Comparisons of these results with those obtained in previous
studies revealed a number of difficulties. First, in Brazil, there are
only a few studies on beef production using the Life Cycle Assessment
methodology (Ruviaro et al., 2012). One very significant
problem is the variation in choice of functional unit and time scale
among studies (de Vries and de Boer, 2010). For example, a study of
a Japanese beef fattening system (Ogino et al., 2004) estimated a
32.3 kg CO2-e/kg of beef gain during the fattening of the animal, but
this did not include cow emissions for the entire system. Furthermore,
the production efficiency in the Japanese cattle system was
very different from that observed in this study.