HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Richards, C. J. Articles by Waller, J. C. Search for Related Content PubMed PubMed Citation Articles by Richards, C. J. Articles by Waller, J. C.

Influence of soybean hull supplementation on rumen fermentation and digestibility in steers consuming freshly clipped, endophyte-infected tall fescue¹

Department of Animal Sciences, The University of Tennessee, Knoxville 37996

² Corresponding author: chris.richards{at}okstate.edu

Six steers (288.6 ± 2.1 kg of BW) fitted with rumen and duodenal cannulas were used in a crossover design to evaluate intake, rumen fermentation, and site of nutrient digestion of freshly clipped, endophyte-infected (E+) Kentucky 31 tall fescue with or without soybean hull (SH) supplementation at 0.60% of BW (OM basis). Steers were placed in metabolism units within an environmentally controlled room and provided with free-choice access to fresh forage, water, and a vitamin/mineral supplement. The spring growth of E+ tall fescue was harvested daily during the experiment. Supplement was fed at 0700 with approximately 65% of the estimated daily forage. To maintain a fresh forage supply, additional forage was stored in a cooler and fed at 1900. Periods were 21 d with 14 d of adaptation and 7 d of digesta sample collection. Chromic oxide was used as a marker of duodenal digesta flow. Duodenal samples were taken 4 times daily with times shifting by 1 h each day to represent all 24 h of a day. Treatments were considered significant at P < 0.05. Supplementation of SH decreased forage OM intake from 1.64 to 1.41% of BW but increased total OM intake from 1.64 to 2.01% of BW. Apparent percentages (53.1%) and quantities (2,786 g/d) of rumen OM disappearance were not affected by supplementation. Percentages of total tract OM disappearance were not different (70.8%). Percentages of apparent rumen NDF disappearance also were not different (65.6%). Percentages of N disappearance were not different. Supplementation of SH resulted in increased total N (34.1 g/d) and microbial N (17.1 g/d) flowing to the duodenum. Rumen pH (6.5) was not affected, and rumen ammonia concentrations exhibited a time x treatment interaction in which SH decreased ammonia for 12 h after supplementation. Total VFA concentrations (103.9 mM) were unaffected. Liquid dilution rate (12.7%/h) and rumen OM fill (4.3 kg) were not different between treatments. Supplementation of SH at a rate of 0.60% of BW (OM basis) to calves consuming fresh E+ tall fescue decreased forage consumption but resulted in greater total intake, greater flow of N to the duodenum, and increased total tract OM disappearance.

Key Words: cattle • digestibility • forage intake • supplementation • tall fescue

This article has been cited by other articles:

				S. A. Gunter, P. A. Beck, D. L. Kreider, P. Gregorini, and C. B. Stewart The Effects of a Modified Glucomannan on the Performance of Stocker Cattle Grazing Endophyte-Infected Tall Fescue Professional Animal Scientist, June 1, 2009; 25(3): 300 - 306. [Abstract] [PDF]

				E. Pavan and S. K. Duckett Corn oil or corn grain supplementation to steers grazing endophyte-free tall fescue. I. Effects on in vivo digestibility, performance, and carcass quality J Anim Sci, November 1, 2008; 86(11): 3215 - 3223. [Abstract] [Full Text] [PDF]