Less meal, earlier finishing and more profit - the benefits of companion forages

Are you looking to grow your lambs quicker, achieve an earlier age of finish and reduce concentrate input to finishing lambs? Then results of a major study undertaken at the Teagasc Animal & Grassland Research and Innovation Centre, Athenry may be of interest to you.

As part of the Teagasc National Lowland Sheep Conference, Sarah Woodmartin, a Research Officer at Teagasc, shared the key results of the Athenry companion forages study. Taking place over the production years 2018-2022, the study compared flock performance when grazed on a perennial ryegrass only sward with that achieved from combinations of either: 1). perennial ryegrass and white clover (PRG+WC); 2). perennial ryegrass and red clover (PRG+RC); 3). perennial ryegrass and chicory (PRG+Chic); or 4). perennial ryegrass and plantain (PRG+Plan).

To reflect practices on mid-season commercial farms, Sarah Woodmartin explained, each farm system was stocked at 11.5 ewes/ha and all pasture treatments received chemical nitrogen applications of 120kg N/ha/year. Lambs were also weaned at ~15 weeks of age and drafted to produce a target carcass weight of 20kg.

On the benefits of companion forage inclusion, Sarah Woodmartin told the farmers in attendance: “By increasing legumes or herbs, we have seen the potential to increase intakes, animal performance, improve sward quality in the latter half of the grazing season, and there is also potential environmental benefits from their inclusion.”

A second half player

Due to the summer active nature of the legumes and herbs studied, she noted that the real benefits of their inclusion occur in the second half of the grazing season. Across the five pasture types, no differences in lamb birth weights, weaning weight or pre-weaning average daily gain were recorded. However, it was in the post-weaning period where the real benefits in terms of lamb performance were witnessed. Some of the key results witnessed in the post weaning period include:

• In the post weaning period, average daily gains were higher from the PRG+WC (+33g/day), PRG+RC (+41g/day), PRG+Chic (+40g/day) and PRG+Plan (+25g/day) lambs, when compared to those grazing the perennial ryegrass only treatment.
• The additional performance achieved over the post-weaning period had a positive impact on lifetime ADG. PRG+WC (+27g/day), PRG+RC (+33g/day), PRG+Chic (+28g/day) and PRG+Plan (+14g/day) lambs all had higher lifetime average daily gains when compared to lambs grazing the perennial ryegrass only treatment.
• This increase in performance resulted in a younger age to finish. On average, lambs on the perennial ryegrass only treatment took 231 days to reach the point of sale; this was significantly reduced for the PRG+WC (-26 days), PRG+RC (-32 days), PRG+Chic (-27 days) and the PRG+Plan (-16 days) lambs.
• As a consequence, meal required to bring the lambs to finish was also reduced when grazed on pastures containing either of the four companion forages.
• Using average costs from the 2018-2022 period, perennial ryegrass only lambs required, on average, €4/head of concentrates, whereas this reduced for the lambs grazed on either the PRG+WC (€2.20/head), PRG+RC (€0.37/head), PRG+Chic (€0.74/head) and PRG+Plan (€1.85/head) swards.
• Although not a central focus of the study, the number of dosing events also reduced for the lambs grazed on swards containing companion forages, as a result of the reduced days to slaughter.

Along with assessing the impacts on animal performance, researchers in Athenry also evaluated the impact of including companion forages on sward quality (digestibility) and dry matter intake – two factors known to drive lamb performance in the post weaning period. Notably, animals offered swards containing companion forages had higher intakes in comparison to perennial ryegrass only, with the intake differences being 11% higher for PRG+WC, 12% higher for PRG+RC; +14% higher for PRG+Chic and 5% higher for PRG+Plan. Additionally, swards containing PRG+WC, PRG+RC and PRG+Chic had higher organic matter digestibility.

Sarah Woodmartin, pictured above, addressed the Teagasc National Lowland Sheep Conferences in Tuam and Trim.

Financial and environmental effects

Additionally, Sarah Woodmartin also detailed how the inclusion of companion forages impacted on greenhouse gas (GHG) emissions and farm profitability.

“We found that the inclusion of white clover (-5%), red clover (-13%) or plantain (-8%) reduced methane output. It is very positive to see that we can achieve increased intakes and performance, while there is potential to reduce the methane coming from the lambs grazing these swards,” she told the farmers in attendance.

To quantify the impact on total farm gate emissions, a life cycle assessment of the study’s results were also undertaken, with Sarah Woodmartin adding: “If you express kilograms of CO₂ equivalent per kilogram of carcass weight or per hectare, we saw the same trend; the inclusion of companion forages reduces total farm gate emissions, and the inclusion of white clover, red clover and chicory does so to the greatest extent.”

A brief economic analysis of the systems has confirmed positives in terms of profitability, with all four companion treatments generating higher farm net profits, driven by the reduced age to finish, lower concentrate input and the quicker drafting pattern.

  “These animals are around for less time. They are costing you less money and they are also reducing the environmental effect because their lifetime emissions is that bit lower,” she added.

Although there are positives to take from the systems study, Sarah Woodmartin did admit that challenges relate in terms of plant persistency, primarily with the inclusion of red clover, chicory or plantain to the sward, a lack of concise management advice available at farm level and the costs associated with adding the companion forages to swards.

The Athenry companion forage study also assessed carcass performance and meat quality. For more information, see Sarah Woodmartin’s presentation to the Teagasc National Lowland Sheep Conference here (PDF).