Forage Attributes and Animal Performance from Native Grass Inter‐Seeded with Red Clover

Abstract

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.

Overseeding Eastern Gamagrass with Cool‐Season Annual Grasses or Grass–Legume Mixtures

“…Keyser et al (2016) reported little effect of overseeding red clover into NWSG on forage mass, CP, neutral detergent fiber, or animal performance, likely due to low levels of clover after establishment. The study concluded that alternative legume options for overseeding NWSG systems should be explored.…”

Risk and returns from grazing beef cattle on warm‐season grasses in Tennessee

“…For the perennial forages, a 10-yr production horizon with no grazing in the establishment year was assumed, which is typical for this region (Boyer, Tyler, Roberts, English, & Larson, 2012Lowe et al, 2015;Zhou, Boyer, Larson, & Lieb, 2014). Total establishment and production costs of native warm-season grasses were calculated following previous studies (Boyer, Griffith, Roberts, Savoy, & Leib, 2014;Keyser et al, 2016;Lowe et al, 2015Lowe et al, , 2016McFarlane, Boyer, & Mulliniks, 2018). Establishment costs, which included seed, fertilizer, herbicide, machinery, and labor, were annualized over the pasture production life using a discount rate of 5.5% (Boyer et al, 2012Lowe et al, 2015;McFarlane et al, 2018;Zhou et al, 2014).…”

“…These net returns to grazing ranged from a low of $244 to $852 ha −1 , depending on WSG species and grazing management. Similarly, animal performance and economics of grazing bred heifers on WSG have proven favorable with cost of gain as low as $0.14 kg −1 for switchgrass ( Panicum virgatum L.; SG) pasture and $0.18 kg −1 when a combination of big bluestem ( Andropogon gerardi Vitman) and indiangrass ( Sorghastrum nutans L.; BI) was grazed (Keyser et al., ). Furthermore, costs for dairy heifers grazing SG and a BI blend were $0.38 and $0.65 head −1 d −1 , which are lower than the $1.89 head −1 d −1 that was estimated for using harvested commodity feeds (Lowe et al., ).…”

Legume Addition to Perennial Warm‐Season Grass Swards Increases Harvested Biomass

“…The production of a legume and warmseason grass mixture might also increase farmer flexibility because the legume crop can be harvested and used as highquality animal feed (Bow et al, 2008). Field evaluations of mixtures of legumes and warm-season grasses for forage production have sometimes shown promising results (Ashworth et al, 2015), but it has also proved difficult to establish (Keyser et al, 2016) or maintain productivity (Biligetu et al, 2014) of these mixtures. Field evaluations of mixtures of legumes and warm-season grasses for forage production have sometimes shown promising results (Ashworth et al, 2015), but it has also proved difficult to establish (Keyser et al, 2016) or maintain productivity (Biligetu et al, 2014) of these mixtures.…”

“…The agronomic and environmental benefits of legume and cool-season grass mixtures in pasture systems have long been appreciated (Rochon and Doyle, 2004). Field evaluations of mixtures of legumes and warm-season grasses for forage production have sometimes shown promising results (Ashworth et al, 2015), but it has also proved difficult to establish (Keyser et al, 2016) or maintain productivity (Biligetu et al, 2014) of these mixtures. Several legume species have been found to be compatible in legume-switchgrass (Panicum virgatum L.) mixtures, although there is wide variation in biomass yields and combining abilities (Springer et al, 2001) among the legume species.…”