Evolution of Production Indicators over Time in Nelore Cows from the Bolivian Tropics

The objective of the present work was to analyze evolution productive indicators over time in Nelore cows Bolivian tropics. period between 1991 and 2016, corresponding 3899 calvings were used for research which belong Technology Center on Agriculture Livestock Bolivia belonging (FUNDATION CETABOL) Cooperativa Agropecuaria Integral San Juan de Yapacaní used. Cows ordered by birth into three groups (1991-2000; 2001-2010; 2011-2016). following variables analyzed: Age at first calving days, Live weight cow kg, Calf weaning Calving interval Longevity Accumulative Productivity kg Total calf production (CP) kg. age has decreased compared decade 1991-2000, however last (2011-2016) increased one more month (2001-2010) showing significant differences (p≤0.05). weights followed same behavior sense decreasing, that 2011-2015, had lowest live calving-calving interval. showed an increase two periods with difference (p≤0.05) 1991-2000. That longest-lived those from 1991-2000 period, 2001-2010 presented best value Accumulated Production (p≤0.05), although highest weaned It concluded tropics individually improvement their indicators, analysis complex did not show results.