An economic evaluation of steer livemass gain from kikuyu differentially fertilized with nitrogen

Abstract

Livemass gain of steers grazing kikuyu fertilized at different levels of nitrogen has not yet been economically evaluated in South Africa. This paper reports the findings of an evaluation of kikuyu in terms of dry matter production, nutrients (crude phosphorus, potassium, magnesium and calcium), leaf:stem ratio, animal-livemass gain and economics when fertilized at four levels of nitrogen (150, 300, 450 and 600kg nitrogen/ha). Four 1ha paddocks were allocated to each nitrogen level and rotationally grazed by steers of four breed types: Brahman cross, Simmentaler, Brahman and British types. Dry matter production increased with an increase in nitrogen applied as did gain/ha, but gain/head decreased. Differences in gross returns did not quite cancel differences in costs of the various nitrogen levels and so the marginal returns per ha were R878 and R788 for the low and high nitrogen levels respectively with the other two treatments intermediate.

Keywords: economic evaluations|steers|masses|kikuyu|fertilisation|nitrogen|weight gains|grazing|dry matter production|nutrients|chemical analyses|chemicals|cows|treatments