Dairy Heifers behind Target on a lot of Farms

By John McCabe, Teagasc – Aurivo Farm Profitability Programme

I have seen many bunches of heifers weighed in the past few weeks and their progress is worrying in many cases. 2023 was a hard year on replacement heifers. July was wet and so was the autumn. 2^nd cut silage was poor in a lot of cases.

I have also seen many bunches of heifers behind target in the years preceding 2023 and my suspicion is that it is not all down to the weather of 2023 - some farms have taken the eye off the ball with rearing replacements.

Some reasons I believe we are seeing more examples of underweight heifers are:

• In some scenarios it is an overall stocking rate/grass supply issue whereby as much ground as possible is closed to fill the pits and the heifers are not allocated enough area yet expected to grow well.
• Calf rearing can go wrong and if it does, weanlings will struggle to reach target weight.
• Labour –having the time to give heifers the attention they need
• Lack of focus on the important and simple things – are we focused enough on the next generation of milking cows?

Milk and Fertility:

It is a well-documented and proven fact that underweight heifers achieve poor fertility results; milk poorly in 1^st and subsequent lactations, and less of them reach their 3^rd lactation.

New Herdplus Facility:
ICBF Herdplus have launched a superb new facility whereby you can enter the weight of the heifers and it will highlight in red, any animals that are behind target based on her potential size as a cow. Not all cows are created equally. One heifer will grow into a bigger cow than another and thus needs to be at a different weight than a heifer that will grow into a smaller cow. See example (figure 1) of a bunch that were weighed last week where 20 out of 22 are deemed to be behind target.

And see example (figure 2) of another bunch that were weighed in January where just 3 out of 25 are deemed to be behind target.

For farms with underweight heifers – be very careful with either synchronisation programmes; sexed semen; or both this season as underweight heifers hit puberty later and have compromised fertility compared to on-target animals.

Scales are available to rent
If you don’t have your own scales - Aurivo Homeland Stores will rent you a weighing scales for €50. There are also technicians that will weigh the animals for you (search “Weighing

ICBF” on the internet and you will find the name and number of someone local to you).