As we move into autumn it is important to ensure that replacement heifers are achieving their growth targets.
Grass growth will start to slow down soon, and grazing conditions are likely to become more difficult.
Because of this, it is advisable to continue to monitor replacement heifers and continue to check on their growth performance.
To determine whether or not heifers are on target the entire group needs to be weighed.
The weight of each of the heifers needs to be examined; a group average is irrelevant in this situation.
The heifers with the worst weight need to be either monitored more closely, or moved to a smaller group where there is less competition for food.
Farmers should use the maintenance figure to determine what the weights of their replacement heifers should be.
Heifers calves should be at least 33% of their mature cow weight, while in-calf heifers should be at least 75% of their mature cow weight.
If the mature cow weight is 570kg, then the calves should 190kg and the in-calf heifers should be 440kg.
Depending on the quality of the grass the animals that are behind may need to be supplemented
until housing time to maintain or increase growth rates. 1-2kg of concentrates/head/day should be sufficient, but farmers should make sure to prioritize energy rather then protein.
Using a concentrate that contains rolled barley should give the energy that is required.
It might also be worthwhile to look back at why there are a number of heifers that are behind target – if that’s the case.
2023 has been a challenging year and would have been difficult on stock at grass – which may have contributed.
But if most of the group is on, or ahead of target, then there may be another issue – this could include being sick as a calf.
Does where they are grazing need to be reseed? Was there an issue with worms? Is there a high level of pneumonia cases in the shed?
If there is an ongoing issue with animals failing to reach their growth targets farmers need to figure out the cause and come up with a solution.