Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 19, 2005
Publication Date: January 20, 2006
Citation: Burns, J.C., Fisher, D.S. 2006. Intake and digestion of jesup tall fescue hays without the fungal endophyte compared with novel and wild type endophytes. Crop Science. 46:216-223. Interpretive Summary: This study determined the intake and digestion of hays harvested in April and in June of the recently released 'Jesup' tall fescue. Jesup was evaluated having no endophyte with Jesup containing either a novel endophyte, which benefits plant persistence, or a wild-type endophyte that may negatively impact the daily performance of the consuming animal. Jesup tall fescue with the novel endophyte is presently available on the market and sold under the name of 'MaxQ'. In general, the presence of the novel endophyte (MaxQ) gave similar or greater animal intake and digestion as did the endophyte-free Jesup. This is in contrast to Jesup with the wild-type endophyte which resulted in similar or least dry matter intake and digestion. Consequently, if Jesup with the novel endophyte (MaxQ) shows an advantage in long-term plant survival than it could be fed without concern relative to causing toxicosis in ruminants. Tall fescue harvested in April, regardless of endophyte state, was superior in dry matter intake and digestion compared to a harvest taken in June. In all cases hays were fed during the winter when ambient temperature did not exceed 13 C, therefore, heat stress on the animal, which increases the severity of toxicosis, was not a consideration in these studies.
Technical Abstract: Tall fescue (Festuca arundinacea Schreb.) is an important forage resource for beef cattle enterprises across the North/South transition zone. The recently released 'Jesup' tall fescue, an improved cultivar and 'Jesup' tall fescue with a novel (nontoxic) endophyte marketed under the trademark 'MaxQ' with improved agronomic stability, warrants evaluation as a winter hay source for ruminants. Three intake and digestion experiments were conducted using goats, sheep and cattle as experimental animals. Jesup tall fescue with no endophyte, Jesup containing the MaxQ endophyte presumably without ergot alkaloids and Jesup with a wild type endophyte capable of producing ergot alkaloids were harvested in April and in June. These six hays were fed to goats and sheep. Hays harvested in June only were also fed to cattle. The forages were fed in intake and digestion trials during the winter period with ambient temperatures below 13°C. The tall fescue hays harvested in April compared with June were consumed similarly by goats, but not by sheep. Sheep had greater digestion and digestible intakes of dry matter, CP, and NDF and its constituent fiber fractions with hays harvested in April. Among hays within a harvest date the dry matter intake and dry matter and CP digestions were similar for April and June harvests with all three animal species. An exception occurred for the April harvest in the experiment with goats in which we found greater dry matter intake (P = 0.06) and CP digestion (P = 0.07) of the MaxQ hay than the hay with the wild type endophyte. The digestible dry matter intake of the MaxQ hay harvested in April was greater for goats (P = 0.05) and sheep (P = 0.10) compared with the hay with the wild type endophyte and for sheep, the digestible dry matter intake of the MaxQ hay was greater than the hay without an endophyte (P = 0.08). The digestible CP intake of hays from both the April and June harvests were greater when goats were fed either the MaxQ (P = 0.08; P = 0.06) or endophyte free (P = 0.08; P = 0.05) hays. Short-term intake and digestion indicate that Jesup tall fescue with the MaxQ endophyte provides a good source of nutrients when preserved as hay for the winter-feeding of ruminants in the Mid-Atlantic Region.