The influence of fractionating daily food intake from 1st to 30th days of pregnancy, on serum progesterone concentrations (ng/ml) in multiparous sows was evaluated on 3rd, 5th, 8th, 12th, 21th and 28th days after insemination. The progesterone concentrations were determined by radioimmunoassay (RIA) from blood samples collected from cava vein in 15 sows between the third and the sixth parturition. The sows were distributed into three groups of five animals each. One group was treated once a day with 2.0kg of ration (T1); a second group was treated twice a day with 1.0kg of ration (T2); and a third group was treated three times a day with 670 grams of ration (T3) for 30 days during pregnancy. No effects of fractionating daily food intake on serum progesterone concentrations were observed.
swine; progesterone; pregnancy; ration
