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.

Effects of dietary zinc/copper ratios on the metabolism of zinc and copper in weaned pigs.

This study compared the effects of different dietary zinc/copper ratios on zinc (Zn) and copper (Cu) metabolism in weaned pigs. One hundred and sixty piglets (7.81 ±â€…0.25 kg; 21 d of age) were used in a completely randomized 2 × 2 factorial design composed with high (H) and low (L) levels of added dietary Zn (100 and 3,000 mg/kg) and dietary Cu (6 and 130 mg/kg). Piglets were slaughtered at 21, 28, 35, and 42 d of age for blood and tissues collection. Serum, jejunum mucosa, liver, and kidney concentrations of Zn and Cu were analyzed as well as tissues mRNA abundance of genes related to their metabolism. Serum and liver Zn concentrations increased at days 28, 35, and 42 in HZn groups compared to pre-treatment levels (day 21; P ≤ 0.01) but for LZn animals, values decreased at days 28, 35, and 42 in liver (P ≤ 0.01) but remained stable vs. day 21 levels in serum (P ≥ 0.37). Serum, jejunum mucosa, liver, and kidney Zn concentrations were greater in HZn groups from day 28 (P ≤ 0.01). In jejunum mucosa, the mRNA expression of ZIP4 was lower in HZn piglets at day 28 (P ≤ 0.01) and at day 42 whereas HCu supplementation increased ZIP4 expression in LZn but not in HZn diets (P = 0.05). For ZNT1, MT3, and MT1, values of relative mRNA expression were greater for HZn animals in jejunum mucosa, liver, and kidney (P ≤ 0.01) from day 28. In kidney (P < 0.01) at day 42, HZn supplementation increased MTs expression in both LCu or HCu groups. Serum and liver Cu concentrations decreased at days 35 and 42 in all treatments compared to day 21 (P ≤ 0.04), except LZnHCu in liver that was not different from day 21 (P ≥ 0.17). Serum Cu concentrations were lower in HZn and greater in HCu groups at days 35 and 42 (P ≤ 0.01) whereas hepatic Cu was reduced by HZn diets in both LCu and HCu groups at days 35 and 42 (P ≤ 0.01). Jejunum Cu concentrations were increased by HCu diets in HZn but not in LZn groups at days 28 and 42 (P ≤ 0.04). Renal Cu concentrations were greater in HZn groups at day 28 (P < 0.01) whereas at day 42 HZn diets increased Cu values in both LCu and HCu groups (P ≤ 0.01). The expression of ATP7A in kidney at day 42 was greater for HZn groups (P = 0.02). In conclusion, high dietary Zn levels were not efficiently regulated by homeostatic mechanisms and significantly impaired Cu homeostasis. Low dietary Zn/Cu ratios allow a more efficient regulation of the metabolism of these trace minerals in post-weaning piglets. The current official recommendations for Zn and Cu to post-weaning piglets apparently do not fulfill their requirements.

Zinc oxide and copper sulfate are commonly used as growth promoters and alternatives to antibiotics to prevent diarrhea in weaned piglets but their use in post-weaning pigs diets has been challenged due to environmental issues and concerns related to bacterial resistance to antibiotics and heavy metals. Recently, it was reported that high dietary zinc levels interfere with copper status and may be detrimental to post-weaning piglets' health. In fact, the optimal dietary zinc/copper ratios need to be determined. Therefore, this experiment was conducted to evaluate the effects of different dietary zinc/copper ratios (3,000/130, 3,000/6, 100/130, and 100/6 mg/kg) on zinc and copper metabolism in weaned piglets. This study demonstrated that high dietary zinc/copper ratios impaired zinc and copper homeostasis but also that 100 mg/kg of dietary zinc and 6 mg/kg of dietary copper are apparently not sufficient to fulfill the piglets' requirements during the first weeks post-weaning.

Effects of dietary zinc oxide levels on the metabolism of zinc and copper in weaned pigs.

