Influence of folic acid supplements on the carry-over of folates from the sow to the piglet

Effect of nutritional status on nutrient and gas utilization by the mammary gland of lactating sows

Milk synthesis being a continuous process in lactating sows, the mammary gland has to adapt its metabolism in response to extreme short-term changes in nutrient availability in the arterial bloodstream, due to the feeding pattern. The objective of the present study was to better quantify and understand these adaptations. The effect of morning refeeding after an overnight 16-h feed withdrawal was measured on the uptake of energy-supplying nutrients, amino acids (AA), and some vitamins and minerals. After farrowing, catheters were fitted in the right anterior mammary vein and in the carotid artery of six sows. Blood samples were drawn on days 7, 14, and 21 of lactation, every 30 from 60 min before the morning meal to 300 min after the morning meal. Plasma concentrations of glucose, lactate, triglycerides (TG), non-esterified fatty acids (NEFA), glycerol, α-amino nitrogen (N), vitamins B₁₂, and folates were determined on all samples. Riboflavin and AA concentrations were only measured 30 min before the meal and 120 min after the meal. Arterial and venous plasma concentrations of glucose, lactate, and α-amino N increased after the meal (P < 0.01), and concentrations of NEFA, glycerol, and TG decreased (P < 0.01). Mammary arteriovenous concentration difference increased after the meal for glucose, lactate, and α-amino N (P < 0.01), remained constant for TG, and decreased for NEFA (P < 0.01) and glycerol (P < 0.05). Arterial concentrations of all AA increased after the meal, but changes of arteriovenous difference with the meal differed among AA. Arteriovenous difference of energy (7.6 kJ/l plasma) concentration was similar in feed-deprived and fed sows, but the contribution of the various nutrients differed, and the respiratory quotient was lower (P < 0.01) before the meal (0.95) than after the meal (1.54). The relative contributions of glucose, lactate, TG, NEFA, and AA to arteriovenous difference in energy concentration were 50.2, 3.8, 25.1, 0, and 20.8% in fed and 24.6, 2.2, 24.9, 32.9, and 15.0% in feed-deprived sows, respectively. The daily mammary extraction of vitamin B₁₂, estimated from arteriovenous differences was higher than the amount of this vitamin bioavailable from the diet, probably contributing to the 50% decrease in plasma concentration between day 7 and day 21 of lactation. For both riboflavin and folates, arteriovenous differences in plasma concentrations were small or not different from zero. These results indicate that the mammary gland has a great capacity to adapt nutrient uptake very rapidly and modify its metabolism according to the nutrients available in the bloodstream.

Increased vitamin supplement to sows, piglets and finishers and the effect in productivity

With still limited information on vitamin requirements and considering that many commercial practices adopt dietary vitamin levels above the values suggested by nutritional tables, this study aimed to assess the effect of administering vitamin supplementation to sows in gestation and lactation and to their litters on the reproductive performance and body condition of the sows and on the performance and immune profile of the litters until slaughter. The trial was split into two phases. The first phase used 104 sows, assigned to be randomized to blocks according to parity, submitted until 21 days of lactation to two treatments: control-standard (standard levels of vitamins) and test-elevated (elevated levels of vitamins). Each sow and its respective farrow were considered an experimental unit. The sows underwent evaluations of body condition score, back fat thickness and reproductive performance. In the second phase, 60 barrows and 60 gilts at 21 days of age and mean initial weight of 5.33 ± 1.5 kg until slaughter at 164 days of age. The piglets were assigned to randomized blocks according to the weight and sex of the animals in a 2 × 2 factorial model, with 10 replicates per treatment, where a pen with three animals represented the experimental unit. Following the same treatments of the first phase, the piglets were evaluated for daily weight gain, daily feed intake, feed conversion, mortality rate and humoral immune response. Vitamin supplementation had no positive effects on the reproductive parameters or body composition of sows. However, it positively impacted the performance of the litters in the early nursery stage, but did not lead to superior effects on the immune responses to vaccination against circovirus or mycoplasma.

