Experimental Diets
The broilers were supplied a pelleted basal wheatmaize-
soya diet without supplemental zinc from day of
arrival to 3 d of age. A basal diet (Table 2) was formulated,
which contained 33.5 mg of Zn/kg. Experimental
diets were manufactured by adding the respective zinc
source to the basal diet. All diets met or exceeded nutrient
requirements of broilers according to Dutch standards
(CVB, 2007), except for dietary zinc. From d 3
onward, the birds were fed their respective pelleted experimental
diets until the end of the experiment (d 21).