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

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.

The combination of nutraceuticals and functional feeds as additives modulates gut microbiota and blood markers associated with immune response and health in weanling piglets

This study aimed to evaluate the effects of a combination of feed additives with complementary functional properties on the intestinal microbiota, homocysteine, and vitamins E and B status as well as systemic immune response of weanling piglets. At weaning, 32 litters were assigned to one of the following dietary treatments (DT): 1) conventional diet (CTRL); 2) CTRL diet supplemented with antibiotics (ATB); 3) a cocktail of feed additives containing cranberry extract, encapsulated carvacrol, yeast-derived products, and extra vitamins A, D, E, and B complex (CKTL); or 4) CKTL diet with bovine colostrum in replacement of plasma proteins (CKTL + COL). Within each litter, the piglets with lowest and highest birth weights (LBW and HBW, respectively) and two piglets of medium birth weight (MBW) were identified. The MBW piglets were euthanized at 42 d of age in order to characterize the ileal and colonic microbiota. Blood samples were also collected at weaning and at 42 d of age from LBW and HBW piglets to measure insulin-like growth factor-1 (IGF-1), cysteine, homocysteine, and vitamins E, B₆, and B₁₂, and to characterize the leukocyte populations. At 42 d of age, cytokine production by stimulated peripheral blood mononuclear cells was also measured. In a second experiment, piglets were reared under commercial conditions to evaluate the effects of the DT on the growth performance. At the indicator species analysis, the highest indicator value (IV) for Succinivibrio dextrinosolvens was found in the CKTL group, whereas the highest IV for Lactobacillus reuteri and Faecalibacterium prausnitzii was evidenced in the CKTL + COL group (P < 0.05). Compared with the other DT, CTRL piglets had higher concentrations of homocysteine, whereas the CKTL and CKTL + COL supplementations increased the concentrations of vitamins E and B₁₂ (P < 0.05). DT had no effect on IGF-1 concentration and on blood leukocytes populations; however, compared with HBW piglets, LBW animals had lower values of IGF-1, whereas the percentages of γδ T lymphocytes and T helper were decreased and increased, respectively (P < 0.05). CKTL + COL also improved the growth performance of piglets reared under commercial conditions (P < 0.05). This study highlights the impact of birth weight on piglet systemic immune defenses and the potential of weaning diet supplemented with feed additives and bovine colostrum to modulate the homocysteine metabolism and the intestinal microbiota.

The strategies for the supplementation of vitamins and trace minerals in pig production: surveying major producers in China

Objective

Adequate vitamin and trace mineral intake for pigs are important to achieve satisfactory growth performance. There are no data available on the vitamin and trace mineral intake across pig producers in China. The purpose of this study was to investigate and describe the amount of vitamin and trace minerals used in Chinese pig diets.

Methods

A 1-year survey of supplemented vitamin and trace minerals in pig diets was organized in China. A total of 69 producers were invited for the survey, which represents approximately 90% of the pig herd in China. Data were compiled by bodyweight stages to determine descriptive statistics. Nutrients were evaluated for vitamin A, vitamin D, vitamin E, vitamin K, thiamine, riboflavin, vitamin B₆, vitamin B₁₂, pantothenic acid, niacin, folic acid, biotin, choline, copper, iron, manganese, zinc, selenium, and iodine. Data were statistically analyzed by functions in Excel.

Results

The results indicated variation for supplemented vitamin (vitamin A, vitamin D, vitamin E, vitamin K, vitamin B₁₂, pantothenic acid, niacin, and choline) and trace minerals (copper, manganese, zinc, and iodine) in pig diets, but most vitamins and trace minerals were included at concentrations far above the total dietary requirement estimates reported by the National Research Council and the China’s Feeding Standard of Swine.

Conclusion

The levels of vitamin and trace mineral used in China’s pig industry vary widely. Adding a high concentration for vitamin and trace mineral appears to be common practice in pig diets. This investigation provides a reference for supplementation rates of the vitamins and trace minerals in the China’s pig industry.

A ketogenic drink improves cognition in mild cognitive impairment: Results of a 6-month RCT

Introduction

Counteracting impaired brain glucose metabolism with ketones may improve cognition in mild cognitive impairment (MCI).

