We may not always realise it but our cows are very effective machines that require the right input for the desired output. Like other machines, regular maintenance is important and because we are dealing with live animals and internal organs that all function in a complex and intricate way, there are a lot of aspects we need to manage.
When it comes to input, the feed intake of a cow provides her with the energy to keep her healthy, growing, producing and thriving. If we want her to make the most of the energy she takes in, we need to make sure we limit unnecessary use of this energy. For example, a sick cow will prioritise the available energy for her immune system meaning other functions temporarily go without.
A cow that didn’t get to body condition score (BCS) target at calving, will have less reserves to fall back on after calving. Condition means muscle and fat, which she can mobilise during times of need. Following calving, a cow can’t physically eat enough to meet her requirements. This is for a number of reasons:
- Her rumen and feed capacity needs to almost double from that during pregnancy to peak lactation and this takes time
- Her demands have sky rocketed now that she is:
- lactating
- recovering from calving
- walking
- competing for food
- showing oestrus behaviour (on heat)
Expected loss of BCS post calving is around 1 score. Cows at target can deal with this, however cows under BCS 5 will end up under BCS 4 at mating, which will impact their ability to show heat and conceive. On top of this, some cows will lose more condition between calving and mating, which means they will also end up at BCS under 4, even if they were at target at calving time.
Why does BCS matter?
It has been shown that above mentioned factors leading to low BCS at mating can reduce conception by 10 to 15%. As it is too late now to impact calving BCS, management of the herd should focus on minimising condition lost post calving. Management strategies could include:
- Once a day (OAD) milking for 2 and 3 year olds as well as cows that always struggle to get to BCS target or those that lose condition excessively post calving
- Adding supplement with high ME
- Preferentially feed at risk mob as identified above
Remember BCS is also linked to storage of fat in the ‘fat pad’ at the back of cows’ hooves, which acts as a pressure distributor. With less available fat, pressure from rocks, weight and concrete, will not be distributed across the claw as effectively, leading to an increased chance of lameness. Lameness in turn also has a negative impact on reproduction.
There are plenty of reasons to get your vet in to score your herd and identify those cows that should be part of your at risk mob. This can be done at the same time as metrichecking and will leave you with plenty of time ahead of mating to make some management changes.
