Oxidative Stress In Pigs Research Articles

Physiology, gene expression, and behavior as potential indicators of oxidative stress in piglets

The goal of the current study was to develop a pig model to investigate oxidative stress with a low negative impact on piglet welfare. Four independent trials (A, B, C, and D) were performed using a single intraperitoneal shot of lipopolysaccharide (LPS) as an immune challenge, aiming to assess the minimal LPS dose for piglets of different age to trigger a measurable acute oxidative stress response in healthy animals. In trial A, piglets received an LPS dose of 25 µg/KgBW at 41 days post-weaning (p.w.). In trial B, piglets received 25 µg/KgBW of LPS at 28 days p.w., in trials C And D, piglets were injected with 50 µg/KgBW of LPS at 21 days p.w., respectively. Piglets were randomly allocated either to the T1) Control group with saline solution (Ctrl), or T2) LPS challenge (LPS). The oxidative stress response was measured through the enzymatic activity of glutathione peroxidase (GPx), glutathione-S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT), in both plasma and intestinal tissues. Intestinal gene expression of oxidative stress and inflammatory markers was assessed. Discomfort behaviors (panting, prostration, trembling, and vomits) were also recorded. Plasmatic and intestinal oxidative stress response was inconsistent across the four trials even when the dose and pig age were similar, possibly due to individual variability. Relative gene expression differences of anti-inflammatory cytokines (IL10), oxidation precursor (iNOS), and antioxidant markers (GPx4, MnSOD, and CAT) were detected between Ctrl and LPS treatment (P < 0.05) when assessed. Behavioral observations were sensitive to the LPS dose relative to Ctrl (P < 0.05) in all four trials. These results suggest that behavioral observations can be used as a non-invasive methodology to detect the presence of oxidative stress in pigs in challenging conditions. Behavioral observations were more sensitive than other indicators (i.e., biomarkers and gene expression) in the current study. However, a sensitivity scale system needs to be developed to qualify and rank the impact of oxidative stress in pigs.

Exposure to natural stray currents of low voltage affects the behaviour and some stress biomarkers of weaned piglets

With the modernisation of pig breeding facilities, pigs may be exposed to both on-farm and off-farm sources of stray voltages. Data from ruminant species suggest that exposition to stray voltages may be a source of stress and impair animal welfare, but data are scarce for pigs. The aim of this study was to evaluate the impact of stray currents of voltages under 0.5 Volts in pig housing on piglet behaviours and some biomarkers after weaning. Two replicates of 820 piglets were reared in a farm naturally exposed to stray voltage for seven weeks. The difference in electrical potential between the floor and each drinker and feeder was measured every two weeks. Piglets exposed to high-voltage drinkers (HVD > 125 mV) spent more time orally manipulating pen mates (P = 0.0031). They also spent more time lying inactive with open eyes (P = 0.0027) and less time nosing pen mates (P = 0.043), but these effects were influenced by the voltage in feeders (P = 0.0021 and P = 0.024, respectively). Piglets exposed to high-voltage feeders (HVF > 50 mV) spent less time lying with their eyes closed (P = 0.024) and more time aggressing pen mates (P = 0.0081). Fifty days after entering the farm, blood hydroperoxide concentration was higher in piglets exposed to HVD (P = 0.039). The increase in socio-negative behaviours and oxidative stress in pigs exposed to stray voltages in pig housing suggested that stray voltages might have moderate detrimental consequences for piglets in post-weaning facilities.

Dietary fat supplementation relieves cold temperature-induced energy stress through AMPK-mediated mitochondrial homeostasis in pigs.

