Calving heifers at two years is vital for the profitability of the suckler herd, but according to Teagasc there are a number of factors that must be considered to make this enterprise successful.

These include applying a replacement strategy and meeting growth targets for these heifers while also considering the genetic potential of your suckler herd.

Fertility and performance

The fertility of the national suckler herd has become a worrying trend in recent years, according to Teagasc.

It says that the calving interval has increased over the last number of years while the fertility performance which is defined as calves/cow/year has reduced.

These two factors are key to the profitability of the suckler herd and farmers breeding their own replacements must aim to produce as many good quality calves as possible.

Key facts on the national suckler herd
  • Replacement rate in the national herd is 14%.
  • 60% of replacements are homebred
  • 40% of replacement heifers are bought-in
  • 75% of replacement heifers are three-quarter bred
  • The remaining 25% are first crosses from the dairy herd

Replacement strategy 

According to Teagasc, the long-term success of the suckler system will depend on the regular replacement of breeding stock but this can be affected by the average herd size.

Too small of a herd size can make breeding replacement heifers from within the herd complicated as more groups of animals may be required on farm.

The existing cows on the farm should also be examined, especially for milk and fertility traits, it says.

Teagasc also says that rearing replacements from within herd will allow the farm to focus on maintaining or even improving the milking ability of replacement heifers.

But to achieve this, they should breed by using the ICBF replacement index to select both AI straws and stock bulls while also only selecting heifers from the best-producing cows in the herd.

The use of hybrid vigour may also benefit suckler farmers, it says, as this will give better weanling weights as hybrid vigour can give a 22% increase in weaning weight.

Another major benefit of keeping a closed herd is that the existing stock on the farm are much less exposed to disease risks such as BVD and Leptospirosis.

Weight gain targets

Farmers breeding their own replacement heifers should aim to have these animals at 60% of their mature weight at breeding and 80% at first calving.

According to Teagasc, cows don’t reach their mature weight until they are five years old, so heifers which calve at two will be lighter as first and second calvers and will require preferential treatment.

To achieve these targets at breeding and calving, these heifers should have an average daily weight can of 1.1-1.3/kg/day up to weaning.

Home bred replacements should also grow by approximately 60-80kg over the first winter period and this can be achieved on good quality silage and 1-2kg of concentrates per day.

Breeding Replacement Heifers

Teagasc research indicates that heifers are the most fertile group of animals on farm and so should be bred for an eight-week period which allows each heifer to be served twice.

Heifers which are not in-calf after this period are less fertile and may become problem breeders in the future, it says.

These heifers should be calved down in fit condition but not fat. Once calved, they require preferential treatment, particularly if they are to remain indoors for a period.