Forty sows (Landrace×Yorkshire), with an average body weight (BW) of 184.5 kg and average parity of 2.65, were used to determine the effects of a phytogenic feed additive (PFA) on growth performance, digestibility of nutrients, faecal NH₃-N gas content, blood and milk characteristics and litter performance. Dietary treatments included: 1. control (CON) and 2. PFA (basal diet + 0.04% phytogenic feed additive). Digestibility of dry matter (DM) was increased significantly (P<0.05) in PFA treatment. Faecal ammonia nitrogen (NH₃-N) measured at the end of experiment was reduced (P<0.05), however no significant effect (P>0.05) was observed on the digestibility of protein in PFA. On day 1 of lactation, albumin and lymphocyte were decreased (P<0.05) whereas WBC was increased significantly (P<0.05) when sows were fed the PFA diet. IgG content in milk was increased by PFA at farrowing and after farrowing 12 h (P<0.01; P<0.05). Similarly, IgA content in milk was increased by PFA after farrowing 12 h (P<0.01). Protein and solid concentration in colostrum were significant lower (P<0.01; P<0.05) in PFA treatment than CON treatment after farrowing 12 h. In conclusion, feeding 0.04% of PFA from day 107 of gestation to day 21 of lactation improved DM digestibility, RBC and WBC concentration, and lactose, IgG and IgA production in colostrums and decreased faecal NH₃-N concentration.