Bioacoustics as a tool for evaluating grazing behavior of Girolando heifers

ABSTRACT Aiming to validate the analysis of bioacoustic data for describing grazing behavior of heifers in integrated crop, livestock (ICL) and forestry (ICLF) systems. Eight 25±6.8 month-old Girolando (¾Holstein × ¼Gir) heifers with 268±83kg of live weight (LW) were distributed in 2x2 crossover design (two systems x two evaluation periods). Data collection for bioacoustic analysis was done with MP3 recorders. These data were analyzed by Audacity® software for identification of the activities of grazing, rumination, and resting. Concomitantly, behavior was also analyzed by the method of visual observation from 8AM to 4PM in intervals of 15 minutes. There was no difference (P>0.05) between the methods of bioacustic and visual observation considering the means of time (minutes) of grazing, rumination, and resting, respectively: 127 vs. 137; 122 vs. 113; and 238 vs. 216 in ICL system and; 134 vs. 103; 130 vs. 165 and 233 vs. 203 in ICLF system. In conclusion, the bioacustic method is a tool that can be useful for evaluating bovine grazing behavior within different grazing systems, with the advantage of allowing report of activities during the night with higher practicality and precision than the visual observation method.