By Lesley Wylie, beef consultant at SAC Consulting, part of Scotland’s Rural College (SRUC)

With bull sales of all breeds fast approaching, albeit in a different format, now is the time to consider what type of bull you need to take your herd forward and what to look for to achieve that.

One key consideration, after the obvious answer of getting the cows in calf, is improving the efficiency of the herd to help reduce its carbon footprint.

The Scottish Government’s target to reduce carbon emissions by 75% by 2030 and be net zero by 2045 requires agriculture to play its part. As we are all aware suckler beef systems do contribute considerably to the emissions from agriculture. However, there are many changes that can be implemented into our breeding decisions and management strategies that can reduce the carbon footprint of the beef herd.

With 2030 only nine years away we need to start now – the bull you buy this spring will not have calves on the ground until 2022, those calves won’t be slaughtered until 2023/24 and heifers retained for breeding won’t calve down until 2024 at the earliest and the calves from those heifers won’t be slaughtered until 2025/26 so it is imperative that the bull can help you to improve efficiency within your herd and, in turn, reduce emissions.

One of the biggest contributors to carbon emissions from the beef herd is the cow herself (47%) with empty, non-productive cows being the main offenders as they continue to emit methane without contributing to beef production.

By focusing on maternal traits when looking at a bull we can move to counteract some of these fertility problems. We must be careful not to just increase cow numbers as this will increase carbon emissions. What we need to do is to make the existing cows / numbers more productive. The more live calves we can have on the ground the lower the emissions per kg of beef produced and the better the overall profitability of the beef enterprise.

Once you are satisfied that the bull is physically fit for purpose (locomotion, condition, testicles, semen tested, health status etc) you can then move on to looking at his Estimated Breeding values (EBVs).

EBVs worth considering when looking to improve fertility:

• Calving Ease EBV – less assistance required therefore less chance of calf loss at calving and associated problems with getting cows that have had bad calvings back in calf, we must also be mindful that the management of the cows themselves will have a large bearing on whether there are any calving problems.

• Gestation length EBV – shorter gestation length usually results in a smaller calf and fewer calving difficulties

• Age at first calving EBV – Calving heifers younger (two years instead of three years – if applicable to the breeds and system) will reduce the number of non-productive cattle held while also reducing feed and fertiliser requirements

• Scrotal circumference – a larger size is linked to earlier puberty in heifers, allowing the potential for these heifers to calve down at two years of age (which can lead to potential reduction in emissions of 4%)

Come calving time, how easily a cow calves will be down to 75% the management of the cows and 25% down to genetics so although these EBV’s will help, our own management can make a big difference.

In addition to EBV’s, many bulls for sale will have a myostatin status which will show what, if any, myostatin variants are present in the bull. There are certain variants of myostatin which, when present, will increase the risk of difficult calvings and often cause reduced fertility in heifers, delayed puberty and smaller testicles in bulls.

Aside from the cow, the next biggest improvement in emissions can be seen by reducing the age at slaughter (a reduction of around 10%). For this to happen, we need healthy calves that are fast growing but can still lay down the required fat to meet buyer specification.

EBVs worth considering when looking at reducing age to slaughter:

• 200-day growth EBV - the higher this is, the better growth that animal has to weaning

• 400-day growth EBV – the higher this is the better growth to yearling weight

• Fat EBV – look to avoid producing fast-growing animals that are too lean (also linked to milkiness in females)

While there are a few breeds out there working on providing net feed efficiency figures that would allow you to select animals that require less feed to achieve similar growth, it is an area that all breeds should be looking at. With feed costs being around 70% of variable costs of a livestock enterprise, being able to select animals that can be more efficient at converting feed into liveweight will help to reduce feed costs as well as reducing emissions.

As always, EBVs are a tool to be used alongside the eye when selecting a bull. When considering EBVs look at the accuracy as anything below 70% is more likely to change when future data becomes available and so the figures are less robust.

Ensure the health status of the herd you are buying from is at least at the level yours is and, if possible, better. By improving the health of our herds through BVD / Johnes / IBR control and reduction, we can reduce emissions considerably as many of these diseases results in reduced fertility and productivity within the herd.

Bull selection in 2021 will have an impact on where your herd is in terms of its carbon footprint come 2030 and, like it or not, there is more and more focus on this area in terms of government support. On the plus side, many of the improvements that can help to reduce carbon emissions will also improve your bottom line.