Block calving Vs. all-year-round calving: what works best?

Block calving Vs. all-year-round calving: what works best?

Decision-making is a major aspect to any dairy farmer’s life. One of these decisions includes whether you choose the Irish-favoured block calving system, where all calving takes place in a specific time period, or the approach most commonly adopted in Britain, of all-year-round calving where of course calving takes place consistently all year round.

Dairy farming in Ireland

The majority of Irish dairy farmers will operate on a seasonal grass-based system where an intensive calving period takes place. This is where calving occurs within a 12-week window in Spring or Autumn. Any cows calving outside of this window are considered surplus and will often be sold elsewhere.

Irish dairy farmer Peter Hynes, who works on a Spring calving basis, offers his opinion:

“We have a relatively mild climate, so there is usually an adequate supply of grass for cows. This gives us an advantage on feed costs. However, it does require labour which farmers need to be rewarded for, through a sustainable milk price.”

He continues to describe the benefits of Irish calving: “...cows can reach peak yield on a grass-based diet. The workload is extreme however compact calving means this is only for a short period. Heifer calves also get to spend the full summer at grass.”

Peter also explains the importance of hygiene. Whilst exemplary hygiene must be displayed whether you choose AYR or block calving – block calvers will see some of their facilities and utensils being used at a faster rate as calving takes place all at once. This means that hygiene checks must occur just as frequently too.

Peter continues: “…if high levels of hygiene with calf utensils & facilities aren't adhered to, disease can break out easily as there are large numbers of calves on the farm.”

Dairy farming in the UK

A reported majority of 80% of dairy farmers in the UK are all-year-round (AYR) calvers. AYR calving generates a continuous flow of milk, allowing British farmers to meet the demands of the market and spread the workload.

Anglesey farmer Trevor Lloyd, an all-year-round calving farmer, told Farmers Weekly:

“The reason we run this system is because land is our limiting factor. In order to scale the business and get it big enough, we have constantly expanded on a high-yielding route to get critical mass within the business. We enjoy working with high-yielding cows – it motivates us to go to another level of efficiency that we otherwise wouldn’t get to.”

Key considerations

AYR calvers can benefit from extra flexibility when it comes to calving. This is because calving is a process that’s spread throughout the year, allowing greater opportunity to make changes to management and infrastructure, without disrupting this intensive period. Block calvers are unlikely to have this opportunity, meaning the majority of decisions that impact calving will have to take place prior to the season.

Both AYR and block calvers must ensure they have the most appropriate land and location for their herd.  However, block calvers must place extra consideration on whether it’s suitable for an intensive calving period which for example may include extra space and sick bay areas.

The same thinking is applied to infrastructure. It must be fit for purpose for block calving. By purpose, we mean facilities that can handle an entire herd calving one after the other, alongside separate medical and maternity areas that adhere to the highest of hygiene standards where calves can be born into. For AYR calvers the cog is always turning, so they benefit from a reduced risk of farm capacity issues.

The correct breed of cow is vital for both AYR and block calving systems. A herd that will offer the utmost productivity and fertility, cannot be compromised on - particularly if you are relying on cows to calve in a chosen season.

However, whilst it may seem that the pressure is really piled on for calving to take place all within one short season it must be noted that herdsman, calf pens and equipment benefit from a longer recovery time post calving to allowing you to be able to make any changes you need to your system without compromising your calf management.

High-quality grass

This grass and silage availability of block-calving is a key factor to consider. If done effectively, the block calving season boasts better-grazed grass and with Ireland’s notoriously wet climate, this presents a major preference for block calving. Farmers will tightly manage the rotations ensuring the fresh grass is readily available to meet the energy demands of the calving cows.

Resource Management

Labour is another major consideration. Block calvers with a herd calving within weeks of each other are extremely busy, so extra resource during this time is most definitely required.

This is less of a concern for AYR calvers as their labour requirements for calving will remain consistent. However, scheduling time off when calving will be less busy is an obvious challenge.

The AHDB discovered that block calving herds who calve 90% of their cows in the first 6 weeks of calving season often outperform those with longer calving periods – but this doesn’t come without great planning and focus.

As reported in the Farmer’s Guardian, block calvers can take advantage of focused seasonal management (a management style where the given season is the primary focus, in this case calving) can have the power to “increase production efficiency”. For some, determination and resilience can be stronger over a fixed period, which can explain the potential increase of production efficiency.

However, this depends on the farmer and the way in which they would prefer to work – it is the decision of the individual. Some may show similar determination and resilience with an AYR system where they have a continuous stream of calving with no break in the regime.


According to AHDB: “Seasonality payments mean typical autumn block calvers achieve slightly higher prices than both AYR and spring block calving systems, regardless of the type of contract.”

Although these gains tend to be relatively small, this provides the opportunity to save funds and benefit from potentially larger profit margins.

AHDB analysis also reveals that “switching away from all-year-round calving (AYR) can typically offer savings of 1-3ppl” but they also highlight the necessity not to take this decision lightly as: “there are significant costs involved with the switching process, including an immediate need for capital and an impact on cash flow”.

For AYR calvers, the mention of savings and higher prices may sound instantly attractive. However, a continuous flow of milk and a flat milk price are enticing prospects for the market’s demand and its subsequent buyers - which may leave seasonal producers as the second choice.


The way you choose to calve will have a tremendous impact on the way in which you operate. If you have a strong availability of grazing, housing, milking, calves, labour, and the determination to calve all in one block – then block calving will be a viable option for you. But if you don’t have the required resource, equipment or desire to calve all in one go, then AYR calving would be the better choice.

Over to you

The conclusion of whether block calving or AYR calving works better should be taken on a farmer by farmer basis. Seasonal peaks; seasonal management; availability of grazing; farm infrastructures; labour; cash flow; and the impact on lifestyle are all significant considerations when deciding what’s best for your farm. As long as you’ve weighed up all potential benefits and downfalls while evaluating what’s possible on your farm, we’re sure you’re doing the right thing.

Published on: 09 June 2020

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