Since mastitis is a disease that has different levels of intensity and which may be caused by different organisms, there exists a complete jargon to describe the disease. It is therefore important to be able to recognize the different types of mastitis in order to decide what preventive measures to use as well as what treatment (Table 1).
To infect a quarter, a microorganism must first enter the quarter and the cow must be unable to get rid of it before it multiplies. Following is a typical scenario that leads to mastitis infection.
1. Contact with the microbe: The number of microorganisms multiplies near the orifice (or sphincter) of one or several teats. This is where hygiene and milking habits play an important role in preventing microbes from entering the quarter.
2. Entry of microbe into the teats: Entry may be forced by the milking machine, particularly at the end of milking. Injured teats (injuries, keratin injured inside teat) or teats whose openings are too large may be easily invaded.
3. Immune response of the cow: the cow’s first line of defense is to send white blood cells (Ieucocytes) to eliminate the microbes that have penetrated the teat. If the response is insufficient, the microbes multiply and the cow shows other immune responses such as fever. The effectiveness of the cow’s immune system depends on many factors.
Table.1 Main microorganisms involved in mammary infections, their characteristics and prevention
Species |
Main source |
Living condition |
Propagation factors |
symptoms |
Preventivetreatment |
| Streptococcus
agalactiae |
Infected cows | Infected quarter and udder only | Using same rag for cleaning udders | Mild fever for about 24 hours. | Wash udders after milking, reduces problem by 50%
|
| Staphylococcus
aureus
|
Infected cows | On abnormal udder and teat, milkers, vagina, tonsils | Transmitted by hands or rags, enters during milking | Often quite acute for a few days after calving. Quarter swells and turns purple. Quickly affects the entire system. In a chronic state, udder hardens aqueous secretion, eventual atrophy of the quarter. Intermediate form with granular secretion.
|
Cull infected cows |
| Streptococcus
dysgalacti |
Infected cows | Infected quarter, injuries | Pronounced swelling of one or more quarters. Milk highly abnormal. High fever in serious cases | ||
| reptococcus uberis | Contaminated
environment |
On cow’s skin, mouth, ground | Neglected udder washing, insufficient drying, lack of bedding | Pronounced swelling of one or more quarters. High fever in serious cases. Affects mostly dry cows.
|
Wash udders only, dry well with disposable paper towels for each cow.
|
| Contaminated
environment |
Ground,bedding(sawdust and shavings),
manure,water |
Dirty calving stall, lack of bedding, inadequate udder washing | Often very serious. May lead to loss of quarter or even death. Thin yellow secretions, with a granular texture resembling bran. | ||
| Corynebacterium
pyogenes
|
Certain insects | Humid valleys, wooded areas | Pronounced systematic reaction due to toxins caused by bacteria. Often more than one quarter affected. They become hard, produce thick smelly secretion like cheese. |
Source-
- Central Coastal Agricultural Research Institute, Ela, Old Goa, Goa
