Evaluation of alternative forage species to reduce risk for cow-calf production systems in the Appalachian region

Tall fescue is the main cool-season forage in cow-calf production systems across the Appalachian region. However, cool-season species suffer a slump in biomass production during the hot, dry summer months. An experiment was initiated in summer 2008 at three research stations in Virginia at Kentland Farm in Blacksburg, the Northern Piedmont AREC in Orange and Shenandoah AREC in Steeles Tavern. Seven forage species were established as small plots (3m x 9m) arranged in a randomized complete block design with 4 replications at each location. The treatments included endophyte-infected tall fescue (KY31 E+) (Festuca arundinacea Schreb.), endophyte-free tall fescue (KY31 E-), novel-endophyte tall fescue (MaxQ), Caucasian bluestem (CB) (Bothriochloa bladhii (Retz) S.T. Blake), Teff (var. Tiffany) (Eragrostis tef Zucc. Trotter), Bermudagrass (BG; var. Wrangler) (Cynodon dactylon (L.)(Pers.)), and Crabgrass (var. Red River) (Digitaria spp.) in combination with endophyte-infected tall fescue. Samples were taken throughout the production seasons of 2009 and 2010 (April 15-Nov 1) at the late-boot stage for forage biomass and quality. Forage production and quality values followed the typical seasonal distribution for cooland warm-season species. Specifically, all cool-season grasses produced adequate amounts of biomass in spring but declined in production for the remainder of the season. Similarly, high levels of crude protein (CP) were observed in spring and early fall from cool-season grasses. On the contrary, biomass yield of warm-season grasses was highest in mid-summer. While the CP values of cool-season grasses ranged from 8-9% mid-summer, warm-season grasses held a CP value between 9 and 15%. Despite these values, the yield 21 potential of perennial warm-season grasses was substantially reduced due to problems associated with establishment. Depending on location, unseasonably wet or dry spring contributed to poor establishment and sparse stand. However, regardless of variability in biomass yields, warmseason grasses; both annual and perennial, produced biomass yields and nutritional values adequate to fill the summer slump from cool-season forages. Introduction In the Appalachian region of the Southeastern United States, cool-season perennial forages can potentially be integrated with warm-season species in order to extend the growing season. Tall fescue (Festuca arundinacea Schreb.) is the main cool-season forage across the Appalachian region. It is adapted to the “transition zone”, defined as the area between the successful zone of cultivation for cool and warm-season grasses. Tall fescue is the most important forage species worldwide of the Festuca genus and the principal cool-season perennial grass in the humid areas of the USA (Moser et al., 1996). Classified as a cool-season perennial grass, peak production of tall fescue occurs in the spring months with a secondary peak of vegetative growth in early fall (Barnes et al., 2003). If stockpiled starting late summer, the accumulated growth is often used as a feed source throughout the winter in the southeastern and mid-Atlantic United States. Tall fescue is especially advantageous over other cool-season grasses because of its persistence under low management input of part-time operations and those favoring low economic risk over high return (Moser et al., 1996). Unfortunately, as with most cool-season plants, tall fescue experiences a “summer slump” or lack of production in July and August when temperatures rise above the optimum 20-25C and is only able to withstand relatively short periods of drought (Moser et al., 1996). When considering a year-round grazing system, tall fescue must be supplemented with alternative forages that have the ability to offer 22 greater yield in mid-summer months, thus reducing the risk of shortages in forage. In any grazing system, optimizing forage productivity is essential to reduce pasture seasonality and ensure available forage to meet the nutritional needs of grazing livestock. In many circumstances, alternative forages are used to complement or replace existing species in an effort to reduce the risk of yields falling below minimum requirements of the grazers (Griffith, 1978). This study examined seven different cooland warm-season forage species. Tall fescue varieties were compared with warm-season annuals and perennials to evaluate performance based on production yields and nutrient content during the summer slump. As a burgeoning field in agriculture, year-round grazing systems are becoming increasingly important in a growing world economy. With proper techniques using alternative forages and risk management strategies, producers will have confidence that they can reach optimal production and satisfy livestock needs in a forage-based operation. Methods and Materials Small plot experiments were conducted in 2009 and 2010 at three Virginia geographical locations: Kentland, Northern Piedmont AREC and Shenandoah AREC (Fig 31). A randomized complete block design was utilized with seven forage species as the main plot. The seven forage treatments included endophyte-infected tall fescue (KY31 E+), endophyte free tall fescue (KY31 E-), novel endophyte tall fescue (MaxQ), Crabgrass (var. Red River) in combination with endophyte-infected tall fescue (KY31 E+), Teff (var. Tiffany), Bermudagrass (BG; var. Wrangler), and Caucasian bluestem (CB). Each plot measured 3 x 9 meters with 3 meter alleyways between treatments and 4.5 meters between replications.