Late calving cows are one of the biggest drains on the profitability of suckler beef production. Suckler farmers operating a spring calving herd must plan their breeding season to ensure that calving remains compact and in line with grass growth.

Failure to adopt a strict breeding plan means that calving, in many spring herds, runs well into the summer. It is these later calving cows that are draining profit from the herd.

To maximise output, control production costs and reduce labour, the calving spread should run to no more than 12 weeks. Therefore, if the first cow calves in February then calving should be completed by the end of April.

Farmers operating on heavy ground may delay calving until mid-February due to the later turnout date.

On these farms it is even more important to keep the calving spread tight, otherwise calving will run into late May or early June. Typically the aim should be to

have around 50% of the herd calved down before target turnout date.

Differential between February and April born calves

The Average Daily Gain (ADG) for the April born calf is 0.3Kg lower than for the early born calf.

The reason for the massive difference in liveweight is because the April born calf fails to cash in on grass. A February born calf that is turned out to grass along with its mother in March, at two to four weeks old, literally hits the ground running. It is strong enough to make full use of all the milk produced by the cow that has access to

top quality grass from March through to August.

In late August when grass quality and milk yield starts to decline the calf is not as dependant on its mother.

Performance levels can be maintained either by introducing creep feed through until weaning or by allowing the calves to graze ahead of the cows until weaning. At weaning in mid-October the February born calf is 405kg.

Therefore to try and increase output, weaning is delayed until mid November. With grass quality poor and the cow almost dry, meal feeding is increased to 2kg per day to maintain performance levels. Overall the late born calf will consume around 100kg of meal compared to the early born calf consuming 40kg.

Meal costs at €250/t for the late born calf are €25 compared to €20/t for the late born calf.

An additional €10 charge has been attributed to the February born calf to cover two weeks meal feeding and additional bedding charges while indoors.

In general the cost of running a spring calving cow is the same irrespective of whether she calves down in February or April.

In fact on dry farms it could be argued that the costs associated with the February calving cows are lower as then can be turned out to grass earlier.

Overall the difference in output value between the two cows is in the region of €215.

In a spring calving herd there is always going to be a percentage of the herd calving down in April.

On an exceptionally dry farm it will still be difficult to get freshly calved cows out to grass before mid-February.

Therefore, even assuming a relatively tight calving spread of 12 weeks, there will still be 8% to 10% of the herd calving down in early April.

It is important not to pull the start of the calving date back too early unless you have excellent housing facilities. Calving too early and having calves housed for five to six weeks before turnout can increase feeding costs and disease risk.

Ideally spring born calves should be turned out to grass within four weeks of age. Therefore, if in a typical year you get to grass in early March, calving should commence in early February. The critical factor is when you finish calving.

While heavy farms will have to delay calving in line with turnout date it is critical that they keep the calving spread tight to ensure that the bulk of the herd calve down before mid-April. Early grazing farms that can start calving in mid-January can get away with running a 12 week calving spread, e.g finishing up in mid-April.

However, farmers operating on heavy ground do not have the same luxury. These farms really need to be on top of their game to try and limit the calving spread to a maximum of ten weeks.

Otherwise 20% to 25% of the herd will be calving down in May and June and herd output will take a hammering.

Heavy farms are also hit at the other end of the cycle in that they do not have the luxury of holding calves out later into the autumn in a bid to try and improve weaning/housing weights.