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Conversion of Fertilized Annual Range Forage to Beef Cattle Liveweight Gain
Author(s) -
Raguse C. A.,
Taggard K. L.,
Hull J. L.,
Morris J. G.,
George M. R.,
Larsen L. C.
Publication year - 1988
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1988.00021962008000040010x
Subject(s) - forage , grazing , zoology , agronomy , stocking , biology , beef cattle , growing season , dry matter , legume , human fertilization
A 3‐yr field experiment evaluated average daily (ADG) and total seasonal (LG) weight gains of growing beef cattle ( Bos taurus ) on fertilized California foothill annual range. Soils were a mixture of four series of alfisols. Nitrogen was applied alone at 45 or 90 kg ha −1 , P and S were applied together at 34P 37S or 67P 74S kg ha −1 , and the two N rates were combined with 34P 37S. Two 13.2‐ha replications were stocked with 215‐kg steers in late November, and stocking rates were increased twice during a grazing season averaging 190 d. Forage on offer (FL) varied from 400 to 2500 kg ha −1 . Annual forage production (FP) varied from 2500 to 5700 kg ha −1 and differed ( P <0.05) between treatments and years. Year‐to‐year and within‐year variations in rainfall influenced FP. Average daily gains over the season varied linearly from less than 0.2 to over 1.0 kg steer −1 . Differences in ADG due to treatments were largely restricted to the first year and to treatments with N, P, and S or the higher level of PS, but 3‐yr trends were not significant. Average daily gain was not strongly influenced by either FL or legume content of the forage. Three‐year LG was highest for the two NPS and the higher PS treatment. Fertilization increased forage organic matter digestibility and N concentrations over the control. Results indicate that either N, P, and S or a sufficient level of P and S to stimulate production of legume N was required for high forage production.