MLBA5:  October / November 2008


Diagnosing subclinical mastitis


ByDr. Mirinal Kumar Sharma


Mastitis, from the words "mast" which means breast and "itis" which means inflammation, is defined as an in­flammatory reaction of udder tissue to bacterial, chemical, thermal or mechanical injury.


Mastitis may be infectious and is caused by microbial organisms or it may be noninfectious resulting from physical injury to the gland. The in­flammatory response consists of an increase in blood proteins and white blood cells in the mammary tissue and the milk. The purpose of the response is to destroy the irritant, repair the damaged-tissue and return the udder to normal function.


Dairy farmers and veterinarians across the world know well that mastitis means losses - loss of time and money. The disease cripples milch cows and in almost all cases the animal is never able to return to its peak milk yield.


Milk from mastitic cows spoils fast and also has a huge impact on bulk milk quality. Further, it is a proven fact that this evil called clinical mastitis is actually only the tip of the iceberg. Analysts say that only about 5-15 percent of dairy ani­mals actually suffer from the clinical form of the disease and as much as 60 percent of the animals which produce milk lurk in the borderline of the sub clinical state.


Animals harbouring Subclinical Mastitis (SCM) are definitely not in their peak condition. However, the fact that they suffer from a disease is not evident from external ap­pearance or behavior. It is up to the farmer and the veterinarian to rec­ognize and ensure that the disease is nipped at the bud.


The various ways subclinically mastitic animals can affect herd performance are: somatic cell counts will always be high in the milk and milk quality will be at risk, milk production will always be 10-15 percent less than the potential of the animals, animals will always be un­der mild disease pressure and stress which leads to wastage of energy, mastitis pathogens will always be around the farm and keep hopping from one animal to the other and the percentage of animals developing clinical mastitis will remain high and the losses associated with clini­cal mastitis from lost milk produc­tion, death and premature culling, milk discarded at treatment, and cost of drugs and veterinary expenses will remain.


It is therefore very essential that a constant monitoring is maintained to detect the disease early and elimi­nate the prospect of the clinical form of the disease from developing.


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