Acidosis in cows: Causes, Symptoms, Treatment and Prevention
The name of the disease acidosis (acid in Latin – acid, osis in Greek – condition) refers to the condition when the body has an excessive level of acid. In cattle, acidosis is usually associated with nutrition and rumen activity, when its contents and microflora change.
Causes of acidosis
In cattle, the cause of acidosis is usually associated with rumen dysfunction resulting from a diet of high grain rations, acidic forages (e.g. corn silage) and low fibre forages. Cattle can also contract the disease after eating a lot of concentrated feed at one time. Cattle are most susceptible to the disease in the first 3-5 months after calving. Due to intensive milk production, increased energy needs and limited ability to eat the required amount of feed, the cattle are given rations with a relatively high proportion of concentrated feed and often lacking in fibre.
It can be argued that acidosis is a disease of high productivity cattle herds. In order to increase production, it is necessary to include a larger amount of cereal crops and concentrates in the diet, while reducing the proportion of grass fodder. Fodder should be chopped with fodder distributors, but if the technology is not followed, it is chopped incorrectly, which may lead to acidosis.
Symptoms and types of acidosis in dairy cattle
Based on the level of acidification of the rumen and the symptoms that appear, acidosis may be subacute and acute. Normally, the pH of the large rumen of healthy cows ranges from 6.3 to 7.3. Acidosis begins to develop when the drop in rumen pH lasts more than 4 hours.
In subacute acidosis (SARA), the pH decreases over a period longer than 24 hours and is around 5.0-5.5. The cattle’s appetite becomes reduced, the contractions of the rumen become weaker and it fills up less. Feces become lighter in colour and more liquid in consistency, with visible particles of undigested feed in them. Due to impaired digestion of fibre, the fat content of milk decreases, and the ratio of milk fat to protein changes (<1.2). As the disease progresses and lasts longer, laminitis, uterine inflammations, dislocations of the uterus, calcium deficiency, etc. will develop.
In acute acidosis, the rumen pH drops to <5.2 and symptoms become more pronounced. The disease usually occurs when cattle accidentally overeat concentrates or when the composition of rations is abruptly changed, so the amount of concentrated feed is much higher than in the previous ration (for example, suddenly switching from the ration of draught cows to the ration of fresh dairy cows). In cattle, when the rumen’s activity is disturbed, the appetite decreases, and the milk yield decreases. Cows have diarrhoea, feces become liquid, slimy and foamy, signs of dehydration develop, and the work of the heart becomes more difficult. Cattle are apathetic, lie down more often and gnaw their teeth. Sometimes they may be restless, shivering and kicking themselves in the abdomen due to gastrointestinal colic. If the disease is prolonged and measures are not taken in due time, the general condition of the body worsens, and inflammatory processes develop in other parts of the digestive tract. Due to complications, the animal may need to be slaughtered as soon as possible. In the case of very severe acidosis, cattle often fall into a coma.
Subacute acidosis in the first half of lactation can be diagnosed in 15-40% of cattle. The main economic losses are caused by a decrease in milk production and a decrease in its quality. Greater losses occur when a severe form of the disease occurs. Then the cattle require complex treatment, and sometimes even a productive cow with high genetic potential has to be culled.
How to detect acidosis in cows?
pH monitoring of rumen contents
It is possible to identify the disease through its characteristic clinical symptoms and the composition and structure of cattle rations. Rumen activity and its pH content monitoring is an effective method for diagnosing acidosis. One of the first signs of acidosis is the weakening of the rumen. In cases of acute, severe acidosis, cattle may not ruminate at all. The rumen of healthy cattle contracts 5-7 times in 5 minutes, and rumination lasts about 40-50 minutes 7-8 times a day. On farms, it is quite popular to use boluses that record rumen activity indicators and pH. This makes it possible to detect some health problems in cattle in time and prevent their progression. Some specialists advise performing a rumen puncture in order to take a sample of rumen contents and determine its pH. This procedure should be carried out 4-8 hours after feeding with a feed mixture made with a dispenser or 2-4 hours after feeding with concentrates. The pH of the rumen content is measured by pH-meter or paper indicators. While the procedure is somewhat simple, it requires skill and time and can only be performed by qualified persons. This may be impractical on larger dairy farms, where livestock experience additional stress during the procedure.
