Weaning is a stressful period for both you and the calf.

Get your weaning strategy wrong and all your hard work over the past eight to ten months goes out the window. In order to help you plan your weaning strategy, over the next four weeks we will be looking at what steps you can take to make sure you win the weaning challenge.

This week, we look at what steps can be taken in advance of weaning to ensure calves are in good health ahead of the high-stress period.

Pneumonia is one of the main challenges threatening calf health during weaning. In whichever form it presents itself, the consequences to farm output can be devastating. High mortality rates, increased vet bills and reduced animal performance are just some the ways an outbreak can hit your bottom line.

While the stress factor does provide an ideal opportunity for pneumonia to take hold, it is often a combination of factors that result in an outbreak. These can range from weather conditions, herd health status and shed ventilation to poor weaning practices.

Pneumonia will not be a problem in a healthy animal weaned from its mother in the correct fashion.

Herd health programme

Ensuring you have an adequate herd health programme in place is essential to avoiding any health issues at weaning.


The main area under attack during the high-stress weaning period is the calf’s lungs. Therefore, the importance of worm dosing as a means of avoiding problems during weaning cannot be overemphasised.

I often compare a calf’s lungs to the fuel filter on a tractor. You will get away with a dirty fuel filter while you are toddling around the yard feeding a few cattle.

However, put a 2,000-gallon slurry tanker on behind, and head up the road, and you will soon see the impact on performance.

A calf’s lungs are the same — but instead of dirt, there are worms. A spring calf that has not been dosed over the summer will often appear to be fine, perhaps coughing a little when you move them from field to field.

However, the weaning procedure is similar to putting the tanker onto the back of your tractor. When the lungs really have to work, what happens? They pack in and you have a calf standing with its tongue out, gasping for breath — or, even worse, you have a dead calf.

You could invest €40,000 to €50,000 in a new tractor, but if you fail to spend €10 of €15 on a fuel filter, it will have no more power than a Massey 135.

Farmers invest in top-of-the-range heifers and use top-quality sires to produce good-quality weanlings. Yet because they fail to invest €2 or €3 in a summer worm dose, they end up with an animal that has a lower market value than a Jersey bull calf.

Dosing plan

Advice on dosing will largely depend on how calves have been treated over the first part of the grazing season.

For farm-specific advice, you should consult with your vet.

In most cases, all spring-born calves should have received at least one worm dose at this stage. If not, a worm treatment should be administered right away.

Advice on when to administer the second dose will also depend on previous dosing history and projected weaning date.


In general terms, a spring-born calf should receive a midsummer dose with an Avermectin-based product, followed by a second treatment two or three weeks before weaning. Calves that are not going to be weaned until late in the season will possibly require three treatments.

However, if housing is to take place immediately after weaning, the pre-weaning dose will eliminate the need for further treatment at housing. Dosing should not be carried out two or three days before weaning, nor within two weeks after weaning.

When an animal is wormed, it must discharge the dead worms from the lungs by coughing them up, and then swallowing them into the stomach, where they are then digested and passed out in the dung. This process can actually increase the level of stress on the lungs for a short period, especially if there is a heavy worm burden. Therefore, dosing calves during the weaning process will only pile on the pressure.

If you skip the midsummer dose, you will be playing with fire come weaning. At 100kg to 200kg liveweight, it will cost you from 80c to €1.50 per head to worm a calf with an Avermectin pour-on, and approximately 50c/kg head for the injection.

In total, your two worm doses (first in midsummer and a second two or three weeks pre-weaning) will cost you less than €4 per head.

Don’t be penny wise and pound foolish.

Creep grazing to reduce stress and increase performance

The key to reducing stress levels at weaning is trying to weaken the bond between the cow and calf prior to weaning. This can be achieved by allowing the calves to graze ahead of the cows for three or four weeks before weaning. It will also improve the performance of the calves, as they will be offered top-quality grass up to the point of weaning.

There are a number of ways to allow calves to creep graze ahead of cows. Probably the most secure method is to install a creep gate between paddocks. A creep gate is similar in design to the front gate on your creep feeder.

Other farmers simply raise the electric fence and allow calves to move in under the wire. This is satisfactory when calves are small, but it does not work as well for older calves.

If you are planing to insert a creep gate, make sure the vertical bars are adequately spaced to allow calves to pass through easily without getting stuck at the hips. A horizontal bar about 14 inches off the ground will prevent cows from going on their knees and trying to squeeze through.

Some farmers will put a cull cow in the adjacent paddock for a few days in order to encourage the calves to move ahead of the cows. Creep grazing also allows you to target meal feeding, as opposed to feeding ad-lib meals through a creep feeder.

This is very beneficial in the case of heifers, or if calves are being retained on the farm and there is no benefit from ad-lib meal feeding.

Tip: Put a date in the diary

The first step when putting a weaning strategy in place is to establish a weaning date for the various groups of calves on the farm. Farms with a tight calving interval will perhaps have one or two weaning dates, while this may increase to five or six dates on farms with a spread-out calving interval.

Nonetheless, put dates into your diary, as everything from meal feeding to dosing will be dependent on these dates.