Ad libitum feeding in calves – as much as the calf wants
The topic of ad libitum feeding of calves has been increasingly discussed over the last year. It should, moreover, be very positive for the development of calves, yet there is a lot of uncertainty and many unanswered questions on this subject.
The term ‘ad libitum feed’ refers to freely available feeds of milk or milk replacer. This type of feeding should be limited to the first weeks of life. The recommendation to administer the ad libitum feeds over the first three to four weeks is based on the fact that the digestive system of the calf is designed to recycle milk at the beginning of its life. The change to solid feed, and accordingly to a ruminant portion, takes its time. Nevertheless, the calf must be able to absorb the necessary nutrients, because otherwise the calves' susceptibility to various diseases increases and their optimal development may be impaired.
With restrictive feeding, the calf receives a feed quantity that is allocated to it according to a fixed feeding plan. Due to a particular feeling of hunger created in this way, the calf should be encouraged to start eating solid feed as soon as possible. Initially, only small amounts of feed are consumed, but they do, however, play a particularly important role in the formation of the enzymes required for digestion.
Depending on the feed quantity and milk replacer concentration, restrictive feeding may result in the calf not being able to meet its energy requirements with the quantity allocated to it. This can lead to lower weight gain if no high-quality supplementary feed is offered by way of compensation or the calves do not consume sufficient quantities.
The cost of ad libitum feeding should also not be underestimated. Milk is a very expensive foodstuff. The intake of solid animal feedstuffs is delayed due to the high milk intake, so more money has to therefore be invested in feeding. Whether a decision is made for or against ad libitum feeding depends, in principle, on individual opinions and the operational conditions. Ad libitum-fed calves should be kept in individual pens during the first 3 weeks of life and milk should be freely available to them at all times. It is then possible to switch to group rearing and gradually reduce the quantity of milk so that the calves are weaned from the milk at an age of approx. 10 weeks.
In order to cover the average energy requirements of calves in the first weeks, approx. 1 kg of milk replacer must be fed daily. With 6l feed quantity and 125 g milk replacer/l water, this target is not met. With a feed quantity of 6l at a concentration of 160 g/l water, the amount of milk replacer required is therefore 960g per day. Standard feeds often look quite different from this. The concentration is often limited to 120–140g/l. The situation is different with ad libitum feeding. Experiments have shown that the feed intake of ad libitum-fed calves being fed according to these procedures reaches up to 11 litres of milk per day. It is particularly important that milk is always available to the calves. They should never have the feeling that they cannot drink their fill, because otherwise they will take up the milk too hastily the next time and digestive problems may occur.
The fact is, you can raise calves using either method. With restrictive feeding, care must be taken to ensure that the concentration of the milk replacer is sufficiently high. With ad libitum feeding, there must always be enough milk available during the first few weeks so that it can be consumed at will. It is always important that the calves quickly start to eat solid food so that the rumen can develop well. Therefore, the calves should be offered solid feed as early as possible, even if intake is still limited in the first few days. Special calf mueslis are particularly suited to this, because they are very tasty and well received by the calf.