This study compared different dietary zinc oxide (ZnO) levels on zinc (Zn) and copper (Cu) metabolism in weaned pigs. One hundred twenty weaned piglets (7.96 ± 1.17 kg; 21 d of age) were used in a completely randomized 3 × 4 factorial design composed with three levels of dietary ZnO at 100 (100Zn), 1,000 (1,000Zn), or 3,000 mg/kg (3,000Zn) and four ages at slaughter at 21 (day 21), 23 (day 23), 35 (day 35), and 42 d (day 42). Dietary Cu levels were constant at 130 mg/kg. Serum, jejunum, liver, and kidney levels of Zn and Cu as well as mRNA abundance of genes related to Zn and Cu metabolism were analyzed. Zinc levels were greatest in 3,000Zn piglets from day 35 in all tissues (P ≤ 0.01). In 3,000Zn piglets, mRNA expression of ZIP4 was reduced in jejunum whereas ZnT1 and MT3 were stimulated in jejunum and liver and MT1 in kidney (P ≤ 0.04) from day 35. Copper levels were greatest in jejunum (P = 0.06) and kidney (P ≤ 0.01; days 35 and 42 only) and lowest in liver and serum (P ≤ 0.01) of 3,000Zn piglets. In conclusion, the treatment containing 3,000 mg ZnO/kg triggered Zn homeostatic mechanisms in weaned pigs and impaired Cu metabolism through high enterocyte and kidney Cu sequestration.

Zinc oxide (ZnO) is commonly used in post-weaning pig diets as growth promoter alternative to antibiotics to prevent diarrhea. The use of supranutritional levels of ZnO in post-weaning pigs diets has been challenged due to environmental issues and concerns related to bacterial resistance to antibiotics and heavy metals. However, the limited knowledge of the consequences of high levels of dietary ZnO on the metabolism of trace minerals has hampered advances to replace this nutritional strategy without compromising piglets health. Therefore, this experiment was conducted to evaluate the effects of increasing levels of dietary ZnO (i.e., 100, 1,000, and 3,000 mg/kg) on Zn and Cu metabolism in weaned piglets. In this experiment, it was demonstrated that systemic Zn levels were not effectively regulated with supplementation levels at 3,000 mg of ZnO/kg of diet. In addition, this level of dietary ZnO increased the intestinal intracellular sequestration of Cu and impaired its renal reabsorption, negatively impacting hepatic, and systemic serum Cu concentrations. These results emphasize the potential risk of Cu deficiency under long-term supranutritional supplementation of dietary ZnO during the post-weaning period, with potentially detrimental impacts on piglets growth.

Impact of birth weight and neonatal nutritional interventions with micronutrients and bovine colostrum on the development of piglet immune response during the peri-weaning period.

Immune system development of piglets is influenced by birth weight and colostrum and milk intake. Moreover, the dam transfer to piglets of vitamins A and D and copper, which play important role in immunity, is limited during lactation. In this study, we evaluated the potential of maternal and neonatal supplementations with vitamins A and D and copper, with or without neonatal supplementation of bovine colostrum (BC), to modulate the immune system development of low birth weight (LBW) and high birth weight (HBW) piglets during the peri-weaning period. Litters from 23 control sows (CONT) were assigned to one of the following treatments: 1) control (C); 2) oral administration at 2 and 8 days (d) of age of retinol-acetate, 25-hydroxyvitamin D and CuSO4 and exposure to UVB light for 15 min every second day from d 5 to d 21 (ADCu); 3) oral administration of dehydrated BC (4 g/d) from d 5 to d 10 (BC); 4) ADCu + BC. This experimental design was repeated with 24 sows fed extra daily supplements of 25-hydroxyvitamin D (4,000 IU), ß-carotene (30,000 IU) and Cu-yeast (equivalent 45 mg of Cu) from 90 d of gestation until weaning at d 21 (SUPPL). Within each litter, 2 LBW and 2 HBW piglets were euthanized at d 16 and d 23 in order to characterize leukocyte subsets in mesenteric lymph nodes (MLN) and blood by flow cytometry, and to measure gene expression in the MLN and jejunal mucosa by qPCR. At d 16, results revealed that the percentages of γδ and cytotoxic T lymphocytes were significantly reduced in LBW compared to HBW piglets. The jejunal expression of interleukin (IL) 22 was also up-regulated, along with MLN expression of C-C Motif Chemokine Ligand 23, bone morphogenetic protein 2 and secreted phosphoprotein 1 (SPP1), whereas jejunal expression of tumor necrosis factor α was decreased in LBW piglets. At d 23, LBW piglets showed lower amounts of γδ T lymphocytes, higher percentages of CD3- and CD3-CD8α+CD16+ leukocytes (which include Natural killer cells) and lower jejunal expression of IL18. Furthermore, supplementation with BC increased the blood percentage of CD3-CD16+ leukocytes and reduced jejunal IL5 and MLN IL15 expression whereas supplementation with ADCu + BC increased jejunal TNF superfamily 13B and MLN SPP1 expression. Our results suggest that immune system development after birth differed between LBW and HBW piglets and that early dietary supplementation with BC and ADCu has the potential to modulate development of immune functions.

