Native warm‐season grasses (NWSG) could provide desirable complementary summer forage for tall fescue [TF; Schedonorus arundinaceus (Schreb.) Dumort.] systems, especially for reproductive animals that may be disproportionately affected by TF toxicosis. Inter‐seeding legumes into pastures is a common practice but has received only limited attention for NWSG. Switchgrass (SG; Panicum virgatum L.) and a big bluestem (BB; Andropogon gerardii Vitman) indiangrass (IG; Sorghastrum nutans Nash) blend (BB/IG), each with and without inter‐seeded red clover (RC; Trifolium pratense L.), were grazed (46–54 and 38–46‐cm canopy heights for SG and BB/IG, respectively) by bred dairy heifers for 3 yr. Establishment of RC was inconsistent leading to limited influence on forage mass, crude protein (CP), and neutral detergent fiber (NDF). Similarly, RC had minimal influence on average daily gain (ADG; kg d−1), animal days (AD) ha−1, and total gain (GAIN; kg ha−1). The ADG was 1.03 (SG), 1.23 (SG+RC), 1.25 (BB/IG), and 1.33 (BB/IG+RC) kg d−1 during the early season and 0.36 (SG+RC), 0.37 (SG), 0.54 (BB/IG), and 0.86 (BB/IG+RC) kg d−1 later in the season. Higher stocking was possible with SG (234, 330, and 222 AD ha−1 in 2010, 2011, 2012, respectively) than BB/IG (196, 240, and 162 AD ha−1 in 2010, 2011, 2012, respectively), but total gain (kg ha−1) was not consistently different. Switchgrass and BB/IG both provided acceptable forage quality and good animal performance and could be used for summer forage for bred heifers; RC had limited benefit and competed with NWSG.

Closed-canopy upland hardwood stands often lack diverse understory structure and composition, limiting available nutrition for white-tailed deer (Odocoileus virginianus) as well as nesting and foraging structure for other wildlife. Various regeneration methods can positively influence understory development; however, non-commercial strategies are needed to improve available nutrition in many stands, as some contain timber that is not ready to harvest and others are owned by landowners who are not interested in harvesting timber. Applications of herbicide and prescribed fire have improved availability of food and cover for deer and other wildlife in pine (Pinus spp.) systems. However, this strategy has not been evaluated in hardwood systems. To evaluate the influence of fire and herbicide treatments on available deer forage in upland hardwood systems, we measured forage availability and calculated nutritional carrying capacity (NCC) at 14% crude protein mixed diet, following 7 silvicultural treatments, including controls, in 4 mixed upland hardwood stands July-September 2007 and 2008. We compared NCC among forest treatments and within 4 paired warm-season forage food plots to evaluate the usefulness of food plots in areas where forests are managed. Nutritional carrying capacity estimates (deer days/ha) were greatest following canopy reduction with prescribed fire treatments in both years. Understory herbicide application did not affect species composition or NCC 1 year or 2 years post-treatment. Production of forage plantings exceeded that of forest treatments both years with the exception of early-maturing soybeans and retention cut with fire 2 years post-treatment. We encourage land managers to use canopy reducing treatments and low-intensity prescribed fire to increase available nutrition and improve available cover where needed in upland hardwood systems. In areas where deer density may limit understory development, high-quality forage food plots may be used to buffer browsing while strategies to reduce deer density and stimulate the forest understory are implemented. ß 2011 The Wildlife Society.KEY WORDS food plots, forage availability, prescribed fire, silviculture, understory herbicide applications, upland hardwoods, white-tailed deer.

Native warm-season grasses (NWSGs) have demonstrated potential to reduce summer forage variability, and furthermore, there has been growing interest in the use of NWSGs as lignocellulosic biomass crops. Th e objective of this research was to determine if there was a diff erence in net returns for full-season summer grazing beef steers (Bos taurus) on three NWSGs. Additionally, the expected price for biomass that a beef producer would need to break even between using the dual-purpose early-season grazing and biomass system and the full-season grazing system was calculated for these three NWSGs. Weaned beef steers grazed switchgrass (Panicum virgatum L.) (SG), a big bluestem (Andropogon gerardi Vitman) and indiangrass [Sorghastrum nutans (L.) Nash] mixture (BBIG), and eastern gamagrass [Tripsacum dactyloides (L.) L.] at Grand Junction (AP) and Highland Rim (HR), TN, from 2010 to 2012. Th e dual-purpose grazing occurred for 30 d beginning in early May, with subsequent growth harvested as biomass post-dormancy, and full-season grazing occurred for 90 d beginning in early May. Budgets were developed for each NWSG to calculate net returns, and mixed models were used to determine diff erences in beef yield and net returns across each NWSG and location. Expected yield and net returns to full-season grazing were not diff erent among NWSGs at AP. However, net returns to full-season grazing were higher for BBIG than SG at HR. A profi t-maximizing, risk-neutral individual would increase net returns by grazing any of the NWSGs over marketing calves at weaning. Th e breakeven biomass prices ranged between US$10 and US$98 Mg-1 depending on the NWSG and location.

