Fertility is one of the leading factors affecting the efficiency of any dairy herd.

It can account for one of the major costs of production and represents an area where significant improvements can be made.

As soon as a heifer calf is born, factors that influence her future fertility and whether she gets in calf on time, every time are controlled by the dairy farmer.

Heifer management greatly determines her growth, health, and age at first calving; her first lactation performance, return to oestrus and subsequent mating and conception success can all be influenced early on.

Monitoring herd performance, identifying areas of improvement, and considering selection options can help build a framework to improve fertility across your herd. Poor dairy herd fertility is recognised as having many consequences, both direct and indirect.

While the first step in reducing unnecessary fertility losses should include an assessment of herd fertility performance, it is important to appreciate that fertility is best appraised as part of the whole farm system.

Brothers Wallace and James Hendrie, who farm at Millands, Ayrshire, identified fertility as one of the key areas they need to improve on with their spring block calving herd.

Wallace explained: “One of our key objectives in joining AHDB’s Strategic Dairy Farm programme was to be able to concentrate on the fertility of our herd as a way of increasing output per cow and reducing costs.

"We want to better understand what we can do to improve our fertility rates and learn as much as we can from the resources that AHDB has to offer. Last year, we calved down 73% in six weeks, for management purposes the herd is split over two grazing blocks.

"The empty rates differed between the two spring groups, with group A of 320 cows at 23% and group B of 285 cows at 15%. We hope to get our empty rate to below 10%, which is quite an ambitious target.”

Following a review of the 2020 fertility performance of the 600 strong herd, the main drivers leading to good fertility were shown to all be under the targets Wallace and James are striving for (see Table 1).

Table 1 key indicators for measuring block calving performance

Table 1 key indicators for measuring block calving performance

At the start of 2021, the biggest question on fertility was what to tackle first and what was going to have the greatest impact on the herd. As part of the Strategic Dairy Farm programme, the Hendrie brothers were bold enough to reveal their 2020 fertility records which have been analysed and scrutinised by Dave Gilbert, from Dairy Insight, Shropshire who specialises in dairy herd fertility.

Millands' vet, Alan Walker, of Armour Vet Group, also agreed a plan to reach set targets agreed for the herd for 2021 spring calving.

Dave said: "Millands' six-week in calf rate has scope for improvement and this is the most important issue for the herds long term performance. Given the current six-week calved rate at 59%, it will require some input to hit a targeted six-week in calf rate of greater than 78% over the next couple of years, but this is achievable."

He also observed after looking at key performance indicators (KPIs) that it was apparent that both submission rate and conception rate were challenges for the herd at present. Table 2 highlighted the findings from Millands and proposed actions working towards improving their fertility.

Table 2, Millands Key performance indicators and action to improve

Table 2, Millands Key performance indicators and action to improve

Following the review of Millands' 2020 fertility performance, Wallace and James highlighted a number of areas themselves that need to be tackled going forward.

Firstly, bull fertility – the bulls used were not tested and this left an obvious dent in in-calf rates across cows and heifers where bulls were used. Wallace investigated the data captured over the previous season, he added that this could be improved to help make decisions during the breeding season and for analysis of performance going forward.

Following metabolic profiles carried out as part of the Dairy Herd Health and Productivity service (DHHPS), run by Alastair Macrae, from the Royal Dick Veterinary School, Edinburgh. Maiden heifer results were very good across all the parameters, the sample of cows tested indicated a lack in ERDP in the diet and suggested that checking for liver fluke is also carried out.

Doreen Anderson, AHDB's senior knowledge exchange manager for dairy, said: “As you can see, fertility can be affected by many factors and getting your ‘team’ all involved and balancing their input to help improve it is key to success.

"There is no overnight fix and fertility is by far one of the trickiest areas to improve but can have one of the biggest financial impacts. It will take time; knowing your current performance, having the ability and people to help identify areas for improvement and keeping your eye on the ball will help you reach the targets you have set yourself.”

Visit the AHDB knowledge library to access a wide range of information and fact based webinars in the section on fertility in dairy cows. There, you will also find a podcast on reducing the calving block and fertility factsheets for AYR and block herds freely available to download.


Both the ‘all year round calving’ and ‘block calving’ Scottish strategic dairy farms are holding online events in April, 2021. To find out more and get involved contact Doreen Anderson doreen.anderson@ahdb.org.uk

Spring block herd, Thursday, April 22, at 7.00pm

Youngstock growth targets and grazing. Join Wallace and James Hendrie, Millands Farm, alongside Joe Patton, Teagasc, for an online question and answer session on heifer growth targets, achieving these targets while grazing and a practical youngstock grazing plan for Millands.

All year-round calving, Wednesday, April 28, 11.30am:

Genomics and their influence on breeding decisions of heifers. Join William Baillie, Hillhead of Covington, Lanarkshire, alongside Marco Winters, from AHDB and David Guthrie, from Genus ABS, for an informative discussion on the use of genomic testing of heifers and how this management tool has influenced breeding decisions on a commercial dairy herd.