Diagnosis of acidosis with BROLIS HerdLine
The in-line milk analyzer BROLIS HerdLine is like a small laboratory on your dairy farm. The analyzer examines the composition of each cow’s milk during each milking. It is installed in milking stations or milking robots in the milk line and does not use additional reagents or samples.
The first signs of acidosis can be identified through analysis of changes in protein, fat and other indicators of milk. This has become one of the most reliable ways to diagnose the disease as this information is gathered regularly.
BROLIS HerdLine acidosis diagnostic guidelines:
- When digestion is impaired, there is a decrease in the amount of milk produced and the concentration of its constituents.
- When the activity of the rumen is disturbed, the fibre-degrading bacteria decreases – the fat content of milk decreases. If the fat content of a cow’s milk has decreased from 4.2% to 3.0-3.3%, this is a strong sign that the cow is suffering from acidosis.
- The optimal ratio of fat to protein in dairy cows is ~1.2. When the ratio approaches the limit of 1.0-1.1, we can suspect subacute acidosis, and if it is less than 1.0 and clinical symptoms appear – acute acidosis.
Early diagnosis of subclinical acidosis can be limited to light and simple treatment – prophylaxis, increasing the body’s supply of energy substances. As the disease progresses and passes into the clinical form, the treatment may last 2-5 days. Complications may require more serious treatment with anti-inflammatory drugs or antibiotics. In this case, the milk may not be suitable for selling to buyers depending on the preparations used and the requirements for the withdrawal period for milk applied to them.
Treatment of acidosis in dairy cattle
Depending on the established severity of the disease and the causative agent, the veterinarian prescribes treatment. But it is worth paying attention to general tips:
- If signs of acidosis are observed, part of the feed containing rapidly degradable starch (grains, concentrates) should be replaced with feed rich in easily digestible fibre (e.g. sugar beet pulp, straw or overgrown hay is also suitable).
- Cattle that accidentally overeat sugar beet, concentrates or other carbohydrate feed should be given acid neutralising drugs as soon as possible. It is advisable to give sodium bicarbonate 250 g, calcium carbonate 200 g or magnesium oxide 100-200 g dissolved in 20-40 litres of water. However, such remedies may only work if the rumen is free of toxic breakdown products. If the health of the cattle does not improve after 4-6 hours, the drug treatment should be repeated.
- To restore rumen activity, it is recommended to give yeast, special plant extracts or other feed additives.
- Cattle with a mild form of acidosis can recover by changing the feed ration: reducing carbohydrate feed and giving more roughage.
- If necessary, antibiotics or other veterinary preparations are given.
- It is advisable to transfer the rumen contents of a healthy cow (5-10 l).
- The rumen washing procedure is also applied to cattle with acute acidosis. This is the most radical treatment and should be performed as early as possible. After the procedure, it is advisable to pour the rumen contents of a healthy cow, give antibiotic and proteolytic enzyme preparations, and inject hypertonic solutions into the vein.
- Without treatment, if the disease is not noticed in due time and no measures are taken, the cows’ hooves become damaged and deformed, with ulcers appearing on the soles and the animals will develop a limp.
Prevention of acidosis in cows
In order to avoid acidosis and maintain proper milk quality, comprehensive prevention is very important:
- In order to avoid problems caused by acidosis, it is recommended to introduce cattle to concentrated feeding type rations gradually.
- The diet must contain sufficiently good quality and properly crushed fibre. Avoid feed materials contaminated with mycotoxins.
- Concentrated feed is recommended to be fed in moderation, the intended daily amount should be given in several servings, preferably mixed together with coarse feed.
- Additives that alkalise the rumen content and improve its activity should be used – baking soda (1-2 percent of feed DM), calcium carbonate, magnesium oxide, group B vitamins, yeast, enzymes, etc.
- Feed soda may be used prophylactically by mixing it with other feed additives, but it is recommended to do this periodically, because over time the body adapts and it may become ineffective.
- Monitor and analyse changes in milk indicators with BROLIS HerdLine. An in-line milk analyzer may provide a lot of useful information about the state of the udder in cows. The presented data on changes in the composition of milk and other indicators during milking make it possible to quickly and efficiently identify animals the bodies of which are undergoing changes that are not characteristic of a healthy organism. By assessing the values of milk protein, fat, lactose, electrical conductivity and other indicators obtained during each milking, the system immediately provides data on cattle at risk of acidosis. This enables quick and timely decisions and prevents the progression of the disease.