The present study was carried out at Sakha Research Station , Kafr El — Sheikh Governorate, belonging to Animal Production Institute (APRi), Agricultural Research Center, Ministry of Agriculture from September to December (2005). Eighty New Zealand White rabbits (70 does and 10 bucks) and 10 Californian bucks (CL) were randomly selected at 7 months old. Thirty were immunized with bovine serum albumin ( BSA ), classified later into high (HR) and low response (LR) responded groups. Ten does from each group were selected at random. They formed with the remaining un-immunized (40) does six equal groups. The Cior antibodies sera immunized with BSA to obtain immune sera US) or antibodies sera (Abs), used for NZW buck semen treatments. Such treatments were as follows; 1- Control un-immunized semen ( Culm), 2-Semen + Abs, 3- Semen + Egg-Yolk—Tris extender (YET) + Abs, 4- Semen + (YET) + caffeine + Abs, and 5- Semen + YET). The HR and LR and LR groups were artifically inseminated with the control unvimmunized semen. The four un-immunized does groups were subjected to Al. using semen from treatments 2, 3, 4, 5, respectively. insemination was conducted after Receptal injection for does to induce ovulation. Seventy-two hours after insemination does were dissected, and then fertilization rate and embryos numbers were detected. Sperm motility percentage was significantly higher (P