The number of bullocks over the age of 30 months or ‘overage steers’ being slaughtered at Irish factories has fallen by 54% in 2021 compared to corresponding figures for 2011.
As part of a project to assess changes over time in animal slaughter ages and fat scores, researchers Edward O’Riordan, Paul Cormican, Mark McGee and Paul Crosson from Teagasc, examined the national ‘prime’ cattle slaughter data from 2011 to 2021.
The 11-year dataset included 550,000-600,000 steers, 350,000-450,000 heifers and 120,000-180,000 young bull carcasses for each year.
Changes in the breed make-up of the national herd from 2011 to 2021 resulted in the proportion of steer carcasses derived from dairy cows increasing from 52% to 62% over that time period.
The number of beef heifers bred from dairy cows that were slaughtered in this time period rose from 31% to 47%.
The findings of the data when assembled and analysed showed “there is scope to further reduce slaughter age” according to the Teagasc researchers.
Over the past 11 years, age at slaughter has decreased by approximately one week/year for steers. This corresponds to a total of three months in this timeframe (from approximately 29.5 to 26.5 months).
For heifers, it has decreased by 1.25 days/year. However, heifers out of late-maturing sires had the least reduction in slaughter age, with progeny out of late-maturing suckler cows mated to late-maturing sires actually increasing their slaughter age by approximately two weeks.
Age at slaughter for young suckler bulls has decreased from around 19 to 17.5 months, whereas dairy bulls have remained constant at around 20 months.
From 2011 to 2021, steer carcass weight has decreased by, on average, 0.5kg per annum and carcass conformation score decreased by approximately 0.04 units (15-point scale) annually for dairy-bred steers and it increased by nearly an equivalent amount for suckler-bred steers.
In that timeframe, overall heifer carcass weight has shown a gradual increase of 1.25kg annually and the corresponding carcass fat score has increased by 0.036 units. Carcass conformation decreased by a similar amount (on a 15-point scale).
Proportion slaughtered at more than 30-months
Although the total number of steers slaughtered in 2021 was 37% (164,200) higher than in 2011, the proportion of steers slaughtered at over 30 months of age (overage) has decreased by 54% since 2011. Overall there were 63,890 fewer overage steers slaughtered.
It is a similar picture for heifers as the number slaughtered in 2021 was nearly 29% (101,300) higher than in 2011. The proportion slaughtered at over 24 months of age fell from 17% in 2011 to 11% in 2021.
This suggests there were 10,080 fewer heifers slaughtered at over 30 months in 2021 than 2011.
However, this still means approximately 108,000 steers and 49,000 heifers were slaughtered at more than 30-months of age in 2021.
The research concluded by outlining that a large number of prime cattle are currently slaughtered at a fat score greater than the minimum necessary ‘in-spec’ fat score of 2+.
Considering the extra carcass weight associated with increased carcass fatness is relatively small, there is considerable scope to further reduce age at slaughter for many types of animals.