Cold stress has negative effects on the growth and health of mammals, and has become a factor restricting livestock development at high latitudes and on plateaus. The gut-liver axis is central to energy metabolism, and the mechanisms by which it regulates host energy metabolism at cold temperatures have rarely been illustrated. In this study, we evaluated the status of glycolipid metabolism and oxidative stress in pigs based on the gut-liver axis and propose that AMP-activated protein kinase (AMPK) is a key target for alleviating energy stress at cold temperatures by dietary fat supplementation. Dietary fat supplementation alleviated the negative effects of cold temperatures on growth performance and digestive enzymes, while hormonal homeostasis was also restored. Moreover, cold temperature exposure increased glucose transport in the jejunum. In contrast, we observed abnormalities in lipid metabolism, which was characterized by the accumulation of bile acids in the ileum and plasma. In addition, the results of the ileal metabolomic analysis were consistent with the energy metabolism measurements in the jejunum, and dietary fat supplementation increased the activity of the mitochondrial respiratory chain and lipid metabolism. As the central nexus of energy metabolism, the state of glycolipid metabolism and oxidative stress in the liver are inconsistent with that in the small intestine. Specifically, we found that cold temperature exposure increased glucose transport in the liver, which fully validates the idea that hormones can act on the liver to regulate glucose output. Additionally, dietary fat supplementation inhibited glucose transport and glycolysis, but increased gluconeogenesis, bile acid cycling, and lipid metabolism. Sustained activation of AMPK, which an energy receptor and regulator, leads to oxidative stress and apoptosis in the liver; dietary fat supplementation alleviates energy stress by reducing AMPK phosphorylation. Cold stress reduced the growth performance and aggravated glycolipid metabolism disorders and oxidative stress damage in pigs. Dietary fat supplementation improved growth performance and alleviated cold temperature-induced energy stress through AMPK-mediated mitochondrial homeostasis. In this study, we highlight the importance of AMPK in dietary fat supplementation-mediated alleviation of host energy stress in response to environmental changes.

Bioavailability of Li-enriched mushrooms and protection against oxidative stress in pigs: First study in vivo.

Mycelia and mushrooms are able to bioaccumulate minerals. Lithium is the active principle of drugs used in the treatment of psychiatric diseases. However, a dietary source of Li can reduce the side effects of these drugs. Thus, the objective of this study was to evaluate the bioavailability of Li-enriched mushroom of Pleurotus djamor in pigs and the effects of this element on oxidative stress in the animal tissues. Pigs 28-30days-old were fed with diets containing or not Li for five days. Levels of serum cortisol were related to the Li dosage from diet. Li-enriched mushrooms were more bioavailable source of Li to the body than Li2CO3. These mushrooms also improved the effects of oxidative enzymes and showed less oxidative damage than Li2CO3. These results demonstrate the potential to use Li-enriched P. djamor as a source of Li that is more bioavailable and present protective effects against oxidative stress.

Using Recombinant Superoxide Dismutase to Control Oxidative Stress in the Gastrointestinal Tract of Cyclic Heat-Stressed Pigs.

Climate change is associated with an increased frequency and intensity of heat waves, posing a threat of heat stress to pig production. Heat stress compromises the efficiency of pig production partly due to causing oxidative stress, intestinal dysfunction, and inflammatory responses. Superoxide dismutase is an antioxidant enzyme reported to reduce oxidative stress and inflammation. Therefore, this experiment aimed to investigate whether recombinant superoxide dismutase (rSOD) could ameliorate oxidative stress and inflammatory responses in heat-stressed grower pigs. Sixty-four female pigs (Large White × Landrace, 27.8 ± 1.65 kg, mean ± SD) were randomly allocated to a control diet (standard grower feed, CON) or the control diet supplemented with 50 IU recombinant superoxide dismutase (rSOD) for 14 days. After acclimation to the diet, pigs were then housed under thermoneutral (TN, 20 °C, 35-50% relative humidity) or cyclic heat stress conditions (CHS, at 35 °C: 9 a.m. to 5 p.m. and 28 °C: 5 p.m. to 9 a.m., 35-50% relative humidity) for 3 days. Heat stress increased respiration rate (RR), skin and rectal temperature (RR and RT) (p < 0.001 for all), and reduced plasma thyroid hormone concentration (p < 0.001). The amount of oxidized glutathione (GSH:GSSG) was increased in the jejunum and ileum of CHS pigs. In the jejunum, rSOD also increased the amount of oxidized glutathione in both TN and CHS pigs, without any change in endogenous SOD activity. In the ileum, rSOD prevented increases in oxidized glutathione formation in the CHS pigs only. Taken together, this may reflect increased oxidative stress in both the jejunum and ileum in CHS pigs. Alternatively, rSOD increased the conversion of reduced to oxidized glutathione independently of CHS, possibly reflecting an increased overall SOD activity due to the addition of exogenous SOD. In conclusion, the use of in-feed SOD enzymes at a dose of 50 IU/kg may be a useful strategy for preventing oxidative stress in pigs.

