The study was carried out  in Animal Production Research Unit in the Sustainable Development Center for Matrouh  Resources  (SDCMR), Matrouh Governorate, belonging to Desert Research Center, El-Matarya, Cairo, Egypt. The main problem of utilizing Jojoba meal as a feed source is the presence of simmondsin as a major toxic compound with other anti –nutritional factors. The main objective of the present study was  to assess the influence  of  replacing (70%) of  undecorticated cotton seed meal (CSM) of concentrate feed mixture (CFM)  with  Jojoba meal (JM) (Simmondsia chinensis), either as untreated JM (UJM) (R2) or treated biologically  with lactic acid bacteria (JMB) (R3)  or treated chemically with 70% isopropanol (JMI) (R4) on the concentration of anti –nutritional factors ANFʼs ( mainly simmondsin), dry matter intake (DMI), daily gain, digestion coefficients, rumen fermentation, some of blood biochemical parameters and consequently  animal performance. Control group (R1)  fed on traditional CFM. Twenty four Barki lambs weighed  24 kg  6 months  old were used in this experiment. Obtained Results indicated that  both treatments (biologically or chemically) showed a positive effect in reducing ANFʼs while chemical composition of all the experimental rations had comparable values. Detoxified JM with bacteria or with isopropanol showed the highest feed intake as dry matter, crude protein (CP), total digestible nutrients (TDN) and digested crude protein (DCP) with significant differences . Consequently, the average daily gain (ADG) g/h was descendingly arranged as follow : lambs fed on   (R4), followed by those fed on (R3), control lambs (R1) then those fed on  (R2).The values of DM,TDN and DCP intake /kg gain indicated that lambs fed JMI were  the highest , followed by R1 fed lambs then JMB fed lambs, while the least values for lambs fed on UJM. Rumen parameters as pH,  ammonia –Nitrogen (NH₃-N) and  volatile fatty acids (VFAʼs) concentrations were affected with treatments. No significant differences  were detected in serum metabolites, except that for  liver enzymes (AST and ALT). Since both treatments showed  elevated activities in all JM fed animals, compared with control one. Generally, the endocrine function tests (T₃ and T₄) showed a significant elevations in lambs fed JM rations either treated or untreated. It could be concluded that, chemical or biological treatments of Jojoba meal with isopropanol or with lactic acid bacteria could offer a good solution for the reduction or elimination of toxic and bitter simmondsin and some of phenolics  from Jojoba meal and could be used in animal nutrition without negative effects on  animal performance.