The aim of this study was to evaluate the effects of fish oil supplementation, as an omega-3 fatty acids source, to ration of does in the different periods of pregnancy on the fattening performance of kids after weaning. Eighty German Fawn × Hair crossbred does were randomly divided into two groups; half were given fish oil in the first half of pregnancy (FO group), while the other half were given saturated fat (PF (control) group). Then, the goats in the FO and PF groups were randomly divided into two subgroups, and half of the goats were fed fish oil during the second half of pregnancy (FO-FO and FO-PF groups), while the other half was fed saturated fat (PF-FO and PF-PF groups). Thus, study groups of kids were formed according to the nutrition program of the does described above. Forty-seven male kids (84.6 ± 2.44 days old; 14.5 ± 3.09 kg live weight, mean ± standard deviation) were fed for 56 days after weaning, and their weight, feed consumption, serum biochemical parameters, carcass performance, and meat quality characteristics were evaluated. Maternal nutrition significantly affected live weight gain and serum AST, glucose, total protein, and globulin concentrations (P ≤ 0.050). The live weight gain of kids in the PF-PF and PF-FO groups was higher than that in the FO-FO and FO-PF groups. Maternal nutrition tended to affect the hot and cold carcass weights of male kids (P = 0.078 and P = 0.084, respectively). In conclusion, fish oil supplementation during gestation could negatively affect the fattening performance of kids after weaning, especially the daily live weight gain, although it tended to positively affect hot and cold carcass weights.