Dietary glycine supplementation enhances glutathione availability in tissues of pigs with intrauterine growth restriction.

This study tested the hypothesis that dietary supplementation with glycine enhances the synthesis and concentrations of glutathione (GSH, a major antioxidant) in tissues of pigs with intrauterine growth restriction (IUGR). At weaning (21 d of age), IUGR pigs and litter mates with normal birth weights (NBW) were assigned randomly to one of two groups, representing supplementation with 1% glycine or 1.19% l-alanine (isonitrogenous control) to a corn- and soybean meal-based diet. Blood and other tissues were obtained from the pigs within 1 wk after the feeding trial ended at 188 d of age to determine GSH, oxidized GSH (GSSG), and activities of GSH-metabolic enzymes. Results indicated that concentrations of GSH + GSSG or GSH in plasma, liver, and jejunum (P < 0.001) and concentrations of GSH in longissimus lumborum and gastrocnemius muscles (P < 0.05) were lower in IUGR pigs than in NBW pigs. In contrast, IUGR increased GSSG/GSH ratios (an indicator of oxidative stress) in plasma (P < 0.001), jejunum (P < 0.001), both muscles (P < 0.05), and pancreas (P = 0.001), while decreasing activities of γ-glutamylcysteine synthetase and GSH synthetase in liver (P < 0.001) and jejunum (P < 0.01); and GSH reductase in jejunum (P < 0.01), longissimus lumborum muscle (P < 0.01), gastrocnemius muscle (P < 0.05), and pancreas (P < 0.01). In addition, IUGR pigs had greater (P < 0.001) concentrations of thiobarbituric acid reactive substances (TBARS; an indicator of lipid peroxidation) in plasma, jejunum, muscles, and pancreas than NBW pigs. Compared with isonitrogenous controls, dietary glycine supplementation increased concentrations of GSH plus GSSG and GSH in plasma (P < 0.01), liver (P < 0.001), jejunum (P < 0.001), longissimus lumborum muscle (P = 0.001), and gastrocnemius muscle (P < 0.05); activities of GSH-synthetic enzymes in liver (P < 0.01) and jejunum (P < 0.05), while reducing GSSG/GSH ratios in plasma (P < 0.001), jejunum (P < 0.001), longissimus lumborum muscle (P < 0.001), gastrocnemius muscle (P = 0.01), pancreas (P < 0.05), and kidneys (P < 0.01). Concentrations of GSH plus GSSG, GSH, and GSSG/GSH ratios in kidneys were not affected (P > 0.05) by IUGR. Furthermore, glycine supplementation reduced (P < 0.001) TBARS concentrations in plasma, jejunum, muscles, and pancreas. Collectively, IUGR reduced GSH availability and induced oxidative stress in pig tissues, and these abnormalities were prevented by dietary glycine supplementation in a tissue-specific manner.

Pigs have the highest rate of intrauterine growth restriction (IUGR) among livestock species. These pigs, which have low birth weights (<1.1 kg) and account for ~15% to 20% of newborn pigs, are often culled after birth because they have lower growth performance and feed efficiency due to multiple factors (including oxidative stress in tissues), when compared with litter mates with normal birth weights (NBW). Much evidence shows that glutathione, which is a tripeptide synthesized from glutamate, glycine, and cysteine via enzymes (biological catalysts, γ-glutamylcysteine synthetase, and glutathione synthetase), is a major low-molecular-weight antioxidant in animal cells. Based on the findings of our recent study that dietary glycine supplementation enhanced the growth performance of IUGR pigs from weaning to market weight, the current study tested the hypothesis that this nutritional strategy increased the synthesis and availability of glutathione in their tissues. Our results indicated that the key organs of the digestive system (the small intestine, liver, and pancreas) as well as both longissimus lumborum and gastrocnemius muscles of IUGR pigs had lower concentrations of glutathione as compared with NBW pigs, due to reductions in both the activities of glutathione-synthetic enzymes and the availability of glycine. Dietary supplementation with 1% glycine prevented these metabolic deficiencies in tissues of IUGR pigs. Our findings support the notion that IUGR pigs fed conventional corn- and soybean meal-based diets do not synthesize adequate glutathione and that dietary glycine supplementation plays an important role in enhancing the availability of glutathione and mitigating oxidative stress to improve health and growth in these compromised animals.

Effects of dietary epidermal growth factor supplementation on liver antioxidant capacity of piglets with intrauterine growth retardation.

