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) All Versions of this Article: jas.2006-358v1 85/2/527    most recent 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 Beck, P. A. Articles by Gunter, S. A. Search for Related Content PubMed PubMed Citation Articles by Beck, P. A. Articles by Gunter, S. A.

Effect of crabgrass (Digitaria ciliaris) hay harvest interval on forage quality and performance of growing calves fed mixed diets¹

University of Arkansas, Division of Agriculture, Southwest Research and Extension Center, Hope 71801

² Corresponding author: pbeck{at}uaex.edu

Twelve 0.81-ha crabgrass (Digitaria ciliaris [Retz.] Koel.) hay fields were harvested at 21, 35, and 49 d of regrowth (average phonological growth stage of 30, 51, and 56, respectively). Increased harvest interval exhibited a linear decrease (P < 0.01) in CP (14.1, 13.7, and 10.6% of DM, respectively) and increase (P < 0.01) in NDF (65.3, 70.6, and 70.2% of DM, respectively) and ADF (35.7, 38.9, and 42.7% of DM, respectively). Hays were incorporated into 3 diets that contained 20% (DM basis) crabgrass hay, ground corn (33%), and soybean hulls (32%). Diets contained 14.4, 14.4, and 13.6% CP; 1.83, 1.72, and 1.81 Mcal of NE_m/kg; and 1.21, 1.10, and 1.17 Mcal of NE_g/kg; respectively. Diets were fed to beef calves in 12 pens at a rate of 2.3% (DM basis) of BW in 1 experiment (n = 120, initial BW 210 ± 4.4 kg) and ad libitum in another experiment (n = 60, initial BW 207 ± 4.4 kg). To measure passage rate of the hay and concentrate portions of the diets, 12 heifer calves (BW = 145 ± 4.5 kg) were individually fed at 2.3% of BW for 14 d and dosed with Dy-labeled soybean hulls and Yb-labeled hay. In situ DM digestibility of the hays and diets were determined using 3 ruminally cannulated steers (BW = 584 ± 10.4 kg). Harvest interval did not affect (P 0.11) ADG of limit-fed calves during the diet acclimation or growing phases (average 0.32 and 0.80 kg, respectively) or ADG of calves fed ad libitum (average 1.21 kg). Dry matter intake of calves fed ad libitum averaged 7.9 kg/d (3.28% of BW) and was not affected (P 0.22) by harvest interval. Gain:feed was not affected (P 0.20) by harvest interval (0.13 and 0.15 for limit-fed and ad libitum-fed calves, respectively). Increased harvest interval linearly increased (P < 0.01) ruminal retention time of the hay and tended (P = 0.06) to linearly increase ruminal retention time of the concentrate portions of the diet. Harvest interval linearly decreased (P 0.05) the extent of degradability and effective degradability of DM and NDF of hays, but DM disappearance of the total diet did not differ (P 0.35). In the conditions of this study, increasing harvest interval of crabgrass hay from 21 to 49 d had no deleterious impact on animal performance or efficiency of gain when fed to growing calves in a high-concentrate mixture.

Key Words: cattle • Digitaria ciliaris • growth • hay quality

This article has been cited by other articles:

				P. A. Beck, C. B. Stewart, H. C. Gray, J. L. Smith, and S. A. Gunter Effect of wheat forage maturity and preservation method on forage chemical composition and performance of growing calves fed mixed diets J Anim Sci, December 1, 2009; 87(12): 4133 - 4142. [Abstract] [Full Text] [PDF]