Methods

Cognition, plasma ketone response, and metabolic profile were assessed before and 6 months after supplementation with a ketogenic drink containing medium chain triglyceride (ketogenic medium chain triglyceride [kMCT]; 15 g twice/day; n = 39) or placebo (n = 44).

Results

Free and cued recall (Trial 1; P = .047), verbal fluency (categories; P = .024), Boston Naming Test (total correct answers; P = .033), and the Trail‐Making Test (total errors; P = .017) improved significantly in the kMCT group compared to placebo (analysis of covariance; pre‐intervention score, sex, age, education, and apolipoprotein E4 as covariates). Some cognitive outcomes also correlated positively with plasma ketones. Plasma metabolic profile and ketone response were unchanged.

Conclusions

This kMCT drink improved cognitive outcomes in MCI, at least in part by increasing blood ketone level. These data support further assessment of MCI progression to Alzheimer's disease.

Beneficial antioxidant status of piglets from sows fed selenomethionine compared with piglets from sows fed sodium selenite

BACKGROUND

Studies in mammals proved dietary organic selenium (Se) being superior to inorganic Se regarding effects on growth performance, antioxidative status, immune response, and Se homeostasis. However, the picture of possible effects of different Se sources and - levels can be expanded. The present field study evaluated the effects on weight gain, hematological and selected biochemical variables as well as plasma concentrations of vitamin E (vitE), total Se and selenobiomolecules in piglets throughout the suckling period.

METHODS

Piglets were monitored from birth to 38 days of age (d). The mother sows' diets were enriched with l-selenomethionine (SeMet-0.26 and -0.43 mg Se/kg feed) or sodium selenite (NaSe-0.40 and -0.60 mg Se/kg feed) from 1 month prior to farrowing until the end of lactation period. Piglets received pelleted feed supplemented with Se similarly to the sows' diets from one week of age. Selenite at 0.40 mg Se/kg (NaSe-0.40) represents a common Se source and -level in pig feed and served as control diet.

RESULTS

From 24d, piglets in SeMet-groups had higher mean body weight (BW) compared with piglets from sows fed NaSe-0.40. Furthermore, from five-d and above, piglets from sows fed NaSe-0.60 had significantly higher BW than offspring from sows fed NaSe-0.40. Neonatal piglets in group SeMet-0.43 had significantly lower red blood cell counts (RBC), hemoglobin (Hgb) and hematocrit (Hct) concentrations compared with piglets from sows fed with NaSe-0.40. Neonatal and 5d-old piglets in group SeMet-0.26 showed higher gamma-glutamyl transferase activity than piglets in group NaSe-0.40. From five d and above, group NaSe-0.60 excelled with increased specific hematological variables culminating at age 38d with increased Hct, mean corpuscular volume (MCV), and MC hemoglobin (MCH) as well as increased activities of aspartate transaminase and lactate dehydrogenase compared with the other groups. Generally, offspring in the SeMet groups had higher total Se-concentrations in plasma than those from sows fed selenite, and showed a dose-response effect on plasma Se-concentrations. Furthermore, SeMet-fed piglets had higher plasma levels of the selenoproteins (Sel) glutathione peroxidase 3 (GPx3) and SelP as well as selenoalbumin. Plasma vitE levels were significantly negatively correlated with RBC throughout trial period.

CONCLUSIONS

Maternal supplementation with SeMet during gestation influenced hematology and clinical biochemistry in neonatal piglets in a different way than in offspring from sows receiving selenite enriched diets. Growth performance was positively influenced by both dietary Se source and Se level. Higher plasma levels of GPx3 observed in piglets receiving SeMet probably improved the protection against birth or growth related oxidative stress. These might prime the piglets for demanding situations as indicated by higher weight gain in offspring from sows fed with SeMet-supplemented diets. Our results on some enzyme activities might indicate that piglets fed NaSe-0.60 had to cope with increased levels of oxidative stress compared with those originating from sows fed SeMet or lower dietary levels of selenite. We assume that combining inorganic and organic Se sources in complete feed for breeding sows might be beneficial fro reproduction and the offspring's performance.

