At this point, the 140 yearling stock on the Thrive demonstration farm outside Cashel, Co Tipperary, have been at grass for almost 80 days.
A mid-season weighing is important to assess performance over the first few months at grass, which is typically the period of greatest liveweight gain throughout the year.
This mid-season weight also gives us a good barometer as to where stock are compared to recent years, as well as comparing the weight to the 19-month production system blueprint (Figure 1) to see what proportion of stock is on target to be slaughtered off grass at the end of the grazing season.
The blueprint outlines where stock need to be at certain time points throughout the production system.
In Figure 1, the blue line represents steer target weights while the red line represents the target weight for heifers.
As can be seen on the yellow line, the 2020-born heifers, as an average, are currently on target at a weight of 411kg. The bullocks (green line) are currently ahead of target by around 15kg, weighing 458kg on average. The mean date of birth of these animals is 25 February 2020.
Performance at grass
Since turnout, the bullocks have an average daily liveweight gain of 1.1kg/day, while the heifers have gained 0.9kg/day. When we compare this to the performance of last year’s stock over the same period, average daily gain is about 0.1kg/day lower.
However, when we compare the two years in terms of grazing conditions, it is hardly unexpected. While last March was wet, throughout April and May stock hardly saw a shower of rain, grass growth was excellent and grazing conditions were almost perfect.
This spring, in contrast, had a false start with cattle rehoused for a short period in the second week of March due to poor weather conditions.
Once cattle got back to grass, conditions did improve greatly and while grass growth remained slow throughout April, grass quality was very good.
The arrival of heavy and persistent rain in May has seen a few difficult weeks’ grazing with poorer graze-outs and sticky conditions underfoot. As a result, cattle have had to be moved from paddocks 24 hours earlier than we would like, in order to avoid poaching.
As can be seen in Figure 1, the additional 15kg ahead of target that the bullocks now have was actually accrued during the winter, thanks to superb silage quality.
Average daily gain during the winter period was just over 1kg/day on 75DMD silage plus 1.5kg concentrate.
The task now turns to maintaining performance over the coming weeks. As we enter June, seed heads can be seen emerging in some swards.
The difficult grazing conditions and poorer clean-outs of paddocks over the past three weeks will mean that we will be fighting more seed heads in the sward in the next rotation.
It is important to maintain a leafy sward ahead of stock to maximise performance.
One benefit or lower grass growth rates so far this year has been that stock constantly entered lower swards of grass which, in many cases, has helped performance.
Over the last week or so, grass growth rates have improved with increased temperatures.
Hopefully this will continue and we will start to see surplus grass build ahead of stock.
If this is the case, paddocks that were poorly grazed in the last round will be targeted for cutting for silage. This will remove any stem in the sward, improving quality in the next rotation.
Where this cannot be done, some topping will be carried out post-grazing to reset the swards.
Try to keep stock entering sward heights of 8cm to 10cm, offering a fresh break of grass at least twice a week to help keep cattle content and thriving.
2021 calf performance
This year’s calves were also weighed on the same day. Performance of calves this spring has been somewhat underwhelming. They have averaged 0.75kg/day since arrival.
While this is acceptable, it is not outstanding for the level of management and nutrition that has gone into them.
Bull calves are averaging 103kg while heifers are 101kg. Again, looking at the blueprint, the aim is to have these calves at 115kg (bulls) and 110kg (heifers) by 10 June.
Forward projecting their weight at their current average daily gain will see us on target.
However, we are feeding more meal this year than last, with calves eating between 1.5kg and 2kg/day at the moment.
The hope is to bring this back to 1kg once weather conditions have settled.
It has been a difficult spring for calves, with huge variations in temperatures during the rearing phase, as well as poorer grazing conditions and low grass dry matter since turnout.
Weighing calves that fortnight earlier has perhaps seen us capture the period just after weaning when thrive can be somewhat affected.
Once settled out at grass, thrive should kick on again in the coming weeks. Calves will be weighed again in early July to assess performance.
January-born calves are 118kg on average, February-born calves are weighing 107kg and March-born calves are averaging 90kg.
This shows the importance of getting calves on to the farm as soon as possible in spring. The 17kg difference between February- and March-born calves is very hard and/or expensive to eliminate. Last year, the 40 youngest calves received meal throughout the summer in order to bridge the weight gap to the older calves. While we managed to do so, it took €21/head in additional meal costs.
Of the 150 calves on farm, just 18 remain on milk with the plan being to wean within a fortnight.