A research project focused on the performance of dairy-beef cattle on different sward types has been running in conjunction with ABP Food Group and University College Dublin (UCD) since 2019.
UCD’s Prof. Tommy Boland explained that the study consists of three farms, each comprising of 8Ha and each supporting 20 livestock units. The cattle used in the trial are all Hereford-cross steers (bullocks) with 20 finishers and 20 calves on each farm.
There are a total of 120 cattle enrolled in the study at any one time with the exception of the gap between when animals are slaughtered and the new calves enter the system.
Each of the three farms have a different type of pasture and different levels of chemical fertiliser are applied. The three sward types and treatments are as follows:
- Perennial ryegrass (PRG) at 210 kg N/Ha/year;
- PRG/White Clover (WC) at 90 kg N/ha/year;
- Multi-species Sward (MSS) (PRG, timothy, WC, Red clover, chicory and plantain) at 90kg N/ha/yr.
Commenting on the trends being seen from the research, prof. Boland said: “Over the years of the study we are seeing the MSS yield 25% more herbage than the PRG with the WC intermediate between the two.
“The RC component of the MSS is the engine driving this enhanced herbage yield and we have seen good persistence of the RC under our leader-follower grazing system.
“Both plantain and chicory have had to be rejuvenated in the MSS sward via over-sowing after silage harvest (50% of the farm is closed for silage in mid-late May and the area closed for silage is rotated each year).
“We are aiming for 20-25% of the herbage DM coming from herbs and another 25-30% of the herbage DM yield coming from legumes. “
The cattle on the MSS were slaughtered on Thursday, December 10 and average performance of the group was as follows:
- Fat score: 3+;
- Conformation: -O+/O=;
- Carcass weight: 315kg;
- Kill out: 50%;
- Average price: €5.74/kg.
The UCD lead researcher said: “Based on the current weights and growth rates of the PRG and PRG/WC groups of cattle, these groups will be fit for slaughter around January 21/22 so six weeks after the MSS cattle.”
The three research cattle groups
Prof. Boland explained that the only difference between the three groups is the forage they are offered.
Once an animal enters the study, it is allocated to one of the three forages types and then receives that forage – either grazed or as silage – for the duration of their life.
All groups receive 1.25kg concentrate supplementation during the first winter with this stopping six weeks before turnout and then being finished on a 50:50 forage to concentrate diet.
The researcher said: “We don’t normally feed concentrates at pasture, but this year due to a grass deficit, finishing animals received concentrate at pasture for the final-three-four weeks of the grazing season to extend the time spent at grass.
Commenting on the research findings, he said: “The lower N inputs and the shorter duration to slaughter has resulted in a 14% lower carbon footprint for beef produced on the MSS but we are about to re-run the modelling work with updated coefficients arising out of the ABP/BiOrbic project.”