By Teagasc Green Acres Calf to Beef Programme advisor Seán Cummins
Drafting fit cattle for slaughter is a key management component of successful calf-to-beef systems. At a fat score of 3+, the carcass weight potential of Holstein Friesian steers is maximised.
Once cattle reach the desired fat score, their efficiency in terms of average daily gain diminishes significantly.
Any decision on holding cattle for longer must be made on the basis of the animal’s performance, the costs associated with keeping the animal and the potential increased return achievable from the market.
Another area that warrants consideration is the age of the animals.
Where animals are fit and there’s the potential of surpassing the 30-month mark at slaughter, any increase in price or carcass weight may be wiped out through a reduced quality assurance payment and/or additional feed costs.
Finishing cattle off grass
Peter and Thomas O’Hanrahan – participants in the Teagasc Green Acres Calf to Beef Programme – began slaughtering their 28-30 month steers off grass in mid-June.
A total of 51 Holstein Friesian steers were slaughtered during the summer months without any concentrate supplementation.
An average carcass weight of 326kg was achieved, alongside a fat score of just under 3+ was recorded. Meanwhile, the conformation was intermediate with grades of P+ and O- achieved across the group.
The table below highlights the performance of four steers slaughtered off the farm during the summer months.
Individual slaughter performance
In order to illustrate the story of this slaughter performance, images and weights were taken immediately before animals were transported for slaughter – with carcass images being taken in the slaughter plant also.
Born on February 1, 2018, one steer (with tag no. ending 10072) weighed 611.5kg prior to slaughter and produced a 293kg carcass.
Typical of some plainer-type Holstein Friesian steers, this animal was a little light for fat on the rib and loin, while the steer’s tail head was sufficiently covered, which resulted in a fat score of 3-.
This steer produced a P+ grading carcass, as a result of being very narrow along the shoulder and being concave in his hind quarter.
Standing at 700kg prior to transport, another steer (with tag no. ending 41106) produced a 362kg carcass weight (51.7% kill out) and was above target in terms of the Teagasc beef production guidelines for a 28-30-month-old Holstein Friesian steer.
This steer produced a carcass of 3+ for fat – which is the optimum level for carcass weight performance.
A good handful of fat was present over the tail head, while the loin, rib and shoulder were all soft to the touch – an excellent indication that the animal was sufficiently covered for slaughter.
Although still narrow on the shoulder, this had sufficient carcass depth to produce an O-grade carcass at slaughter.
Focusing on carcass conformation first, a different steer (with tag no. ending 60798) was one of the worst animals produced on farm this summer. The steer below produced a P= grading carcass of 326kg (50.5% kill out).
The relative width of the carcass (both across the shoulder and hips) was a major contributing factor to his poor carcass grade. Unlike some other Holstein-influenced animals, the steer was also lacking height, which resulted in a narrow and shallow carcass upon slaughter.
In terms of fat score, this steer was well finished at 4-. The steer’s rib, loin, shoulder and tail were all ‘warm’ and a good ‘soft’ layer of fat could be felt along these key points prior to slaughter.
Although weighing 700kg prior to slaughter, the steer with tag no. ending 70078 was another animal which produced a P+ grading carcass.
Again, like the previous steer (with tag no. ending 60798), this bullock was lacking carcass width and was narrow across both the hips and the shoulder. The width between both the front and hind legs is a good indicator of an animal’s ability to carry meat and, as can be seen from the images below, this steer was very narrow set.
Despite being of P-grade, this steer still produced a heavy carcass weight of 356kg – at a fat score of 3+. A good degree of fatness was evident along the loin and ribs, while the tail head was sufficiently covered.
Bridging the gap on lost performance
Although the O’Hanrahans’ steers graded sufficiently for fat, the group average – in terms of carcass weight – is running approximately 20-30kg/head behind target.
To correct this, we first must understand where the kilograms of liveweight are being lost from the system.
The O’Hanrahan’s farm is very dry, and in most years, it facilitates the early turnout of cattle. As yearlings, these animals were turned out on February 11, 2019; they did not see a shed again until November 6, 2019.
Over this period, the Holstein Friesian steers gained 207kg or 0.77kg/day – an underperformance of 0.13kg/day (34.84kg) over the grazing season. This reduced level of gain represents a potential carcass weight loss of 17.42kg at slaughter.
To resolve this issue, a more aggressive approach to grassland management has been taken this grazing season. Previously, there was a tendency to force cattle to graze too heavy of covers and this had a knock-on effect on animal performance.
Now, instead of being asked to graze heavier covers, surplus bales are being taken from the grazing platform in order to maintain pre-grazing yields at optimal levels.
All-in-all, given the length of time in which these animals were housed, approximately 48kg of liveweight gain was lost over the winter months. In carcass terms, this equates to a loss in performance of 24kg.
By making simple changes to the system, there’s potential to improve the quantity of beef sold at farm level.
If grassland performance can be maximised and animals can gain these desired weight gains over the final winter – the O’Hanrahans will be in a strong position to maximise the carcass weights achieved from a 28-30 month-old Holstein Friesian steer system going forward.