Comparison the short-term effects of CIDR and MAP sponge insertion on the reproductive performance of Arabian ewes out of breeding season

A number of 52 Arabian ewes with 2-5 years old were randomly divided to three groups: 1) insertion of CIDR for 6 days (n=18), 2) insertion of MAP sponge for 6 days (n=15) and 3) control group without treatment (n=19). In hormonal treatment groups, 600 IU eCG was injected intra muscularly at the time of withdrawal of the above devices. Then, one fertile and health Arabian ram introduced to each five ewes in order to standing heat detection and mating. Estrous response rate, estrous onset time, repeat breeding, fertility, lambing rate, gestation length, litter size, lamb weight and blood serum progesterone values in experimental treatments were studied. Estrous response in CIDR and sponge groups were significantly higher than the control group (P<0.05). Estrous response was not differ between hormonal treatments (P>0.05). There were not significant differences for mean time of estrous onset after withdrawal of progesterone devices, repeat breeding rate, fertility rate, lambing rate, pregnancy duration, litter size, lamb weight and blood serum progesterone concentrations at before and 3 days after insertion of these hormonal devices as well as 50 days after mating between short term CIDR and sponge treatments (P>0.05). One day after removing the CIDR and sponge devices, blood serum progesterone level in CIDR treatment was significantly higher than that in sponge group (P<0.05). The highest estrus responses in short term CIDR and sponge treatments were observed in 36-48 and 48-60 hours after removal of these devices, respectively.