Achieving lifetime live weight gain targets for beef cattle, while maintaining a predominantly grass-based diet, is a key factor determining the profitability of beef farms.

Meeting these targets will also facilitate a reduction in the average finishing age of the Irish prime beef cattle population (i.e. steers, heifers and young bulls) which has been identified as one of the most effective greenhouse gas (GHG) mitigation strategies for the Irish agricultural sector.

Research conducted by Teagasc, now embodied in the national Climate Action Plan, has shown that reducing the average finishing age from 26 months to 22-23 months by 2030 will reduce Irish agricultural emissions by an estimated 0.73 million tonnes (Mt) of carbon dioxide (CO2) equivalents (eq), accounting for near 15% of the sector’s 2030 GHG reduction target. GHG emissions reductions associated with lowering the finishing age of beef cattle are largely due to a reduction in methane emitted over the animals’ lifetime, predominantly those produced when cattle digest feed.

Live weight gain performance

In recent years there has been an increase in the lifetime live weight gain performance of the national beef herd and consequently average finishing age in 2024 was some 45 days earlier than in 2010.

Over this time period, the greatest reduction in finishing age was observed in steers with an average reduction of 6.2 days per year. For young bulls and heifers, the annual reduction has been less, with an average reduction of 1.4 and 1.1 days per year, respectively.

While difficult to say exactly, differences in the annual reduction to finishing age between steers and heifers/bulls, may in part be as a result of the current upper limits on carcase weight and finishing age required to achieve the highest beef price which has a greater impact on steers than heifers/bulls.

The improvement in live weight performance and consequent reduction in finishing since 2010 demonstrates longer-term progress in the Irish cattle sector.

However, changes since 2018 (see Figure 1 and Table 1) must also be considered since this is the base year for climate legislation in Ireland and so the year against which climate targets are measured.

In 2018, 1.27 million prime beef cattle were finished with an average age and carcase weight of 26 months and 338 kg, respectively. In 2022, the average finishing age had reduced to 25.6 months of age.

However, since then there have been consecutive yearly increases in finishing age from 26.1 to 26.5 months in 2023 and 2024. In addition to the increase in finishing age, as can be seen in Table 1, there has been a reduction in the carcase weight produced for most categories.

Challenging weather conditions in 2023 likely explained the poorer animal performance across all types of cattle in 2023.

These impacts will also have carried over into the 2024 finishing ages. Moreover, the inclement weather conditions continued into spring 2024 further compounding the impact on finishing age.

An additional factor contributing to the increase in average finishing age is the reduction in the number of male cattle being finished as young bulls.

In 2024, the average young bull was finished approximately 258 days earlier than steers, whilst producing a 20kg heavier carcase.

Therefore, as the percentage of male cattle being finished as young bulls decreases, a corresponding increase in the national finishing age occurs.

For example, if the same proportion of the prime beef cattle population was finished as young bulls in 2024 (8%), as in 2018 (14.6%), last year’s national average finishing age would have been 16 days younger at 25.9 months.

It is interesting to note the change in the source of beef cattle since 2018. In that year the proportion of the national prime beef kill originating from the suckler herd was 49% and this had decreased to 41% in 2024.

Over the same period, the usage of beef genetics in the dairy herd has increased from 60% to 68% as the period of dairy herd expansion stabilised and the use of sexed semen increased.

The average late-maturing (predominantly continental breeds) sired suckler steer was finished approximately 53 days older, but produced a 51 kg heavier carcase, in comparison to early-maturing (predominantly British breeds) sired steers.

Similar trends for finishing age and carcase weights were observed for dairy-beef animals, with the average late-maturing sired steer being finished approximately 32 days older, but producing a 25 kg heavier carcase then early-maturing sired steers.

There is a difference in breed preference between suckler and dairy-bred cattle, with late-maturing breeds accounting for 81% of suckler steers and 22% of dairy-beef steers.

While year-to-year variation in finishing age is inevitable, understanding the key on-farm factors impacting the growth performance of the national prime beef cattle population, will help develop practical and targeted measures capable improving the lifetime live weight gain performance of beef cattle.

Beef-Quest Project

Through the Teagasc lead Beef-Quest Project, funded by the Department of Agriculture, Food and the Marine, research is underway to identify the predominant animal nutrition, health and on-farm environmental related factors currently constraining animal growth performance and the subsequent finishing age of cattle on commercial beef farms.

In collaboration with ICBF and UCD, the Beef-Quest project is undertaking a multifaceted approach to identify the key factors impeding lifetime live weight performance on commercial beef farms across a variety of different systems, and assess the barriers to technology adoption on farm.

One of the key elements of the Beef-Quest Project, is a new large-scale on-farm study which commenced in late 2024, and is focused on determining the key animal nutrition, health and on-farm environmental related factors presently constraining growth performance, and subsequently contributing to the older finishing age of cattle on Irish farms.

Data assembled from the on-farm study, as well as other tasks within the project, will be utilised to determine both the environmental and economic benefits associated with the optimisation of animal nutrition, health and on-farm environment, and subsequently aid the identification of the most effective on-farm measures for improving daily live weight gain and ultimately reducing the finishing age of Irish beef cattle.