Describing patterns of mastitis indicators during a clinical mastitis episode

Our master thesis student Ditsa Panchal was invited by the Scientific Committee at DeLaval to present her project on the development of mastitis indicators for a case of clinical mastitis. 

In the VMS, the udder inflammation indicators measured by its sensors have mostly been used to detect clinical mastitis. However, the udder inflammation indicators can be used to observe the development of the disease. This could also be used to follow the possible recovery of the cow from the disease.

The results showed that for recovered cases, the SCC (Somatic Cell Count) and EC (Electrical Conductivity) values took 20-24 days to drop to the pre-clinical mastitis level, whereas for LDH it took up to 28 days. Implying, SCC, EC, and LDH values dropped to pre-CM levels for all the recovered cases in a span of approximately four weeks. Only a few more studies mention a drop to pre-CM levels for these indicators. Moreover, this time span highlights the need to reduce the recovery period to a minimum possible time.

LDH, one of the mastitis indicators, is an enzyme present in cell cytoplasm that is released in response to cell damage, from the cell to milk in case of mastitis. It is an important milk parameter for the early detection of bovine mastitis (Chagunda et al. 2006; Friggens et al. 2007) as it starts to increase before SCC and EC. The present study also showed that the LDH values, for both, recovered and non-recovered cases started to increase the earliest, that is approximately 9-12 days before attaining a peak value. An increase in SCC values started approximately 5-8 days before achieving a peak whereas the EC values began to increase relatively later, i.e., approximately 1-4 days before attaining a peak. Therefore, it was concluded that LDH can be a better indicator for early detection of CM.

For recovered cases, it took approximately 20 days for the SCC, EC, and LDH values to stabilize after achieving a peak value. This aligns with the results obtained by Bonestroo et al., (2021) mentioning that in their recovery subsets, both σ-conductivity and SCC stabilized, mostly within 3 to 4 weeks after the initial inflammation. Hence, this result expanded our current knowledge on the progression of SCC, EC, and LDH in the recovery period. This knowledge can further be used to make predictions on CM recovery, ultimately aiding the farmers in an earlier and better decision making.

The results have been published in her master thesis, which can be found here:  

https://stud.epsilon.slu.se/17135/

References

Bonestroo, J., van der Voort, M., Fall, N., Hogeveen, H., Emanuelson, U. & Klaas, I.C. (2021). Progression of different udder inflammation indicators and their episode length after onset of inflammation using automatic milking system sensor data. Journal of Dairy Science, 104 (3), 3458–3473. https://doi.org/10.3168/jds.2019-18054

Chagunda, M., Larsen, T., Bjerring, M. & Ingvartsen, K. (2006). L-lactate dehydrogenase and N-acetyl-β-D-glucosaminidase activities in bovine milk as indicators of non-specific mastitis. The Journal of dairy research, 73, 431–40. https://doi.org/10.1017/S0022029906001956

Friggens, N.C., Chagunda, M.G.G., Bjerring, M., Ridder, C., Hojsgaard, S. & Larsen, T. (2007). Estimating Degree of Mastitis from Time-Series Measurements in Milk: A Test of a Model Based on Lactate Dehydrogenase Measurements. Journal of Dairy Science, 90 (12), 5415–5427. https://doi.org/10.3168/jds.2007-0148