Maternal perinatal transfer of vitamins and trace elements to piglets

Nursing piglets are entirely dependent, for their micronutrient provisions, upon in utero, colostrum and milk transfers from the dam. An adequate maternal transfer of micronutrients is all the more important during these periods which, in fact, lasts for approximately half the life cycle (conception to slaughter) of modern pigs. The present study aimed to set up a simple approach to assess the maternal perinatal transfer of vitamins and trace elements in sows. Prenatal transfer (R-u) was estimated as limited, passive or active using the ratio between pre-colostral serum concentrations of a given micronutrient in newborn piglets and corresponding pre-farrowing values in sows. Efficiency of the postnatal transfer (R-c) was estimated from the ratio between serum concentrations of post- and pre-colostral micronutrients in piglets. Data from literature (12 studies) were used for vitamins A, D, E, C, folic acid and B12, whereas vitamins B2, B3, B6 and B8 as well as Zn, Fe, Cu and Se were generated from a trial where blood sera from 20 sows, and their litter were collected during the perinatal period. In sow trial, statistical t tests were used to determine if ratios differed from 1. Prenatal transfer was active and in favour of piglets (R-u > 1, P < 0.03) for Zn and vitamins B6 and B8 (sow trial) as well as for vitamins C and B12 (literature data). This transfer was limited (R-u < 1, P < 0.01) for vitamin B2, Fe, Cu and Se (sow trial) and for vitamins A, E, D and folic acid (literature data) whereas it was passive for vitamin B3 (R-u = 1, P > 0.37). After birth, the early postnatal transfer through colostrum was active towards piglets for most micronutrients but vitamins B6 and B8 (R-c < 1, P < 0.01). Globally, the perinatal transfer (combination of R-u and R-c) was favourable to the neonatal piglets for most micronutrients except for vitamins A and D as well as Fe, Cu and Se whereas there is apparently a barrier for prenatal transfer which is not compensated by the colostrum provision to neonatal piglets. Then, post-colostral concentrations of these micronutrients in piglets remain below prenatal levels of their dam. Neonatal strategies of micronutrient provision are known for Fe (intramuscular injection) and Se (sow milk enrichment). Further studies are needed to assess the importance of the unfavourable perinatal transfer for Cu and vitamins A and D for piglet robustness later in life.

Genome-wide survey reveals dynamic effects of folate supplement on DNA methylation and gene expression during C2C12 differentiation

Folic acid supplements taken during pregnancy can prevent neural tube defects and other developmental abnormalities. Here, we explored the effects of folate supplementation on gene expression and DNA methylation during C2C12 differentiation. Based on the folic acid concentration, this study comprised three groups: low folate (L), normal folate (N), and high-folate supplement (H). Our analyses revealed that differentiation and the mRNA expression of the gene myogenin in C2C12 cell were enhanced by folic acid; however, the overall methylation percentage in myogenin promoter between different treatment groups was not significantly different ( P > 0.05). The results of MeDIP-chip showed that hundreds of differentially methylated regions (DMRs) were identified between every two groups in both promoter and CpG islands, respectively. Genes with DMRs between N and L groups were mainly enriched in the processes of cell differentiation and cell development, whereas those with DMRs between H and N groups were frequently enriched in cellular process/cycle and cell metabolic processes. In addition, correlation analysis between methylation profile and expression profile revealed that some genes were regulated by methylation status directly. Together, these analyses suggest that folate deficiency and supplementation can influence the differentiation, genome-wide DNA methylation level and the expression of myogenesis-related genes including myogenin in the C2C12 cell line.

Folate deficiency during early-mid pregnancy affects the skeletal muscle transcriptome of piglets from a reciprocal cross

Folate deficiency (FD) during pregnancy can cause fetal intrauterine growth restriction in pigs, of which the skeletal dysplasia is a major manifestation. Factors influencing muscle development are very important in the formation of porcine meat quality trait. However, the effect of folate deficiency on skeletal muscle development and its molecular mechanisms are unknown. The objective of this study is to determine the effect of maternal folate deficiency on the skeletal muscle transcriptome of piglets from a reciprocal cross, in which full-sibling Landrace (LR) and full-sibling Chinese local breed Laiwu (LW) pigs were used for reciprocal cross matings, and sows were fed either a folate deficient or a normal diet during early-mid gestation. In addition, the difference in the responsiveness of the piglets to folate deficiency during early-mid pregnancy between reciprocal cross groups was investigated. Longissimus dorsi (LD) muscle samples were collected from newborn piglets and a 4 × 44K Agilent porcine oligo microarray was used for transcriptome analysis of porcine LD muscle. The results showed that folate deficiency during early-mid pregnancy affected piglet body weight, LD muscle fiber number and content of intramuscular triglyceride. The microarray results indicated that 3154 genes were differentially expressed between folate deficient and normal piglets from the LR♂ × LW♀ cross, and 3885 differentially expressed genes (DEGs) in the ones from the LW♂ × LR♀ cross. From functional analyses, sow folate deficiency affected almost all biological processes in the progeny. Lipid metabolism-related genes and associated metabolic pathways were regulated extensively by folate deficiency, especially in LR♂ × LW♀ cross piglets. Most of the genes that are regulated by folate deficiency in the LD muscle of piglets were different between LR♂ × LW♀ and LW♂ × LR♀ crosses, suggesting some epigenetic effects of FD exist in genes underlying myogenesis and intramuscular fat deposition in piglets.

