Folic acid fortification is recommended and prudent for milk replacers. As discussed above, supplementation with folic acid may be warranted during the immediate postweaning period in ruminants. Data from lactating and gestating dairy cows suggest that folic acid status may be less than optimal in multiparous cows, although the responses have not been completely consistent across three experiments. Current studies are examining a possible interaction of folic acid with vitamin B12 (Girard, 1998b).
Gadient (1986) reported that folic acid is very sensitive to heat and light, slightly sensitive to moisture and insensitive to oxygen. Folic acid can be lost during storage of premixes, particularly at elevated temperatures (Frye, 1978). After three months temperature storage at room temperature, 43% of the original folic acid activity was lost. Verbeeck (1975) found that folic acid is stable in premixes without trace minerals but that there may be as much as 50% loss in a premix with trace minerals stored at room temperature for three months. Adams (1982) reported only 38% retention of folic acid activity in a premix without trace minerals after three weeks of storage at 113†F (45†C); however, 57% of activity was retained after three months of storage at room temperature. After six months of storage in a vitamin premix, 97% of folic acid was recovered, but only 43% was recovered in a vitamin premix combined with choline and trace minerals.
