Correct concentrate feeding – the key to rumen development in your calves

The intake of calf starter concentrates is the single most important factor in the development of the rumen, which is very small and undeveloped at birth. Starter intake is important in ensuring a smooth transition from milk feeding to an adult diet at weaning without setbacks to growth.

Dairy Specialist James Dunne gives information & advice below on feeding concentrates correctly to calves. 

What are the important qualities of a calf starter?

It is essential that any calf ration is:

• Palatable - the calf should be willing to eat the ration, starting as early as possible.
• High quality - the ration should be highly digestible in energy and protein and contain the necessary amount of other nutrients.

Coarse ration v pellets - which is better for calf performance?

A coarse calf ration has ingredients of similar size (e.g. rolled barley, flaked maize), with no dust or fine meal present.

The young calf will accept a coarse ration more readily than pellets. A course ration encourages more chewing and saliva secretion. In addition, calves fed coarse starter mix eat more and have been shown to have higher weight gains than those fed pellets. The coarseness also benefits growth of the muscle layers in the rumen wall.

Therefore, calf concentrate feeding should begin as a coarse ration. After a few weeks, pelleted starters can be gradually introduced. Pellets that are either too hard or too soft will adversely affect the calf’s concentrate intake.

Dusty meals can pose a problem, leading to increased incidence of respiratory disease. Finely ground ingredients increase the incidence of digestive disorders. Adding molasses (approximately 5%) helps to control the dustiness of rations and can also improve ration palatability.

Calves prefer a high quality coarse ration of uniform size (left). A dusty ration (right) will reduce feed intake.

What ingredients do coarse rations usually contain?

Most coarse rations contain ingredients such as flaked maize, rolled barley, peas, processed soya, beet pulp, linseed flakes, molasses and a pelleted protein balancer. Each ingredient must be palatable in its own right to prevent the calf from selecting out individual components of the ration.

When should you start feeding concentrates to calves?

Calves should have access to clean, palatable starter concentrates from three days of age. From three weeks of age calves will begin to eat considerable amounts of starter concentrates. From then on, the higher the quantity of milk fed, the lower the amount of concentrates they will consume.

What allocation of concentrates is recommended?

When it comes to stimulating calf starter consumption in young calves, always remember “less is more.” At first, a small handful of concentrate should be offered after milk is fed. The ration should be placed in front of the calves in shallow troughs/buckets to encourage the calf to ‘nose around’ in it.

By two weeks, the allocation should be increased to two handfuls. The idea is to encourage consumption while not overwhelming the calves or wasting feed. The ration offered should be changed daily, keeping it fresh and encouraging the calf to eat. Use a measure for meal dispensing as it helps to prevent overfeeding which can lead to digestive upsets and scouring.

Concentrate should be increased gradually, with calves consuming at least 1kg of concentrate daily by weaning. It is vital to check that the calves’ dung does not loosen too much as the ration allocation is increased.

What are the factors affecting calf starter intake?

There are a number of variables that contribute to differences in calf starter intake. These include:

• Milk feeding programs; the amount being fed, protein and fat percentage of MR.
• Water intake/availability.
• Calf starter formulation and its physical form.
• Calf genetics, gender, birth weight.
• Calf housing, management and environmental conditions.
• Starter quality - dusty, mouldy, off-flavours will reduce palatability. 

Calf starter nutrient specification

A ration that meets the calf’s nutrient specifications, as well as their preference for texture, taste and smell, will encourage early intake.

To promote growth and maintain health, calf rations must contain:

• Energy for growth and functions like breathing, walking and grazing.
• Protein for all basic metabolic processes and growth.
• Fibre for rumen function and to ensure cud chewing.
• Vitamins for metabolic processes, bone formation and disease resistance.
• Minerals for carbohydrate metabolism, cartilage and muscle function.

Protein content: Calf rations should contain 18% crude protein (CP) on an as fed basis.
Energy content: Calf starter should have adequate energy supplied from a grain base. Energy values of 13-14 MJ ME/kg dry matter are acceptable (12 MJ/kg DM minimum). A target energy density of 0.95 UFL is recommended
Oil content: The oil content of a starter can be up to 4%. The ration should not contain added fat.
Fibre content: A fibre content of 8-10% is sufficientto prevent digestive upsets 

In summary:

• The calf should have access to concentrates from three to four days to stimulate rumen activity. The rumen is usually functioning well by 10-12 weeks.
• Concentrates should be introduced by placing a small amount in a clean shallow trough and this should be changed daily.
• Calf concentrates should be highly palatable, coarse-textured, high in energy and protein and low in roughage (> 15%).
• By three weeks a calf should be able to digest small amounts of grain, meal and fibre in the form of hay / straw.
• Any feed changes must be introduced slowly.
• Calves should have free access to clean water at all times.