Two diets, a control diet (C) and a diet including HSC (H), were fed to 1,200 Ross 308 chickens which were divided over 8 pens.
Birds were housed indoors until 21 d, and thereafter kept in the same groups in two chicken houses with access to outdoor pasture up to slaughter at 70 d.
Production performance was registered weekly. The number of Clostridium perfringens in caeca, as well as leg and foot health and carcass quality was registered during the study period or at slaughter.
Total mortality was high regardless of diet due to a short heat wave extreme for Swedish conditions which predominantly affected the heavy male broilers.
The inclusion of HSC did not affect total production performance or mortality.
Furthermore, no effect of HSC inclusion in the feed was seen on the number of C. perfringens in the caeca.
There were differences in litter condition and foot health of birds, which may have been related to the high crude fibre content of the H diet.