Assessment of folate and cobalamin concentrations in relation to their dependent intracellular metabolites in serum of pigs between 6 and 26 weeks of age

Folate (vitamin B₉) and cobalamin (vitamin B₁₂) play an important role in amino acid metabolism, nucleic acid synthesis, and methyl group transfer. Two intracellular enzymes, methionine synthase and methylmalonyl-CoA mutase, are folate and/or cobalamin-dependent, respectively. At the cellular level, a lack of folate and cobalamin leads to accumulation of serum homocysteine (HCY) and a lack of cobalamin leads to increased methylmalonic acid (MMA) concentrations. Altered serum HCY and MMA concentrations can influence amino acid metabolism and nucleic acid synthesis in pigs. Therefore, we aimed to evaluate serum folate, cobalamin, HCY, and MMA concentrations in postweaning pigs between 6 and 26 weeks of age. Serum samples from 12 pigs collected at week 6, 7, 8, 9, 10, 14, 18, 22, and 26 as part of an unrelated study were analyzed. Serum folate (p < .0001), cobalamin (p = .0001), HCY (p < .0001), and MMA (p < .0001) concentrations differed significantly during the postweaning period between 6 and 26 weeks of age; with significantly higher serum HCY (at weeks 6 and 7 compared to weeks 9, 14, 18, 22, and 26) and MMA concentrations (at weeks 6, 7, and 8 compared to weeks 14, 18, 22, and 26) and an overall decrease of serum MMA concentrations from week 6 to week 14 in the pigs studied. This study suggests age-dependent changes in intracellular folate- and cobalamin-dependent metabolites (i.e., HCY and MMA) in pigs between 6 and 26 weeks of age, possibly reflecting decreased availability of intracellular folate and/or cobalamin for amino acid metabolism, nucleic acid synthesis, and methyl group transfer.

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.

Role of homocysteine metabolism in animal reproduction: A review

Homocysteine (Hcy) is a thiol-containing essential amino acid, important for the growth of cells and tissues. Several hypotheses exist regarding Hcy toxicity in humans; Hcy is involved in protein structural modifications, oxidative stress, and neurotoxicity induction and is therefore associated with several pathological conditions in humans. In veterinary science, knowledge regarding Hcy has increased recently due to several studies; however, many aspects remain undiscovered. Many details remain unknown regarding the effect of Hcy levels on pregnancy and the optimal management of pathological conditions associated with Hcy levels during pregnancy in various species. In this review, we aimed to compile various studies on Hcy metabolism to elucidate its current status in the veterinary field, particularly for ovine, bovine, equine, porcine, canine, and feline species.

Methyl donors dietary supplementation to gestating sows diet improves the growth rate of offspring and is associating with changes in expression and DNA methylation of insulin-like growth factor-1 gene

The study aimed to investigate the effects of maternal dietary methyl donors on the performance of sows and their offspring, and the associated hepatic insulin-like growth factor-1 (IGF-1) expression of the offspring. A total of 24 multiparous sows were randomly fed the control (CON) or the CON diet supplemented with methyl donors (MD) at 3 g/kg betaine, 15 mg/kg folic acid, 400 mg/kg choline and 150 μg/kg VB₁₂ , from mating until delivery. After farrowing, sows were fed a common lactation diet through a 28-days lactation period and six litters per treatment were selected to be fed until at approximately 110 kg BW. Maternal MD supplementation resulted in greater birthweight (p < 0.05) and increased the piglet weights (p < 0.01) and litter weights (p < 0.05) at the age of day 28, compared with that in CON group. The offspring pigs in the MD group had greater ADG (p < 0.05) and tended to lower F:G ratio (p = 0.07) compared with that of CON group from day 28 to 180 of age. The offspring pigs from MD group had greater serum IGF-1 concentrations and expressions of hepatic IGF-1 gene and muscular IGF-1 receptor (IGF-1r) protein at birth (p < 0.05), and greater hepatic IGF-1 protein (p = 0.03) and muscular IGF-1r gene expressions (p < 0.05) at slaughter, than that from the CON group. Moreover, the methylation at the promoter of IGF-1 gene in the liver of newborn piglets and finishing pigs was greater in the MD group than that of the CON group (p < 0.05). In conclusion, maternal MD supplementation throughout gestation could enhance the birthweight and postnatal growth rate of offspring, associated with an increased expression of the IGF-1 gene and IGF-1r, as well as the altered DNA methylation of IGF-1 gene promotor.

