Relationship among productive and economic variables of beef cattle in Brazil

ABSTRACT: The present study aimed to obtain, through statistical methods, the independent variables that influence the economic and productive results of Brazilian beef cattle. Economic and productive information was collected from 106 farms in Brazil. Data collection was performed by the Instituto de Métricas Agropecuárias (Inttegra). The variable selection method used was stepwise regression followed by polynomial regression analyses. The variable beef cattle economic result showed the positive effect of disbursement per head per month and average weight gain. An average daily gain of 520 g in live weight was obtained, and this variable was influenced especially by nutrition cost. The arroba production (arroba is a unit of weight corresponding to 15kg) was influenced by the linear effect of nutrition cost and stocking rate. The variable arroba production in pasture showed a linear and positive effect of average weight gain in pasture and stocking rate in pasture. For profit per arroba, the variables nutrition cost, disbursement with pasture, and average sale price had a linear effect. The independent variables that had the greatest influence on the response variables were stocking rate, average daily weight gain, and nutrition cost. Thus, increases in investment in nutrition and stocking rate should result in higher production rates and improvements in the profitability of this activity.

摘要：本研究旨在通过统计方法筛选出影响巴西肉牛经济与生产绩效的自变量。研究从巴西106家牧场收集了经济与生产相关数据，数据采集工作由农业计量研究所（Instituto de Métricas Agropecuárias，Inttegra）完成。本研究采用的变量筛选方法为逐步回归结合多项式回归分析。结果表明，肉牛经济绩效变量受每头月均支出与平均增重的正向影响。研究测得肉牛平均日活重增重为520克，该变量尤其受营养成本的影响。阿罗瓦产量（arroba，一种重量单位，对应15千克）受营养成本与放牧载畜率的线性效应影响。牧场放牧模式下的阿罗瓦产量则受牧场平均增重与牧场载畜率的线性正向影响。针对每阿罗瓦利润而言，营养成本、牧场相关支出与平均售价均呈现线性效应。对各响应变量影响最为显著的自变量依次为载畜率、平均日增重与营养成本。由此可见，提升营养投入与放牧载畜率，可有效提高肉牛生产效率与该养殖活动的盈利能力。