Establishment failures linked to seed dormancy are a challenge to wide‐scale use of switchgrass (Panicum virgatum L.) for biomass feedstock and forage production. One prospective strategy for breaking dormancy is dormant‐season planting. The objectives of this study were to evaluate (i) three switchgrass dormant‐season planting dates (1 December, 1 February, and 15 March) vs. a growing‐season (1 May) control; (ii) two seeding rates (6.7 and 10.1 kg pure live seed [PLS] ha−1); and (iii) high‐ and low‐dormancy seed lots. Treatments were assigned in a split‐plot design with three replications at two locations in Tennessee in 2008 and 2009. Neither seeding rate nor seed‐dormancy level affected plant density or yield (P > 0.05). However, a seeding date × year interaction impacted first‐year density at both locations. Although patterns differed by year for the two locations, density of March plantings equaled or exceeded (P < 0.05) those at other dates for both locations and years. These variations in density did not carry over to impact yield in year two. A sigmoidal regression of seedling density vs. yield was significant (P < 0.001) albeit not strong (R2 = 0.13); yield response approached an asymptote above ∼8 plants m−2. Results suggest March planting dates, using standard seeding rate recommendations (6.7 kg PLS ha−1) irrespective of seed‐dormancy rates, may be more reliable than planting in May. Thus, a broader establishment window than traditionally used may be practical. However, results should be validated over a broader range of soils and climatic conditions, especially over a winter severity gradient.

Alfalfa (Medicago sativa L.) has not been well suited for pasture because of its intolerance to grazing. ‘Alfagraze’, a cultivar bred for grazing tolerance, offers potential to use alfalfa as pasture. A 3‐yr grazing study was initiated in central Georgia to investigate persistence and animal performance of ‘Apollo’ and Alfagraze alfalfa at low, medium, and high forage allowance (FA). The FA for this study were targeted at 1000, 2000, and 3000 lb dry matter (DM)/1100 lb animal unit for low, medium, and high FA, respectively. Low FA reduced stand of both cultivars (P < 0.05) after only 1 yr (low = 6.8, medium = 8.2, high = 8.8 plants/sq ft). After 2 yr, high FA paddocks averaged 8.6 plants/sq ft, while medium and low FA had decreased to 5.4 and 4.4 plants/sq ft, respectively. The difference in grazing tolerance between cultivars became evident after 2 yr of grazing, when, averaged across FA, Alfagraze had 7.3 plants/sq ft and Apollo had 5.0 plants/sq ft. After an additional year of continuous stocking, Alfagraze had approximately 150% more plants than Apollo. Persistence differences between cultivars were most evident at low FA. After 2 yr of low FA, Alfagraze had 5.5 and Apollo had 3.3 plants/sq ft. After 3 yr, Alfagraze maintained stands of 5.5 plants/sq ft, while Apollo stands decreased to 1.5 plants/sq ft. Lower FA resulted in greater bermudagrass [Cynodon dactylon (L.) Pers.] encroachment. Lower FA decreased average daily gain (ADG) in yr 1. At low FA, improved persistence of Alfagraze resulted in 0.45 lb/d higher ADG than Apollo in yr 2. The better grazing‐tolerance of Alfagraze alfalfa resulted in longer stand persistence and better animal performance. Research Question Alfalfa is a high quality forage that can produce good animal gains. Little acreage of alfalfa in the USA is grazed because of poor persistence of hay‐type cultivars. ‘Alfagraze’, a grazing‐tolerant cultivar, offers livestock producers extended productivity of alfalfa used for pastures. This study investigated persistence differences between Alfagraze and ‘Apollo’ alfalfa, as well as the effect of forage allowance (FA) on stand persistence and animal performance of steers continuously stocked on alfalfa pasture. Literature Summary High quality forage is important for profitable stockering of weaned calves. Various forages can provide this during fall, winter, and spring in the southeastern USA, but a forage is needed that will produce high animal gains in summer. Alfalfa is a high quality forage for the late spring and summer, but its use as a grazing crop has been limited because of poor persistence when grazed. Rotational stocking has been recommended for alfalfa, but even then stand life is limited because of periodic overgrazing. ‘Alfagraze’, a grazing‐tolerant cultivar with high yield potential, should provide excellent animal gains during summer and good stand persistence. Study Description A 3‐yr grazing study was conducted at the Central Georgia Branch Experiment Station near Eatonton. Alfagraze and Apollo alfalfa were planted in fall...