Quercetin supports acaricidal activity of ivermectin against naturally acquired sarcoptic mange in pigs

Sarcoptic mange triggers continuous oxidative onslaughts, resulting in severe oxidative stress in pigs and, to date, no antioxidant has been evaluated for the treatment of naturally infested pigs. This randomized clinical trial aimed to assess the ameliorative potential of the antioxidant quercetin (QR) when integrated with ivermectin (IVM) in the treatment of sarcoptic mange in pigs. The control group (T0 , n=10) consisted of healthy subjects. The first treatment group (T1 , n=10) consisted of infested pigs receiving the standard treatment (subcutaneous IVM only) while the second treatment group (T2 , n=10) consisted of infested pigs receiving integrated treatment (subcutaneous IVM plus oral QR). On day 0, the circulating malondialdehyde (MDA) was significantly higher and superoxide dismutase (SOD), reduced glutathione (GSH), catalase (CAT), total antioxidant capacity (TAC) and antioxidative minerals (zinc, copper, iron) were lower in all infested pigs compared to the healthy subjects. On day 14 post-treatment, maximum recovery was observed in the MDA, SOD, GSH, CAT, TAC, zinc, copper and iron in group T2 and the results returned to normal earlier in group T2 than in T1 . Likewise, more significant improvements in parasitological cure rate, scratching index and skin score were recorded after treatment in group T2 than group T1 . These results suggest the greater effectiveness of IVM plus QR than IVM alone against sarcoptic mange, and quercetin may be recommended as an ancillary therapy with IVM to negate severe oxidative stress, improve post-therapy convalescence and produce a speedy recovery in pigs.

Glutamate attenuates lipopolysaccharide induced intestinal barrier injury by regulating corticotropin-releasing factor pathway in weaned pigs.

ObjectiveThe purpose of this study was to evaluate the protection of glutamate (GLU) against the impairment in intestinal barrier function induced by lipopolysaccharide (LPS) stress in weaned pigs.MethodsTwenty-four weaned pigs were divided into four treatments containing: i) non-challenged control, ii) LPS-challenged control, iii) LPS+1.0% GLU, and iv) LPS+2.0% GLU. On day 28, pigs were treated with LPS or saline. Blood samples were collected at 0, 2, and 4 h post-injection. After blood samples collection at 4 h, all pigs were slaughtered, and spleen, mesenteric lymph nodes, liver and intestinal samples were obtained.ResultsDietary GLU supplementation inhibited the LPS-induced oxidative stress in pigs, as demonstrated by reduced malondialdehyde level and increased glutathione level in jejunum. Diets supplemented with GLU enhanced villus height, villus height/crypt depth and claudin-1 expression, attenuated intestinal histology and ultrastructure impairment induced by LPS. Moreover, GLU supplementation reversed intestinal intraepithelial lymphocyte number decrease and mast cell number increase induced by LPS stress. GLU reduced serum cortisol concentration at 4 h after LPS stress and downregulated the mRNA expression of intestinal corticotropin-releasing factor signal (corticotrophin-releasing factor [CRF], CRF receptor 1 [CRFR1], glucocorticoid receptor, tryptase, nerve growth factor, tyrosine kinase receptor A), and prevented mast cell activation. GLU upregulated the mRNA expression of intestinal transforming growth factor β.ConclusionThese findings indicate that GLU attenuates LPS-induced intestinal mucosal barrier injury, which is associated with modulating CRF signaling pathway.

