What to look for in your replacement heifers

Calving heifers at 24 months of age brings many benefits, but a key to making it a reality on farm is selecting the most appropriate heifer early.

Nationally just 23% of suckler replacements calve between 22 and 26 months. This is despite the numerous benefits that earlier calving can give. Not only does it mean that breeding females have the opportunity to produce more calves over their lifetime, it also means:

• There will be a lower stocking rate on the farm than if older heifers are being carried as replacements.
• By getting your genetically superior heifers to calve down younger, you will increase the rate of genetic improvement in your herd. This can be further improved by breeding replacements from your best heifers and cows.
• If you calve your heifers at an older age, it will cost you €54/heifer/month in a 50-cow herd for the extra unproductive time she spends on the farm until calving.
• Heifers that calve at 24 months can reduce the carbon footprint on your farm by 7% versus calving at 36 months of age.

How can you calve your heifers at two years of age?

If you are breeding your own replacements, your replacement heifers should be identified early. These can be selected based on the following criteria:

• Visual assessment - the heifer should have good feet and legs, which can also be assessed from her dam, if possible. She should have a good frame too, particularly in the pelvic area, but care should be taken that she is not too well muscled either as this can cause difficulties later at calving if she is small.
• Weight for age - the heifer should have gained over 1.1kg/day from birth and have a 200-day weight of over 250kg.
• Eurostar Index - heifers should be genotyped as 4 or 5 star on the Replacement Index, with positive figures for milk and docility, and negative figures for calving interval.
• Family history - the heifer should have a good milky dam that is docile and fertile. The sire should have positive figures for daughter milk and a negative figure for daughter calving interval.

You should also examine your ICBF weaning performance report, which will inform you of the average weight of your cows. This will help to determine what the mature weight of your heifers will be. Based on this information, performance targets should be set as within the table below.

Table 1: Performance targets for heifers calving at 24 months

First winter management

With the winter housing period fast approaching, farmers must ensure heifers are fed well over the first winter. Selected replacements have to gain between 60kg and 80kg over the winter to ensure they meet their weight targets.  The silage on the farm should be tested and they should be given >70% dry matter digestibility (DMD) silage. Their diet should be balanced with ration as appropriate to ensure that there is adequate energy and crude protein for them to gain 0.6 kg/day over the housing period.

The above article was adapted for use on Teagasc Daily from the paper titled: ‘Calving Beef Heifers at 2 Years of Age’, which was published in the Future Beef Programme booklet from Shane Keaveney’s farm walk. The full booklet is available to view here (PDF).

To find out more about the Teagasc Future Beef Programme, click here.