Intravenous infusion of iron and tetrahydrofolate does not influence intrauterine uteroferrin and secreted folate-binding protein content in swine

The effect of exogenous iron and folate on reproductive performance in swine is equivocal. However, the effect of exogenous iron and folate on secretion of their respective uterine transport proteins has never been reported. Twenty gilts were infused (n = 5 per treatment) with either 1) saline, 2) alpha-tocopherol, 3) alpha-tocopherol plus iron citrate, or 4) alpha-tocopherol plus tetrahydrofolate on d 11 to 14 of pregnancy. Intravenous infusion of iron citrate and tetrahydrofolate increased (P < 0.05) plasma iron and folate, respectively, for 6 to 8 h after treatment. Treatments had no effect on uterine content of uteroferrin or secreted folate-binding protein in uterine flushings obtained on d 15 of pregnancy. These data suggest that uterine secretion of uteroferrin and secreted folate-binding protein are not influenced by plasma levels of iron and folate, respectively, and may provide an explanation for the equivocal effect of iron and folate treatment on reproductive performance in gilts.