Coenzyme B12 synthesis as a baseline to study metabolite contribution of animal microbiota

Microbial communities thrive in a number of environments. Exploration of their microbiomes – their global genome – may reveal metabolic features that contribute to the development and welfare of their hosts, or chemical cleansing of environments. Yet we often lack final demonstration of their causal role in features of interest. The reason is that we do not have proper baselines that we could use to monitor how microbiota cope with key metabolites in the hosting environment. Here, focusing on animal gut microbiota, we describe the fate of cobalamins – metabolites of the B12 coenzyme family – that are essential for animals but synthesized only by prokaryotes. Microbiota produce the vitamin used in a variety of animals (and in algae). Coprophagy plays a role in its management. For coprophobic man, preliminary observations suggest that the gut microbial production of vitamin B12 plays only a limited role. By contrast, the vitamin is key for structuring microbiota. This implies that it is freely available in the environment. This can only result from lysis of the microbes that make it. A consequence for biotechnology applications is that, if valuable for their host, B12‐producing microbes should be sensitive to bacteriophages and colicins, or make spores.

Oral supplementations of betaine, choline, creatine and vitamin B6 and their influence on the development of homocysteinaemia in neonatal piglets

Homocysteine (Hcy) is an intermediary sulphur amino acid recognised for pro-oxidative properties in several species which may weaken immune competence in piglets. In this species, there is an acute 10-fold increase of concentrations of plasma Hcy (pHcy) during the first 2 weeks of life. The present experiment aimed to determine if pHcy in piglets can be regulated by oral supplementations of betaine as a methyl group supplier, creatine for reducing the demand for methyl groups, choline with both previous functions and vitamin B₆ as enzymic co-factor for Hcy catabolism. A total of seventeen sows (second parity) were fed gestation and lactation diets supplemented with folic acid (10 mg/kg) and vitamin B₁₂ (150 µg/kg). Eight piglets in each litter received daily one of the eight following oral treatments (mg/kg body weight): (1) control (saline); (2) betaine (50); (3) choline (70); (4) creatine (300); (5) pyridoxine (0·2); (6) treatments 2 and 5; (7) treatments 3 and 4; and (8) treatments 2, 3, 4 and 5. According to age, pHcy increased sharply from 2·48 µm at birth to 17·96 µm at 21 d of age (P < 0·01). Concentrations of pHcy tended to be lower (P = 0·09) in treated than in control piglets but the highest and sole pairwise significant decrease (23 %) was observed between treatments 1 and 8 (P = 0·03). Growth from birth to 21 d of age was not influenced by treatments (P > 0·70). Therefore, it appears possible to reduce pHcy concentrations in suckling piglets but a combination of all chosen nutrients is required.

Homocysteine metabolism, growth performance, and immune responses in suckling and weanling piglets

