Mastitis

Mastitis is inflammation of the mammary gland. It is usually bacterial, although injuries and environmental conditions contribute. It remains the main cause of economic losses on dairy farms.

Bacteria enter through the teat canal and release toxins that damage milk-producing tissue, reducing milk yield and quality. Mastitis can occur at any stage of lactation, but it is most common in fresh cows and late lactation.

Causes

Most cases stem from poor environmental conditions, the animal's own health problems or gaps in herd management: hygiene of milking equipment and housing, an incomplete ration, gynaecological diseases and injuries. Prevention has to cover the whole farm, not only treatment.

Symptoms and types

Clinical mastitis

• Thickened, elongated teats on one or more quarters; the affected quarter becomes swollen, red, warm and painful.
• Cows move less, walk cautiously, may limp or kick at the udder.
• Sick cows look tired, lose weight, run a temperature and may abort.
• The first spurts of milk may contain mucus, clots, flakes or blood, and the colour changes.
• Laboratory tests show high somatic cell counts, altered milk components and changed electrical conductivity.

Subclinical mastitis

The milk looks normal and there are no visible signs — only changes in milk composition reveal it: higher somatic cell count, altered conductivity and lower lactose. Milk components fall by 5–15 %.

Milk should be examined at least monthly, 10–14 days before drying off and 8–10 days after calving. In-line “mini-laboratories” in the milking line give immediate results and avoid sampling.

What it costs

• Mastitis is the second most frequent reason for culling.
• At 100,000 cells/ml, a quarter's daily output falls by 25–35 % and whole-lactation output by 10–15 %.
• Subclinical mastitis is the most common form and may account for up to 70 % of losses — early detection is essential.

How to detect it

Somatic cell count

A count above 200,000 cells/ml indicates mastitis. Laboratory tests are slow; on-farm tests such as the California mastitis test need individual testing, labour and an experienced operator; automated systems save labour but need reagents and maintenance.

With Brolis HerdLine

The in-line analyser measures fat, protein and lactose and tracks spectral changes in each cow's milk at every milking. HerdLine uses this data for early warnings of health disorders. Mastitis detection is coming soon.

Treatment

A veterinarian chooses treatment based on severity and the causative agent. Subclinical cases may need only simple treatment; clinical cases usually need antibiotics, anti-inflammatories or other preparations. Treatment during the dry period is several times more effective than during lactation.

• Examine the animal and identify the causative agent before choosing a drug; base selection on antimicrobial susceptibility testing.
• Do not stop treatment early when the animal improves, and do not switch abruptly.
• Consider culling cows that cannot be cured, have severely damaged quarters, did not recover after dry-period treatment, or had clinical mastitis three times in one lactation.

Prevention

• Keep cows, bedding, floors, milking machines and milkers' hands clean.
• Ventilate the barn well and avoid drafts, which cool the udder and weaken its defences.
• Keep beds dry, clean and disinfected, avoid overcrowding and give every animal a place to rest.
• Feed high-quality, complete rations.
• Check that teats are healthy, clean and dry before attaching the cluster; disinfect before and after milking.
• If more than 5 % of animals have dirty udders, teats or feet, environmental conditions are poor.