While spring block calving makes for efficient and cost effective milk production, what happens when your milk buyer wants a level supply – and pays accordingly?

Operating a split block calving system, with two concentrated periods of calving in the year, is more efficient than the daily drag associated with year round calving, believes consultant Tony Evans of Andersons.

It will fill a level milk profile as well as improve herd performance, he says.

Simply resorting to a year round calving pattern to fill a level profile leads to inefficiency in every department.

“Run as one herd, unequal cow yields in groups lead to longer milking times.

Plus there is always the risk of fresh calvers grazing the same area as stale cows, or having to juggle diets to suit a 50 litre cow in the same group as a 10 litre cow.

“Too many management groups consumes time and there is a wide age range of heifers to rear.

Split block calving is less complicated than year round, though it is a compromise.

It makes more work than the payment benefit and has higher labour, power and machinery demands than normal block calving.

“But when your management is good and the scale is right, you should do better than year round calving.

Herd performance improves and overhead costs fall because you can manage one group of cows rather than a herd of individuals.”

Mr Evans suggests herds with more than 250 cows could reap the benefits of block calving, while avoiding penalties on the milk cheque.

But it isn’t easy, he warns.

“It’s hard to justify unless you’ve got a big mob of cows and the financial side is a minefield.

Milk buyers operate a pricing structure not only requiring a flat profile, but also factor in seasonality so it adds to confusion.

“Producers need to work out for themselves what their farm is best suited to.

For instance, when there is no rain in July or August and consequently no grass growth, management has to look at other more expensive dietary options or cows would be better dry.”

Ideally both calving blocks should be on separate sites to avoid the need for four different groups of cows to be at grass.

However, the aim should still be a 10-week block.

“It’s too easy to let cows slip in fertility, as there is no single focal point for getting them back in-calf resulting in cows moving between groups.”

This is the only slackness in the system for Cheshire producer Robert Wain, who runs two herds of 350 cows near Macclesfield.

One calves from January to April, the other in August to November to fill a liquid milk contract.

“We move cows between the herds when they don’t get back in-calf on time.

There is always a pool of cows in a herd that you hold off serving – you can just see it more clearly in block calving because you put a line in the ground and measure things,” he explains.

Despite this, Mr Wain believes the benefits outweigh any disadvantages.

“I wouldn’t go back to year round calving.

We started block calving four years ago because year round was getting too complicated.

We were having to run at least two different lactation groups, plus dry cows.

“Feeding is now much easier, we can manage each herd as one cow and concentrate on one task at once such as calving or serving.

It focuses the mind.”

The spring herd is run on a grass-based system, whereas the autumn herd is on a winter system which aims for early turnout.

Keeping the autumn herd has helped maintain a level supply now encouraged by his milk buyer, adds Mr Wain.

His advice to other producers is to consider buying in cows to achieve the end result.

“We moved gradually by sorting cows according to when they calved, then stopped serving to fit that block.

“This all takes time and money, so if you want to get the end result quicker, it might be better to sell cows calving in the wrong months and buy in – particularly when you can buy whole herds these days.

It is also critical to front-load the block by calving replacements one week before the main herd.”

fwlivestock@rbi.co.uk