Continued monitoring of your heifer calves is vital to ensure that growth targets are achieved ahead of breeding next year.
Calving dairy heifers at 24-months-old has been shown to achieve maximum lifetime productivity, and long-term profitability in the milking herd.
A significant reason as to why dairy heifers don’t calve down at 24 months is due to them failing to achieve growth targets throughout their life.
Heifer calves
Ongoing weighting of heifers should have been taking place throughout their first year at grass.
Grazing this year due to weather was a challenge, but the target for these calves is to be 60% of their mature weight at breeding next May.
This means that replacement heifers need to achieve a steady gain of approximately 0.70-0.80 kg/day from birth.
During the year calves that were below target should have drafted out and given preferential treatment (access to higher quality grass and concentrates).
Now that these calves have entered the shed, they should be weighted again and separated into groups relative to the target weight.
These groups can then be fed accordingly to their requirements to achieve the target weight at breeding.
Housing
The target for your heifer calves at housing is to be 40% of their mature body weight, and the weight in kilos should be determined by their maintenance figure.
When these calves leave the shed in February, the target is for them to be 50% of their mature body weight.
Feeding good quality silage to these calves to avoid growth checks and reduce the reliance on concentrate feeding.
Weighing the heifers while housed is also advised, to ensure that they continue to grow and targets are being achieved.
Silage quality
Heifer growth targets can be achieved with high quality silage, but lower quality forage will require concentrate supplementation.
Knowing the quality of the feed being over to your heifers is important to ensure that they do not fall behind.
E.g., heifers being fed a 70% dry matter digestibility (DMD) silage will continue to achieve their targets with supplementation of 0.5 to 1kg/head/day.
For every 5% drop in DMD, an additional 1kg of concentrates will be required for targets to be met.
When concentrates are fed either on top of the silage or in a feed trough, it is essential that all of the animals can eat at the same time to reduce competition.