Inflammation of the udder in cows – causes and preventive treatment
Inflammation of the udder is one of the main causes of culling of cows in dairy cattle herds. Compared to other medical conditions, mastitis generates loses for the breeders in terms of quantity and quality of milk. Treatment is also an important factor, which raises the extent of veterinary costs, thereby effectively reduces the profitability of farming.
Mastitis – risk factors and formation
The basic factor responsible for the occurrence of mastitis are micro-organisms that penetrate the udder via the teat canal. Due to the pathogenicity, we distinguish them into infectious and environmental. The first group includes Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae and Mycoplasma bovis. Environmental pathogens include Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, Serratia sp., Proteus sp., Pseudomonas sp., coagulase-negative staphylococci, streptococci, yeast and fungi. In the case of infectious micro-organisms, the primary source of infection is the discharge from infected quarters of an udder, which can be transmitted to other cows via milking cups or through the hands of a milker. Speaking of environmental pathogens, it is worth mentioning that they are always present in cows’ surroundings. The biggest threat is present when these pathogens multiply intensively as a result of favourable micro-climatic conditions (heavily soiled, warm and moist substrate). Another predisposing factor is the reduction of the udder’s protective barrier, which is the case most often during two physiological periods. The first is the beginning of lactation, when the volume of milk produced reaches the highest level. It is the time when an intensive metabolic cycle contributes to the rapid process of wearing out of secretory cells of the udder’s tissue. As a result, dead cells exfoliate and get into the milk. If this process occurs rapidly, the results of the milk cytology tests indicate an increased somatic cell count (SCC), which indicate the presence of subclinical mastitis. Additionally, some metabolic disorders (liver steatosis, retained placenta) may lead to weakening the protective qualities of leukocytes. What is more, this is also the reason for the increase of the number of leukocytes in the total number of somatic cells from 20% to even 80%. The second critical period in terms of the threat of mastitis is the beginning of the dry period. Older cows (with over 5-6 lactation periods) and cows which produce even up to 25 kilograms of milk, are in the highest risk group. Rapid discontinuation of milking at such a level of productivity may weaken immunity, therefore leading to a higher susceptibility to inflammation of the udder.
The main symptoms of mastitis are swelling, redness, tenderness and painfulness of the udder, as well as change in the cytological characteristics (SCC over 300-400 k/ml) and physiochemical qualities of milk (flocculation, increased pH value, higher electrical resistance) What is more, the effectiveness of treatment depends on the timeliness of diagnosis and the type of the factor responsible for the occurrence of this disease. With infectious and environmental pathogens, too late diagnostics may result not only in lowering the quality of produced milk (by 25-30% daily on average) but can also lead to complete agalactia. However it is worth to remember, that mainly in the case of infectious factors, symptoms can easily become chronic, which significantly hinders the treatment and follow-up actions. From the economic point of view, such cows should be removed from the herd, as treatment with antibiotics will not get the desired effect, and the risk of the spread of micro-organisms onto other animals is highly probable. In addition to the high costs of treatment and production losses, high somatic cell count in the bulk tank milk results in lower income from the sale of the raw material.
Prevention is better than cure – recommendations for breeders.
Each breeder should remember to follow the basic hygiene principles of milking to eliminate infections caused by infectious pathogens (mainly Staphylococcus ureus, Streptococcus agalactiae, Mycoplasma bovis). Constant monitoring of cleanliness of milking equipment, teat rubbers, milkers’ hands and towels for wiping the udder reduces the frequency of transferring infectious pathogens between cows within a herd. It is also helpful to implement a program enabling segregation of infected cows by maintaining the correct order of milking (healthy first-calf heifers, healthy multiparous cows, and infected cows as last). Optimizing nutrition is also significant, especially in the perinatal period, when the immune barrier of the organism may be weakened. An important factor in the prevention of infections due to environmental micro-organisms is monitoring the cleanliness of animals’ beds and regular teat cleansing in disinfection solutions both before and after milking. Many breeders forget the importance of applying udder gels, which not only protect the udder against inflammation, but are also a condition for proper care. For mastitis An additional benefit resulting from the application of ointment is the massage of the udder. Against many opinions, it should be carried out not only before milking (stimulation for milking), but also after the process. According to some experts, this improves blood circulation in the udder area, which greatly reduces the risk of potential infection.