A Thesis Submitted in Partial Fulfillment of the Requirement for the Degree of Master of Science, School of Environment, Resources and Development

Thesis (M.Sc.) - Asian Institute of Technology, 1989

Two studies were carried out to identify opportunities for an improvement of ruminant livestock production in small- scale integrated crop/livestock/fish farming system in rainfed area . A long - term experiment to study the effect of phosphorus fertilizer on yield and quality of guinea grass (Panicum maximum) and verano style (Stylosanthes hamata cv Verano) in a mi x ed pasture was conducted in AIT Experimental Field . The application of phosphorus increased markedly P contents in the forage but had little effect on cumulative yields of both species. Guinea grass showed a response to applied phosphorus in first year but not in second year, while the responsiveness of verano style to phosphorus fertilizer was not evident. Anthracnose (Coletotrichum gloeosporoides) caused heavy loss in plant stands of verano in second year's dry season and the experiment was over after two years . A simulation model was set up to evaluate the profitability from the enterprise of four ruminant species within on- farm green fodders and stored crop by-products. Gross margins and returns to labor obtained from cross- bred dairy cow and murah buffalo were significantly higher than those from native buffalo and native cattle . Highest net return (net present value) was obtained from raising dairy cattle with 23900 baht for an investment period of ten years . There was a considerable increase in net returns when draft animals were used for working.