To provide animals with high quality forage, practical methods are needed to estimate nutritive value to optimize harvest timing. The objective of this study was to develop such models to estimate warm‐season forage nutritive value in the southeastern United States. The experiment was conducted at the University of Tennessee Plateau AgResearch and Education Center in Crossville, TN, from 2013 to 2015. Four warm‐season forages were evaluated separately, each in a randomized complete block design and, each for 2 yr: switchgrass [Panicum virgatum (L.) ‘Alamo’‐ a lowland variety from Texas with high forage quality and biomass production], sorghum–sudangrass [Sorghum bicolor (L.) Moench ×Sorghum sudanese (P.) Stapf, ‘FSG208BMR’‐ a vigorous, drought tolerant variety with improved digestibility], bermudagrass [Cynodon dactylon (L.) Pers. ‘Vaughn's # 1’‐ a cold tolerant, upright variety] and crabgrass [Digitaria sanguinalis (L.) ‘Quick‐N‐Big’‐ a fast germinating variety with a quick growth rate]. Monthly initiations were established based on cutting timing, in which a single cut was made at the beginning of the assigned month with nutritive value and herbage mass (HM) of the regrowth observed in the following weeks. Results determined that HM was influential on crude protein (CP) and neutral detergent fiber digestibility (NDFD) for all species tested, except crabgrass. Based on differences in nutritive value and morphological composition by maturity, as well as the successful prediction of CP and NDFD from HM through linear regression, it was determined that June and July initiations are preferred for switchgrass and bermudagrass, while July initiation is preferable for sorghum–sudangrass. Nutritive value was analyzed over time for four warm‐season forage grasses. Herbage mass accumulation was estimated for each management strategy. Nutritive value can be predicted from herbage mass for most species. Early initiation cuts are preferable to produce forage of high value in all cases.

T he development of renewable bioenergy resources has become increasingly important over the last three decades (Lynd et al., 1991; McLaughlin and Kszos, 2005; Sanderson et al., 1996). Switchgrass has often been a primary species investigated for bioenergy (Lynd et al., 1991; Sanderson et al., 1996), with a single late fall or early winter harvest resulting in the greatest sustainable biomass yield (Parrish and Fike, 2005). There is the potential to remove an early-season forage harvest in a biomass system, which may provide more options to producers from the same crop (Mosali et al., 2013; Sanderson and Adler, 2008). Research has indicated that an early-season forage harvest followed by a fall biomass harvest will result in a reduced biomass yield but will also result in an increase in total yield influenced by the forage harvest timing (McIntosh et al., 2015). Just as harvest timing influences yield, timing is a major factor influencing forage nutritive value (Ball et al., 2015). In hay production, nutritive value is an important consideration when using native warm-season grasses (NWSGs) in mixture and can be affected by plant maturity (Springer et al., 2001). As harvest is delayed from early to late seedhead production, nutritive value decreases dramatically, making it important to include plant maturity as one of the considerations for hay production instead of yield alone (Waramit et al., 2012). With proper management, switchgrass (SG) in monoculture can produce good nutritive values before maturity causes reduced values, usually after the vegetative stage at late boot when the head is emerging (Mitchell et al., 2001; Richner et al., 2014). Species mixtures that include SG provided good quality forage with increased yields, depending on the management system (

Abbreviations: BB, big bluestem; BB+IG, two-way blend of big bluestem and indiangrass; BH, biomass harvest; EB, early-boot harvest; EB+BH, early-boot plus biomass harvest; ESH, early-seedhead harvest; ESH+BH, early-seedhead plus biomass harvest; DAP, diammonium phosphate; IG, indiangrass; NWSG, native warm-season grasses; PLS, pure live seed; SG, switchgrass; SG+BB+IG, three-way mixture of switchgrass, big bluestem, and indiangrass.