Background Bermudagrass (Cynodon spp.) is one of the most common perennial warm‐season forages grown in the Southeastern United States. The incorporation of alfalfa (Medicago sativa) into bermudagrass pastures could serve as an alternative source of nitrogen (N) while also improving the nutritive value of the forage base. Methods A 2‐year grazing evaluation arranged in a randomized complete block design was conducted from May to September 2018 (Year 1) and May–August 2019 (Year 2) in Tifton, GA, USA. The objective was to compare the production of alfalfa–bermudagrass mixed pastures (BGA) with bermudagrass monoculture pastures with (BGN) or without (BG) the application of synthetic nitrogen on forage production and stocker cattle performance. Results Differences were observed for average daily gain (p = 0.10), gain per hectare (p = 0.02) and stocking rate (p = 0.01), in that BGA was greatest compared to BGN and BG, which did not differ from each other. Furthermore, BGA had increased forage crude protein (p = 0.01) and total digestible nutrients (p = 0.01) compared to BGN and BG. Finally, BGA provided the greatest economic return per hectare compared to BG or BGN. Conclusions These data illustrate improved animal performance and forage nutritive value using alfalfa–bermudagrass systems and offer a viable option for producers seeking alternatives to synthetic N sources for bermudagrass pastures in the Southeastern United States.

Incorporation of alfalfa (Medicago sativa) into bermudagrass pastures improves forage quality and decreases the reliance on synthetic nitrogen fertilizer. The objective of this study was to determine forage mass (FM), nutritive value (NV), and botanical composition of ‘Bulldog 805’ alfalfa and ‘Tifton 85’ bermudagrass (T85; Cynodon dactylon) mixtures managed under three defoliation strategies: 1) hay production (H), 2) grazing (G) or 3) dual-purpose (DP) use. The study was conducted in two locations (Headland, AL and Tifton, GA) using a randomized complete block design with two replicates. In spring 2020, grazed plots were divided in four strips and every 7-d, animals were rotated to a new strip and stocking rate was adjusted. Under DP, plots were grazed until mid-July, then forage was harvested in late August. For H plots, forage was harvested every 28 to 35-d. Forage samples were collected prior defoliation to determine FM and on grazed periods, pre- and post-grazing samples and disk meter measurements were collected. Nutritive value responses were determined using near-infrared spectroscopy. There was no effect of defoliation strategy on FM (P = 0.604; mean 3471 kg DM/ha). Greater FM (P = 0.002) was observed in July and August than June (3531 and 3976 vs 2905 kg DM ha-1, SE= 263). This response was associated with an up to 40% increase of T85 proportion in the mixture (P = 0.001). Alfalfa percentage was 78% greater for DP than G (P = 0.029). There were no differences among treatments for NV responses (P > 0.05). Among defoliation periods, crude protein, neutral detergent fiber and acid detergent fiber concentrations ranged from 14 to 22%, 45 to 58% and 28 to 35%, respectively. These preliminary results demonstrate multi-use options for this mixture in the region while aiming for increased forage nutritive value, and extended growing season, and sustainability of forage-livestock systems.

High quality forages produced in the southeastern U.S. can benefit from being harvested as baleage when environmental conditions are not favorable for hay production. Current recommendations are to feed baleage within 9 mo of harvesting; however, wet summers or mild winters can reduce the need for utilizing stored forage in this timely manner. Limited data exist on the nutritional value of baleage stored beyond a 9-mo period. Therefore, the objective of this research is to determine if storage length affects the nutritive value of baleage in the southeastern U.S. This study was conducted from 2016–2020 at the University of Georgia Tifton Campus, using ‘Tifton-85’ bermudagrass baleage (BG) and ‘Bulldog 805’ alfalfa-bermudagrass mixed baleage (BGA) harvested on a 28–35-d interval, baled at approximately 55% moisture, and individually wrapped for storage. Bales were marked by treatment, sampled prior to wrapping for initial determination (INT), and sampled again post fermentation at 6-wk, 9-mo and 12-mo timepoints for nutritive value analyses. Additionally, a subset of bales harvested in June and August of 2017 and 2018 were maintained and sampled at 24-mo time point. Statistical analysis was conducted using the PROC MIXED procedure of SAS 9.4. Nutritive analysis showed a difference in the CP% between pre and post fermentation events for BGA (INT=22±2.39 and 6-wk, 9-mo, 12-mo=20±2.39; P < 0.01), while no difference was found for BG. TDN% was different only at 6 wk for BGA (66±0.63; P = 0.03) compared to all other timepoints, with no difference for BG. The 24mo storage analysis showed a decline in the CP% and TDN% for both BGA and BG from pre and post fermentation. Results from this study conclude there no effect on the nutritive value of baleage stored up to 12 mo post fermentation. Maintaining bale integrity can be attributed to the decline in nutritive value observed when stored longer than 12 mo.

