As we switch our attention to the breeding season, we need to ask ourselves: is it financially viable keeping late calvers?

Should we hold onto them even though they may not have calved before the start of the breeding season? Or should we sell them now and focus on avoiding them in the herd next year?

Late calvers

The whole idea of a grass-based milk production system is about matching your herd’s calving date and pattern to the grass-growth curve. As such, your herd’s energy demand will match your feed supply.

If a cow is calving in May, or even April, her energy requirements are not matching the grass-growth curve, so in most cases she will require additional and more expensive feeding.

Not only that, late-calving cows come with a whole list of problems.

Higher feed costs

Each day that the late-calving cow is waiting in the shed to calve she is costing you money. A cow calving in May will eat twice the amount of silage than a cow calving in February.

A late calver also often tends to be overfat by calving. Overfat cows have a much higher tendency to experience calving difficulty and incidences of milk fever, retained placenta and ketosis.

Additionally, a cow calving in May will reach her peak lactation yield in mid-to-late June when the grass plant is entering the reproductive stage and so grass quality is reduced. This will have a knock-on effect on her milk production potential.

Poor fertility

Late-calving cows are also much slower at regaining oestrus and have less than a 50% chance of conceiving in the first six weeks of the breeding season. And so, they have a greater chance of being late again the following year.

Furthermore, studies have shown that they are more likely not to conceive at all and be scanned as empty at the end of the breeding season.

Not to forget, if you begin breeding and you still have cows left to calve this will reflect poorly on your farm’s three-week submission rate.

Lower milk sales

It is no secret that if a cow is calving late she will have overall less days in milk. Therefore contributing to a lot less milk sales than a cow calving 80 days before her.

Additionally, after a cow reaches her peak lactation yield, her milk production will naturally decrease. If a cow calves in May, she will reach her peak lactation yield later than the rest of the herd.

This will mean that her milk production curve will be different compared to the rest of the herd and she will be producing a higher volume of milk by the drying-off period.

So in a lot of cases, she will be dried off before her time or she will be milked on the basis of producing expensive milk off silage and meal.

Extra Labour

Late-calvers bring additional labour requirements at a time when the need for labour should be reduced.

This added workload typically involves feeding these cows silage, when they should be calved and out at grass. Plus, spending time feeding the late-born calves while indoors in the months of May and June , while the earlier born calves are reared and out at grass.

Late-born calves also often struggle or fail to reach target weights. They also generally require a lot more attention and meal so that they can catch up with comrades.