J. Anim Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gunter, S. A.
Right arrow Articles by Phillips, J. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gunter, S. A.
Right arrow Articles by Phillips, J. M.
J. Anim. Sci. 2005. 83:2235-2242
© 2005 American Society of Animal Science

ANIMAL PRODUCTION

Effects of stocking and nitrogen fertilization rates on steers grazing dallisgrass-dominated pasture1

S. A. Gunter2, P. A. Beck, S. Hutchison and J. M. Phillips

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

2 Correspondence: 362 Hwy 174 N. (phone: 870-777-9702, ext. 107; fax: 870-777-8441; e-mail: sgunter{at}uaex.edu).

To compare the performance of steer calves managed under different stocking rates (SR; 3.7, 6.2, 8.6, and 11.1 steers/ha for 140 d; {chi}I1) and N fertilization rates (112, 224, and 336 kg of N/ha; {chi}I2) in May 1996, 1997, and 1998, 72 steer calves (BW = 231 ± 2.5 kg) were assigned randomly to one of 12 0.81-ha dallisgrass (51%)/common bermudagrass (32%) pastures. One-third of the fertilizer was applied in the form of ammonium nitrate in May, June, and August to achieve the prescribed totals. Treatments were separated using a polynomial regression equation: {gamma}i = ß0 + ß1{chi}I1 + ß2{chi}I2 + ß11{chi}2I1 + ß12{chi}2I2 + ß12{chi}i1{chi}i2 + {varepsilon}I, with years as replicates. Within the range of the data, ADG and BW gain per steer were greatest at a stocking rate of 3.7 steers/ha and 336 kg/ha of N. Body weight gain per hectare peaked at 701 kg when cattle were stocked at 8.9 steers/ha and the pasture was fertilized with 336 kg/ha of N. The least cost of production was at a stocking rate of 3.7 steers/ha, with 112 kg/ha of fertilizer N applied, and the greatest cost of production was at a stocking rate of 11.1 steers/ha with 336 kg/ha of fertilizer N applied. Fertilization at 336 kg/ha of N produced the most profitable stocking rate at 7.3 steers/ha and returned $355.64. The optimal stocking rate for net return was 79, 81, and 82% of that for maximum BW gain per hectare for 112, 224, and 336 kg/ha of N, respectively. Under the assumptions made in the financial analysis, these data show that the economically optimal carrying capacity of similar pastures can be increased with N fertilizer up to at least 336 kg/ha annually.

Key Words: Cattle • Nitrogen Fertilizer • Paspalum dilatatum • Stocking Rate






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2005 by the American Society of Animal Science.