Linoleic acid, α-linolenic acid and enterolactone affect lipid oxidation and expression of lipid metabolism and antioxidant-related genes in hepatic tissue of dairy cows.

Although beneficial effects have been attributed to PUFA supplementation in high-yielding dairy cows, diets rich in PUFA may also increase oxidative stress in tissues such as the liver. To fully exploit the health benefits of PUFA, we believe that the addition of natural antioxidants could help in preventing oxidative damage. Using an in vitro precision-cut liver slices (PCLS) tissue culture system, we investigated the effects of different linoleic acid (LA, n-6):α-linolenic acid (ALA, n-3) ratios (LA:ALA ratio of 4, LA:ALA ratio of 15 and LA:ALA ratio of 25) in the presence or absence of the antioxidant enterolactone (ENL) on (1) the mRNA abundance of genes with key roles in hepatic lipid metabolism, oxidative stress response and inflammatory processes, (2) oxidative damages to lipids and proteins and (3) superoxide dismutase activity in early-lactating dairy cows. The addition of LA and ALA to PCLS culture media increased oxidative damage to lipids as suggested by higher concentrations of thiobarbituric acid reactive substances and increased the expression of nuclear factor erythroid 2-related factor 2 target genes. The addition of ENL was effective in preventing lipid peroxidation caused by LA and ALA. Transcript abundance of sterol regulatory element-binding transcription factor 1 and its lipogenic target genes acetyl-CoA carboxylase α, fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD) was decreased with LA and ALA, whereas ENL decreased FASN and SCD gene expression. Our results show that addition of LA and ALA to PCLS culture media lowers hepatic lipogenic gene expression and increases oxidative damages to lipids. On the other hand, addition of ENL prevents oxidative damages provoked by these PUFA.

The potential effects of antioxidant feed additives in mitigating the adverse effects of corn naturally contaminated with Fusarium mycotoxins on antioxidant systems in the intestinal mucosa, plasma, and liver in weaned pigs.

Seventy-two piglets (6.0 kg BW) were randomly distributed within six different dietary treatments to evaluate the effect of deoxynivalenol (DON) and the potential of four antioxidant feed additives in mitigating the adverse effects of DON on growth performances and oxidative status. Dietary treatments were as follows: control diet 0.8 mg/kg DON; contaminated diet (DON-contaminated diet) 3.1 mg/kg DON; and four contaminated diets, each supplemented with a different antioxidant feed additive, DON + vitamins, DON + organic selenium (Se)/glutathione (GSH), DON + quercetin, and DON + COMB (vitamins + Se/GSH + quercetin from the other treatments). Although DON was the main mycotoxin in the contaminated diet, this diet also contained 1.8 mg/kg of zearalenone (ZEN). The "mycotoxin" effects therefore included the combined effect of these two mycotoxins, DON, and ZEN. The DON-ZEN ingestion did not affect growth performances, average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F ratio), but partially induced oxidative stress in weaned pigs as shown by increased malondialdehyde (MDA) content in the plasma and superoxide dismutase (SOD) activity in liver (P < 0.05). However, no change in the activity of other antioxidant enzymes or GSH concentrations was observed in plasma and liver of piglets fed the DON-contaminated diet (P > 0.05). Supplementation with individual antioxidant feed additive had a limited effect in weaned pigs fed DON-ZEN-contaminated diets. Combination of antioxidants (vitamins A, C, and E, quercetin, and organic Se/GSH) reduced plasma and liver MDA content and SOD activity in liver (P < 0.05) of piglets fed DON-ZEN-contaminated diets. Furthermore, this combination also reduced MDA content in the ileum (P < 0.05), although activity of glutathione peroxidases (GPx), SOD or catalase (CAT) in the ileum was not affected by DON-ZEN contamination or antioxidant supplements. In conclusion, DON-ZEN contamination induced oxidative stress in weaned pigs and combination of antioxidant feed additives restored partially the oxidative status. Further studies will be necessary to assess whether the effects of antioxidant feed additives on oxidative status are specific when feed is contaminated with DON-ZEN.

The importance of pyridoxine for the impact of the dietary selenium sources on redox balance, embryo development, and reproductive performance in gilts.

