Grazing and Subsequent Feedlot Performance by Steers That Grazed Different Types of Fescue Pasture

Abstract

Toxicity symptoms manifested by cattle grazing tall fescue (Festuca arundinacea Schreb.) infected with the endophytic fungus Acremonium coenophialum are well documented. However, subsequent feedlot performance by these cattle has been variable. This study was conducted to compared grazing and subsequent feedlot performance of steers that grazed N‐fertilized, A. coenophialum‐infected ‘Kentucky 31’ tall fescue (IF); IF interseeded with ladino clover (Trifolium repens L.; IFL); or endophyte‐free ‘Missouri 96’ tall fescue (MO). Grazing experiments were conducted from 1986 to 1988 and followed by a dry lot phase with the cattle offered high‐concentrate rations for 124 to 134 d. Significant (P < 0.05) year effects and interactions were detected for weight and gain parameters and carcass quality grade. A pasture type × phase (grazing vs. feedlot) interaction also was observed for daily gain in 1986 (P = 0.07), 1987 (P < 0.05), and 1988 (P < 0.05). Cattle grazing IF had lower pasture daily gain than those grazing IFL in 1987 (P < 0.01) and MO in 1988 (P < 0.05), but higher feedlot daily gain from than from MO in 1986 (P < 0.10) and IFL in 1987 (P < 0.05). Feed‐to‐gain ratios from cattle previously grazing IF were lower (P < 0.05) than those from cattle previously grazing IFL and MO. Cattle that previously grazed IFL had greater (P < 0.01) fat thickness and USDA yield grades. Those cattle also had higher (P < 0.05) USDA quality grades than cattle that previously grazed IF and MO in 1986 and IF in 1988. Therefore, while steer performance was reduced while grazing A. coenophialum‐infected fescue compared with those grazing low‐endophyte fescue or infected fescue interseeded with ladino clover, those steers apparently recovered from the endophyte effects such that feedlot gain and feed efficiency were enhanced.

Weaning and post-weaning performance by fall-born calves weaned on different dates from endophyte-infected tall fescue pastures managed with two different rotation frequencies

“…Numerous studies have evaluated feedlot performance following a grazing period on E+ fescue. Generally, cattle that previously grazed E+ pastures showed improved gain during a subsequent feedlot period (Coffey et al, 1990;Lusby et al, 1990;Allen et al, 2001;Cole et al, 2001b), but some studies have reported no improvement (Hancock et al, 1987) in feedlot gain or even reduced feedlot gain (Hancock et al, 1988) by calves that grazed E+ pastures previously. However, each of these studies used yearling cattle during post-weaning evaluations on E+ or other non-toxic forages.…”

“…No advantage in calf weights was detected from a twice weekly compared with a twice monthly rotational grazing system. Body weight gain by calves grazing E+ pastures has been consistently lower compared with calves grazing non-toxic pastures, but the effects of grazing E+ on subsequent animal performance have been variable (Cole et al, 2001b;Hancock et al, 1988;Coffey et al, 1990;Lusby et al, 1990). Furthermore, weaning age and post-weaning management also may impact long-term calf performance (Myers et al, 1999a,b;Thrift and Thrift, 2004;Sexton et al, 2005).…”

Nodulation and root growth of forage legumes sown into tall fescue swards

“…nov. One means for overcoming this problem is to include legumes (Hoveland et al. , 1981; Coffey et al. , 1990; McMurphy et al.…”

“…are often deleterious to livestock performance because of toxins produced by association with the endophyte, Neotyphodium coenophialum (Morgan-Jones and Gams) Glenn, Bacon and Hanlin comb. nov. One means for overcoming this problem is to include legumes (Hoveland et al, 1981;Coffey et al, 1990;McMurphy et al, 1990;Chestnut et al, 1991) in the sward. However, introducing legumes into tall fescue swards is difficult, particularly in well-established and endophyte-infected stands (Fribourg et al, 1978;Luu et al, 1982).…”

Improved grass cultivars increase milk and meat production—A review

“…Such increases in intake have been associated with a reduced intake of ergovaline (Peters et al 1989). In a complete production system, the depressed performance on endophyte-infected grass may be more than made up by compensatory gain during the subsequent finishing phase on feedlot rations (Coffey et al 1990). …”