As we approach the autumn, one of the next steps on many suckler farms will be to begin preparing for weaning spring calves. Whether you are a weanling producer, an under 16-month bull producer or a steer-beef finisher, restricting calves’ growth and performance during weaning will mean facing an uphill battle to meet performance targets for the rest of these animals’ lifetimes. With this in mind, it is vital to ensure that proper management of these animals is carried out to maintain full health and performance; before, during and after weaning.

Laying the foundations

It is critical to understand that, for a successful weaning to take place, the level of stress experienced by the animal must be minimised.

Stress is the number one cause of an animal health breakdown during weaning. With this in mind, we must consider what steps can be taken prior to weaning to reduce stress. One such way of reducing weaning stress is to feed concentrates. Concentrates can help to make up the sudden loss of milk from the diet.

As well as that, if weanlings are being housed immediately after weaning, an abrupt change from a grass and milk diet to a silage and meal diet is severe – concentrates in the diet prior to weaning will help to bridge the gap.

As a general rule of thumb, concentrates should be introduced one month prior to weaning and their allowance gradually increased to 1kg/day by weaning time. Do not think that concentrates fed to calves are fallen goods. Weanlings are the most efficient feed converters on the farm. Research has shown that when weanlings are fed 1kg/day concentrates in autumn and winter, the conversion rate to liveweight at the end of the winter is about 4.5:1.

If feeding concentrates is not for you, then another method of reducing stress at weaning is to reduce the calf’s bond with its mother. Creep-grazing calves ahead of cows will contribute to this. In a paddock system, raising wires and allowing calves to graze ahead on the best-quality grass will reduce the calf’s milk dependency and bond with its mother.

Aside from calf management prior to weaning, there are also treatments that can be administered to reduce a health breakdown.

The primary health concern during weaning is pneumonia, which is discussed in detail later in this article. No matter how successful weaning is, animals will undoubtedly be subject to some level of stress. Stress is the main inducer of pneumonia. In an attempt to prevent pneumonia, vaccination can be very successful. Vaccines will provide a window of protection against the virus. Intra-nasal vaccines can provide almost immediate protection while injected intra-muscular vaccinations can take up to a month to work. With this in mind, consult your vet now about the possible vaccination of calves to minimise pneumonia risk in weanlings this winter.

The weaning process

The ideal age for weaning calves is seven to eight months. In extreme years, weaning can take place after six months under good management. Calves weaned at less than five months will suffer setbacks in performance.

Again, during weaning, the key threat to animal health is stress. The best way to avoid stress during the weaning process is to avoid weaning animals abruptly in large groups. Gradual weaning is better for the entire group. The general rule of thumb here is to wean calves in at least two separate groups, with each cow group being removed at a minimum interval of five days.

Note, it is best practice to remove the cows from the calves. This means calves are not removed from the environment they are used to, they are kept with their comrades and they are familiar with where grass and concentrates are accessible.

Try to avoid any treatment of animals during the weaning period if possible. As mentioned, vaccines should be administered a week to a month in advance of weaning, depending on the method of administration.

The temptation may be to give calves their full winter health treatment immediately after weaning. However, any further treatments for at least two weeks should be avoided as further handling will cause even more stress. To maintain animal health during weaning, best practice is to monitor animals at least once each day, to ensure clean feed and water is available and to treat or seek veterinary assistance for any animal that looks off colour.

Post-weaning management

Once weaning is complete, the key to maintaining animal health lies with diet and housing.

Starting with diet, weanlings are growing and maturing animals and, with this in mind, should be given access to a high-quality diet to meet their nutritional requirements. If available, 70 DMD silage or greater should be fed along with at least 2kg/head of concentrates. A weanling ration should contain at least 15% protein to nourish the animal’s growth requirements. Where silage quality is low, extra meals should be given as supplementation. Remember, a weanling is the most efficient animal to feed.

Housing also has a big part to play in the health of your weanling. All houses should be adequately ventilated allowing for a good supply of fresh air. This prohibits conditions for viral growth and spread, allowing heat dissipation and preventing the buildup of carbon dioxide, ammonia or slurry gases.

Again, poor ventilation can play a huge role in the buildup of viruses and disease, with pneumonia being the first to spring to mind. Also, floors should be non-slip to prevent injury from falling.

When fully settled in their winter environment, weanlings can then be given their full winter treatment.

Clipping of backs and tails should be carried out. After this, a lice dressing should be administered. A pour-on type product works well, especially on clipped backs.

Finally, animals should be treated for stomach worms and there are various products on the market for this. The treatments mentioned can all be completed at the one time and should be sufficient to keep weanlings healthy for the entire winter.

Weanling pneumonia

Pneumonia is usually caused by pathogens combining with external factors. The most common strains of pneumonia are viral, such as IBR, RSV and PI3. There are also bacterial strains of pneumonia. However, pneumonia is a classical multi-factorial disease, and it is the combination of these infectious agents with inappropriate management and husbandry factors that cause outbreaks of the disease. In terms of severity, IBR in particular is quickly becoming one of the most common animal health problems on Irish farms, affecting 70% to 80% of herds.

Symptoms

In terms of the symptoms, it must be acknowledged that the severity of disease associated with pneumonia can range from mild to very severe. First and foremost, reduced feed intake will raise alarm bells, as with many diseases. Inflammation of the nostrils and upper airways of cattle, associated with a high temperature are then the most common clinical signs. Other common signs include rapid and loud breathing, which many identify as a ‘‘blow’’ on an animal. Later signs include nasal discharge and severe respiratory distress.

Farmers should be aware that pneumonia viruses are contagious. Airborne spread can occur over distances of up to 5m, while physical spread can be through semen from infected bulls, through the use of contaminated equipment and by people who have recently handled infected animals.

Prevention and cure

There are a number of different preventative measures for pneumonia, depending on the viral status of your farm. For a herd with some or all of the above viruses present, or for a herd that has previously been exposed to these viruses, it is important to implement a strict vaccination programme to prevent against future outbreaks. Currently, the only pneumonia vaccine on the market in Ireland is the Rispoval marker vaccine. If testing has been carried out, it may also be possible to identify and cull latent virus carriers to prevent possible shedding of harmful pathogens.

If you have had no previous cases of pneumonia within the herd, at the very least, it is critical to eliminate the potential entry of the virus. Best practice is to operate a closed-herd policy, as well as implementing good biosecurity measures for livestock, personnel and equipment coming onto your farm.

In terms of curing an animal infected with pneumonia, a call-out from your vet as soon as possible is necessary. Treatment will then vary depending on the level of severity of the disease. Antibiotics are not effective for viral infections. In the meantime, infected animals should be isolated from the main group immediately to prevent the spread of the virus.