Like many of the programme farms, the Thrive demonstration farm aims to slaughter cattle off grass at the end of the grazing season. This sees cattle slaughtered at an average age of between 19 and 21 months.
Why slaughter off grass?
The reason for choosing this system is that in order for it to make financial sense, cattle need to be gone prior to a second winter period. Over 75% of all variable costs in livestock production systems are associated with feed costs. Most of these costs are racked up while indoors during the winter period.
All farmers know grazed grass is the cheapest, most cost-effective feed we have available to use and therefore maximising its contribution to the overall diet is a must if dairy-beef systems are to return a viable margin for producers.
In recent years we have seen budgets from both the Irish Farmers Journal and Teagasc for winter finishing systems needing a beef price of up to €4.50/kg to leave a positive margin. The number of years where this beef price was realised in spring have been few and far between.
Therefore, the programme feels that finishing off grass alongside some concentrate supplementation is the way forward for dairy-beef systems.
While it may result in a lighter carcase, the cost of producing this animal is also greatly reduced. Farmers need to focus less on the size of the cheque received for the slaughtered animal and more on the margin over the cost to get to the point of slaughter.
300kg at 19 months
A 300kg carcase from an animal that is less than 600 days old is no mean feat. There is no room for a store period or a period of underproduction in this system. Figure 1 outlines the target weights for bullocks and heifers at each point in the process.
Falling behind in any one of these periods can have a detrimental effect on either the carcase weight achieved or the date of slaughter – both of which will add to costs and erode profits.
The most common area where cattle fall behind target is during the first winter period. Where cattle need to be growing at between 0.7kg and 0.8kg/day, often they are doing less than 0.5kg/day on farm.
This comes down to the quality of the silage being fed not being good enough and/or incorrect levels of concentrate supplementation in order to make up for poorer silage quality.
Animal type and genetics
In 2020, across the 140 bullocks and heifers slaughtered off the Thrive demonstration farm, the heifers achieved an average carcase weight of 280kg at 19.7 months of age while the bullocks averaged 324kg at 20.3 months of age.
Sex, breed and the animals’ genetic potential all play a pivotal role in achieving the targets outlined. In 2020, almost 80% of the Angus and Hereford heifers and 60% of Limousin heifers were drafted off grass at an average carcase weight of 272kg.
However, none of the Belgian Blue heifers were slaughtered off grass. Lifetime meal intake ranged from less than 400kg for heifers slaughtered off grass to as high as 750kg for the final heifers finished indoors.
Similarly, for the bullocks, 0% of Belgian Blue, just 23% of the Limousin, 31% of Angus and 64% of Hereford have been drafted for slaughter off grass.
In fact, the Belgian Blue bullocks looked so lean and far away from being drafted off grass, they were housed earlier than the rest of the cattle in order to increase the energy of the diet through higher meal feeding and get a sufficient level of finish.
It is important to note that on a liveweight gain basis, the Blue bullocks performed as well on average as the other breed types. It was simply down to achieving a sufficient level of carcase fatness that saw them need to be adapted to a high concentrate indoor diet.
Source animals to suit the system
It is, therefore, important that farmers source cattle, both in terms of breed and sex, that suit the system in which they hope to operate.
What is also worth noting is that the average birth date of the animals slaughtered from the demonstration farm last year was 12 March 2019.
While many dairy-beef calves are not born until late-March and into April, these later born calves will really struggle to hit the targets to achieve a sufficient carcase weight off grass at the end of the second grazing season.