The final eight heifers on the Irish Farmers Journal Thrive demonstration farm in Cashel, Co Tipperary, were slaughtered on 23 December. These heifers were all Belgian Blue-sired, had been getting meal at grass since August and were housed for a final finishing period in late October.

Table 1 outlines the slaughter performance of the batch. With an average birth date of 21 March 2019, the group was just slightly over 21 months old with an average slaughter weight of 579kg. This translates to a lifetime average daily gain of 0.85kg/day.

However, there was a huge variation in liveweight within the group from 504kg to 654kg, resulting in a spread of lifetime daily liveweight gains from 0.78kg/day to 1.02kg/day. The lightest was a DFD-sired heifer from a Holstein Friesian cow and the heaviest was a BB4286-sired heifer from a Holstein Friesian cow with 12% Montbéliarde also in the dam’s genetic makeup.

Cattle on the demonstration farm are drafted for slaughter based more on being sufficiently fleshed rather than on liveweight alone.

The average slaughter weight of the 65 heifers drafted throughout the last four months of 2020 was 538kg. This includes 40 predominantly Angus and Hereford heifers and a small number of Limousins drafted off grass throughout September and October.

This sees the farm finish 2020 with an average heifer carcase weight of 281kg at an average slaughter age of 19.7 months old. This is an increase of 13kg of carcase weight on the 2019 heifer kill at a similar slaughter age.

Belgian Blue heifers

With an average carcase weight of 308kg, these final eight heifers were 27kg heavier than the average of all the heifers slaughtered in 2020. However, they had also been fed for longer, incurring greater feed costs. Lifetime meal input for this batch of heifers comes to 782kg, meaning a meal cost of just over €200/head.

For the last three weeks prior to slaughter, the diet consisted of 5kg/day of concentrates which, along with grass silage, amounted to a daily feed cost of almost €2/head/day.

We must remember that this is simply the cost of the feed and does not include the labour or machinery costs associated with delivering the feed or any cost on the sheds required to house these animals for a partial second winter.

Tag 2035. This DBZ sired heifer had a carcase weight of 295kg, graded R=3= and came to €1,179.

Daily liveweight gain over the indoor finishing period was just over 1kg/day. Assuming a daily carcase gain of 550g/day, this means heifers were gaining €2.24/day.

Nineteen- to 20-month system

It is for this reason that the aim on the farm is to finish as many cattle as possible off grass at the end of the second grazing season. When we do the figures, it does not make economic sense putting cattle back in the shed for a second winter period.

Speaking to some farmers about the current system, they feel we are slaughtering cattle too light at too young an age. However, the average fat score of the 65 heifers slaughtered in recent months is 3+ meaning they were adequately finished. Further feeding would only result in cattle going out of spec for carcase fatness, which would lead to price penalties.

Also, as animals get fatter, their feed-gain conversion ratio decreases, meaning that every extra day we feed these cattle past the point of them hitting carcase weight and fatness specifications, the more money we lose.

Store and feed

A batch of the heaviest heifers started getting meal at grass at a rate of 3kg/day from 1 August. The lighter heifers started meal feeding from 1 September. Even if we were to hold off meal feeding at grass, house cattle in the last weeks of October and store on a silage diet plus 2kg of concentrate until this time of year and start to increase meal feeding from now on, the economics would not change.

Performance at grass late in the season would have been poor if there was no concentrate being fed, meaning a lighter housing weight. Likewise, performance in the shed on silage and a low level of meal would have been quite poor. Therefore, the cost-per-kilo gain on the store diet would actually have been higher than in the current system’s finishing phase on 5kg/head/day concentrate.

While we may end up with a slightly heavier carcase at the end of the 24-month system, the cost of getting there would have been significantly greater – extra housing requirements, labour and machinery costs. It is for this reason that farmers who do choose to go down the winter finishing route, need some sort of winter finishing bonus or contract for the higher costs incurred.


Table 2 looks at the entire system economics for these eight heifers. Initially, the Belgian Blue heifers cost €275/head as three-week-old calves, €84 more than the average price paid for all heifer calves in 2019. If we divide this by the average beef price received this year of €3.85/kg, it means Belgian Blue heifers need more than 20kg additional carcase weight on the same slaughter date to make up for this price difference.

The system is being run to a high level of technical efficiency, which is reflected in the gross margin being achieved.

However, when fixed costs are included the system comes under pressure. While these costs will be different on every farm, in this case we have put realistic figures in place based on similar systems of production. It is important that those operating dairy calf-to-beef systems sit down and calculate their own costs ahead of purchasing in calves again this spring.

In the coming weeks, we will look further into both the heifer and steer cattle kill data, break down each category by breed, look at the best- and worst-performing sires and the effect of dam genetics on the overall performance of the calf.