Differentially Expressed Hepatic Genes Revealed by Transcriptomics in Pigs with Different Liver Lipid Contents.

The liver is the center for uptake, synthesis, packaging, and secretion of lipids and lipoproteins. The research on lipid metabolism in pigs is limited. The objective of the present study is to identify the genes related to lipid metabolism and oxidative stress in pigs by using transcriptomic analysis. Liver segments were collected from 60 Jinhua pigs for the determination of liver lipid content. The 7 pigs with the highest and lowest liver lipid content were set as group H and group L, respectively. Liver segments and serum samples were collected from each pig of the H and L groups for RNA sequencing and the determination of triglycerides (TG) content and high-density lipoprotein cholesterol (HDL) content, respectively. The HDL content in the serum of pigs in the H group was significantly higher than the L group (P < 0.05). From transcriptomic sequencing, 6162 differentially expressed genes (DEGs) were identified, among which 2962 were upregulated and 3200 downregulated genes with the increase in the liver content of Jinhua pigs. After GO enrichment and KEGG analyses, lipid modification, cellular lipid metabolic process, cholesterol biosynthetic process, fatty acid metabolic process, oxidoreduction coenzyme metabolic process, oxidoreductase activity, acting on CH-OH group of donors, response to oxidative stress, nonalcoholic fatty liver disease (NAFLD), sphingolipid metabolism, and oxidative phosphorylation pathways were involved in lipid metabolism and oxidative stress in Jinhua pigs. For further validation, we selected 10 DEGs including 7 upregulated genes (APOE, APOA1, APOC3, LCAT, CYP2E1, GPX1, and ROMO1) and 4 downregulated genes (PPARA, PPARGC1A, and TXNIP) for RT-qPCR verification. To validate these results in other pig species, we analyzed these 10 DEGs in the liver of Duroc×Landrace×Yorkshire pigs. Similar expression patterns of these 10 DEGs were observed. These data would provide an insight to understand the gene functions regulating lipid metabolism and oxidative stress and would potentially provide theoretical basis for the development of strategies to modulate lipid metabolism and even control human diabetes and obesity by gene regulations.

Plant Feed Additives as Natural Alternatives to the Use of Synthetic Antioxidant Vitamins on Livestock Mammals' Performances, Health, and Oxidative Status: A Review of the Literature in the Last 20 Years.

In the last two decades, the interest in natural plant feed additives (PFA) as alternatives to synthetic vitamins in livestock nutrition has increased. After a systematic review, a total of 19 peer-reviewed papers published between 2000 and 2020 were retained to evaluate the antioxidant effects of PFA compared to synthetic antioxidant vitamins (mainly vitamin E; VitE) in livestock nutrition. These studies demonstrated that PFAs could be as efficient as VitE in counteracting oxidative stress in pigs, rabbits, and ruminants. However, PFAs only positively affected animals’ growth performance and feed efficiency in some monogastric studies. The PFA can affect antioxidant enzyme activity in a dose- and method of administration-dependent manner. The antioxidant capacity of both PFA and VitE were depressed in cows fed with diets rich in polyunsaturated fatty acids. Variability among studies could be related to species differences. Despite the interest of the feed industry sector in PFA, there are still very few studies evaluating their antioxidant effect in species other than poultry.

Research Progress on Oxidative Stress and Its Nutritional Regulation Strategies in Pigs.

