Milk fever is a non-infectious condition usually occurring in high-producing dairy cows, but also less commonly in ewes and sows. It occurs usually within the first four days after giving birth, but can occasionally occur before the cow calves or months afterwards. Heifers never have milk fever and it is rare in second lactation cows. It is usually seen in cows in the third lactation on.
The cows that are most affected are usually in good condition and have had an easy calving. There are breed differences with Jersey cows being the most susceptible.
Milk fever is caused by a calcium deficiency. Calcium is important in brain function and is essential in maintaining consciousness. Severe deficiency results in loss of consciousness, coma and death. The role played by calcium is closely linked with phosphate, magnesium and dextrose and deficiencies of any of these can result in similar symptoms.
During pregnancy calcium is needed by the foetus for development of bone. If calcium is deficient in the diet, the cow draws on her own body reserves and draws calcium from her bones to supply this requirement. The demand for calcium is slow and so blood levels of calcium remain normal.
Giving birth requires a sudden demand for calcium, both for the actual process of giving birth, but mostly to make colostrum, which has a much higher percentage of calcium than milk. The calcium is drained from the blood of the cow and she no longer has body reserves to draw on. This acute deficiency of calcium blood levels affects brain function and the cow goes down.
• The cow at first appears unsteady, inbalanced and stumbles when walking.
• The hindquarters sway
• Her eyes are dull and she appears drowsy.
• She gets weaker and eventually goes down.
• She may groan, but this not a sign of pain.
• She usually lies on her brisket with her head turned into her flank (see picture)
• Some cows will lie flat on their side, with their legs straight out. If this happens it is vital to turn her onto her brisket, propping her up with sand-bags if necessary. If she lies her side, the stomach contents can be regurgitated, enter the lungs and then you have to deal with an inhalation pneumonia as well as the milk fever !
• Despite the name, there is no fever, in fact temperature may be sub-normal.
It is essential to get calcium into the blood as quickly as possible. The standard treatment is calcium borogluconate intraveneously or subcutaneously. CALCI 50 PI contains calcium, magnesium and phosporus. It is best to inject several sites at once to get as much in as quickly as possible. It is ideal to inject a remedy that contains magnesium as well. Improvement is often rapid and dramatic. (I have had a cow rise from semi-coma and run off down the paddock, intravenous lines still in place with several people running after her ! ) If there is no marked improvement, repeat the treatment after 6 hours. Relapses can occur even after several days. Watch the cow carefully and repeat the treatment if she relapses. It is a good idea not to empty the udder for the first days after recovery and in severe cases, withhold concentrates for a few days.
A cow that has succumbed to milk fever is more likely to get it again. Borogluconate can be given as a preventative measure.
• Do not allow cows to get over-fat before calving. They should calve at a body condition score of 3.5
• Ensure that the cow is eating the correct ration. Lactating rations and dry cow rations are formulated to suit the needs of that cow and should never be substituted.
• Ensure the dry cow has a good source of roughage in her dry period (See Management of the Dry Cow)
• Dry, pregnant cows should get adequate exercise.
Acetonaemia is a non-infectious condition of dairy cows and lactating ewes and nannies occurring in the first few weeks of lactation. High-producing cows are particularly susceptible.
The cause is a deficiency of carbohydrate in the body. Fat metabolism is interfered with and ketones accumulate. Ketones may cause rumen paralysis and affect brain function, causing nervous symptoms.
These occur in the first few weeks after calving. They may also occur when the cow has been off her feed eg suffering from another disease or condition.
• Swaying gait
• Licking the nostrils or curling the lips
• Wry neck, pressed into flank
• Depraved appetite – cows may refuse good food, but eat stones, soil or bark from trees.
• Glucose intraveneously or subcutaneously. (60-90g glucose in 350 -450mls boiled sterile water) Repeat every 24 hours. Most animals will respond after 2 or 3 treatments.
• Epsom salts by mouth or tube
• 250-500g sugar or molasses and 120-170g bicarbonate of soda in water by mouth or tube.
Symptoms of milk fever and ketosis may be very similar. If unsure as to which condition it is, there is no harm in giving both treatments at the same time ie glucose and calcium borogluconate.