Organ and carcass measurements
At the end of the trial, all chickens were fasted
overnight to minimise interference from intestinal
content, then weighed. Those chickens (®ve per
treatment) having odd-numbered wing bands were
killed ®rst by stunning (35V and 75mA electric stun)
followed by bleeding and scalding.10 Similarly, those
chickens (®ve per treatment) with even-numbered
wing bands were killed by stunning/cervical dislocation
while avoiding loss of blood. They were thenracteristics of the breast and thigh meat were best in the group receiving
300 ppm XT. In all supplemented groups the number of E. coli and Clostridium perfringens in
rectal contents was significantly lower than in the control group; supplementation of the diet with 300
ppm XT and feed antibiotic had a similar effect on the number of evaluated microorganisms. Apparent
ileal digestibility of nitrogen, nutrients, and amino acids, particularly of threonine, serine, asparagine,
phenylalanine, histidine and lysine, in 21-day-old chickens was positively affected by XT supplementation.
The coefficients of apparent ileal digestibility of nutrients in older birds (32-day-old) in groups fed
diets with XT or feed antibiotic were similar.