The incorporation of alfalfa (Medicago sativa L.) into bermudagrass [Cynodon dactylon (L.) Pers.] forage systems in the southern United States has increased. Stockpiling this mixture may extend the grazing season into the fall and winter months with high‐quality forage. The objective of this 2‐year study was to evaluate agronomic and structural responses of alfalfa–bermudagrass mixtures managed under five stockpiling periods (6, 8, 10, 12, or 14 weeks) in two locations (Shorter, AL, and Tifton, GA). Across locations, stockpiling mixtures for 8 weeks or longer (2400 lb DM ac−1, on average) resulted in greater (P = 0.001) herbage accumulation than 6 weeks (3185 lb DM ac−1). The alfalfa proportion was similar among stockpiling periods in Shorter but greater (P = 0.043) at 10 and 14 weeks than 6, 8, and 12 weeks in Tifton. A location × year × stockpiling interaction was observed for crude protein (CP, P < 0.001) and in vitro true dry matter digestibility over 48 h (IVTDMD48, P < 0.001). Crude protein concentrations were similar among stockpiling periods in 2020 in both locations. In 2019, however, CP concentrations reduced with increasing stockpiling period length in Shorter and were similar among treatments in Tifton, except for the lesser CP at 8 than at 10, 12, and 14, weeks. Forage IVTDMD48 concentrations declined with increasing stockpiling period length at both locations, with a more pronounced decline in Shorter in 2019. Results suggest that stockpiling alfalfa–bermudagrass mixtures for up to 8 weeks is a viable option to supply high nutritive value forage and lower lodging losses into the early winter months.

Enhanced microbial activity in the equine hindgut increases nutrient availability, reduces fecal waste, and adds value to low quality forages. The dietary supplement DigestaWell® Fiber (DF; fibrolytic cofactors: methionine and B vitamins), designed to increase microbial efficiency, has been shown to improve in-vitro digestibility of alfalfa and tall fescue forages after 48-h incubation. The objective of this study was to determine if DF would improve in-vitro dry matter digestibility (DMD) and ADF digestibility (ADFD) of alfalfa and coastal bermudagrass hays incubated for 48h or 72h. Utilizing a crossover design, four mature Quarter Horse mares were fed 2% BW daily of alfalfa (AF; 32.8% NDF, 27.1% ADF) or coastal bermudagrass (CB; 63.2% NDF, 35.4% ADF) hay for 19-d periods. DMD and ADFD were determined after 48-h or 72-h incubation with or without treatment (320mg/L DF) at 37.5°C in an ANKOM Daisy II incubator inoculated with 200g fresh feces. Forage samples were run in triplicate. Data were transformed to approximate normality, then analyzed using a repeated measures mixed model in SAS with main effects of forage, treatment, incubation time, and feeding period, and statistically significant interactions. Across incubation times, DMD was higher for AF than CB (P < 0.01; 49.4% vs 42.1%). Across forages, DMD was higher at 72h than at 48h incubation (P < 0.01; 47.5% vs 43.9%). DF improved DMD across forages at 48h (P = 0.03), but not at 72h (P = 0.47). Across incubation times, DF improved DMD of CB (P < 0.01), but not AF (P = 0.79). Additionally, across both forages and both incubation times, DF improved ADFD (P < 0.01). In conclusion, DF may improve microbial fermentation in the equine hindgut. Future research should investigate in-vivo effects of oral supplementation of DF on forage digestibility measures.