Bee-friendly beef possible with native grasses, wildflowers
Virginia Tech research seeks to promote existing environmental stewardship of beef producers
By Jonathan Omar, Cole Kubesch, Parry Kietzman and Ben Tracy
Consumers are increasingly asking for more from farmers and ranchers. In addition to feeding the world, producers are asked to protect natural resources, maintain cultural landscapes and support other ecosystem services.
Cattle producers are among the best stewards of our natural resources, protecting soil and waterways across the majority of the country. However, cattle pastures could potentially also support pollinators such as bees and butterflies. Populations of these insects are in decline across much of North America, and these losses threaten pollination services for agricultural crops and natural ecosystems.
Research at Virginia Tech seeks to promote the existing environmental stewardship of beef producers as well as determine whether biodiverse native grass-wildflower mixtures (NWSG-WF) can support bees and beef together.
Experiments across VirginiaForage is only useful to producers once it has had the chance to go through an animal. The bee-friendly beef project is not only looking at how to establish these NWSG-WF stands, but also at their utility in grazing systems across the mid-Atlantic.
To this end, a grazing study is underway at the Shenandoah Valley Agricultural Research and Extension Center in Raphine, Virginia. The study is comparing beef cattle performance on pastures with toxic endophyte tall fescue and fescue combined with NWSG-WF strips to add biodiversity. Another treatment is using artificial shade structures on the toxic fescue as a way to help reduce body temperature. Fescue toxicity is often expressed as elevated body temperature in cattle.
We hypothesize that both shade structures and native grasses in the biodiverse treatment will help reduce body temperature and improve cattle performance.
Weaned heifers from a fall-calving commercial Angus cross herd were turned into paddocks in groups of four in June 2021 and May 2022 and set stocked until roughly Labor Day in both years. Heifers in the biodiverse paddocks only had access to the NWSG and WF areas in June, August and September. Forage, flowers and animal weights were measured every 4 weeks from May to September. Body temperature was monitored for 1 wk in July and August of 2021 and 2022 using a novel intravaginal datalogger assembly.
In addition to the grazing experiment, we have been doing a lot of on-farm work associated with the bee-friendly beef project. At 11 cattle farms across Virginia, wildflowers and native grasses were planted into tall fescue pastures to evaluate how well they are established and to monitor bee populations. The wildflower- enhanced plantings have ranged from 1- 10 acres in size.
ResultsA key question related to this project is whether or not the wildflower enhanced pastures successfully offer any benefits to pollinators. In 2021 and 2022, we monitored the presence of pollinating insects, including bees, wasps, pollinating flies, beetles, butterflies and moths, in multiple wildflower-enhanced pastures.
During that time, we found that pollinators were much more likely to visit blooms from the sown seed mix than other flowers already present in pastures, such as white clover and fleabane. These are exciting results that show pollinators do forage on and as a result benefit from the added native wildflowers.
NWSG-WF seedings look less visually appealing than tall fescue seedings in the first few months after planting. Weed competition is intense, but declines in the second year. A lot of these weeds are warm-season annual grasses, like crabgrass, which can provide useful forages. Establishment year weeds might be controlled through a brief, low-intensity grazing event about a month after planting.
In the grazing experiment, we have seen that heifers in biodiverse paddocks have similar or superior average daily gain (ADG) compared to heifers in traditional or shade-enhanced tall fescue paddocks. The potential advantages of the biodiverse paddocks over the other treatments were limited in 2021 by drought. Heifers grazed the NWSG aggressively.
The productivity of the NWSGs maintained forage production in the biodiverse paddocks and probably helped sustain better weight gain in summer compared with the other treatments. Body temperature measurements suggest that heifers in biodiverse paddocks had lower body temperatures than heifers in control or shade paddocks.
ImplicationsThrough a combination of on-farm and research station experiments, the mechanisms of establishing, maintaining and monitoring bee-friendly pastures are underway. Insect pollinator research indicates that native wildflowers are preferable to the flowers already present in tall fescue pastures.
The beef side of this project has shown that NWSG-WF stands take time to establish and that biodiverse stands might support heifer development programs. Our results so far suggest that creating more biodiverse bee-friendly beef pastures could be a promising system that will benefit both pollinators and beef cattle.
Omar and Kubesch are graduate students, Kietzman is a a research associate, and Tracy is a project leader and a professor, all in Virginia Tech’s School of Plant and Environmental Sciences.
