Intake and Digestibility of Improved Selections of Tall Fescue and Orchardgrass Hays

Improved cool-season grass cultivars may add production potential to ruminant enterprises across the North–South transition zone. Quality among hays of ‘MaxQ’ (‘Jesup’ with novel endophyte), HM4 (‘HiMag’ with novel endophyte No. 4) and ‘Cajun’ (without endophyte) tall fescues [Lolium arundinaceum (Schreb.) Darbysh.] and ‘Persist’ orchardgrass (Dactylis glomerata L.) was evaluated. Forage was harvested in the fl ag-leaf stage in three of 4 yr and a regrowth (late fl ag-leaf to heads-emerging stage) in 1 yr. Goats (four trials) consumed MaxQ, HM4, and Persist similarly (P = 0.12; mean = 2.49 kg 100–1 kg body weight [BW]) and Cajun least (P < 0.01; mean = 1.62 kg × 100–1 kg BW). Apparent digestibility was similar among tall fescues (P ≥ 0.07; mean = 609 g kg–1), but MaxQ and Cajun were greater than Persist (P ≤ 0.05; mean = 610 and 623 vs. 582 g kg–1). Digestible dry matter intake (DMI) was similar among MaxQ, HM4, and Persist (P ≥ 0.09; mean 1.49 kg 100–1 kg BW). Steers (three trials and Cajun not evaluated) consumed more Persist than MaxQ (P = 0.01; 2.40 vs. 2.14 kg 100–1 kg BW) or HM4 (P = 0.01; 1.98 kg 100–1 kg BW). MaxQ had greater apparent digestibility than HM4 (P = 0.01) or Persist (P = 0.04; 626 vs. 585 vs. 597 g kg–1, respectively) but digestible DMI of MaxQ and Persist was similar (P = 0.12; mean = 1.39 kg 100–1 kg BW). Improved tall fescue cultivars, with novel endophyte, offer the ruminant producer a cool-season forage of similar quality as orchardgrass for their enterprise. J.C. Burns, USDA–ARS and Dep. Crop Science and Dep. Animal Science, North Carolina State Univ., Raleigh, NC 27695; D.S. Fisher, USDA–ARS, 1420 Experiment Station Rd., Watkinsville, GA 30677. Cooperative investigation of the USDA-ARS and the North Carolina ARS, Raleigh, NC 27695-7643. The use of trade names does not imply endorsements by USDA–ARS or by the North Carolina ARS of the products named or criticism of similar ones not mentioned. Received 26 Mar. 2009. *Corresponding author ( [email protected]). Abbreviations: ADF, acid detergent fi ber; BW, body weight; CELL, cellulose; CP, crude protein; Diff , diff erence; DM, dry matter; DMI, dry matter intake; HEMI, hemicellulose; HM4, ‘HiMag’ tall fescue infected with the novel No. 4 endophyte; NDF, neutral detergent fi ber; NIRS, near-infrared refl ectance spectroscopy. Published in Crop Sci. 50:419–426 (2010). doi: 10.2135/cropsci2009.03.0157 © Crop Science Society of America 677 S. Segoe Rd., Madison, WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher.