RELATIONSHIP BETWEEN THE NUMBER OF MEALS PER DAY AND RUMINATION PROCESS IN DAIRY COWS

In this study rumination activity of ten lactating Romanian Black and White multiparous cows housed in total confinement in tied stalls was observed continuously 24 hours per day. Researches were carried out during two weeks, in February 2008. To record the behavior, four video cameras were used connected to a video capture device of 125 fps (frames per second) of CC9622BIR type. There were two experiments, first experiment (96 h) in which cows were fed two times per day, and in second experiment (96 h) three times per day. During the experimental period, cows were fed a diet consisted in 20 kilograms of corn silage; 8 kilograms of lolium hay; 3 kilograms of concentrates and 4 kilograms of browerʹs yeast. During first experiment, cows spent ruminating on average in 24 hours 489.6 minutes, in 16 periods, with an average length of a rumination period of 30.7 minutes. During second experiment, cows spent ruminating on average per day, 545.5 minutes, in 18.7 ruminating periods and with an average length of each period of 29.8 minutes. Differences between the two experiments during 24 hours were registered to be 55.9 minutes for total time spent ruminating, 2.7 ruminating periods and 0.9 minutes for the average length of a rumination period. Thus, despite of same housing and feeding conditions, number of meals per 24 h influenced both duration of the rumination process and number of rumination periods (p<0.05).