Vet Advice

Prevention of neonatal diarrhea focuses on several different aspects of management. These infectious agents are found in healthy calves too. Whether the disease will occur or not depends on:

• the calf's ability to fight infection,
• the severity of the strain of the disease-causing agent,
• the presence of more than one disease-causing agent at a time, and
• the stress on the calf.

Some causes of stress on calves are poor diet, poor environment, and lack of shelter.

The major factor that determines if a calf will get sick or not is known as the success or failure of passive transfer. Passive transfer refers to the transfer of immunity from the cow to the calf through the colostrum.

Dam management

Cow and heifer nutrition is critical. The animals need to be in good body condition at calving time. Good nutrition of the dam allows more efficient labour, better quantity and quality of colostrum and better mothering behaviour. More efficient labour decreases probability of neonatal problems especially those caused by lack of oxygen during the birthing process (hypoxia). This also prevents a swollen tongue or head, which cause problems with nursing. A more efficient labour produces a lively calf, which stimulates maternal instincts.

If cows are thin, then need to gain weight during the first and second trimesters of pregnancy. Adequate vitamin E and selenium supplementation must occur throughout pregnancy and lactation. Cows and heifers should be managed separately to reduce competition and allow for different nutritional needs to be met.

Vaccination of cows and heifers for calf scours increases a calf's ability to fight infection. Sometimes the dam doesn't have natural immunity to all the common diseases herself, so vaccination helps to provide her with the immunity to pass to her calf through the colostrum. This is especially true with heifers. There are several calf scour vaccines commercially available. It is best to use a product that protects against the common viral and bacterial causes of calf scours.

Individual animals need a primary vaccination several months precalving the first year they are vaccinated, along with a booster shot four to six weeks later. This booster needs to be four weeks pre-calving. In subsequent years only one vaccine booster four weeks prior to calving is required. With extended calving periods, another booster should be given to any animal that haven't calved during the first part of the calving season. Exact recommendations for this vary with the product used. This is to maintain optimum immunity.

Manage the calving environment to reduce calf exposure to disease-causing organisms. This is often the hardest thing to do, but is crucially important. The main goal again is to decrease the number of infectious organisms in environment that calves can pick up. To achieve this:

• Use separate calving facilities from wintering areas. The calving areas should have been left empty over the summer and fall to be cleaned out and dried up.
• Do not mix cows and heifers in the management areas because calves from heifers are at a higher risk for developing scours due to poorer-quality colostrum and more problems with calving and maternal abilities in heifers.
• Isolate sick animals. They shed high numbers of infective organisms.
• Use adequate bedding to decrease contamination of manure on udders, etc., where calves pick up infections.
• Prevent overcrowding of animals in the calving area, by regularly moving out cow-calf pairs to a nursery area within 48 hours after they have mothered up well.
• If possible, it is ideal to move cattle that haven't calved every 10 to 14 days to a fresh area to decrease environmental contamination. Then they are not exposed to all the manure from the area where other cows and calves have been living.

Calf management

Ensure adequate colostrum intake. The calves need to ingest at least four to six litres (or a volume equivalent to at least five per cent of their body weight) of good quality colostrum, within six hours of birth. This colostrum intake needs to continue for the next 48 hours twice daily at similar amounts.

Colostrum varies in quality. The quantity required is based on the average immunity it will give the calf. If supplementing colostrum, it is always best to use fresh or frozen colostrum from one of your own mature, healthy cows. This should give antibody protection for organisms found on your farm. Then you know what she's already been vaccinated for. Only save colostrum from the first milking after calving from mature cows that should have good quality colostrum.

If you do not have any colostrum available and you need to supplement, you can use powdered colostrum replacers. Some good quality products exist but they are not all equal. You need to discuss with your veterinarian how much to use in your situation and which product is appropriate. In cow-calf herds we assume colostrum intake is likely appropriate if the calf is vigorous and nursing within two hours of birth. You should supplement calves that are not up and nursing within this time frame. You should also supplement in situations that have a high risk for failure of passive transfer such as an assisted birth, swollen tongue, or weak calf. These calves should be supplemented within two hours of birth and then allowed to nurse naturally.

If no natural colostrum intake occurs with an orphan calf, several packages of colostrum replacer are necessary for the first feeding and then the colostrum replacer needs to be fed for the next few days too.

Calves can also be given an oral calf scours preventative. This is a paste or a liquid given in the mouth within 12 hours of birth. This does not replace the use of dam vaccines but is good in some situations, such as in the face of an outbreak.

The outbreak

Your veterinarian can help you develop good management strategies for your herd, including vaccination protocols, nutrition questions, and facility development. The veterinarian can also develop treatment recommendations. If you are having a scours outbreak, this will require taking a history and a farm visit to examine sick animals. Your veterinarian can help identify which organism(s) are causing the problem to aid in treatment and prevention. It is best for the veterinarian to perform autopsies and sample tissues from calves that haven't been treated and are in the early stages of disease.

It is important to remember that some of these organisms can also cause disease in humans (zoonotic disease). Careful hand washing when handling sick animals is essential for human health.