Co-ordinated block calving systems are on the rise across Great Britain, according to the Agriculture and Horticulture Development Board (AHDB).
The AHDB made the announcement following its analysis of British Cattle Movement Service (BCMS) data highlighting a rise to 19.6% of farms operating block calving systems for the year 2024, up 3.1% since 2021.
Autumn calving saw the largest rise to 7.1% of total farms, a 1.8% increase from 2021.
All year-round systems (AYR) remained remained at a steady 35% rate of farms
Dairy farms calving down more than 500 cows a year still tend to run ‘non-defined’ or AYR calving systems compared to farms below 500 births a year.
Block calving systems
Block calving is a system where a herd calves over certain period, (block of time). This can be one block, where all cows calve in a defined 12-week period, or a split-block, where cows calve in two distinct 12-week periods each year, usually spring and autumn.
What are the benefits?
In terms of labour efficiency, planning and managing labour resources on a block calving herd can often be easier, due to having a set period of calving, breeding, and a dry period.
Production costs can be reduced in these systems, especially when all cows are on the same nutritional plan. For example, a spring calving herd usually has a much reduced cost of production, as cows are producing a larger percentage of milk from grazed grass.
What are the implications?
With all cows calving during a 12-week period, infrastructure can come under pressure. Calving pens and calf houses will need to be able to accommodate this larger volume. This system also often leads to a higher risk factor for disease pressure due to high numbers at once.
When calving in a condensed period, the block will be a very busy time. It is often advised to hire extra labour to overcome calf rearing and night-calving.
In addition, when transitioning from AYR to block calving, a proportion of the herd will be left non-productive for a period in order to sync with spring/autumn calvers. This will affect cashflow and create pressure during the change-over.
