There are many reasons for cows to go down at calving. Aside from the more obvious metabolic diseases, conditions such as calving paralysis, leg fractures, dislocations, mastitis, uterine infections, pneumonia and salmonella may all have similar symptoms.

Milk Fever

Milk fever, or hypocalcaemia, usually occurs in the 72 hours around calving, most commonly in older cows and rarely in first and second calvers. All cows experience a temporary drop in blood calcium levels as they start lactating but some go on to develop clinical signs of milk fever, normally beginning with muscle tremors, followed by a staggered gait and then recumbence. As a preventative measure, at risk cows may be treated with a starter drench such as Starter Plus or Calstart directly after calving, or with Calol 12 hours before calving and again 12 hours later.

Grass Staggers

Grass staggers, or hypomagnesaemia, is caused by low blood magnesium levels. Unlike calcium, magnesium is not stored in the body and a daily intake is required from the diet. Grass staggers is most commonly seen in spring due to the cow’s increased need for magnesium for lactation and also due to the fact that faster growing spring grass is low in magnesium. A cow with grass staggers will often initially exhibit symptoms similar to those seen with milk fever. Often spasms of the eyelids are seen. The cow becomes jumpy and aggressive, and if untreated she will go down, convulse and die. Magnesium pasture dressing, drenching or administration of magnesium boluses should be started three weeks out from calving, continuing through to September. This will help prevent grass staggers.

Ketosis

Acidosis, or ketosis, usually occurs within the first few days of calving up to a few weeks into milking and is a result of an energy deficit. Clinical signs of ketosis include loss of appetite, constipation, depression, sudden drop in milk production, acetone smelling breath, (similar to nail polish), compulsive behaviour such as head pressing and rail chewing. This is usually followed by a staggered appearance before the cow goes down. A starter drench after calving will administer an energy boost that will be helpful in reducing the incidence of ketosis.

Treatments

Downer cows require time spent on them for good results. They require an adequate source of food and water brought to them. A downer cow may require more than 40 litres of water per day. Hip lifters should not be used for more than 5 minutes per day, as a cow left hanging is likely to end up with more damage.

Milk fever cows require calcium. Calol or Calstart are oral treatments, while Calpro or Calpromag are given subcutaneously, and Calpromax can be given intravenously.

Cows with grass staggers require magnesium. Calpromag, Calpromax or Mag Sulphate can be given subcutaneously.
Cows suffering from ketosis need energy. Acetol can be given orally, and calcium may also be needed.

When using oral treatments you must first be absolutely sure the cow is able to swallow, to avoid accidental administration into the lungs. Calol will give 12 hours calcium supply.

IV treatments should be administered carefully and slowly using a new sterile needle. Slowly run the contents into the cow over a ten minute period, as running it in too fast can be fatal. NEVER give magnesium sulphate treatments by IV.

Subcutaneous, or under the skin, treatments should be given using a new sterile needle. Insert the needle under the skin along the neck or ribs. The area should be rubbed afterwards to spread out the solution, as calcium products are slow to absorb from under the skin. Treatments containing dextrose should not be given under the skin as they may cause abscesses.

Whatever the reason, downer cows need urgent treatment and if no dramatic improvement is noticed immediately following treatment an urgent vet visit is required. The longer the cow is down, the more muscle damage occurs and the likelihood of the cow getting up again reduces.

Why look at prevention strategies?

Farmer-treated downer cows will cost around $40 plus around 8 hours lost time, at the very least. Vet assisted treatment will cost around $250. Downer cows often go on to have further problems with uterine infections, mastitis, losses in milk production and fertility. The cost of Agrimag is around $15/day for 200 cows. This is based on a maintenance dose of 30gm/cow/day. Starter drenches cost around $7.00 per litre when purchased in bulk.

Good pre-calving nutrition and starting magnesium supplementation three weeks out from calving will greatly decrease the incidence of downer cows. If pasture dressing is not possible due to weather it may be mixed with molasses and added to dry feed. Magnesium helps regulate the calcium stores in cows and is therefore very important for both grass staggers and milk fever prevention; however even supplemented cows can still go down if feed is short. If using lime flour, seek vet advice if using pre-calving as care should be taken not to cause metabolic imbalances in this critical period and accidentally increase the incidence of down cows. For further advice on preventative strategies for your herd contact your vet.