26 August 2024

Are your replacement heifers on track?

Achieving weight for age targets in heifer calves is important for future productivity of the herd.

When visiting farms, we see huge ranges in growth performance of heifer calves throughout the rearing period. Throughout the first summer, variations from 12kg to 30kg gain per month are common. This in turn results in heifers often being underweight (and sometimes overweight) at breeding.

Research has found that both under and overweight heifers have disadvantages in terms of fertility and milk production.

The most important management practice for heifer rearing is regular weighing. It is the gold standard for assessing decisions to date and planning for the months ahead. It allows you to identify any individual animals that need extra attention.

Table 1 below shows the targets for mid to late August weights based on mature weight (and breeding index for maintenance). How do your calves measure up to target? Calculate the group average and the number behind target. Discuss results and possible actions with your advisor and discussion group. It is a couple of hours well spent at this time of year.

Table 1: Weight targets for February-born dairy heifer calves in August

This article was adapted for use on Teagasc Daily from the August Teagasc Dairy Advisory Newsletter, edited by Dr Joe Patton, Head of Dairy Knowledge Transfer at Teagasc. Access the full publication here.