Intervals between observations at different time scales in the feeding behavior of dairy confined cows

Abstract

This study aimed to analyze different time scales to determine the most appropriate interval in the study of ingestive behavior of confined dairy cows. The experiment was conducted at the farm Blue Water, city of Macarani-Bahia, in the period from October to November 2005. 12 crossbred Holstein cows were used, with an average body weight of 478.5  15.89kg. The treatments of this study were the intervals (five; 10; 15; 20 and 30 minutes), observed during ingestive behavior. Behavior observations occurred on the second to last day of each period of 15 days data collection for 24 hours. There has been analysis of variance and Dunnett test application, adopting 0.05 as the critical level of probability. There was no significant effect of record scales of time spent eating, ruminating, idling and efficiencies of feeding and rumination. For the variables of the numbers of periods of eating, ruminating and idle and times per period of feeding, ruminating and resting, the ranges of 10, 15, 20 and 30 minutes were different when compared with the interval of five minutes of observation. Total collection of times of feeding ruminating and idling, and efficiencies of feeding and ruminating on the different nutrients can be performed with an interval of observation of up to 30 minutes. For the discretization of the time series of ingestive behavior, it is recommended the scale of five minutes between observations.