This study was conducted to investigate the effects of adding different levels of date palm pollen (DPP) to the diets of Ossimi lambs on growth performance, nutrient digestibility, nutritional values, feed conversion ratio, and blood parameters. Twelve Ossimi male lambs aged 5–6 months with an average body weight of 24.00 kg ± 0.5 were allocated into three treatment groups of four. All lambs were fed on a basal diet consisting of a concentrate mixture and wheat straw at 2 and 1% of live body weight, respectively. Lambs in the first group were fed the basal diet without additives (control). While those in the second and third groups were fed the basal diet supplemented with doses of 15 or 30 g DPP/head per week, respectively. Blood samples were collected monthly over the three-month experimental period. At the end of the trial, a digestion experiment was conducted to estimate the digestibility coefficients and nutritional values of all treatments. The results indicated significant differences in total dry matter intake, daily growth rate, and total weight yield in favor of the third treatment followed by the second treatment compared to the control group, while the lowest cost/kg of growth was for the control group (63.0 L. E/kg growth), while it was 84.26 and 99.05 L. E/kg growth for the second and third groups, respectively. As for blood constituents, there were no significant differences between the groups for TP, AL, GL, A/G ratio, and cholesterol, while differences were significant in favor of the third treatment followed by the second compared to the control in the liver enzyme levels (ALT and AST), with no significant differences detected between the DPP-supplemented groups. The digestion trial showed significant differences in the digestion coefficients of OM, CP, and CF in favor of the second and third treatments compared to the control, with no significant differences found between the DPPG-supplemented groups. However, significant differences were observed between all three groups for DM, EE, and NFE in favor of the third group. These findings suggest that while DPP can enhance growth performance and nutrient utilization in lambs, its use may need to be evaluated against economic returns for practical applications.