Acidosis in cows

Acidosis means an excess of acid in the body. In cattle it is usually linked to the diet and to changes in rumen contents and microflora — a disease of high-productivity herds.

Causes

• High-grain rations, acidic forages such as corn silage, and low-fibre forages.
• Eating a large amount of concentrate at once.
• Improperly chopped fodder.
• Intensive milk production, which pushes rations toward more concentrate and less fibre. Risk is highest 3–5 months after calving.

Symptoms and types

Normal rumen pH is 6.3–7.3; acidosis begins when a drop lasts more than 4 hours.

Subacute ruminal acidosis (SARA)

pH falls to about 5.0–5.5 for more than 24 hours. Signs: reduced appetite, weaker rumen contractions, loose faeces with undigested feed, lower milk fat and a milk fat-to-protein ratio below 1.2. Prolonged SARA can lead to laminitis, uterine inflammation, abomasal displacement and calcium deficiency.

Acute acidosis

pH below 5.2, usually after overeating concentrate or an abrupt ration change. Signs include falling appetite and milk yield, diarrhoea, dehydration, apathy, teeth grinding and colic. Untreated cases can end in forced slaughter.

What it costs

The main losses are lower milk yield and quality; severe cases need complex treatment and high-potential cows may be culled.

How to detect it

Rumen pH and activity

A healthy rumen contracts 5–7 times in 5 minutes; rumination lasts 40–50 minutes, 7–8 times a day. Boluses that record rumen activity and pH flag problems early. Rumen puncture needs skilled staff and stresses animals.

With Brolis HerdLine

HerdLine measures fat, protein and lactose at every milking and tracks each cow's milk spectrum, flagging at-risk cows so action can be taken before the problem progresses. Milk fat depression detection.

Treatment

• Replace rapidly degradable starch (grain, concentrate) with digestible fibre — sugar beet pulp, straw or mature hay.
• After carbohydrate overload, give acid neutralisers quickly (e.g. sodium bicarbonate 250 g, calcium carbonate 200 g or magnesium oxide 100–200 g in 20–40 litres of water); repeat after 4–6 hours if there is no improvement.
• Yeast, plant extracts and other additives help restore rumen activity; transfer of 5–10 litres of healthy rumen contents may help.
• The veterinarian decides on antibiotics, rumen washing and other treatment in acute cases.

Prevention

• Introduce concentrate-heavy rations gradually; split concentrate into several feeds, ideally mixed with roughage.
• Provide good-quality, properly chopped fibre and avoid mycotoxin-contaminated feed.
• Use rumen buffers (e.g. baking soda at 1–2 % of dry matter) periodically.
• Monitor milk indicators with HerdLine to catch at-risk cows early.