Richness measures (alpha diversity) for the cecal bacterial communities in the second trial. The richness has been visualized for the control group and the group receiving wax and fat-protected butyrate. Cecal content was collected from the 21-day-old chickens in the first trial 4 days after Salmonella infection and receiving a standard diet supplemented with wax or fat-protected butyrate or non-supplemented diet for 21 consecutive days. The horizontal lines at the bottom, the middle and the top of the box represent the first quartile, median and third quartile, respectively. The whiskers indicate the min/max value.