In the making of olive oil there are wastes, including olive leaves and cake which can have positive (reduction of oxidative stress, beneficial effects on gastrointestinal health) as well as negative effects (high concentrations of polyphenols). In our study we performed nutritional and balance experiments on broiler chickens Ross 308. In both experiments the animals were divided into five groups, FKON, F+5OL, F+10OL, F+5OT and F+10OT, 4 experimental groups were supplemented with olive leaves or cake in concentrations of 50 or 100 g/kg of feed. After completion of the nutritional experiment, chickens were sacrificed and blood, gastrointestinal tract (GT), GT contents and liver samples were taken. In the balance experiment, excreta from chickens were collected for further analysis. The activity of liver enzymes (GGT, AST, ALT), concentration of malondialdehyde (MDA) and isomers of vitamin E (VE), antioxidant capacity of water-soluble antioxidants (ACW) were all measured in liver, the pH, viscosity and volatile fatty acids (VFA) of the GT contents and contents of fatty acids (FA) in chicken excreta were also measured. Based on the results of both experiments, we concluded that the addition of olive leaves or cake did not significantly affected the indicators of oxidative stress, nor did they affect the indicators of digestion. Supplementation with olive cake improved utilization of fats, SFA and MUFA. From the perspective of oxidative stress, animal and GT health, both supplements, olive leaves and cake, can be safely used as feed ingredients in broiler chicken diets.
|
