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Ensuring the health and success of your replacement heifers

Ensuring the health and success of your replacement heifers

Managing pre-breeding replacement heifers in spring after turnout to grass can be a critical component of a successful dairy cattle operation. George Ramsbottom, Teagasc Dairy Specialist, highlights some key considerations and practices to keep in mind.


Replacement heifers need to receive adequate nutrition to reach their target weight and develop their reproductive systems properly. They require a daily allowance of approximately 2.2% of their body weight as dry matter for maintenance and growth. So for example, a heifer weighing 300kg at turnout requires a minimum of 6.6kg DM/head/day. Daily growth rates of 1kg or more from housing to breeding are often achieved if grass allowance is not limiting. If grass is in short supply, prioritise the underweight heifers for early turnout or supplement with a high-energy concentrate.


Regularly monitor the condition and health of your replacement heifers. Check for signs of illness, such as weight loss, lameness, and abnormal behaviour. Keep accurate records of their weight, body condition score, and any treatments or vaccinations they receive.


To achieve the desired calving date, heifers should be bred when they reach a target weight and age. The appropriate pre-breeding target is 60% of their mature live weight. The Maintenance sub-index (SI) is the best guide to mature live weight. So for example, a replacement heifer with a maintenance SI of €10 has a pre-breeding target of 354kg live weight because her mature live weight is estimated to be 590kg.

Health management

It is essential to have a sound health management programme in place for your replacement heifers. This includes an appropriate vaccination programme and a biosecurity plan to minimise the risk of disease transmission.

By following these best practices, you can help ensure the health and success of your replacement heifers, leading to a productive and profitable dairy cattle business.

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