Rearing replacements is vital for future of suckler herds

Rearing replacement heifers is a key component of suckler herd management.

An annual 20% replacement rate is recommended for suckler herds in order to maintain long term herd productivity and output.

Aim to replace cull cows and barren cows with your home bred heifers which should be well developed and robust at mating time next year (weighing at least 370 to 430kg depending on heifer breed), while calving down at a minimum age of two years.

Replacement Plan:

Plan to keep some of your homebred heifers for replacements. These are the heifers that you know the most about compared to going out and buying heifers of unknown background.

Rearing your own replacements will help keep your herd free of diseases such as BVD, Leptospirosis and Johne’s disease, while maintaining the genetic merit of your herd.

NOW is the time to look at your heifer calves and decide which might be suitable for breeding next year. Along with your own knowledge of the herd, pay particular attention to records such as Herd Plus and Eurostar Replacement Index figures, if in BDGP scheme.

Don’t concentrate completely on beef traits, look at mothering ability, milk productivity, temperament and herd longevity.

Milk Supply:

Most of the weight they have put on is because of the amount of milk their mothers supplied throughout the summer. Suckler cows with a good milk supply should now have well grown heifers.

It follows that their daughters should also be reasonable in the milk department. If you have signed up for the ICBF Herd Plus service you can check their mother’s lifetime breeding data especially their calving interval each year.

Keeping nicely shaped heifers out of cows that have been regular breeders and that are good milkers must be better than buying replacement heifers of unknown origin.

Maintain Thrive:

Maintaining thrive in selected weanling heifers and in calf heifers is hugely important if a twenty four month calving target is to be achieved.

The target daily liveweight gain is 0.7 to 0.9kg per head/day. You should aim to achieve optimum weight gains between now and housing. In this regard, maintaining grass supply and sward quality, along with parasite control is vital.

Weanling heifers should have access to creep grazing. This helps break the cow/calf bond and ensures a supply of quality grass. Organise the feeding of concentrates to weanling heifers in open troughs in the creep grazing area, feeding at least 1kg per head/day of a 16% crude protein ration for 6 weeks pre-weaning and for 2 weeks post-weaning.

Continue to feed concentrates depending on grass supply and heifers thrive. All weanling heifers should be treated for parasites, especially stomach worms and hoose.

Consult your vet on the best product to use. Once weaned, young heifers should have no contact with stock bulls or weanling bulls. When housed heifers should continue to thrive and gain weight in order to be robust and well developed, weighing between 370 to 430kg at mating next year.

Data compiled by ICBF has shown that the average age of heifers calving down in the suckler herd is 32.4 months so they are almost three years old. Calving for the first time at three years of age suggests the loss of a year in the productive life of a young female bovine, while resulting in increased costs and fodder demand on farms.

  • Plan to introduce some replacement heifers each year that will calve at the start of calving. These home bred heifers should be bred to an easy-calving bull. With good management and targeted weight gain you can calve your heifers at two years old. Therefore, ensure that thrive and weight gain is maintained in replacement weanling heifers.
  • Don’t forget to select heifers with good temperament it will make life safer and easier in the long run!

Other factors:

Every farm is different. When drawing up a replacement plan, consider factors such as herd size, bull traits, performance and background. Remember, your stock bull is half your herd.

For example A farmer with a good terminal stock bull producing 15-20 weanlings every year might be better off sourcing suitable replacements from a reliable source rather than complicating what he is doing by trying to breed his own.

Equally a farmer using AI or with a larger herd where perhaps he is running two stock bulls might be well advised to have one of the bulls with good replacement traits and they could breed their own.

In an ideal world it would be nice if everyone could breed their own replacements but the reality is that for many people given their stock bulls background it might actually be a bad idea.

By Anthony O’Connor, Teagasc Adviser, Galway/Clare Regional Unit