WEANING AT 5 WEEKS
The Early Weaning System of calf rearing was developed by Dr Preston of the Rowett Research Institute of Aberdeen in Scotland in the 1960s. He realised that the old system of feeding calves relatively large quantities of milk was both wasteful and expensive, as milk is a human food and is more profitable when fed to humans.
Early weaning depends, for its success, on the fact that the amount of milk fed to the calf is restricted, and the calf is encouraged to eat solid food as soon as possible. Once it starts eating, it must have access to clean water and solid food at all times, and must be able to eat and drink whenever it feels the need to do so. The other important point to remember is that the milk fed to the calf must be whole milk, and not skim milk. Whole milk is a highly nutritious food and a high fat food.
When you consider milk in terms of what is called a Dry Matter Basis (that is, looking at the solids in milk), it contains 28% fat. The total solids in milk are roughly 12.5% and the butterfat in milk is about 3.5% on average; a simple calculation of: 3.5 x 100 = 28% indicates that milk does contain 28% fat on a Dry Matter Basis.
You know from the course on Foods and Feeding, fat is a very high energy food, more so than carbohydrates, and the calf must have this energy to build up its reserves, so that it can be weaned early in life. If the calf is fed on skim milk, it cannot build up the reserves of body fat which it requires, and if it is weaned early, it will probably die. The steps to follow for weaning calves at 5 weeks, or 35 days, are given below:
• At Birth Make sure that the calf is suckling the cow and getting the cow’s colostrum; this is of utmost importance. Cover the calf’s navel cord with a solution of 20% iodine shortly after it has been born and do this at least twice more during the first 24 hours of its life. This is to prevent infection entering the calf’s body through the navel cord.
• At 4 Days Old Remove the calf from its dam, and bring it into the calf house, putting it into a single pen or into a calf crate. At this stage, Earmark the calf, and remove any surplus teats if it is a heifer calf (see Lecture 8). Start bucket feeding the calf with whole milk. Teach it to drink from a bucket. Feed 3 litres a day in two feeds of 1.5 litre per feed. Feeding times should be early morning, and late afternoon.
Feed the milk at blood heat (38°C) and in a clean bucket. Buckets should be washed out with hot water and dairy detergent after each feed, and, if possible sterilised, along with the rest of the dairy equipment. Make sure that the calf has access to clean water and calf meal.
Use a “calf starter” meal. Encourage the calf to begin eating meal by placing a small amount of meal in the calf’s mouth after it has had its milk. It is most important to get the calf eating solid food as soon as possible, and some calves will begin to eat at 6 – 7 days old. The calf meal must be highly palatable and highly digestible. In other words, the calves must like the taste and it must not be too fibrous, so that they can digest it easily.
At this stage of its life, the rumen of the calf has not developed; therefore it cannot digest fibre and cellulose. The best meal is one bought from a food firm. All the food compounders make a calf starter meal containing 20% protein together with the right amount of carbohydrates, minerals and vitamins which the calf will need, and which are very important for its growth. This meal, which should be a meal and not pellets or nuts, should be mixed with ground hay – hay which has been put through a hammer mill – at the rate of 10% ground hay and 90% calf meal by weight. This will give a mixture containing all the nutrients required by the calf, together with just enough roughage or fibre to help the calf’s rumen to develop. You can tell when the calf starts using its rumen, because it will lie down in the pen and chew the cud.
• At 10 Days Continue feeding the milk twice a day, feeding 1.5 litres of whole milk in two feeds, early morning and late afternoon. Make sure that the calf has clean water and the calf meal/roughage mixture is in clean buckets or troughs in front of it at all times. Water buckets should be removed and emptied each time calves get their milk, and only put back 1 hour later, or the calves will drink too much water when their milk finishes. Only small quantities of calf meal mixture should be put into the bucket or trough at each feed – just enough to keep the calf going to the next feed, with a little bit to spare. It is no use giving the calf a big scoopful of meal, because it will not eat very much. The meal will go sour and the calf won’t eat it at all. The meal must be fresh and the water clean. • At 20 Days Change the feeding of milk to ONCE a day, feeding 3 litres each time. Dehorn the calf. In the case of bull calves that are being reared for beef, these should be castrated, see Lecture 8.
• At 35 Days On the 35th day, the calf should be weaned. It should receive no more milk after that. Continue to give it clean water and calf meal/roughage mixture. At this stage, the calf should be eating about 1kg of the mixture a day. Gradually change the meal (over 5 days) to a complete calf meal with a crude protein content of about 16%. After this change in meal, the calf can be moved into a larger pen with other calves, and they can be fed from the same food trough and water trough.
• At 84 Days Switch the calves from the calf meal/roughage mixture to a mixture of ordinary dairy meal with 10% ground hay added. This mixture will have a lower protein content than the calf meal (14%), but at this stage the calves need less protein, and the mixture will be cheaper than the calf meal mix. This change over should be done gradually, taking about 7 days to change completely from one mixture to the other. Once the calves are eating the new mixture, they can be moved out of the calf house and into grass paddocks, where they will begin to graze. They should be provided with shelter against rain and sun, and the trough where they are being fed their meal should be covered against rain and damp. At this age, the calves should be eating about 2kg of meal/roughage mixture a day, and as this is enough for them, they can be put onto twice a day feeding 1 kg of meal mixture in the morning and1kg in late afternoon.
DIPPING AND DOSING: While the calves are in the calf house, they will not need to be dipped, although they should be inspected, just to make sure they are not carrying any ticks. Once they have been turned out into a paddock, they should be dipped along with the other cattle, according to the dipping recommendations for that area. At 40 days, and while the calves are in the calf house, they should be dosed against tapeworms. At 60 days, and again, while they are in the calf house, they should be dosed against roundworms.