Improving dairy herd repro performance
March 2024

How did scanning go this year?

Every scanning season we get asked how the results have been going so here is the answer. Across our clients there is a wide range in performance. Below is a graph showing the 6 week in calf rate for Vetora Waikato clients for 2023 mating. Each farm’s result (total of 244 farms) is shown as a vertical blue bar from the lowest (37%) to the highest (85%). The average across all farms was 69% (blue horizontal line). The industry target is 78% (green horizontal line).


The range in empty rates is even more variable and depends on mating length. The take home message is that for the majority of our herds there is huge potential for improving the 6 week in calf rate and empty rate.

How to improve your herd repro results

There are many ingredients that go into making a good repro cake in your herd, from BCS to genetics to how young stock are grown out. Some ingredients will be more important for your herd than others. To get an idea on where to start, work through your fertility focus report with your vet. This report gives a great overview of which ingredients are already working and which ones can be improved.

Once you have identified what you want to work on you can choose how you want to work on it. Just because you are getting advice from a vet doesn’t mean you’ll be doing more metrichecking and CIDRs. The main thing to remember is that improving repro is a long-term game and it will take more than one season to get real results. 

A case study

The case farm is spring-calving and milks around 700 cows. The graph shows the in calf rate by week of mating for the last 3 mating’s compared to the industry target. The 2021 results were 69% 6 week in calf rate and 23% empty (77% in calf) after 9 weeks. Before mating 2022 the herd was fitted with collars but mating performance got worse. The collar data was used to identify the issues and a plan was made for 2023 mating specific to the case farm. The result was a 12% increase in 6 week in calf rate and 12% drop in empty rate (although mating was 1 week longer).

Using the industry figures of $4 per % improvement of 6 week in calf rate and $10 per % improvement in empty rate multiplied by herd size, the value of the improvement was worth around $115,000.

The next step for this farm is to review the 2023 collar data and make a plan to get another step closer to the herd’s potential.