Simple SummaryIn the process of production, especially the modern intensive scale farming where high quality and high efficiency are pursued, pigs are subjected to a series of adverse stimuli from birth to slaughter (e.g., immunotherapy, environmental changes, uncomfortable temperature, feed contamination, improper transportation, slaughter methods, etc.). These adverse stimuli eventually translate into an imbalance in redox levels in the body, resulting in oxidative stress. The generation of oxidative stress, in turn, eventually causes damage to the pigs. To eliminate/reduce this harmful effect and counteract oxidative stress, pigs use part of the energy reserved for growth, which eventually leads to a decrease in production performance and causes unnecessary economic losses.Oxidative stress refers to the dramatic increase in the production of free radicals in human and animal bodies or the decrease in the ability to scavenging free radicals, thus breaking the antioxidation–oxidation balance. Various factors can induce oxidative stress in pig production. Oxidative stress has an important effect on pig performance and healthy growth, and has become one of the important factors restricting pig production. Based on the overview of the generation of oxidative stress, its effects on pigs, and signal transduction pathways, this paper discussed the nutritional measures to alleviate oxidative stress in pigs, in order to provide ideas for the nutritional research of anti-oxidative stress in pigs.

161 Dietary oxidized protein result in growth and histology differences in pigs

Abstract Rendered by-products are common feedstuffs in diets. During processing, these sources have potential to become oxidized. While most research on oxidative stress has focused on dietary oxidized lipids, little research has been done in dietary oxidized proteins and the potential to induce oxidative stress. Recent studies have shown consumption of dietary oxidized proteins resulted in shifts in oxidative status. The objective of this study was to determine the effects of dietary oxidized protein on oxidative stress in pigs as a model for canines. Fifty-six, 3 weeks old pigs (5.55 ± 0.71 Kg) were fed 4 dietary treatments each varying in dietary oxidized protein. Each treatment was fed the same diet, with the exception of the degree of oxidation in chicken by-product meal which was included in the diet at 23 percent to represent typical inclusion levels of a companion animal diet. Oxidation was induced by 2 levels of heating and 2 levels of antioxidants (mixed tocopherol), in a 2 x 2 factorial design. A significant antioxidant effect was observed in villi height (P-value &amp;lt; 0.05) where pigs fed diets without antioxidant had increased villi height (674 μm) compared to those fed diets with antioxidants (576 μm). Additionally, pigs fed diets without antioxidant had significantly greater villi:crypt (3.22) compared to those fed diets with antioxidants (2.84 ; P-value &amp;lt; 0.05). Additionally, feed efficiency measured by gain:feed, was significantly decreased in pigs fed heated protein (0.65) compared to not heated (0.69; P-value &amp;lt; 0.05). Results from this study are consistent with previous studies (Dibner, et al., 1996). Future studies should examine the effects of feeding oxidized proteins in regard to oxidative status, such as markers of protein, lipid, DNA, and antioxidative enzyme damage. In conclusion, dietary oxidized protein can reduce feed efficiency in pigs.

PSIV-5 Can dietary oxidized protein induce oxidative stress in pigs?

Abstract Endogenous protein oxidation as a result of oxidative stress is known to reduce the efficiency of livestock species (Boler et al., 2012; DeRouchey et al., 2004; Dibner, Atwell, Kitchell, Shermer, &amp; Ivey, 1996). Additionally, rendered by-products are common feedstuffs in livestock diets. During processing, these sources have the potential to become oxidized. While most research on oxidative stress has focused on consumption of dietary oxidized lipids, little research has been done in the area of dietary oxidized proteins and the potential to induce oxidative stress. The objective of this study was to determine the effects of dietary oxidized protein on oxidative stress in pigs. For this study, 30 pigs 6 weeks old were divided into three dietary treatments of control, medium, and high dietary oxidized protein. Each treatment was fed the same diet, with the exception of the degree of oxidation in bovine plasma which was included in the diet at 10 percent. Pigs were fed for 19 days and then euthanized for tissues collected. Jejunum, liver, and colon were collected along with urine and plasma samples on day 0 and 18. Jejunum samples were also collected for histology. Markers of oxidative stress included protein carbonyls, thiobarbituric acid reactive substance (TBARS), 8-hydroxyguanine, and glutathione peroxidase activity. Pigs in the high oxidation treatment had an increase in crypt depth of 16 percent (p-value less than 0.05) when compared to control further resulting in an 11 percent decrease in villi height to crypt depth ratio (p-value less than 0.05). Additionally, lipid oxidation products, measured by TBARS, was 28 percent greater in the liver of pigs in the medium oxidation treatment (p-value less than 0.05) when compared to control. Even with the short duration of this study, dietary oxidized protein did impact the oxidative status of the animal. Using pigs as a model for companion animals, it could be hypothesized then that long-term exposure could have implications on longevity.

