Feeding
Colostrum for a super start
Colostrum is simply the first milk produced after calving; it contains antibodies against all the bacteria the cow has come in contact with. The calf is born without protection against infective bacteria and must absorb the antibodies through the wall of the intestine to gain protection. Colostrum has more than twice the amount of total solids of whole milk and initially about five times the levels of protein and vitamins A, D and E. Within 2 days of calving these levels are about the same as those found in whole milk.
The antibodies in colostrum transfer passive immunity from the mother to the calf. A calf must get adequate colostrum from its mother or from other freshly calved cows in the first 6 hours of life. This is crucial; the alternative is a disease- prone calf.
For a super start, a calf needs to be born on a dairy with ‘colostrum consciousness’, where rearers know the three Qs of feeding colostrum:
- quickly—as soon as possible (preferably within 6 hours of birth)
- quality—only the best
- quantity—at least 4 L.
Stomach Tubing
To reduce losses and sickness, stomach tubing of colostrum is becoming part of Australian calf rearing. The stomach tube is a semi-flexible piece of plastic tubing with a pear-shaped end designed to be inserted easily into the oesophagus but not into the lungs. It is usually attached to a plastic container holding the liquid to be fed.
Four litres of colostrum should be fed to give enough antibodies. Some people prefer to use a nipple bottle rather than stomach tubing, but this takes longer and it is unlikely that a calf would drink 4 L. If calves get the initial 4 L by tube they usually won’t need another feed for 24 hours.
Tubing a calf is not a major drama, but the first time it might pay to get some coaching. Preferably have the calf standing. Leaving the head in a position that feels comfortable for you, pass the tube gently over the tongue. At this stage the calf will start chewing and swallowing; the tube can now be passed down into the oesophagus. When the bulge at the end of the tube can be easily felt as it moves down the oesophagus (indicating that the tube is not in the windpipe) feeding can start. When feeding is over remove the tube slowly. Clean and disinfect it, then leave it to drain and dry. Stomach tubes are available from your local veterinarian or farm supply store.
Providing 4 L of colostrum through a stomach tube is a recommended management practice to give calves the ‘kick start’ they need for life.
For further information on stomach tubing, see the Agriculture Victoria Agnote AG0503, How to stomach tube a calf, included in the Further Reading section of this manual.
Colostrum Quality
The quality of colostrum can be enhanced by vaccinating cows before calving and again 6 weeks later for E. coli and salmonella and with 7 in 1. Thereafter, a booster dose about 2 weeks before calving is all that is needed. Milk freshly calved cows as soon as possible, as reabsorption of antibodies begins immediately after calving.
Colostrum quality can be measured using a colostrum tester (Calf Guard®); these are commercially available through all veterinarians or Northfield Laboritories in South Australia. Another way of assessing antibody transfer in the calf is to use a commercial blood testing kit. The level of antibodies in the blood indicates the calf’s ability to fight infection; if you find it is low you can give the calf extra colostrum within 36–48 hours of birth.
If you decide to freeze some colostrum, try to collect it from mature cows that are among the lower producers, as they tend to have the highest antibody levels. Young cows have a lower natural immunity than mature cows. Cows that suffer from sickness or stress at calving will also have lower antibody levels. Frozen colostrum should be thawed in a bucket of warm water. There is still some concern about using microwave ovens for thawing, but if you use the proper defrost setting the antibodies should not be damaged.
Colostrum can be stored in the refrigerator for a week or so without affecting quality. Frozen colostum can be stored for 6–12 months.
The Water Supply
A liberal supply of fresh, clean drinking water is necessary in any calf rearing program. If your calves are on a once- daily milk feeding program you should check their water twice a day, especially in hot weather.
Milk Feeding
Whole milk is the natural food for young calves. It is especially preferred for minimising digestive upsets. However, milk replacer powders are widely used in some cases for reasons of price and disease control and the fact that they can be fortified with vitamins, minerals and ionophores. The milk replacers now on the market vary widely in quality, so this should be checked, either by using your own experience or by adding some junket tablets to test their clotting ability.
There are two types of milk replacers: those that use butterfat as the basic energy source and those containing tallow. Quality butterfat-based products are preferable. If you have to use tallow- based products because the others are too expensive, make sure you choose a high quality one. Table 2.2 lists the desirable characteristics of high quality replacers
