Effects of sources and routes of administration of vitamins A, D and copper on postnatal status of these micronutrients in piglets.

Twenty-six nulliparous sows were fed conventional gestation and lactation diets supplemented (N = 13) or not (N = 13) with extra daily supplements of 25-hydroxy-cholecalciferol (25-OH-D3; 4 ĸIU), ß-carotene (24 ĸIU), and copper (Cu)-proteinate (45 mg) from day 90 of gestation to 21 d of lactation (L21). In each litter, 10 piglets were divided into 5 pairs received, at 2 (L2) and 8 d (L8) of age, one of the five combinations of micronutrient sources and routes of administration (N = 260 piglets total). These neonatal treatments (N = 26 pairs or 52 piglets each) consisted of oral vitamin D3, retinol acetate and CuSO4 (T1); oral 25-OH-D3, ß-carotene, and Cu proteinate (T2); exposure to ultraviolet light (UVB), oral retinol palmitate and Cu gluconate (T3); intramuscular vitamin D3 and retinyl propionate and oral Cu acetate (T4); oral saline (CTRL). Oral or intramuscular provisions corresponded to 12 mg of Cu and 70 and 12 ĸIU of vitamins A and D, respectively. Blood samples were collected from all piglets at L2, L8, and L21 for determination of serum Cu, retinol, and 25-OH-D3. Body weight was measured at birth, L2, L8, and L21. Piglets were weaned at L21, and liver and blood samples were collected 2 d later to evaluate oxidative enzymes in blood and liver and hepatic ATP concentrations and expression of genes associated with antioxidant status. Sow treatments had marginal or no impacts on Cu, retinol, 25-OH-D3, or antioxidant status in piglet blood serum and liver. However, when supplements were given to piglets, hepatic Cu was 38% greater in for all treated piglets compared to CTRL (P < 0.01), hepatic retinol was 3 times higher in T1 than in CTRL (P < 0.01) and intermediate for other treatments whereas serum 25-OH-D3 was markedly increased with T2 and T3 at L8 and L21, respectively, compared to CTRL (Piglet treatment × Age interaction, P < 0.01). Concerning antioxidant activities, glutathione peroxidase, and superoxide dismutase were increased (P < 0.03) in plasma of T2 piglets whereas the highest values (P < 0.03) for indicators of oxidative damage to proteins were observed in T4 piglets. The study revealed that oral Cu proteinate from T2, oral retinol acetate from T1, oral 25-hydroxy-cholecalciferol from T2, and UVB light exposure from T3 were the most efficient ways of increasing the postnatal status of these micronutrients in suckling piglets and this may have some impacts on their peri-weaning antioxidant status.

Effects of high levels of zinc oxide and dietary zinc/copper ratios on the metabolism of iron in weaned pigs.

The present study compares the use different levels of dietary zinc oxide and zinc/copper ratios on the metabolism of iron (Fe) in weaned pigs. Two experiments were conducted using 120 and 160 weanling piglets (7.96 ±â€…1.17 kg and 7.81 ±â€…0.25 kg body weight, respectively) that were randomly assigned to the experimental treatments. Experiment I: diets supplemented with 100, 1,000, and 3,000 mg/kg of zinc (Zn) as ZnO (LZn, MZn, HZn) and 130 mg/kg of copper (Cu) as CuSO4; experiment II: diets supplemented with 100 or 3,000 mg/kg of Zn as ZnO (LZn and HZn) in combination with 6 or 130 mg/kg of Cu as CuSO4 (LCu and HCu). In both experiments, diets had similar levels of supplemental Fe (100 mg/kg of Fe as FeSO4). Piglets were slaughtered at d21 (weaning), d23 (experiment I), d28 (experiment II), d35, and d42 to assess whole blood, serum, and liver Fe concentrations, hemoglobin concentration, and the relative expression of key genes associated with Fe metabolism in jejunum and liver. Whole blood Fe and hemoglobin concentrations (experiment I) as well as serum Fe concentrations (experiments I and II) were not affected by dietary treatments (P ≥ 0.11). Liver Fe concentrations (experiment II) and total liver Fe content (experiments I and II) were lower (P ≤ 0.05) in HZn compared to LZn groups at d42. In both experiments, the mRNA expression of jejunal DMT1 was lowest and that of jejunal FTH1 was highest at d42 (P ≤ 0.04) for HZn piglets. In experiment II only, jejunal FTH1 and FPN1 expression were greater (P ≤ 0.04) in HCu compared to LCu groups at d42. The highest expression of hepatic FTH1 and FPN1 at d35 and d42 (P ≤ 0.02) was detected in HZn piglets in both experiments. For hepatic HAMP, expression values were greater (P = 0.04) at d42 in HZn groups. In conclusion, high dietary ZnO levels impair Fe metabolism but the effects are not intense enough to impact circulating Fe and hemoglobin concentrations.

