ABSTRACT The objective of this study was to develop a simulation model to analyse the technical, economic, and financial performance of using different reproductive strategies in dairy herds. Strategies simulated were: artificial insemination (AI) using conventional semen after oestrus detection (AIC), AI using sex-sorted semen after oestrus detection (AIS), timed artificial insemination (TAI) using conventional semen (TAIC), and TAI using sex-sorted semen (TAIS). The total time horizon analysed corresponded to 25 years, divided into 425 periods of 21 days. The […]

An economical analysis of milk production systems was made with lactating cows on Mombaça grass pasture receiving different sources of roughage supplementation during the dry season. The supplementations were: black oat pasture, forage sugarcane with urea and sorghum silage. The economical indicators used were: net present value (NPV) and internal rates of return (IRR). For each production system studied one cash flow was used with their particularities and productive and reproductive performances index, obtained experimentally. The cash flows were built […]

Different economic viability of pasture production systems to heifers grazing elephantgrass pasture in North Fluminense region wa analyzed. The economical analysis of three systems of growing fedlot dairy heifers grazing elephantgrass pasture was performed. In order to study the hazard that each system can present due to the oscillations of prices in the market, Monte Carlo simulation was used. The systems studied were: without supplementation (PS1), offer of 0.5% of the alive weight of concentrate (PS2), and alternate pasture of […]

A deterministic approach was used to predict genetic gain and net present value for a breeding program in a dual-purpose zebu cattle population. The considered criterias were body weights, dairy and reproductive traits. High genetic gains and profit were obtained. More than 70% of genetic profit was net present value, justifying selection costs. The small proportion of recorded animals in relationship to the beneficial population of the improvement and the high economic values of traits could explain this profit.