Dual-use cover crops as forage for livestock could offer ecological and economic benefits when incorporated into rotations with corn (Zea mays L.) and soybean (Glycine max (L.) Merr) in the Mid-South USA; however, information on implementation and impact is limited. A factorial of sixteen cool-season species and a no-cover control by two management systems (forage harvest and residue left in the field) was repeated under two cover crop planting/termination timings: long-season (Oct. through May; corn/cover-crop/soybean) and short-season (Nov. through Apr.; soybean/cover-crop/corn), two locations (Spring Hill and Knoxville, TN), and two growing seasons (2017/2018 and 2018/2019). Data were analyzed using a mixed model ANOVA (SAS 9.4.). The forage biomass did not differ by species within the short-season (415 to 1583 kg ha⁻¹) but did in the long-season (475 to 4282 kg ha⁻¹). Within the long-season, crimson clover (Trifolium incarnatum L.) and winter pea (Pisum sativum subsp. arvense (L.)) had crude protein and acid detergent fiber values within the range for prime forage and were among the highest biomasses. The forage harvest did not negatively affect soil properties or succeeding crop yield and quality. If appropriate species are selected, cover crops within a corn/cover-crop/soybean rotation can provide quality forage, without reducing the short term ecological benefits.

Interest in sustainable alternatives to synthetic nitrogen (N) for switchgrass (Panicum virgatum L.) forage and bioenergy production, such as biological N₂ fixation (BNF) via legume-intercropping, continues to increase. The objectives were to: (i) test physical and chemical scarification techniques (10 total) for common vetch (Vicia sativa L.); (ii) assess whether switchgrass yield is increased by BNF under optimum seed dormancy suppression methods; and (iii) determine BNF rates of common and hairy vetch (Vicia villosa L.) via the N-difference method. Results indicate that chemical scarification (sulfuric acid) and mechanical pretreatment (0.7 kg of pressure for one minute) improve common vetch germination by 60% and 50%, respectively, relative to controls. Under optimum scarification methods, BNF was 59.3 and 43.3 kg·N·ha⁻¹ when seeded at 7 kg pure live seed ha⁻¹ for common and hairy vetch, respectively. However, at this seeding rate, switchgrass yields were not affected by BNF (p > 0.05). Based on BNF rates and plant density estimates, seeding rates of 8 and 10 kg pure live seed (PLS) ha⁻¹ for common and hairy vetch, respectively, would be required to obtain plant densities sufficient for BNF at the current recommended rate of 67 kg·N·ha⁻¹ for switchgrass biomass production in the Southeastern U.S.

Fescue toxicosis impacts beef cattle production via reductions in weight gain and muscle development. Isoflavone supplementation has displayed potential for mitigating these effects. The objective of the current study was to evaluate isoflavone supplementation with fescue seed consumption on rumen and serum metabolomes. Angus steers (n = 36) were allocated randomly in a 2 × 2 factorial arrangement of treatments including endophyte-infected (E+) or endophyte-free (E−) tall fescue seed, with (P+) or without (P−) isoflavones. Steers were provided a basal diet with fescue seed for 21 days, while isoflavones were orally administered daily. Following the trial, blood and rumen fluid were collected for metabolite analysis. Metabolites were extracted and then analyzed by UPLC-MS. The MAVEN program was implemented to identify metabolites for MetaboAnalyst 4.0 and SAS 9.4 statistical analysis. Seven differentially abundant metabolites were identified in serum by isoflavone treatment, and eleven metabolites in the rumen due to seed type (p < 0.05). Pathways affected by treatments were related to amino acid and nucleic acid metabolism in both rumen fluid and serum (p < 0.05). Therefore, metabolism was altered by fescue seed in the rumen; however, isoflavones altered metabolism systemically to potentially mitigate detrimental effects of seed and improve animal performance.

The use of living mulch (LM) in corn (Zea mays L.) production must be evaluated under different N fertilization levels. The objective of this study was to determine the optimum amount of N fertilization in white clover (Trifolium repens L. (WC)) LM in corn. The study was conducted in Spring Hill, TN, from 2020 to 2021. The treatments were [C-0] no LM + no N, [C-135] no LM + 135 kg/ha N, [CLM-0] LM + no N, [CLM-45] LM + 45 kg/ha N, [CLM-90] LM + 90 kg/ha N, and [CLM-135] LM + 135 kg/ha N. We evaluated the LM mass and corn production (silage and grain). In general, the LM mass was higher with CLM-45, CLM-90, and CLM-135 during both years. Corn silage production was higher in 2020 compared with 2021 (6.8 and 2.8 Ton/ha, respectively), and showed differences among treatments. The production of corn grain showed the same response pattern with a higher value in 2020 than in 2021 (1.8 and 0.1 Ton/ha, respectively). Thus, the use of LM did not increase corn silage or grain production, even receiving a high N rate as in conventional systems.

Adoption of native warm-season grasses (NWSGs) in the tall fescue belt is limited despite studies documenting the potential contribution of these forages to profitable beef production. On the basis of two surveys conducted in Tennessee, a survey of beef producers and a survey of agricultural professionals, we evaluated perceptions of NWSG forages and how those perceptions could influence their adoption. Although agricultural professionals were more familiar with NWSGs than producers, both populations had limited knowledge regarding these forages, indicating that additional Extension education is needed. Our results provide useful guidance for developing NWSG forage educational programs for producers and agricultural professionals.

Tall fescue toxicosis negatively impacts blood flow, elevates body temperature, and reduces beef cattle’s average daily gain (ADG). In previous studies, isoflavones have diminished the symptoms of tall fescue toxicosis in ruminants. Therefore, this dataset determined the impact of low concentrations of isoflavone doses on animal vasculature, body temperature, ADG, and rumen microbial communities in beef cattle. A 21-day experiment with Angus cattle consisted of four isoflavone doses: 0 g, 2 g, 4 g, and 6 g, along with a control group. Isoflavones were mixed with 0.5 kg of dried distiller’s grains (DDGs). Daily individual rectal temperatures were recorded. Weekly blood serum was collected via coccygeal venipuncture, blood vasculature data were measured via color Doppler ultrasound, and body weight (BW) was recorded. Approximately 100 mL of rumen content was collected at the end of the trial. The pulsatility index (PI) decreased in the control group compared to the 2 g and 4 g groups (p = 0.01). Animals in the isoflavone treatment groups recorded a higher rectal temperature (p < 0.05). ADG was reduced in animals undergoing isoflavone treatments (p < 0.001). Finally, there was no impact on the rumen microbial communities (p > 0.05). Isoflavone supplementation may mitigate tall fescue toxicosis and improve animal performance at greater doses.