Zinc oxide and copper sulfate are commonly used to prevent diarrhea in weaned piglets as an alternative to antibiotics. However, this strategy has been questioned due to environmental issues and public health concerns related to bacterial resistance. Recently, it was reported that high dietary zinc levels and/or high dietary zinc/copper ratios impair zinc and copper homeostasis and are detrimental to postweaning piglets' health. However, the eventual effects on iron metabolism are much less explored in pigs. Therefore, two experiments were conducted to evaluate the effects of increasing levels of dietary zinc (100, 1,000, and 3,000 mg/kg) and of different dietary zinc/copper ratios (3,000/130, 3,000/6, 100/130, and 100/6 mg/kg) on iron metabolism in weaned piglets. This study demonstrates that high dietary zinc levels, independently of dietary copper levels, impair iron metabolism by systemic and local (intestinal) mechanisms but also suggests that preweaning factors may interfere with postweaning iron homeostasis.

Gene ontology analysis of expanded porcine blastocysts from gilts fed organic or inorganic selenium combined with pyridoxine.

BACKGROUND: Gene ontology analysis using the microarray database generated in a previous study by this laboratory was used to further evaluate how maternal dietary supplementation with pyridoxine combined with different sources of selenium (Se) affected global gene expression of expanded porcine blastocysts. Data were generated from 18 gilts randomly assigned to one of three experimental diets (n = 6 per treatment): i) basal diet without supplemental Se or pyridoxine (CONT); ii) CONT + 0.3 mg/kg of Na-selenite and 10 mg/kg of HCl-pyridoxine (MSeB610); and iii) CONT + 0.3 mg/kg of Se-enriched yeast and 10 mg/kg of HCl-pyridoxine (OSeB610). All gilts were inseminated at their fifth post-pubertal estrus and euthanized 5 days later for embryo harvesting. Differential gene expression between MSeB610 vs CONT, OSeB610 vs CONT and OSeB610 vs MSeB610 was performed using a porcine embryo-specific microarray. RESULTS: There were 559, 2458, and 1547 differentially expressed genes for MSeB610 vs CONT, OSeB610 vs CONT and OSeB610 vs MSeB610, respectively. MSeB610 vs CONT stimulated 13 biological processes with a strict effect on RNA binding and translation initiation. OSeB610 vs CONT and OSeB610 vs MSeB610 impacted 188 and 66 biological processes, respectively, with very similar effects on genome stability, ceramide biosynthesis, protein trafficking and epigenetic events. The stimulation of genes related with these processes was confirmed by quantitative real-time RT-PCR. CONCLUSIONS: Gene expression of embryos from OSeB610 supplemented gilts was more impacted than those from MSeB610 supplemented gilts. Whereas maternal OSeB610 supplementation influenced crucial aspects of embryo development, maternal MSeB610 supplementation was restricted to binding activity.

Bioavailability of Vitamin B12 from Dairy Products Using a Pig Model.

The present study compares the bioavailability of vitamin B12 (B12) of dairy products or synthetic B12, using the pig as an experimental model for humans. Eleven pigs were used in a cross-over design to assess the net portal drained viscera (PDV) flux of blood plasma B12 after ingestion of tofu (TF; devoid of B12), Swiss cheese (SC), Cheddar cheese (CC), yogurt (YG), and synthetic B12 (TB12; TF supplemented with cyanocobalamin), providing a total of 25 µg of B12 each. PDV blood plasma flow for SC and CC were higher than for TF and TB12 (p ≤ 0.04) whereas YG was higher than TF (p = 0.05). Porto-arterial difference of blood plasma B12 concentrations were higher for CC and TB12 than for TF and YG (p ≤ 0.04) but not different from SC (p ≥ 0.15). Net PDV flux of B12 was only different from zero for CC. However, the net PDV flux of B12 for CC was not different from SC or TB12. Cumulative net PDV flux of B12 for SC, TB12, and CC were 2.9, 4.4, and 8.3 µg 23 h post-meal, corresponding to a bioavailability of 11.6%, 17.5%, and 33.0%, respectively. In conclusion, CC had the best bioavailability of B12 among the tested dairy products or compared to synthetic B12.

Pyridoxine (Vitamin B6) and the Glutathione Peroxidase System; a Link between One-Carbon Metabolism and Antioxidation.

Vitamin B6 (B6) has a central role in the metabolism of amino acids, which includes important interactions with endogenous redox reactions through its effects on the glutathione peroxidase (GPX) system. In fact, B6-dependent enzymes catalyse most reactions of the transsulfuration pathway, driving homocysteine to cysteine and further into GPX proteins. Considering that mammals metabolize sulfur- and seleno-amino acids similarly, B6 plays an important role in the fate of sulfur-homocysteine and its seleno counterpart between transsulfuration and one-carbon metabolism, especially under oxidative stress conditions. This is particularly important in reproduction because ovarian metabolism may generate an excess of reactive oxygen species (ROS) during the peri-estrus period, which may impair ovulatory functions and early embryo development. Later in gestation, placentation raises embryo oxygen tension and may induce a higher expression of ROS markers and eventually embryo losses. Interestingly, the metabolic accumulation of ROS up-regulates the flow of one-carbon units to transsulfuration and down-regulates remethylation. However, in embryos, the transsulfuration pathway is not functional, making the understanding of the interplay between these two pathways particularly crucial. In this review, the importance of the maternal metabolic status of B6 for the flow of one-carbon units towards both maternal and embryonic GPX systems is discussed. Additionally, B6 effects on GPX activity and gene expression in dams, as well as embryo development, are presented in a pig model under different oxidative stress conditions.