Native breeding improving cow fertility

Output per livestock unit farmed is one of the most important factors associated with profitable suckler enterprises.

Cows must be fertile and functional to produce offspring, but how do we measure fertility?

Calving index is a good indicator, but has its limitations, as it only measures the cows that calve down in that specific year.

Achieving a calving index of 365 days by culling 20% of the herd because they were barren at scanning could not be described as good fertility.

By gathering as much data as possible from farms and using a number of measures, we gain a true reflection of performance.

A Nuffield scholarship report, compiled in 2016, looked at whether “benchmarking targets for suckler herds are achievable”.

The outcome of the report was that some targets are too ambitious for the industry.

This week, we analyse the scanning percentage and live calves produced from cows for 2018-2019.

Scanning percentage

A high scanning percentage reflects good cow fertility. A key industry target is to have 95% of cows put to the bull scanned in-calf.

As Table 1 shows, in 2018 the group achieved 91.22% of cows bred scanning in-calf. It must be noted that this is also within a timescale.

The programme farms had scanning carried out by mid-September and this is therefore a reflection of a 12 to 14-week breeding window.

Declan Rafferty and Aidan Quinn achieved 100% scanning. While this is an exceptional result, it is in reality, and by their own admission, a one-off event.

Oliver McKenna and Ryan McDowell also had excellent scanning results. Interestingly, all of the top-three farms have incorporated native breeding into their cow type which, as found by the Nuffield report, seems to increase levels of fertility.

It is also notable that two of these farms have been in the programme for six years and have reached target cow numbers.

They can, therefore, cull much more stringently than some of the other programme farms that are still building cow numbers.

Paul Jamison had a scanning percentage of 78.75% due to an infertile bull, which eventually had to be put down

It also reflects the hard work of a planned breeding programme to produce fertile, functional cows by criss-crossing between native and continental breeding. The calving patterns were also three weeks shorter on the top-three farms compared with the bottom three. Ultimately, a tighter calving pattern allows cows more time to get back in-calf when working within a defined breeding programme.

Paul Jamison had a scanning percentage of 78.75% due to an infertile bull, which eventually had to be put down.

It is important to note that even when best practice is followed, nature can still take its own path and this can happen on any farm using a stock bull.

Close observation of repeat breeding activity meant Paul was able to intervene quickly, but there was still a large percentage of cows scanned empty.

Based on scanning results, he was able to cull hard at that stage and replace these cows by purchasing in-calf heifers for minimal cost.

Live calves from expected in-calf cows

The farmers in the group have been seen to take pro-active decisions based on scanning. Oliver McKenna sells cows scanned in-calf to add value to cull animals. Others will cull cows and replace with purchased in-calf heifers.

This means the overall figure of live calves born from cows bred is very misleading. For example, Ryan McDowell’s figure for live calves from females bred is 68%. However, this is not a true reflection of herd performance, as Ryan has established a high-value market to sell in-calf heifers after scanning. Therefore, it is better to base it on the number of expectant dams after these changes, and compare live calves back to this figure.

Again, the target for this area is often quoted as 95%. In 2019, the group achieved an average 93.2%, with a range of 87.78-100%.

Declan Rafferty and Aidan Quinn again achieved 100%, but does this mean they had no losses?

Across all farms, 2.47% of cows scanned in-calf failed to calve

Put simply, the answer is no. One cow failed to calve and there were losses, as with any herd. However, five sets of twins allowed fostering of calves. There is a large Simmental influence on this farm, a breed associated with higher numbers of twins.

Calves purchased to foster onto a cow have been excluded from the figures for all of the farms.

Across all farms, 2.47% of cows scanned in-calf failed to calve. This will be down to misjudgment at scanning, re-absorption of embryos, aborted calves and cow mortality.

Typically, embryonic loss is between 1% and 2% in any herd. From the cows that calved, calf mortality was very small on the farms.

Summary and messages

It would appear that while industry targets are difficult to achieve, it is not impossible at individual farm level.

A target is something which people should aim to achieve in order to improve performance. If a group of farmers continually hit the target, year in, year out, is it really a target or just an industry standard?