Homocysteine (Hcy), an intermediary sulfur AA, is recognized as a powerful prooxidant with deleterious effects on physiological and immune functions. In piglets, there is an acute 10-fold increase of plasma concentrations of homocysteine (pHcy) during the first 2 wk of life. This project aimed to maximize pHcy variations within physiological ranges using typical supplies of folates and vitamin B12 (B12) to sows and piglets. Growth, immune response, and Hcy metabolism of piglets were studied until piglets reached 56 d of age. Third-parity sows were randomly assigned to a 2 × 2 split-plot design with 2 dietary treatments during gestation and lactation, S(-) (1 mg/kg folates and 20 µg/kg B12, n = 15) and S(+) (10-fold S(-) levels, n = 16), and 2 treatments to piglets within each half litter, intramuscular injections (150 µg) of B12 (P(+)) at d 1 and 21 (weaning) and saline (P(-)). Within each litter of 12 piglets, 3 P(+) and 3 P(-) piglets were studied for growth and Hcy metabolism, and the others were studied for immune responses. During lactation, plasma B12 decreased and was transiently greater in S(+) vs. S(-) piglets on d 1 and P(+) vs. P(-) piglets on d 7 (sow treatment × age and piglet treatment × age; P < 0.05). From 14 to 21 d of age, pHcy was 33% lower in S(+)P(+) vs. S(-)P(-) piglets (sow treatment × piglet treatment interaction; P < 0.05). At 56 d of age, hepatic B12 was greater and pHcy was lower for P(+) vs. P(-) piglets (P < 0.05). No treatment effect was observed on growth except for a lower postweaning G:F in S(+)P(-) piglets than in others (sow treatment × piglet treatment interaction; P < 0.05). Positive correlations were observed between pHcy and growth (r > 0.29, P < 0.05) before and after weaning. Antibody responses to ovalbumin and serum tumor necrosis factor-α were not affected by treatments, but postweaning serum IL-8 peaked earlier in S(-)P(-) vs. S(+)P(+) piglets (piglet treatment × age; sow treatment × piglet treatment interaction, P < 0.05). Proliferation of lymphocytes in response to the mitogen concanavalin A tended to be lower in culture media supplemented with sera from S(-) vs. S(+) piglets (P = 0.081) and P(-) vs. P(+) piglets (P = 0.098), and the reduction of response was more marked (P < 0.05) with high (>21 µM) compared to medium (17 to 21 µM) or low (<17 µM) pHcy. In conclusion, the present vitamin supplements to sows and/or piglets produced variations of pHcy that were not apparently harmful for growth performance of piglets. The greater pHcy, particularly prevalent in S(-) and/or P(-) piglets, had negative effects on some indicators of immune responses, suggesting that these young animals may be immunologically more fragile.

The contribution of portal drained viscera to circadian homocysteinemia in pigs

Homocysteine (Hcy) is an intermediary S-containing amino acid produced by the methylation process within all cells. It is known as a powerful pro-oxidant with multiple deleterious effects on immune and physiological functions. Blood plasma total Hcy (tHcy), the most common indicator of Hcy status, can be reduced by dietary folates or vitamin B(12) in pigs as in most mammalians. In humans, homocysteinemia is routinely assessed after an overnight fast (≥ 12 h) although information is not available on circadian tHcy changes. Using a subgroup of pigs from a study on portal appearance of vitamin B(12) after a single meal containing 0, 25 or 250 μg of cyanocobalamin, the present study aimed to report the circadian profile of postmeal blood plasma tHcy and estimate the contribution of portal drained viscera (PDV) to the systemic tHcy. Four pigs (39.7 ± 1.1 kg BW) were surgically equipped at 101.0 ± 8.2 d of age with catheters in the portal vein and carotid artery; an ultrasonic flow probe was also fitted around the portal vein for blood flow recordings. Blood samples were collected simultaneously from the 2 catheters once before meal and at least every hour during 24 h after ingestion of 1.2 kg of a vitamin-free semipurified diet. Arterial tHcy changed considerably during the 24-h postmeal period (P < 0.001; SE = 0.8). In fact, from 12.3 μM 10 min before meal, tHcy gradually reached a maximum of 23.4 μM 13 h postmeal and returned to 15.5 μM 23 h after the meal. Net fluxes of tHcy across PDV were not influenced by levels of dietary vitamin B(12), postprandial time, or their interaction (P > 0.25); average net flux did not differ from zero (P > 0.08). These results suggest that systemic Hcy following a meal originates from metabolic pools other than PDV. It appears that an overnight fast of 12 h will reflect the peak rather than the basal value for tHcy. The duration of the fasting period is therefore a critical factor for a reliable interpretation of tHcy homeostasis in pigs. Such information may be also relevant for human health and nutrition because pig is recognized as a reliable model for Hcy metabolism.

Methyl donor supplementation of gestating sow diets improves pregnancy outcomes and litter size

