Prevention of Downer Cows

Downer cow syndrome is not new. The term "downer cow" is currently overused relative to its original definition, prior to the BSE outbreak. A true downer cow by previous clinical definition is a cow that on examination ought to capable of standing, but for some unknown reason cannot. There are many causes of a downer cow; most often due to complications of a primary disease (e.g. milk fever, or mastitis), injury from falling on a slippery floor, or problems related to calving. The option of sending these animals for slaughter or rendering has been removed with the new regulations following the diagnosis of BSE in the United States. Many of these cows did not have to become "downers". Prevention of downer cows is preferable to the loss of milk income and valuable genetic makeup, and to the pain and stress that may be experienced by cows that are down.

A large proportion of cows become "downers" due to metabolic disease and secondary complications. The primary clinical problem debilitates the animal causing recumbency. This is often followed by muscle necrosis due to ischemia as a result of the pressure on the down leg. Often, the failure to rise observed within 24 hours of the cow going off her feet is a result of this secondary muscle and nerve damage, which is made worse by the cow being unable to shift position to prevent continuous bearing of weight. It is important to have recumbent cows moved often to keep pressure off the down leg.

This condition is very difficult to treat. Even with intensive nursing care on the part of owners and veterinarians, these animals may break a leg while trying to get up, die or have to be destroyed due to complications. The following are recommended practices for preventing downer cows.


Prevention of Calving Injury - The calving process is one of the most traumatic events in a cow's lifetime. There are many ways in which the calving event can result in problems that can often lead to traumatic damage to the cow. Most producers are well aware of "calving paralysis" resulting from damage to the obturator nerve on the inner side of the pelvic canal. Damage to this nerve can result in the cow's inability to keep her legs under her. Cows will do the "splits" with this paralysis. Damage may be temporary or permanent. Calving paralysis may result in secondary muscle damage if the cow is left on a hard surface and does not have the ability to rotate from side to side.

1. Be sure to breed heifers only when they have reached appropriate frame size and weight for the breed.
2. Breed heifers to "calving ease" bulls to minimize potential for dystocia.
3. Monitor and provide timely and appropriate assistance to calving cows, especially heifers.
4. Instruct those responsible for handing calving cows to be appropriately trained in providing assistance at calving without causing undue damage or injury.
5. Provide the cow with a large, uncrowded, comfortable, well-bedded calving area.

Prevention of Milk Fever - In-spite-of tremendous amounts of research, prevalence of milk fever in the national dairy herd has not been reduced. Milk fever is the single most important factor leading to downer cow situations. Milk fever results from a cow being unable to adequately maintain blood calcium concentration as she initiates lactation. This is primarily a disease of older (3+ lactations) cows. To prevent milk fever, the diet must be properly balanced for all macrominerals, especially calcium and phosphorus. Excessive dietary intake of potassium, sodium and phosphorus can lead to milk fever problems. Higher intakes of magnesium, chloride and sulfur may be protective. The role of calcium is somewhat debated. Diets providing less than 80 g/day of calcium generally can reduce milk fever incidence. Diets need to be formulated according to forage mineral analyses.

When the available forages contain higher amounts of potassium (>2%), then use of anionic salts may be necessary to control milk fever. Anionic salt supplements provide excessive amounts of chloride and possibly sulfur, which induces a state of metabolic acidosis. Metabolic acidosis facilitates intestinal absorption and bone mobilization of calcium. These supplements need to be fed for 10 to 14 days prior to calving.

Prevention of Mastitis - E. coli and Klebsiella are examples of coliform bacteria found in manure and bedding materials. Mastitis conditions resultant from infection by these organisms can cause severe toxemia and weakness of the cow, often resulting in downer cow problems. Hypocalcemia is often implicated in leading to these cases of mastitis.

1. Treat all four quarters with a long-acting intramammary antibiotic when the cow is dried off.
2. Provide sufficient dietary vitamin E (1000 IU/day) during the dry period to maintain good immunity.
3. Vaccinate dry cows with a gram negative lipopolysaccharide to booster immunity to coliform mastitis.
4. Thoroughly clean, disinfect and dry the teats before milking. Doing so prevents contamination by environmental bacteria and ensures good adherence of the teat cup liners to the teats and prevents slippage.
5. Dip teat with an approved teat dip immediately after milking.
6. Maintain the milking system to ensure proper functioning.
7. Identify cows with infected quarters so that they can be segregated, treated or culled.
8. Provide clean, comfortable, well-bedded stalls for both milking and dry cows.

Prevention of Lameness - Lameness can result from a number of factors, including infectious agents, ruminal acidosis-inducing diets, poor cow comfort, or muscloskeletal damage at calving time. Lameness problems are best controlled through appropriate early recognition and treatment. Timely decisions as to longterm health prognosis need to be made in order for cows to be more appropriately culled before degenerating into a more severe downer cow problem.

1. Select breeding stock for good feet and legs.
2. Feed cows rations that contain adequate fiber and minimize potential for acidosis.
3. Watch amount and source of starch in diet as for its potential to induce ruminal acidosis.
4. Maintain proper management of feeding program to minimize selective feeding or slug feeding behaviors of cows.
5. Properly manage manure in the cow's environment and practice good biosecurity practices to prevent spread of infectious agents.
6. Maintain a good hoof health program (foot baths and trimming).
7. Use foot baths and practice good biosecurity to prevent the introduction of hairy heel warts into the herd.

Prevention of Injury - Characteristics of some dairy cattle housing predispose cattle to injury. Slippery flooring, broken concrete, narrow doorways, 90° and 180° turns, and steps over obstacles are features that can lead to injury.

1. Provide well-designed, comfortable, well-bedded stalls that enable cows to lie down and get up without causing unnatural strain on knees, hocks or fetlocks.
2. Provide safe footing in alleyways, barnyards, laneways, and milking parlors. Non-slip flooring is essential to prevent falls, which can result in fractures, injury, or crippling spreader injuries. The industry standard for dairy facilities is to score the concrete with grooves 3/8 in. deep, 1-1.5 in. wide and 3 - 4 in. apart.
3. Grooved concrete should run in the same direction in which the cow moves. In high traffic areas, they should be in a diamond pattern.