An assessment of dietary folic acid levels during gestation and lactation on reproductive and lactational performance of sows: a cooperative study1

Abstract

Crossbred female swine (n = 393) were used in a multiparity study at five experiment stations to evaluate the effects of dietary supplementation of folic acid (FA) on serum folates status and reproductive performance. The dietary treatments were a corn-soybean meal basal diet (calculated FA, .34 ppm) supplemented with 0, 1, 2, or 4 ppm FA. Experimental diets were fed continuously from a minimum of 21 d before first mating throughout the entire study. At one station, blood samples for radioimmunoassay determination of serum folates concentration were collected by vena cava puncture at mating, d 55 of gestation, d 110 of gestation, and at weaning. Stage of reproduction and dietary FA supplementation affected (P < .005) serum folates concentrations. Serum folates declined from mating to d 55, remained low at d 110, and returned to higher levels at weaning. Linear increases (P < .001) in serum folates with increasing level of dietary FA were observed at each reproductive stage. Over the course of the study, reproductive performance criteria including total pigs born, live pigs at birth and d 21, and individual pig and litter weight at birth and d 21 were not affected (P > .10) by inclusion of FA in the diet. The number of days postweaning to estrus also was not affected by FA treatment. Under the conditions of this experiment, increasing level of FA in the diet had a pronounced effect in attenuating decreased serum folates concentration during gestation but was without benefit to reproductive performance.

Effects of dietary supplements of folic acid on reproductive performance in ewes

“…For instance, it has been demonstrated that serum folate concentrations fall sharply in ewes in the first half of gestation, and that this drop is more pronounced in prolific breeds . These changes are strikingly similar to those observed in sows (Matte et al 1984;Harper et al 1994), where beneficial effects of folic acid supplementations are observed on litter size (Matte et al 1984;Thaler et al 1989;Lindemann 1993). It has also been demonstrated that ewes from prolific breeds have a higher serum folate concentration than ewes from non-prolific breeds .…”

What mineral and vitamin levels to recommend in swine diets?

“…The addition of folic acids on piglets and pigs were tested, without any positive change, by Newcomb & Allee (1986), Easter et al (1983) and Lutz et al (1999). Sow prolificacy is not always increased by acid folic additions: Harper et al (1994) with 1, 2 or 4 mg/kg, Matte et al (1992) with 5 or 15 mg/kg throughout pregnancy. This effect seems dependent on the ovulation rate (Lindemann & Kornegay, 1989), since the latter increases with parity.…”

Folic acid and vitamin B12 in reproducing sows: New concepts

“…(Cerna and Kas 1983;Matte and Girard 1994). In a cooperative multi-site experiment, Harper et al (1994) did not find any effect of additional folic acid (0, 1, 2 or 4 ppm) on the reproductive performance of crossbred sows with live litter size at parturition between 9.8 and 10.2. Using an approach that involved measuring the metabolic utilization of folic acid for five dietary levels of B 9 , Matte and Girard (1999) showed that an adequate dietary concentration would be at least 10 ppm for gestating prolific sows with a live litter size of 12 to 13.1 at parturition.…”

“…elucidated since B 9 supplementation has been reported to produce no response or only attenuated responses in terms of litter size and embryo survival (Harper et al 1994;, especially in nulliparous sows (Lindemann and Kornegay 1989;Matte et al 1992Matte et al , 1993Giguère et al 2000;Guay et al 2002a). This influence of parity has also been reported for conceptus secretion of E 2 (data not shown), uterine levels of PGE 2 (Duquette et al 1997) and uterine levels of TGFβ 2 (Guay et al 2004b) (Table 1).…”