MASTITIS RESEARCH IN SOUTH AFRICA: THE COST TO THE DAIRY FARMER.

Mastitis results in large economic loss to both farmer and processor. In addition it has welfare implications for the cow and antimicrobial resistance concerns. Therefore, describing and analysing the measures used to prevent the disease and to minimize the losses remain important. For example, somatic cell count (SCC) directly affects revenue from the sale of milk and in one of the investigations the revenue loss was studied.   

Bulk-tank SCC was calculated from individual cow test-day SCC for 183 Jersey and 209 Holstein herds that participated in the National Milk Recording Scheme. The economic value of SCC was determined as the simulated change in profit per cow per year, following a one unit increase in individual bulk-tank SCC. The calculations showed that the increase resulted in decreases in profit ranging from R491 to R1796 per cow per year, depending on the breed, the production system and the payment system. The economic value of SCC was nearly double in Holsteins compared with Jerseys, and in the TMR system compared with the pasture-based system.

In a later study, losses incurred subsequent to the disease (failure cost, FC) and those invested to prevent the disease (preventive cost, PC) were estimated. The average total cost (TC) of mastitis was R1982 per cow, with FC contributing R1604 and PC R378. Milk lost due to subclinical mastitis was the most significant, accounting for 73% of FC and 59% of TC, totalling R1394. Other FC estimated, as a proportion of FC, were mastitis-related culling (14%), milk discard (12%) and clinical mastitis treatment (1%). Contributing to PC were post-milking teat disinfection (36%), blanket dry cow treatment (16%), liner replacement (15%), pre-milking teat disinfection (12%), routine whole herd milk testing programs (SCC portion alone, 12%), followed by vaccination for mastitis, veterinary consulting limited to udder health, milker gloves and udder health consultants, all less than 2.5%. Variation between herds in these numbers was substantial with FC ranging from R744 to R2992, PC from R55 to R940 and TC from R1002 to R3728, which suggests that mastitis management remains a priority to ensure a sustainable and profitable dairy industry.

Reference:

Meissner, H. H., 2021. Summary of Research Progress with Mastitis 2015 to 2021. Milk SA, Pretoria.