Ketosis in Dairy Cows
Introduction
Ketosis is a metabolic disease that can affect dairy cows most commonly during the first six weeks of lactation.
Ketosis has no local names in East Africa; in English it is also called Acetonemia or Ketonemia.
Cause
The underlying cause is a combination of high energy requirement at the onset of lactation coupled with too low energy in the feed (e.g. poor quality silage, very coarse hay). The volume of feed a cow can eat in a day is limited. If the ingested feed provides less energy than the cow requires the animal runs into a net energy loss that becomes worse over time and the blood sugar level drops. To provide more energy the liver converts body tissue (protein, fat) into extra glucose (sugar). The by-products of this process are ketone bodies, which are toxic and have to be excreted. If the ketone concentration in the blood is too high the cow becomes sick.
Signs and Symptoms
Ketosis affects the highest yielding dairy cows and begins with very mild signs, which are easily overlooked in the beginning. Affected animals feed less and also give less milk. The cow appears sleepy and passes firm feces often covered by mucous. If the disease worsens the animal also looses weight rapidly (burning its’ energy stores). Sick cattle may refuse to eat grain, concentrate or dairy flour and try to ingest strange feed (coarse straw, twigs, soil, abnormal objects). The animal stands with a humpback and some develop a distinct fruity to musty smell in their breath and urine due to the high ketone. Untreated cows can show abnormal behavior (staggering, circling, head pressing, constant licking, bellowing – like Rabies!) and become unable to stand up.
Diagnosis
Good observation to detect early symptoms is the most important diagnostic tool. There is also a simple dip test that detects ketone in the cow’s urine. It is used by dairy farmers in Europe and North America to test cattle when they suspect ketosis.
Treatment
In some cattle the reduced milk yield may level out with the low energy in the feed and they do not develop the full symptoms. If better quality feed is provided early, the symptoms will gradually disappear.
Cattle with fully developed ketosis need urgent treatment otherwise they can die from liver failure. In very acute ketosis cases (can’t stand up) it is necessary to give a glucose solution intravenously. In addition the veterinarian can inject cortisone and provide oral substances that provide a lot of energy (propylenglykol drench). The most important measure is to check and improve the quality of the basic feed that the cow has been eating.
Prevention
High yielding dairy cows are very difficult to feed. If you do not always have sufficient amounts of high quality silage or hay on your farm it is better not to breed cattle with too high milk yield (e.g. pure bred Friesian cows). Grade cattle are much hardier and remain healthy and produce a good milk even if feed quality is not always perfect (e.g. during dry season).
It is also important to feed pregnant cattle well, such that they can build up sufficient energy stores in their body to be able to cope with mild ketosis after calving.