Milk thistle seed extract consists mainly of flavonolignans, which include silybin (silibinin), sylichrisitn, and silydianin that commonly referred to Silymarin. A total number of thirty six, 9-10 month old New-Zealand white muliparous does, with an average weight of 3641g ± 94.02 were used to evaluate the response to dietary supplementation with ethanolic milk thistle extract (MTE) containing 70% silymarin on some performance aspects during pregnancy and lactation periods.Does were allocated to 4 experimental groups, 9 does of each. Rabbits were fed the experimental diets started one month before first mating. Does were allowed to the following treatments; a control group was fed a basal diet without MTE (T1), then the 2^nd, 3^rd, and 4^th  were fed the basal dietsupplemented with 3ml, 6ml or  9ml  MTE/kg diet, respectively and abbreviated as 3MTE (T2), 6MTE (T3) and 9MTE (T4), respectively.The trail was ended after pregnant period and nursering kits till weaning. The results indicate that feed intake during pregnancy (except T2) and lactation , litter weight at birth and weaning (except T2) were significantly (P≤0.05) increased by supplementing does diets with MTE at 6 or 9ml/kg diet compared to the control. Also, litter size at birth and litter size at weaning (except T2) were significantly (P≤0.05) higher with MTE supplementation compared to the control. Milk production significantly (P≤0.05) was the highest in 9MTE group for the first four weeks compared with the control. Plasma prolactin hormone was significantly (P≤0.05) improved gradually by enriched does diet with MTE, but liver enyzmes (AST & ALT) was insignificantly higher in all MTE groups compared to the control. It could be concluded that adding milk thistle seed extract to does diets enhanced their performance during gestation and lactation periods, in term of increased their milk production and litter weight at birth and weaning.