Farmers must be mindful of targets for their yearling heifers, as they will be turned out to grass for the first time this year once the weather improves.

Heifer rearing is the second biggest cost on the majority of dairy farms after feed, accounting for 20% of total costs.

However, farmers who think of heifer rearing as an investment rather than a cost often pay more attention, hitting correct targets, and having better overall success.

Heifers should be in good shape and on target to hit their weights after a great year for grass growth last year, but any stragglers need to be well monitored, especially when considering breeding is only three short months away.

Ideally, heifers should be out for six weeks before the mating start date, which is typically in April or May to meet their target weight.

Higher weight gains are typically achieved from pasture, with heifers gaining up to 1kg/day at early spring pasture.

If the weather stays poor and grass availability is tight, draft out the lighter heifers and turn them out to grass ahead of the main group to try and get the whole group to a uniform size.

Concentrates may still need to be fed alongside the early grass if heifers are far behind target and grass availability is poor.

Heifer rearing

Maiden heifers that achieve their target body weight by the start of the breeding season typically have higher levels of production during at least their first three lactations.

Therefore, farmers should ideally have a weighing scales in the yard to make sure their heifers are achieving their target weights.

It may be worthwhile weighing heifers every couple of months to check their progress, with many farmers weighing heifers now before they go to pasture.

A lot of farmers also weigh mature cows (3rd lactation +) in early summer to have a better idea of the heifer's potential weight when fully matured, and set tailored targets for the 24-month rearing process.

The bodyweight targets for heifers throughout the 24 months by breed/crossbreed, according to Animal Health Ireland (AHI) are as follows:

The mature bodyweights from the breeds above are only a guideline and an average for the particular breed, as there are many Holstein-Friesian herds out there, for instance, with an average herd bodyweight of 650-700kg.

Heifers were born in early February last year should currently be weighing in at 50% of their mature bodyweight.