The influence of acidosis and live yeast (Saccharomyces cerevisiae) supplementation on time-budget and feeding behaviour of dairy goats receiving two diets of differing concentrate proportion

摘要

Increasing the percentage of concentrate in the diet can influence feeding behaviour of ruminants. It can also lead to subacute rumen acidosis and the addition of yeast to the rumen ecosystem might influence fermentation and subsequently help the ecosystem deal with the consequences of high concentrate diets. The aim of this study was to analyse simultaneously the influence of bouts of acidosis and yeast supplementation (2x5g/day of dried live yeast, Saccharomyces cerevisiae, 2.2x10 super(1) super(0)CFU/g given through the rumen cannula) on feeding behaviour and time-budget of 12 cannulated dairy goats, allocated into two groups, and fed successively two diets containing 20% or 50% concentrate. Increasing the proportion of concentrate in the diet decreased the duration of rumination, especially during the night. Studying the sorting behaviour of the goats showed that yeast-supplemented goats ate a less fibrous diet than the one eaten by control goats. Yeast supplementation increased the duration of eating and DMI of the afternoon main meal but did not influence rumination. Bouts of acidosis influenced most of the tested parameters. They increased time spent eating per gram of DMI and decreased duration of rumination, especially during the night. They also decreased the number of meals per day, daily intake rate, duration of afternoon main meal and number and duration of rumination bouts. The greater effects of bouts of acidosis when compared to the effects of diet and yeast supplementation indicates that experiments dealing with high concentrate diets have to be analysed very carefully accounting for the occurrence of acidosis.