Do you really know the cost of rearing your heifers?

In recent years, the importance of giving your replacement heifers a good start has been brought into focus, with good colostrum management, rapid growth rates and early rumen development all receiving much attention.

Once heifers make it successfully through the weaning period, we often conceive the hardest part is done but these heifers have a long way to go before they make a positive contribution to the economic bottom line.

Heifer rearing is not only the second biggest cost to the enterprise but it also contributes nearly 25 per cent of the carbon footprint of the farm. Your heifers are (in most cases) the highest genetic merit animals in the herd and their ability to express that potential will impact the efficiency of your herd in the future. Therefore, gaining the best understanding of how your heifers are performing can help you improve the efficiency and sustainability of your herd for the future.

So how do we assess heifer performance?

• There are several key performance indicators that are widely used:
• Age at first calving: target 22-24 months;
• Percentage of heifers that reach second lactation: the target for this is 90 per cent;
• Heifer milk yield compared to mature cow yield: target is 80 per cent.

Katie Fitzgerald of Bishopton Vets

Understanding these figures for your farm can help you ascertain where to look to make improvements. For example, if your heifer milk yield is below target you could look at whether heifers are reaching the desired size at calving? Do they have adequate feed access? Is lameness an issue in heifers?

Dr Alex Bach, an expert in calf and heifer rearing encourages farms to look at the following metrics to give a more comprehensive assessment of your rearing process and identify opportunities to improve the overall efficiency of this costly part of your business.

• Rearing efficiency (percentage of heifers born alive that calve at or below the target age) – this metric accounts for losses at any stage as well as growth and fertility performance so is a good overall measure of your rearing process;
• Heifer effectiveness (percentage of heifers born alive that calve at or below the target age and complete three lactations) – this metric helps you understand the longevity of heifers in your herd which underpins the financial and environmental costs of your rearing process.

Heifer economics

Rearing a heifer in the UK costs approximately £2,000. If that heifer produces 8,000 litres in her first lactation, at a feed cost of ten pence per litre (ppl), her overall costs to the end of her first lactation are £2,700. At a milk price of 33ppl, she has generated £2,310 leaving a first lactation debt of £390.

This is carried forward into her second lactation before she begins to become profitable. We know that not every heifer will reach the second lactation and so the ‘debt’ left by heifers that do not reach their second lactation must be ‘paid’ by the remaining heifers before they are truly making a positive contribution to your bottom line.

For example, in a herd with 50 heifers calving each year, but only 80 pre cent reaching second lactation the first lactation ‘debt’ from those ten heifers that leave the herd is nearly £4,000 (ten times the first lactation debt of £390). This must be carried by the remaining 40 heifers at approximately £120 per heifer. This means that each remaining heifer has over £500 or 1,500 litres of milk to produce (at 33ppl) in the second lactation before they become profitable.

Ensuring heifers reach the second lactation is critical to an efficient heifer rearing enterprise. If your herd is not reaching the target of 90 per cent then you can investigate where the losses are occurring. Data on heifer performance and exits should be accessible through your milk recorder. If you don’t know the KPIs for your herd, talk to your vet and begin to monitor your herds’ heifer performance now!