Why late calvers can be an issue

Ideally, all cows should be calved and cycling before the start of the breeding season, however late calvers can be found on nearly every dairy farm.

As the focus on some dairy farms has moved towards preparation for the breeding season that lies ahead, it important to continue to monitor these cows and make a decision about their future.

Late calvers

Late calvers are often over-conditioned, which means they have a much higher tendency to experience calving difficulty, incidences of milk fever, retained placenta and ketosis.

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.

They will have lower milk sales, compared to earlier calving cows, and often have a higher labour input.

All of this increases the workload placed on farms and leads to an extended breeding season.

Late-calving cows are also more likely to have issues at calving time. They have spent a longer period of time dry, eating silage and have a lower energy demand placed on them.

This can lead to these cows becoming over-conditioned, as mentioned above, and having issue such as milk fever at calving.

An over-conditioned cows is four times more likely to develop milk fever.

As most dairy farmers are well aware milk fever is a gateway disease that can lead to other metabolic disorders as well as mastitis.

This will only stunt their milk production further and increase the workload associated with that cow.

Over-conditioned

An over-conditioned cows is a cow with body condition score (BCS) of 3.25 or greater. These cows need to be closely monitored.

It is nearly impossible to change the condition of these cows at this point, but the amount of silage being offered to these cows should be monitored.

It might not be a bad idea to run these cows through the crush to get a good idea of their condition. It can be difficult at time to get a full picture by simply looking at them in the shed.

These cows can then be more closely monitored and preventative measures can be taken in the day leading up to, and after calving.