Calving heifers at 24 months: What’s the big deal?

Calving heifers at 24 months has raised some concerns among farmers in the past. There are many factors which deter farmers away from breeding heifers at the age of 15 months.

Currently, 24% of suckler heifers in Ireland calve down at 22-26 months. This has recently increased from 16%, but this is still very low in the grand scheme of things.

It must be noted that farmers who calve heifers at 24 months operate more profitable farms. Teagasc research indicates that for a 50-cow herd – with a 20% replacement rate – each additional month that calving is delayed costs €490 or €50/heifer/month.

Speaking at the recent BEEF 2018 event – in the live demonstration village – Teagasc’s Alan Nolan outlined that there are two main reasons for the low uptake. These are:

  1. A perception among farmers that the heifer will be stunted and that these heifers will struggle to go back in calf;
  2. Target weights are not being achieved and farmers are not in a position to bull these heifers at 15 months due to undesirable weights.

The Mayo-based advisor said: “Breeding efficiency is reduced if heifers are not calved at two years. When farmers calve a heifer at two years, they will not get as good of a calf as a mature cow would produce; but they will still get that extra calf into the system – output is increased.”

Alan continued by outlining that reaching performance indicators – such as average daily gain (ADG) targets – are extremely important. Weighing heifers on regular occasions is also an essential component of the management process.

“The weight gain of the heifer is very important; farmers that are weighing their animals are at an advantage because they know exactly where they are at,” he said.

A poor performance over the first winter will hamper any chance of the animal meeting weight targets at breeding (15 months).

Alan noted that it is during this period where a lot heifers fall. On this, he said: “Our heifer weanlings go into the shed and – more often than not – they are offered average-quality silage and they don’t perform.”

Heifers need to achieve 0.6kg/day over the first winter. Feeding concentrates over this period will depend on silage quality and Alan stressed that silage with a dry matter digestibility (DMD) of 70-72% – along with 2kg of concentrates – should be sufficient to ensure good growth rates.

When it comes to turnout, Alan highlighted that heifers should be put out to good-quality pasture. If this is achieved, the heifer will reach a target of 1kg/day up to the time of bulling.

Insemination weights

The weight of the heifer when she is served depends on the mature weight of that animal. Therefore, a heifer should be 60% of her mature weight at bulling; it could be 400kg for one heifer and 425kg for another, Alan explained.

Touching on sires used, he said: “A lot of thought has to go into the sire that is selected.

“There are plenty of bulls out there that have easy-calving traits. Farmers should look for sires with 4% or less for calving difficulty and have 80-90% reliability,” he concluded.