Abstract
A feeding trial was conducted to assess the effect of pelleting and enzyme supplementation on performance, carcass and blood parameters of 7 to 28 days old broilers fed on different concentrations of olive cake. The olive cake (OC) was included at 0, 10 and 15% concentrations, with or without an enzyme cocktail (EC, 0.5 g/kg feed). This resulted in three OC concentrations and two EC concentrations, in a completely randomised design with six treatments, eight replicates per treatment and five male Ross 308 broilers in replicate each group. It was observed that the broilers could utilise OC up to 15% in pelleted diets without EC supplementation. Different concentrations of OC and/or EC addition did not significantly affect performance, carcass and most inner organs characteristics, red blood cells (RBCs) profile, plasma protein and plasma calcium. In general, OC diets decreased relative liver weights compared with OC-free diets, while EC addition increased this criterion in OC diets. Conversely, plasma phosphorus was increased in groups fed OC diets compared with those on OC-free diet. EC addition increased plasma phosphorus in broilers fed OC-free diets, and inversely affected plasma calcium/phosphorus ratios. It can be concluded, that broilers from 7-28 days of age can utilise up to 15% OC in their pelleted diet without negative effects on performance and most carcass and blood parameters. Furthermore, some positive effects were noted in terms of survival rate, liver fat and phosphorus utilisation in with OC fed groups. However, using EC did not lead to more improvements in most of the investigated parameters.