Winter milk: Managing the transition to spring production

Over the past number of years, ifac has seen several farmer enquiries about making the transition from a Split Calving System to a Spring-only milk production system. We have outlined the main areas for consideration when assessing the change.

1. Calving interval

In the table below, the current calving interval of winter milking split calving herds is 412 days. This is 47 days over the annual cycle, which means there is a lot of slippage of cows within and between the block calving periods. Teagasc currently uses a target of 370 days for a split calving period. In a spring system, the calving interval needs to be 365 days to avoid slippage and loss of cows from the system.

2. Six-week calving rate

This is a measure of how compact the farm is in each calving period. The target figure is 85-90%, and the average for the split calving system is 48%.

3. Days in milk

In a split calving system, if a cow is infertile and does not hit the targets above, it is easy for that cow to be milked through the following period and bred again. The cow will milk through and achieve the 305+ days in milk for the lactation, however, in a spring block calving pattern, if a farm does not hit the fertility targets above, then the days in milk will drop, and so will the average milk yield for the lactation. This figure is available in the milk recording report on the ICBF Herdplus service.

4. Surplus animals

When making the transition to Spring Block calving, the farmer must ensure that there are no surplus replacement heifers of mixed age kept on the farm. It creates an extra difficulty as it increases the overall stocking rate with non- production stock. The farm will also need to decide whether the autumn herd will be rolled over into the spring period. This will help reduce the number of replacement heifers kept in the transition year but will also cause a drop in the overall milk volume as all these cows will be on an extended lactation and will not produce a peak volume in that year.

5. Infrastructure

Farm buildings required will be similar except for calf accommodation. With most calves arriving in February and March, the farmer will need to have space for all their calves. This is important for any disease breakdown in the herd or changes to calf welfare rules and age of movement.

6. Cashflow

Following the transition to spring production, there will be a change in the structure of the milk cheques. While the winter cheques will drop considerably, there will be stronger cashflow throughout the summer period as the milk produced will move to that period. Speak with your accountant or Bank Relationship advisor on the best way to structure the current repayments.

When assessing the potential to move to a Spring-only production system, we must analyse the current KPIs within the milking herd and compare them to the target value within the industry. The farmer must identify whether improvement is needed to the herd fertility before they begin the transition. Critically, the loss of Days in Milk from an infertile herd will have a huge negative impact on overall milk output from the farm and directly impact profitability. A clear plan is required in advance of the transition year to minimise the overall financial risk to the business.

Table 1: Physical Performance of Winter Milk Herds

Source: Teagasc Winter Milk Outlook 2023.

This article was first published in our 2024 Irish Farm Report.