Biomarkers of oxidative stress in saliva in pigs: analytical validation and changes in lactation

BackgroundBiomarkers of oxidative stress in pigs have been measured in serum/plasma samples. However, blood collection in pigs can be highly stressful to the animals. Saliva is a biological fluid with several advantages in pigs over blood, since it can be easily collected without stress to the animals, being therefore an ideal sample in this species. The objective of this study was the validation of assays for the evaluation of oxidative stress status in saliva of pigs. For this purpose, three assays commonly used to evaluate the total antioxidant capacity (TAC): trolox equivalent antioxidant capacity (TEAC), cupric reducing antioxidant capacity (CUPRAC), and ferric reducing ability of plasma (FRAP)), one individual antioxidant (uric acid) and two assays to evaluate oxidant concentrations (advanced oxidation protein products (AOPP) and hydrogen peroxide (H2O2)) were measured and validated in porcine saliva. In addition, the possible changes of these assays in sows’ saliva during lactation were be studied.ResultsThe methods had intra- and inter-assays coefficient of variation lower than 15%. They also showed an adequate linearity and recovery, and their detection limits were low enough to detect the analytes in saliva of pigs. Overall the analytical validation tests showed that the assays used in our study are valid and reliable for the evaluation of oxidative stress in porcine saliva. In addition, it was observed that these salivary biomarkers can change in a situation of oxidative stress such as lactation in sows.ConclusionsAll assays for salivary biomarkers of oxidative stress evaluated in this study have demonstrated a high analytical accuracy and low imprecision. In addition, it has been observed that these biomarkers showed significant changes in a situation of oxidative stress such as lactation in sows. Therefore, this study opens a new possibility of using saliva as a non-invasive sample to evaluate oxidative stress in pigs.

Omega-3 fatty acids modulate cyclophosphamide induced markers of immunosuppression and oxidative stress in pigs

Immunosuppression directly correlates with economic benefits in livestock. Although omega-3, known as an energy source, is used as a pharmaceutical molecule, it remains unknown whether dietary supplementation with omega-3 can alleviate cyclophosphamide-induced immunosuppression in pigs. Omega-3 treatment increased the number of white blood cell, lymphocytes, and monocytes and decreased tumor necrosis factor (TNF)-α production under CTX challenge. In addition, we confirmed that omega-3 decreased the expression of nuclear factor (NF)-κB, TNF-α, interferon (IFN)-γ, and interleukin (IL)-8 in peripheral blood mononuclear cells. Additionally, omega-3 alleviated the activities of liver injury markers (alanine transaminase [ALT] and aspartate transaminase [AST]) and modulated oxidative stress markers (superoxide dismutase [SOD], malondialdehyde [MDA], and glutathione peroxidase [GPx]) in the blood serum after the CTX challenge. Based on these results, we suggest that omega-3 treatment modulates CTX-induced immunosuppression and oxidative stress in pigs. These results may have important implications in the development of new therapeutic approaches to improve immunosuppression, hepatic injury and dysfunction, and oxidative stress in pigs.

Regulation of functional amino acids on oxidative stress in pigs

Rapid generation of free radical species in the body impairs the antioxidant-oxidative balance, which further causes oxidative stress in humans and animals. In the pig industry, various factors can induce oxidative stress, including birth process, weaning stress, mycotoxin contamination, and feeding environment. Oxidative stress is generally accompanied by other pathologies, which further exerts an important effect on growth performance and healthy status. Currently, various functional amino acids (i.e., sulfur-containing amino acids, glutamic acid, arginine, and tryptophan) are reported to exhibit a potential antioxidant ability. Thus, dietary supplementation with functional amino acids may exert a preventive or therapeutic effect on oxidative stress in pigs. This review mainly discusses the birth-, weaning-, mycotoxins-, and feeding environment-induced oxidative stress and nutritional regulation in pigs, which may provide a reference for the study and scientific application in pig nutrition.