Maternal intake of B-vitamin and methyl donors can affect sow prolificacy. A total of 1079 Large White/Landrace sows (parities 2–9 at mating) were used in a 2 by 2 by 2 factorial design to determine the effects of two levels of betaine supplementation (0 versus 3 g added betaine/kg feed), two levels of folic acid plus vitamin B12 supplementation (0 versus 20 mg/kg folic acid plus 150 µg/kg vitamin B12) during gestation, and two parity groups (parity 2 and 3 versus parity 4 and greater) on litter size and pregnancy outcomes. The number of sows returning to oestrus post-insemination, as well as the number of early (<Day 30) and late (>Day 30) pregnancy losses were recorded. At farrowing, the total number of piglets born, the number of piglets born alive and dead, as well as the number of mummified fetuses were recorded. Pre-prandial blood samples were collected from a subset of 20 sows/treatment on Days 3, 30 and 107 of gestation to analyse homocysteine. The incidence of early pregnancy loss was reduced (P < 0.001) by folic acid plus vitamin B12 supplementation (0.03 versus 0.07). There was a significant interaction between parity at mating (parities 2 and 3 versus parity 4 and greater) and the addition of betaine or folic acid plus vitamin B12 to the gestation diet on litter size. Litter size was higher (0.5 piglets; P < 0.05) for betaine supplemented, compared with unsupplemented, parity 4 plus sows. Folic acid plus vitamin B12-supplemented parity 2 and 3 sows gave birth to more (P < 0.05) piglets than all other treatment groups. Folic acid plus vitamin B12 supplementation decreased (P < 0.001) plasma homocysteine concentration by 2.2 and 2.8 μM, respectively, on Days 3 and 107 of gestation. However, betaine supplementation decreased (P < 0.05) homocysteine on Day 3 only. Overall, folic acid plus vitamin B12 supplementation decreased incidences of early pregnancy failure and increased litter size in early parity sows, while betaine increased litter size in older parity sows.

Dietary oligosaccharides increase colonic weight and the amount but not concentration of bacterially synthesized folate in the colon of piglets

Recently, we demonstrated that the large pool of folate present in the colon of humans can be absorbed. Here, we investigated whether the net amount of folate synthesized by bacteria in the colon of piglets can be modified by feeding prebiotics to alter their microbial milieu. Male piglets (age 5 d, n = 12) were randomized to a milk-based formula containing either 5 g/L inulin + 5 g/L galactooligosaccharides (IN-GOS) or 5 g/L maltodextrin (control). Body weight did not differ between groups during the 28-d feeding intervention. However, the mean weight of colonic tissue (38%) and their contents (238%) was higher in the IN-GOS than in the control group (P = 0.004, P = 0.0001, respectively). Total bacterial load in the colon of piglets fed IN-GOS was 531% greater and the total amount of folate found in the colon contents was 53% greater than that of controls (P = 0.002, P = 0.02, respectively). Indices of blood folate status (plasma and RBC folate and plasma homocysteine) and folate concentrations in liver and kidneys were unaffected. Both groups exhibited low RBC folate (56 ± 23 nmol/L) and elevated homocysteine (24 ± 7 μmol/L) concentrations, evidence of deficiency if present in humans. In conclusion, dietary supplementation with 5 g of inulin + 5 g of galactooligosaccharides increased the weight, bacterial load, and total folate content in the piglet colon; however, these changes were insufficient to modify indices of whole body folate status. Future studies investigating the impact of feeding prebiotics on localized folate status at the level of the colonocyte are warranted.

Methionine, folic acid and vitamin B12 in growing-finishing pigs: impact on growth performance and meat quality

Growth performance, metabolic variables, and meat quality were measured in 78 growing-finishing pigs using supplements of 0 (C), or 0.2% of DL-methionine (M), and three combinations of folic acid [mg/kg] and cyanocobalamin [microg/kg], respectively 0 and 0 (V0), 10 and 25 (V1), and 10 and 150 (V2) in a 2 x 3 factorial arrangement. Feed conversion was lower (p = 0.05) in M than in C pigs during the growing period (0-4 weeks). Both V1 and V2 treatments increased plasma vitamin B12 (p < 0.01) and decreased plasma homocysteine (p < 0.01). Plasma 5-methyl-tetrahydrofolates were the lowest, highest and intermediate in V0, V1 and V2 pigs (p < 0.04), respectively. In V2 meat, folates were 32% higher, vitamin B12, 55% higher and homocysteine, 28% lower than in V0 (p < 0.01). Oxidative stability of the fresh meat was similar among treatments during a storage period of 42 days. Therefore, methionine supplements improved growth performance during the growing period. Vitamin supplements interacted with the methionine cycle pathway, increased vitamin content of pork meat but did not improve oxidative stability of the fresh meat during storage.