This study aimed to determine the effects of dietary pyridoxine and selenium (Se) on embryo development, reproductive performance and redox system in gilts. Eighty-four gilts were fed one of five diets: CONT) basal diet; MSeB60) CONT+0.3mg/kg of Na-selenite; MSeB610) diet 2+10mg/kg of HCl-pyridoxine; OSeB60) CONT+0.3mg/kg of Se-enriched yeast; and OSeB610) diet 4+10mg/kg of HCl-pyridoxine. Blood samples were collected for long-term (each estrus and slaughter) and peri-estrus (fourth estrus d -4 to d +3) profiles. At slaughter (gestation d 30), organs and embryos were collected. For long-term and peri-estrus profiles, Se level and source affected (P<0.01) blood Se concentration whereas B6 level increased (P<0.01) erythrocyte pyridoxal-5-phosphate concentration. A B6 level (P<0.05) effect was observed on long-term plasma Se-dependent glutathione peroxidase (Se-GPX) activity whereas peri-estrus Se-GPX was minimum on d -1 (P<0.01). Selenium level increased sows' organs and embryo Se concentration (P<0.01). Selenium source tended to enhance embryo Se content (P=0.06). Within-litter embryo Se content was increased by B6 level (P<0.01). Selenium level tended to affect Se-GPX and total GPX activities in organs mitochondria (P=0.09 and 0.07, respectively). Selenium source affected kidney ATP synthesis (P=0.05). In conclusion, B6 level affected the Se-GPX activity on a long-term basis, whereas the basal level of Se was adequate during the peri-estrus period. Embryo quality was not improved by dietary Se, and B6 impaired within-litter homogeneity.

Interaction between vitamin B6 and source of selenium on the response of the selenium-dependent glutathione peroxidase system to oxidative stress induced by oestrus in pubertal pig.

This study aimed to assess the interaction between vitamin B6 and selenium (Se) for the flow of Se towards the Se-dependent glutathione peroxidase (GPX) system in response to oxidative stress naturally induced by oestrus in a pubertal pig model. At first oestrus, forty-five gilts were randomly assigned to the experimental diets (n=9/group): basal diet (CONT); CONT+0.3mg/kg of Na-selenite (MSeB60); MSeB60+10mg/kg of HCl-B6 (MSeB610); CONT+0.3mg/kg of Se-enriched yeast (OSeB60); and OSeB60+10mg/kg of HCl-B6 (OSeB610). Blood samples were collected at each oestrus (long-term profiles), and daily from day -4 to +3 (slaughter) of the fourth oestrus (peri-oestrus profiles) after which liver, kidneys, and ovaries were collected. For long-term profiles, CONT had lower blood Se than Se-supplemented gilts (p<0.01) and OSe was higher than MSe (p<0.01). Lower erythrocyte pyridoxal-5-phosphate was found in B60 than B610 (p<0.01). No treatment effect was observed on GPX activity. For peri-oestrus profiles, treatment effects were similar to long-term profiles. Treatment effects on liver Se were similar to those for long-term blood Se profiles and OSe had higher renal Se concentrations than MSe gilts (p<0.01). Gene expressions of GPX1, GPX3, GPX4, and selenocysteine lyase in liver and kidney were greatest in OSeB610 gilts (p<0.05). These results suggest that dietary B6 modulate the metabolic pathway of OSe towards the GPX system during the peri-oestrus period in pubertal pigs.

The submitochondrial distribution of ubiquinone affects respiration in long-lived Mclk1+/- mice.

Mclk1 (also known as Coq7) and Coq3 code for mitochondrial enzymes implicated in the biosynthetic pathway of ubiquinone (coenzyme Q or UQ). Mclk1(+/-) mice are long-lived but have dysfunctional mitochondria. This phenotype remains unexplained, as no changes in UQ content were observed in these mutants. By producing highly purified submitochondrial fractions, we report here that Mclk1(+/-) mice present a unique mitochondrial UQ profile that was characterized by decreased UQ levels in the inner membrane coupled with increased UQ in the outer membrane. Dietary-supplemented UQ(10) was actively incorporated in both mitochondrial membranes, and this was sufficient to reverse mutant mitochondrial phenotypes. Further, although homozygous Coq3 mutants die as embryos like Mclk1 homozygous null mice, Coq3(+/-) mice had a normal lifespan and were free of detectable defects in mitochondrial function or ubiquinone distribution. These findings indicate that MCLK1 regulates both UQ synthesis and distribution within mitochondrial membranes.