Farmers attending the ABP Demo Farm open day earlier this week were presented with research findings which indicate enhanced performance from dairy-beef cattle when consuming multi-species swards through both grazing and silage.
Prof. Tommy Boland was speaking on the day and discussed research findings from University College Dublin’s (UCD’s) Lyons Farm where cattle are currently 70kg heavier on average when grazing the multi-species sward (MSS) as opposed to a conventional perennial ryegrass (PRG) sward.
He told the crowd of over 200 farmers and industry personnel that for the purpose of the trial, cattle on the MSS were the same average weight as the cattle on the PRG when they started the trial and both groups of cattle were treated the same with the exception of the sward type offered.
He said: “The cattle on the MSS sward are also fed MSS silage and the group of cattle grazing the PRG sward were allocated PRG silage.
“The cattle come into our system in the middle of June as calves weighing about 135kg and they’re turned out to grass.
“They start to spread out in terms of growth rate around mid to late-August and that difference gets wider and wider.”
The UCD researcher explained that all cattle involved in the trial are fed their respective silage and 1kg concentrates/head/day during their first winter, but do not receive concentrates at grass.
He said that the biggest difference in growth rates between the MSS group and the PRG group was seen during the course of the first winter.
“Those cattle on MSS silage grow 200g/day faster in the shed than cattle on ryegrass silage and in the second summer grazing, they continue to maintain that 60-70kg liveweight difference,” he said.
All cattle in the trial were slaughtered with the aim of producing a 315kg carcass and meeting the required grade and fat score specifications.
The cattle on the MSS sward met the requirements and were slaughtered six to seven weeks earlier than the cattle on the PRG sward. Both groups were finished indoors.
Multi-species carbon footprint
The cattle involved in the trial were all Hereford-cross dairy-beef cattle and the research from the trial found that the carbon footprint was 15% lower from the MSS group of than the PRG group.
Prof. Boland noted that there was also a group of cattle on the trial that were grazing a PRG and white clover mix. The trial found the performance from this group to be better than the cattle on the PRG-only trial, but not as good as the cattle on the MSS trial.
The researcher added: “Other benefits from MSS was a higher population of more active earthworms which helped with water infiltration in the soil.
“Initial results suggest water quality draining from MSS is better that the water draining from PRG swards.”
In summary, Prof. Boland said: “There are multiple benefits of MSS but there are challenges as well. There are no silver bullets.”
Multi-species swards challenges
The UCD professor also mentioned two of the main challenges associated with managing multi-species swards (MSS).
Firstly, he said that herbs do not persist in the sward for as long as the grass species. He said that when a farmer decided to chose a MSS, there needs to be a plan to rejuvenate the herbs in the mix.
The second big challenge associated with MSS is weed control, he said. While knapsack spraying is an option, the UCD researcher said that there are currently no sprays available for MSS which kill a thistle, nettle or dock but won’t kill chicory and plantain, and do a job on red clover too.