Effects of intrauterine growth retardation and maternal folic acid supplementation on hepatic mitochondrial function and gene expression in piglets

Piglets with intrauterine growth retardation (IUGR) or with normal birth weight (NBW) were selected to evaluate the effects of maternal folic acid supplementation on hepatic mitochondrial function and expression levels of genes involved in mitochondrial DNA (mtDNA) biogenesis and mitochondrial function. During gestation, primiparous Yorkshire sows were fed a Control diet (folic acid 1.3 mg/kg) or a folic acid-supplemented diet (folic acid 30 mg/kg) with 16 replicates per diet. During the 28-d lactation period, sows were fed a common diet. Compared with NBW piglets, hepatic ATP concentrations and mtDNA contents were decreased in IUGR piglets. Furthermore, IUGR piglets exhibited lower membrane potential and decreased oxygen consumption in liver mitochondria, but these parameters were not affected by maternal folic acid supplementation. Intrauterine growth retardation decreased mRNA expression abundance of peroxisomal proliferator-activated receptor-γ coactivator-1α, mitochondrial transcription factor A, uncoupling protein 3, and cytochrome c oxidase subunit I and IV. Impaired antioxidant capacity characterised by increased malondialdehyde content and decreased manganese-superoxide dismutase activity was also observed in IUGR pigs. In IUGR piglets, however, nearly all of these parameters were normalised to the level of NBW piglets when the maternal diet was supplemented with folic acid during pregnancy. Hence, maternal folic acid supplementation was proved to be an effective way to reverse the changes in gene expressions in IUGR pigs, which provided a possible nutritional strategy to improve growth development of IUGR individuals.

Effects of folic acid on the performance of suckling piglets and sows during lactation

BACKGROUND

The present research was conducted to investigate the influences of supplementation with different levels of folic acids in diet on the performance of lactating sows. Twenty Landrace × Yorkshire sows received the same basal corn-soybean diets (folic acid, 1.3 mg kg(-1)) from gestation to parturition (day 107). After parturition, sows were allotted to four treatments: control group (folic acid supplementation level, 0 mg kg(-1)), group 1 (12.5 mg kg(-1)), group 2 (50 mg kg(-1)) and group 3 (100 mg kg(-1)), with five replicates of one sow. The experiment lasted for 21 days.

RESULTS

(1) Folic acid increased milk production (P > 0.05). (2) Compared with the control, supplementation with folic acid (100 mg kg(-1)) increased the concentration of butter fat, total substance and non-lipoid substance significantly (P < 0.01), the concentration of milk protein was also significantly increased in group 2 and group 3 (P < 0.01) in milk. (3) Folic acid supplementation could increase litter weaning weight, average piglet weaning weight and average piglet daily gain (P > 0.05).

CONCLUSION

These results suggested that supplementation with folic acid in the diets of lactating sows increases milk production, improved milk quality and the performance of piglets.

Effects of concentrations of cyanocobalamin in the gestation diet on some criteria of vitamin B12 metabolism in first-parity sows1,2

In swine nutrition, little is known about the role of vitamin B(12) in the reproductive processes. The current study was undertaken to obtain information on the dose-response pattern of different metabolic criteria related to the homeostasis of vitamin B(12) and homocysteine in gestating sows receiving various concentrations of dietary vitamin B(12) (cyanocobalamin). Homocysteine is a detrimental intermediate metabolite of the vitamin B(12)-dependent remethylation pathway of Met. Forty nulliparous (Large White x Landrace) sows were randomly assigned during gestation to dietary treatments containing 5 concentrations of cyanocobalamin (0, 20, 100, 200, or 400 microg/kg). During lactation, a diet containing 25 microg of cyanocobalamin/kg (as-fed) was given to all sows. During gestation, plasma vitamin B(12) increased as concentrations of dietary cyanocobalamin increased (linear and quadratic, P < 0.01) and the effect persisted during lactation (21 d postpartum) both in plasma (linear and quadratic, P < 0.05) and the liver (linear and quadratic, P < 0.04). Plasma homocysteine decreased with concentrations of cyanocobalamin provided to sows during gestation (linear, quadratic, and cubic, P < 0.01). At parturition, vitamin B(12) in colostrum increased as concentrations of cyanocobalamin increased (linear and quadratic, P < 0.01), but the treatment effect persisted (linear, P = 0.01) only up to 1 d postfarrowing. However, in piglets there was no treatment effect (P = 0.59) on plasma vitamin B(12) before colostrum intake, but a linear effect of concentrations of cyanocobalamin (P = 0.04) was observed 1 d later. Plasma homocysteine in piglets during lactation decreased with increasing concentrations of cyanocobalamin given to sows in gestation (linear and quadratic, P < 0.01). Based on a broken-line regression model, the concentrations of dietary cyanocobalamin that maximized plasma vitamin B(12) and minimized plasma homocysteine of sows during gestation were estimated to be 164 and 93 microg/kg, respectively. The maximal residual responses in sows and piglets during lactation were observed with treatments of 100 or 200 microg of cyanocobalamin/kg. The dietary cyanocobalamin concentration necessary to optimize the response of these metabolic criteria remains to be refined within lower and narrower ranges of cyanocobalamin concentrations (i.e., <200 mg/kg). Moreover, the biological significance of such concentrations of cyanocobalamin needs to be validated with performance criteria by using greater numbers of animals during several parities.