A six-week trial was conducted to evaluate the inclusion of date pits and olive pulps into corn-based diets (CDs) and their effects on performance, egg quality traits, serum lipid profiles and blood leucocytes subsets in laying hens. A total of 144 32-week-old Lohmann Selected Leghorn (LSL-Lite) laying hens were randomly distributed in 24 cages (six treatments and four replicates per treatment). The treatments were CD, wheat-based diets (WD), corn- and wheat-based diet (CWD), CD replaced with 20% date pits (DP) or 20% olive pulps (OP), or 10% date pits and 10% olive pulps (DP + OP). The results showed that the egg production and egg mass in the birds fed by-product diets were statistically (p<0.05) better than those fed WD and CWD and equal with those in CD group. The highest feed intake was observed in DP group and the lowest noted in the WD group. Treatments DP and OP also showed better (p<0.05) feed conversion ratio compared with treatments WD and CWD. In terms of egg quality traits, only yolk colour was affected by experimental diets (p<0.05). All serum lipid parameters were not significantly affected by experimental diets (p>0.05). Regarding the leucocyte profiles, only treatment WD showed higher (p<0.05) the heterophil: lymphocyte ratio compared with treatment CD. In conclusion, date pits and olive pulps could be partly used as alternative feedstuffs in the laying hens’ diets, without negatively affected the productive and health parameters
