verlag, 2022 — 108 Seiten

Sprache

Englisch

Verweise

URL (Volltext): https://refubium.fu-berlin.de/handle/fub188/35337

Kontakt

Tierklinik für Fortpflanzung

Königsweg 65
Haus 27
14163 Berlin
+49 30 838 62618
fortpflanzungsklinik@vetmed.fu-berlin.de

Abstract / Zusammenfassung

The objectives of this thesis were (1) to utilizes a dynamometer and a handheld infrared thermometer to diagnose and classify clinical and subclinical mastitis (Publication I), (2) to evaluate the biomarker cathelicidin, milk amyloid A, and haptoglobin to diagnose and classify clinical and subclinical mastitis (Publication II), and (3) to study the advantage of an additional application of the non-steroidal anti-inflammatory drug flunixin in treatment of clinical mastitis using parameter of Publication I and II (Additional unpublished data). In times of ongoing automatization of dairy cow husbandry, objective and reliable methods, are highly in demand. Analyzing specific biomarkers in milk or using tools such as the handheld dynamometer or infrared thermography (IRT) could be advantageous compared to subjective or semi-quantitative criteria such as palpation of the udder in clinical mastitis (CM) cases or evaluation of SSC using cow side tests (e.g., California Mastitis Test) in subclinical mastitis (SCM) quarters. To reduce antimicrobial resistance and economic losses, a treatment of cows with Non-steroidal anti-inflammatory drug (NSAIDs) not only in severe, but also in mild and moderate CM seems to be advantageous. The first study investigated the diagnostic value of a handheld dynamometer and an infrared thermometer to diagnose and score CM and SCM and to compare those values with results from palpation of the udder tissue. Overall, data of 218 cows with CM (i.e., 46 mild, 106 moderate, and 66 severe cases), 142 with SCM, and 68 healthy cows were enrolled. Data provides evidence that the dynamometer is an accurate diagnostic tool to differentiate between healthy and mastitic udder quarters. The severity score of CM could be determined by using the dynamometer. Threshold for udder firmness to detect quarters with CM was 1.002 kg. Using a threshold of 1.175 kg in CM quarters, it was possible to differentiate between negative and positive bacteriological results. A differentiation between healthy and CM quarters with IRT was possible, albeit UST were highly influenced by ambient temperature. We were able to show, that UST increased up to 0.18°C for each degree of ambient temperature. The objective of the second study was to investigate the diagnostic value of three biomarkers, i.e., cathelicidin (CATH), milk amyloid A (MAA), and haptoglobin (HP) for the diagnosis of SCM and CM. Furthermore, the accuracy of these biomarkers to differentiate between mild, moderate, and severe CM and the influence of different pathogens on biomarker levels was tested. A total of 67 healthy cows, 119 cows with SCM, and 212 cows with CM were enrolled in the study. While CATH, MAA, and HP were measured in all samples from healthy cows and those with SCM, HP, and CATH results were only available from 121 cows with CM. Milk amyloid A was measured in all samples. In cows with CM, the mastitis quarter and a second healthy quarter, serving as a healthy in-cow-control quarter were sampled. Several different generalized linear mixed models were used to determine the effect of the health status of the udder quarter (e.g., healthy, SCM, CM and healthy in-cow control) different severity scores (e.g., mild, moderate, and severe) and bacteriological results on CATH, MAA, and HP levels. Furthermore, receiver operating characteristic curves were calculated to establish thresholds between different udder healthy status or different bacteria. A differentiation between healthy quarters, quarters with SCM, and CM was possible, using all three biomarkers. Thresholds for CATH to differentiate between healthy quarters and quarters with SCM or CM were 0.000 NOD450 (Se = 0.83, Sp = 0.97) and 0.053 NOD450 (Se = 0.98, Sp = 0.99), 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 MAA and 3.65 μg/mL (Se = 0.92, Sp = 0.94) and 5.40 μg/mL mL (Se = 0.96, Sp = 0.99) for HP were also calculated, respectively. Healthy in-cow control quarters from cows with mastitis showed elevated MAA and HP levels compared to healthy quarters from healthy cows. Only the level of MAA was higher in severe CM cases compared to mild ones. In contrast to CM, CATH, and HP in SCM quarters were significantly influenced by different bacteriological results. Additional unpublished data were presented in this thesis evaluating whether the application of transdermal flunixin influences cure rates of mild, moderate, or severe CM. Udder firmness measured by dynamometer, levels of the two different biomarker CATH and MAA in milk and bacteriological examination were used to evaluate curing. To be able to compare the curing success, we examined all animals after initially examination on day 1 (D1) the following 4 days (D2 - D5), on day seven (D7) and on day 21 (D21). During these examinations, udder firmness and levels of biomarkers were measured. Two quarters per cow were examined, the mastitic quarter and a healthy in-cow control quarter. In addition, a bacteriological examination of the milk was carried out on D5 and D21 to determine bacteriological cure. Data of udder firmness was available for all enrolled 218 cows (i.e., 46 mild, 106 moderate, 66 severe) for all examination days. For the evaluation of level of biomarker CATH and MAA 121 cows (20 cows with mild, 63 with moderate, and 38 with severe clinical mastitis) could be evaluate. For MAA, data from D1 - D5 and D21 of additional 24 cows (7 cows with mild, 7 with moderate, and 10 with severe clinical mastitis) were available. After examination on D1 mild or moderate CM were treated either with transdermal flunixin or with placebo, severe CM with transdermal flunixin or injected meloxicam, respectively. An udder quarter was considered cured, if the original mastitis causing pathogen of D1 was no longer detectable on D5 or D21, respectively. In mild or moderate CM, there was no significant difference of udder firmness differences and level of CATH between animals treated with transdermal flunixin and those treated with placebo throughout days of examination. Only on D2 and D3 level of biomarker MAA was lower in mastitis quarter in cows treated with transdermal flunixin instead of placebo. Cows, which were treated with transdermal flunixin showed a higher bacteriological cure rate than untreated control cows. Interestingly, all cows treated with transdermal flunixin instead of placebo had a negative bacteriological result on D21. In severe CM, transdermal flunixin and meloxicam treated animals showed similar results in udder firmness difference, level of MAA and CATH, and bacteriological curing. Overall, this thesis demonstrates that the udder health status of dairy cows can be accurately and objectively classified using (1) a dynamometer that measures udder firmness at the udder or (2) biomarkers (CATH, MAA and HP) in the milk. Furthermore, some of investigated parameters (e.g., udder firmness, CATH, and MAA) can be used to objectively evaluate the cure of clinical mastitis.