Effects of pre-slaughter stressor and feeding preventative Chinese medicinal herbs on glycolysis and oxidative stability in pigs.

A total of 64 5-month-old Pietrain pigs were randomly allocated to four treatments with four replicates per treatment according to body weight. The pigs were fed either a standard corn-soybean meal based control diet (treatments 1 and 2), the standard diet with 1% Lycium barbarum (LB) (treatment 3), or the standard diet with 1% Polygala tenuifolia Willd (PT) (treatment 4). Serum lactic acid and glucose concentrations were increased in stressed pigs (P < 0.05). Addition of the herbs in the diet had no effect on the serum lactic acid concentration, but 1% LB decreased (P < 0.05) serum glucose concentration in the stressed pigs. Pre-slaughter stress also decreased (P < 0.01) liver glycogen concentration and the decrease could be inhibited by addition of 1% LB in the diet (P > 0.05). Pre-slaughter stress increased the concentration of maleic dialdehyde (MDA) (P < 0.05) and decreased glutathione peroxidase (GSH-Px) activity in serum, while dietary 1% LB increased (P < 0.05) the activity of GSH-Px and decreased the concentration of MDA in the serum. In conclusion, pre-slaughter stress induces oxidative stress in pigs and dietary supplementation with 1% LB improves antioxidant capacity in stressed pigs before slaughtering.

Dietary L‐Trp supplementation affects growth and stress responses of nursery pigs

Tryptophan (Trp) as a precursor of serotonin can affect serotonin activity in mediating stress. This study was to determine the optimal supplementation level of L-Trp maximizing the biological benefits on growth and stress responses. Pigs (n = 72) at 6 wk of age were housed individually and allotted to 6 treatments (n = 12) representing supplementation of 0, 0.2, 0.4, 0.6, 0.8, or 1.0% L-Trp to corn-soybean meal based diets fed for 15 d. Collection of BW, saliva, and blood were done on d 5, 10, and 15. On d 15, all pigs were euthanized to obtain hypothalamus. During the first 5 d, growth of pigs was improved (P < 0.05) when fed with 0.6 and 0.8% L-Trp compared with pigs without L-Trp. During the entire 15 d, pigs with 0.8% L-Trp tended to grow faster (P = 0.099) than pigs without L-Trp (537 vs 446 g/d, respectively). Pigs with L-Trp had reduced (P < 0.05) salivary cortisol (1.7 ng/mL) and malonedialdehyde in plasma and hypothalamus (15.0 μM and 60.5 μmol/g protein) compared with pigs without L-Trp (2.6 ng/mL, 20.9 μM, and 87.2 μmol/g protein, respectively). Pigs with 0.6 and 0.8% L-Trp had reduced (P < 0.05) plasma urea nitrogen (6.2 and 5.7 mg/dL) compared with pigs without L-Trp (8.0 mg/dL). Overall, dietary L-Trp supplementation improved growth, whereas reduced stress hormone secretion, and systemic and hypothalamic oxidative stress in pigs. These beneficial effects were maximized at 0.8% L-Trp supplementation. Grant Funding Source: CJ Bio, Inc

Effect of road transportation on erythrocyte osmotic fragility of pigs administered ascorbic acid during the harmattan season in Zaria, Nigeria

