Efficient use of cow body condition can help manage the expensive winter period. Feed costs account for three-quarters of all variable costs in livestock production systems. Of these, a large proportion are racked up by the cow during the winter period.
Therefore, anything we can do to reduce the amount of feed required by the cow during the winter and reduce the overall length of winter feeding for the cow will have a massive impact in reducing annual feed costs, leaving more money in your pocket.
Body condition score
When we body condition score (BCS), we are measuring the cow’s body fat reserves. These fat reserves are an energy store for the cow that she can use in times of under-nutrition and store up in times of surplus nutrition.
It’s measured on a scale from 1-5, with 1 being a completely emaciated cow with zero fat reserves and 5 being a cow that is as fat as can be. While it’s easy to distinguish between a 1 and a 5, typically cows will hover between BCS 2 and 4 throughout the year.
How to BCS
There are three sites where we BCS cows;
Targets for spring-calving cows
The key target for cows is at calving time. Get this right and the rest should fall into place. For a spring-calving cow, we want her in a BCS of 2.5. Here, we’re trying to strike a balance between not having a cow over fat that’s going to cause calving difficulties, versus too thin, which will reduce milk production and not be fit to calve.
Also, no matter what diet the cow is on immediately after calving, some condition will be lost, so if she calves at 2.5, we want her no less than 2.25 at breeding.
At this stage, she should also be on an increasing plane of nutrition and increasing body fat reserves. This will kick-start reproductive activity.
The final target for BCS is now upon us at weaning/housing time. Coming into sheds for winter, you ideally want all cows in a BCS of 3.5. This means the cow has a nice fat reserve that we can utilise over the winter period to reduce feed costs. Remember, we are targeting a BCS of around 2.5 at calving. Utilising this condition needs to be a slow and steady decline, typically over the first half of the winter period.
Often, we BCS at housing time without even knowing we are doing so. We will split cows into thin ones that need a bit more TLC and fatter ones that can afford to lose some condition for the winter.
Ideally, you should have three batches of cows. Thin cows and first calvers, cows that need to be maintained in current BCS, i.e 2.5, and cows that can lose condition prior to calving.
Cows in good condition can have silage restricted by 10kg-12kg/day depending on the BCS over the first 40 to 60 days of winter. This can lead to a saving of between €50 and €85 per cow over the winter period – a significant saving.
By all accounts, cows are coming into the back end of the year in good condition. Avoid the temptation to keep calves on cows for too long this autumn, or to hold cows out on low levels of grass as you will use up these excess reserves before winter even starts.