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

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal 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 Davis, G. V. Articles by Erhart, A. B. Search for Related Content PubMed Articles by Davis, G. V. Articles by Erhart, A. B.

Effects of Monensin^{1 ,2,} and Urea in Finishing Steer Rations³

Kansas State University, Garden City Branch Experiment Station, Garden City 67846

Abstract

In a 120-day finishing trial, 192 steers averaging 763 lb (346 kg) were fed rations containing monensin at 0, 10 or 30 g/ton[0, 11 or 33 ppm-90% dry matter (DM) basis] with supplemental urea withdrawn from rations (80% rolled corn, 15% corn silage, 5% supplement-DM basis) after 0, 42, 84 or 120 days to determine whether cattle should be gradually adapted to monensin and whether moensin has a urea-sparing effect. On a DM basis, rations with urea contained 11.5% crude protein (CP) and rations with no urea (urea replaced with rolled corn) contained 9.5% CP. Steers were allotted to 24 pens (eight steers/pen) and fed rations containing monensin as follows: ration 1, no monensin (120 days); ration 2, 10 g monensin/ton (t) for 7 days, then 30 g monensin/t for 113 days; ration 3, 10 g monensin/t for 21 days, then 30 g monensin/t for 99 days; or ration 4, 30 g monensin/t for 120 days. Feed consumed daily on a DM basis, lb (kg); daily gain, lb (kg); and lb (kg) DM per lb (kg) gain, respectively, for rations 1, 2, 3 and 4 were: 20.97 (9.51), 2.81 (1.27), 7.46; 18.48 (8.38), 2.94 (1.33), 6.30; 18.82 (8.54), 2.98 (1.35), 6.31; 17.40 (7.89), 2.77 (1.26), 6.28. Daily gain from ration 3 was higher (P<.05) than from ration 4. Dry matter required/gain was lower (P<.05) for cattle fed rations 2, 3 or 4 than for those fed ration 1. Daily gain and DM/ gain improvements (%) for cattle fed monensin (rations 2, 3 and 4) compared with those fed no monensin (ration 1) were: ration 2–4.6, 15.5; ration 3–6.0, 15.4; ration 4–1.4, 15.8. Feeding urea with monensin improved daily gains. Daily gain, lb (kg) and lb (kg DM/lb gain for monensin rations containing urea for 0, 42, 84 or 120 days were, respectively: (0) 2.81 (1.27), 6.29; (42) 2.89 (1.31), 6.49; (84) 2.90 (1.32), 6.29; (120) 3.03 (1.37), 6.13. Rumen fluid from steers fed monensin contained more (P<.05) propionate and less (P<.05) butyrate than from steers fed no monensin. Carcass characteristics were not significantly influenced by monensin or urea.

¹ This study was partially supported by Eli Lilly and Company, Greenfield, Indiana. Appreciation is extended to Dr. Herman Grueter for his cooperation and assistance in conducting these trials.

² Rumensin® is the trade mark of Eli Lilly and Company, Greenfield, Indiana, for monensin premix for cattle.

³ Contribution No. 124, Garden City Branch Experiment Station, Garden City, Kansas.

⁴ Associate Professor of Animal Science and Station Superintendent, respectively.

This article has been cited by other articles:

				B. E. Depenbusch, J. S. Drouillard, E. R. Loe, J. J. Higgins, M. E. Corrigan, and M. J. Quinn Efficacy of monensin and tylosin in finishing diets based on steam-flaked corn with and without corn wet distillers grains with solubles J Anim Sci, September 1, 2008; 86(9): 2270 - 2276. [Abstract] [Full Text] [PDF]