This study was conducted with the aim of investigating the effect of eight hours road transportation on pigs administered ascorbic acid (AA) during the harmattan season. Twenty nine pigs were used for the study, seventeen pigs were administered with AA at a dose of 250 mg/kg per os and served as experimental animals, while 13 others each administered orally with sterile water served as control animals. The animals were then transported for 8 h at a speed of 40 - 50 km/h covering a distance of 260 km. Blood samples were taken early in the morning a day before transportation, immediately after (within 30 min) and a week after transportation. Thereafter, erythrocyte osmotic fragility (EOF) was determined using a standard method. There was a statistically significant (P < 0.05) difference in percent haemolysis recorded at NaCl concentration of 0.30, 0.40 and 0.60% between experimental and control pigs immediately after transportation. The results of the present study indicated that measuring osmotic resistance of erythrocytes could be used as a determinant of oxidative stress in pigs transported by road. Key words: Ascorbic acid, erythrocyte osmotic fragility, harmattan season, pigs, road transportation.

Efficiency of apples, strawberries, and tomatoes for reduction of oxidative stress in pigs as a model for humans

Objective The present study investigated the potency of apples, strawberries, and tomatoes in decreasing oxidative stress in pigs as a model for humans. Methods Forty-eight growing pigs were individually penned in metabolic cages and divided into six groups. All groups received isocaloric daily rations composed of a basal diet supplemented with starch, linseed oil, linseed oil and apples, linseed oil and strawberries, linseed oil and tomatoes, or linseed oil, apples, strawberries and tomatoes. Oxidative stress was evaluated at the beginning and at the end of the 22-d experimental period by measuring the degree of DNA damage in mononuclear blood cells, the concentration of malondialdehyde (MDA) in plasma, the MDA excretion rate, the concentration of tocopherols in plasma, plasma total antioxidant status, and erythrocyte glutathione peroxidase concentration. Results The results confirmed that the linseed oil diet significantly increased MDA formation in the body and DNA damage to mononuclear blood cells in comparison with the starch diet. Although the MDA concentration in plasma was significantly decreased in all fruit groups, urine MDA excretion rate was decreased only in the linseed oil/apple and linseed oil/apple/strawberry/tomato groups. Supplementation with fruit significantly decreased DNA damage, was more pronounced in the linseed oil/apple and linseed oil/apple/strawberry/tomato groups. Significantly lower glutathione peroxidase concentrations were observed only in the linseed oil/strawberry group. Conclusions Our findings support the hypothesis that supplementation with apples, strawberries, or tomatoes effectively decreases oxidative stress by decreasing MDA formation in the body and by protecting mononuclear blood cells against increased DNA damage. This effect was particularly pronounced in the group supplemented with a fruit mixture; among the single fruit supplements, the most beneficial effect was obtained with apples.

Effect of nucleotide supplementation on lymphocyte DNA damage induced by dietary oxidative stress in pigs

AbstractThe aim of the present study was to evaluate the effect of nucleotide supplementation on the oxidative stress induced by a high proportion of dietary polyunsaturated fatty acids ( PUFAs) in pigs. Twenty-four male growing pigs were penned individually and after an adaptation period divided into three groups. All groups received isocaloric daily rations composed of a basal diet supplemented with either: starch (CONT), linseed oil (LIN) and LIN and nucleotides (LIN + NUC). The experimental period lasted 21 days. Oxidative stress was evaluated by measuring the degree of lymphocyte nuclear DNA damage, the urine malondialdehyde ( MDA) excretion rate, erythrocyte glutathione peroxidase concentration and the total anti-oxidant status of plasma. Malondialdehyde concentrations in the blood and MDA urinary excretion rates were higher (P&lt; 0·01) in animals supplemented with LIN and LIN + NUC compared with CONT animals. The degree of DNA damage in the LIN-supplemented animals was also higher (P&lt; 0·01). Compared with the LIN-supplemented animals, nucleotide supplementation reduced (P&lt; 0·01) the degree of DNA damage in lymphocytes to the level of the CONT group. Erythrocyte glutathione peroxidase concentration and plasma total anti-oxidant status were similar across treatments. The results of this experiment indicate that nucleotide supplementation effectively eliminates the genotoxic effects of high PUFA intakes on blood lymphocytes and demonstrates new evidence for the immunonutritive effect of nucleotides.