This study carried out to evaluate the effect of feeding diets containing olive cake meal (OCM) at 10 % and 20 % with or without citric acid at levels 0.1 % or 0.2 % on growing rabbits performance. One hundred and five weaning New Zealand white (NZW) rabbits about 4 weeks old were allotted at random to seven experimental groups with 15 rabbits in each group contained three replicates ( five rabbits in each ) in a growth trail lasted for forty days. The experimental diets were as follows: Diet 1 was used as a control without adding olive cake or citric acid, and Diets 2, 3 and 4 : contained 10 % olive cake and were supplemented with zero, 0.1 and 0.2 % citric acid respectively, Diets 5, 6 and 7 : contain 20 % olive cake and were supplemented with zero, 0.1 and 0.2 % citric acid respectively.
Results could be summarized as follows:Addition of olive cake plus citric acid to growing rabbit diets significantly increased live body weight (LBW) and daily weight gain (DWG). Feed conversion ratio (FCR) was improved and mean values of feed intake (FI)were increased along with adding 10% olive cake plus 0.1% citric acid in the rabbit diets .
Economic efficiency percentage (EEf), relative economic efficiency (REE) and performance index (PI) were higher in growing rabbits fed diets containing 10% olive cake meal plus 0.1%citric acid than the other groups.
A significant increase in apparent digestibility coefficients of CF, EE, NFE, and TDN were detected while, there was insignificant increase in DM, OM, CP, DCP and DE % and apparent digestibility coefficient with addition olive cake plus citric in the rabbit diets. Carcass, liver, heart, giblets and dressing percentages in rabbits fed 10% olive cake recorded higher values compared with other dietary treatments.
Cholesterol and triglycerides in rabbits fed diet containing 10% olive cake without or with 0.1% citric acid showed lower values compared to the other treatment. Total lipids, total protein, albumin, globulin, albumin /globulin ratio, and liver enzymes activity ALT and AST levels were not affected by the dietary treatments.
Conclusively, dietary incorporation of 10% olive cake meal supplemented with 0.1% citric acid could be recommended to improve growth performance, feed utilization and economic return of growing rabbits production.