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Managing Spring Born Heifers at Grass

Managing Spring Born Heifers at Grass
By Jessica Yeomans, Calf & Youngstock Specialist 3 months ago

Our advice on how you get your spring born heifers to grow, and keep growing!

With the spring calving season upon us it is important to think ahead to the imminent grazing season and how to get the calves born this spring (Feb-April) to grow well and efficiently.

Rearing spring-calved heifers to calve at around two years of age from grazed grass is a specific challenge.

In order to achieve a calving at the desired 22-24 months a calf must average 0.8kg-1kg per day DLWG. To achieve this, they must consume at least 3% of their body weight in dry matter a day. Spring calves born to grazing type crossbreds or small, hardy breeds can be turned out when they are between 6-8 weeks old depending on the weather whilst the calves are still on milk. This is important because it avoids excess stress around the time of weaning and give the calves chance to adapt to grazing whilst on milk. Calves should still be receiving concentrates around this time as they aren’t fully eating enough grass and are not able to effectively utilise it yet. They should have access to water and shelter and additional feed should be provided if weather is poor.

Managing the grass-quality and quantity

For calves that are turned out in late March-early April, it is important that they aren’t limited when it comes to access to quality grass and should be priorities when considering the rest of the cows on the grazing platform. Grazing cover should be between 2500-2800 kg/DM/Ha when the calves go onto the paddock in a rotational grazing system. It is also recommended that the calves are not limited behind a wire or pushed too hard to meet residual in the first few months and should be moved at least every other day, therefore set stocking is not recommended. Measure grass covers as they enter and exit paddocks to accurately monitor intakes, alongside starter feed fed. It is also important to know and regularly review the dry matter (DM) content. DM can vary depending on weather and time of year so make sure you know the value of the grass.

Table 1 Heifer growth rates, DMI and energy requirements:

The weaning process should be done very slowly and carefully to minimise stress and any sort of check. The rate of weaning will largely depend on the weather and amount of grass they are eating. To determine how well the calves are transitioning they should be weighed and monitored regularly- changing group and rationing to support poorer calves. Once the calves are weaned, they can then be put into more of a block grazing system and given three days break at a time. By August/ September the calves can then work the residual to 1800kg/ DM/Ha then follow up with in calf heifers.

In order to achieve a calving at the desired 22-24 months a calf must average 0.8kg-1kg per day DLWG

The importance of concentrates

Concentrates should be provided until the calves can eat enough high-quality grass to sustain growth. The calves should be changed from their starter feed (Start N wean) to a rearer feed when the calves are around 12-14 weeks old. Grazed grass generally has a high crude protein content so there is no need to supplement with high protein concentrates. Low protein, high-fibre concentrates are available and have been specifically designed to help compliment a heifer’s diet whilst at grass, such as Heifer Grazer. Calves can be fed on a purely grass diet only if quality of grass and conditions can be guaranteed.

The energy that a heifer requires to achieve target growth rates will depend on liveweight. It is therefore important to determine whether dry matter intakes from grass will be sufficient to supply heifers with the required levels of energy to sustain daily liveweight growth rate. Concentrate feed should be used to balance any predicted shortfall in energy requirements and to maintain optimum growth rates.

Field and health management

In young calves a decent field shelter (good tall hedges) should be provided for them to escape very extreme conditions and continue to monitor growth and adjust feeding as necessary. Short term losses in growth will take a long time to recover from. Fresh clean water is also of upmost importance to encourage DM intake and balance the body systems. To maintain good pasture management, good electric fencing and access routes are vital to stop calves breaking out and disrupting the grazing plan. Do not forget to discuss with your vet or health advisor a suitable vaccination and health programme, also not forgetting to supplement with vitamins and minerals as required.

To conclude

  • Heifers in their first grazing season should be the priority and fed high quality grass in front of the cows
  • Use concentrates when necessary
  • Monitor growth regularly
  • Measure grass quality
  • Ensure adequate vitamins and minerals
  • Don’t forget about a health plan

Jessica Yeomans

Jessica Yeomans

Calf & Youngstock Specialist

m: 07990 584740

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