Performance of yearling steers grazing bahia grass [Paspalum notatum] pastures with summer annual legumes or nitrogen fertiliser in subtropical Florida [beef cattle]
1992
Pitman, W.D. (Florida Univ., Ona (USA). Agricultural Research Centre) | Portier, K.M. (Florida Univ., Gainesville (USA). Statistics Dept.) | Chambliss, C.G. (Florida Univ., Gainesville (USA). Agronomy Dept.) | Kretschmer, A.E. (Florida Univ., Ft Pierce (USA). Agricultural Research Centre)
Established pastures of bahia grass with either aeschynomene (Aeschynomene americana), phasey bean (Macroptilium lathyroides), or nitrogen fertiliser were evaluated over 3 years at Ona, Florida, for potential to provide sustainable pasture systems of increased productivity. Aeschynomene pastures produced the highest average daily gains (ADG) of yearling steers at 0.57 kg compared with an average of 0.36 kg for the other treatments. Crude protein (CP) concentration of legumes was high (over 20 percent), however, the legumes comprised only 7.2 percent (for aeschynomene) and 2.3 percent (for phasey bean) of the herbage dry matter during the peak period and did not increase CP or in vitro organic matter digestibility (IVOMD) of total herbage samples even during this period. The high nitrogen treatment (224 kg per ha N) produced higher total herbage CP and IVOMD than did the zero N control but did not produce higher ADG. Carrying capacity was lowest on aeschynomene (536 d per ha) and highest at 224 kg per ha N (1322 d per ha). Stands of the legumes were not sustained, apparently due to dense grass sod and erratic rainfall. N fertilisation of bahia grass increased carrying capacity but failed to enhance individual animal performance despite increases in forage quality.
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