Keeping an autumn-born
dairy calf healthy in the first
few weeks of life is critical,
and this process begins
with ensuring its mother is
well looked after, writes
independent vet consultant
IT MAY seem obvious that a healthy calf is produced from a fit, active and healthy mother, but it is often neglected in practice.
As cows milk yields increase, a long dry period becomes even more essential. A 10,000 litre cow is often on a nutritional knife-edge and while it can cope with its lactation, it never has time to build up its body reserves.
During the dry period essential vitamins and minerals can build up – not only for the next lactation, but also to ensure there are sufficient trace nutrients for the calf.
Reports occur each year of calves born with deficiencies in selenium, iodine, manganese, vitamin A and E, but these are the tip of the iceberg. What occurs more frequently, and is often not diagnosed, is the birth of stillborn calves, ones which die soon after birth or which are just slow and weak.
The mother also needs to be looked after to ensure colostrum quality is produced. This depends on dry period length and nutrition as well as any diseases the cow develops.
Many people do not stop to think from where the life protecting antibodies within the colostrum originate. In fact they mostly come from immunity in the mothers blood. As she approaches calving antibodies fall in her blood, making her more vulnerable to infection. This is done as a sacrifice to protect her calf in the first few weeks of life.
If the dry period is less than six weeks, or she has a rapid flush of milk at calving, the concentration of antibodies in colostrum will not be high. The latter is a particular problem in cows giving more than 9000 litres when colostrum quality can vary greatly between individuals.
However, the ability of a cow to transfer immunity to her calf has made vaccination of the cow to prevent scours successful.
On some farms the hygiene in calving areas leaves much to be desired. Often calving at pasture will reduce infection problems, otherwise it is essential to keep calving areas as clean as possible.
Straw should always be generously provided to give a dry clean bed and the areas should be mucked out and disinfected as often as is practical. If infection gets in first, it does not matter how much colostrum is fed, or how good its quality.
At birth or soon afterwards, infections mainly enter via the mouth or navel. In the former, the sooner the calf can take in colostrum the better. In the latter, dipping the navel in tincture of iodine or a strong iodine solution will disinfect it as well as drying it. Ideally repeat this after 12 to 24 hours.
Dipping is better than spraying, as it ensures the whole navel is covered and it is done quickly. Total coverage is almost impossible to achieve with a spray.
The calf is born with almost no immunity, so colostrum provides immunity for the first few weeks of life before it is able to produce its own antibodies. The aim is to have good quality colostrum provided by the mother.
If for any reason the cow is ill or has milk fever or mastitis then it is important to have a ready supply of first day colostrum to feed a newborn calf. This is best stored frozen in litre or half-litre plastic bags. It can be thawed in a bath of warm water or in a microwave on the thaw setting. The calf requires three litres in the first six hours of life, which is best given in two feeds.
It is difficult to estimate when the calf is sucking exactly how much it is taking in. However, vigorous sucking for 20 minutes is about the equivalent of three litres.
While it is important to give colostrum early, feeding should continue after the calf is off the cow. As little as a litre daily will be enough to ensure that the calf keeps a constant flow of antibody through its guts to help kill and prevent multiplication of the organisms which cause scours. If colostrum, which would otherwise be wasted, is stored in lidded bins according to the day of lactation produced it is usually possible to provide calves with a daily dose for two weeks. As the calf becomes older it can graduate to the less concentrated colostrum.
It has always been possible to check how much immunity has been absorbed by the calf by taking a blood sample, but now a saliva test has also been developed.
Most of the bugs which cause scour are on most farms most of the time. Whether or not they cause problems depends on calf management and its good and bad points. Your vet is ideally placed to provide an appraisal of the management and infection causes involved.
In a recent MDC-funded study of calf scour outbreaks, conducted by the National Animal Disease Information Service, it was shown that there was less scouring where milk substitute was fed. This needs further investigation, but it is probable that while milk substitute is consistent, this is not the case with milk.
Milk will probably vary in its quality, quantity and temperature when fed. It may also contain antibiotic milk, bloody milk or any other which is unfit for the milk tank.
Milk substitutes are also supplemented with vitamins and minerals and these again may be helpful, as milk, after colostrum, is not high in all of these.
Other factors influencing scours are that less occurs in single pens than group penning. Disinfection after occupancy and dry bedding are also important. Feeding concentrates early and offering roughage also appear to help calves.
Usually correct vaccination of the cow and colostrum use will help control problems such as rotavirus, coronavirus, E coli and salmonellosis. For salmonellosis, the calf can receive vaccine in time to become immune. However, before any vaccination programme begins the infection cause must be confirmed. *
Left: Scours are less common when calves are kept in single pens and when they are fed milk substitute.
Right: A short dry period can result in a lower concentration of antibodies in her colostrum, says Tony Andrews.
• Ensure mother healthy.
• Clean calving accommodation.
• Check adequate colostrum fed.