19 Jan 2021 | Ear cropping
Colostrum, Colostrum, Colostrum
Good colostrum management is key to preventing disease, improving welfare, and minimising antibiotic use in farm animals.
Although this article is written with dairy cattle in mind, exactly the same principles apply in all farm animals, including sheep, pigs and goats
Whenever I am speaking to veterinary students about good health in calves, I normally list 3 essential things: colostrum, colostrum and colostrum! Colostrum is absolutely essential for a healthy calf.
Without it, the poor animal is likely to be condemned to a life of disease and ill health and may die prematurely before it can enjoy a full and productive life. It is also more likely to need various treatments including courses of antibiotics.
But why is colostrum so essential for a healthy life? When a calf is born, it lacks any of the antibodies it needs to protect itself from disease challenges in early life. In these species, protective antibodies which are present in the dam’s circulation cannot cross the placenta during pregnancy and so the calf is born with a very deficient immune system. It is completely vulnerable to any infectious diseases it encounters.
A natural fix
But nature has a very clever way to get around this problem. The first milk, or colostrum, produced by the dam is full of antibodies. When this colostrum is ingested by the newly born calf, it is able to absorb these antibodies across the gut wall. They then enter the blood stream and so provide effective immunity.
However, this ability to absorb antibodies across the gut wall is only present for the first few hours of life. It is very effective up to about 12 hours after birth and almost completely closed by 24 hours. So, the newborn calf must absorb sufficient colostrum within the first few hours of life. After that it is almost entirely ineffective.
A key part of disease prevention is ensuring that sufficient amounts of good quality colostrum are ingested by calves during the few hours of life. Ideally a calf will simple suck from its mother and the entire process will work very effectively. However, there can be problems, for example if the calf is weak and slow to stand and suckle or if the mother has trouble standing due to milk fever or a difficult birth; in these cases, the calf may simply not be able to ingest the required quantity of colostrum.
Colostrum can also vary in quality - for example, colostrum from first calved heifers may have much lower levels of antibodies than those from older cows. It can sometimes be difficult for even the best stockperson to be sure whether or not calves are getting all the colostrum they need.
How much colostrum does a calf require?
The common rule of thumb is that a calf needs 6 pints of colostrum in the first 6 hours of life. Other often quoted targets are 6 litres in the first 12 hours of life. These are comparatively large volumes. If there is any doubt about adequate colostrum intakes on a farm, some very simple blood tests can be done to check and the great value of these is that they give an objective measure of how well the whole process is working.
It is best to do this as a screening test on a small number of healthy calves between 2 and 6 days of age. A clotted blood sample is taken and the Total Protein Levels can be measured to give an indication of whether sufficient colostrum has been drunk. Alternatively, a more specific test, the Zinc Sulphate Turbidity (ZST) test, can be run by the local Veterinary Investigation Centre.
Both these tests are simple, cheap and quick. This can reassure you that all is well with colostrum intakes or indicate if there may be a subtle problem. It is important not to carry out these tests on sick or dehydrated calves as these may give an artificially high result. Results must be taken from healthy calves to give a reliable indicator of how well colostrum is working on the farm.
Where there are doubts about calves sucking enough colostrum then colostrum can be milked from the cow and fed by stomach tube. This can ensure that a sufficient quantity is being fed in a timely manner. In some units, the preferred system is to milk colostrum from dams, store it and feed all colostrum by stomach tube. This can be very successful but it is very important that that strict hygiene is maintained at all times as poorly stored colostrum can rapidly become a soup of harmful bacteria. These systems require excellent management to be effective. They also require a great deal of work. It is also helpful to test colostrum for quality in this system so that only the best colostrum is fed.
Prevention is always better than cure. Good colostrum management is a key part to preventing disease, improving welfare and consequently minimising antibiotic and medicines use on any farm. Colostrum is pretty amazing stuff. As well as the antibodies it contains we know there are vitamins and nutrients present and we are only starting to learn about some of its other properties. Antibodies may not be the only essential ingredients it holds.
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