The present experiment was conducted to study the effects of dietary epidermal growth factor (EGF) supplementation on the liver antioxidant capacity of piglets with intrauterine growth retardation (IUGR). The present study consists of two experiments. In experiment 1, six normal-birth-weight (NBW) and six IUGR newborn piglets were slaughtered within 2 to 4 h after birth to compare the effects of IUGR on the liver antioxidant capacity of newborn piglets. The results showed that compared with NBW piglets, IUGR piglets had a lower birth weight and liver relative weight; IUGR piglets had a higher serum malondialdehyde (MDA) level, liver MDA level and hydrogen peroxide (H2O2) level, and had a lower liver total antioxidant capacity (T-AOC) level and glutathione peroxidase (GSH-Px) activity; IUGR trended to increase serum alanine aminotransferase activity, aspartate aminotransferase activity, and H2O2 level, and trended to decrease liver total superoxide dismutase activity. In experiment 2, six NBW piglets, and 12 IUGR piglets weaned at 21 d of age were randomly divided into the NC group (NBW piglets fed with basal diet); IC group (IUGR piglets fed with basal diet), and IE group (IUGR piglets fed with basal diet plus 2 mg/kg EGF), and feeding for 14 d. Organ index, serum parameters, liver antioxidant capacity, and liver antioxidant-related genes expression were measured. The results showed that compared to the IC group, dietary EGF supplementation (IE group) significantly reduced serum malondialdehyde level and H2O2 level, and liver protein carbonyl (PC) level and 8-hydroxydeoxyguanosine level of piglets with IUGR; dietary EGF supplementation (IE group) significantly increased serum T-AOC level, liver T-AOC level and GSH-Px activity; dietary supplemented with EGF (IE group) enhanced liver Nrf2, NQO1, HO1, and GPX1 mRNA expression compared to IC group. Pearson's correlation analysis further showed that EGF can alleviate liver oxidative injury caused by IUGR and improve the performance of IUGR piglets. In conclusion, EGF exhibited potent protective effects on IUGR-induced liver oxidative injury, by activating the Nrf2 signaling pathway to mediate the expression of downstream antioxidant enzymes and phase II detoxification enzymes (NQO1 and HO1), thereby alleviating liver oxidative damage and promoting the growth performance of IUGR piglets.

The liver is an important metabolic and secretory organ in vertebrates, which plays an important role in the overall health of animals. Studies have shown that intrauterine growth retardation (IUGR) can cause liver injury in piglets, which is unfavorable to the growth and development of piglets. Epidermal growth factor (EGF) has antioxidant properties, but its effect on liver oxidative damage caused by IUGR remains uncertain. In the present study, we chose newborn piglets with low birth weight as the IUGR models to investigate whether IUGR could cause oxidative damage in the liver. Then, the diet supplemented with EGF was fed to IUGR piglets to study the effects of EGF supplementation on the liver antioxidant function of IUGR-weaned piglets. Results showed that IUGR caused serious damage to the liver of piglets, while dietary EGF supplementation could reverse the oxidative injury induced by IUGR to some extent. Therefore, this study confirmed that EGF has positive effects on the liver health of piglets with IUGR.

Dietary glycine supplementation enhances postweaning growth and meat quality of pigs with intrauterine growth restriction.

Pigs with intrauterine growth restriction (IUGR) have suboptimum growth performance and impaired synthesis of glycine (the most abundant amino acid in the body). Conventional corn- and soybean meal-based diets for postweaning pigs contain relatively low amounts of glycine and may not provide sufficient glycine to meet requirements for IUGR pigs. This hypothesis was tested using 52 IUGR pigs and 52 litter mates with normal birth weights (NBW). At weaning (21 d of age), IUGR or NBW pigs were assigned randomly to one of two nutritional groups: supplementation of a corn-soybean meal-based diet with either 1% glycine plus 0.19% cornstarch or 1.19% L-alanine (isonitrogenous control). Feed consumption and body weight (BW) of pigs were recorded daily and every 2 or 4 wks, respectively. All pigs had free access to their respective diets and clean drinking water. Within 1 wk after the feeding trial ended at 188 d of age, blood and other tissue samples were obtained from pigs to determine concentrations of amino acids and meat quality. Neither IUGR nor glycine supplementation affected (P > 0.05) feed intakes of pigs per kg BW. The final BW, gain:feed ratio, carcass dressing percentages, and four-lean-cuts percentages of IUGR pigs were 13.4 kg, 4.4%, 2%, and 15% lower (P < 0.05) for IUGR pigs than NBW pigs, respectively. Compared with pigs in the alanine group, dietary glycine supplementation increased (P < 0.05) final BW, gain:feed ratio, and meat a* value (a redness score) by 3.8 kg, 11%, and 10%, respectively, while reducing (P < 0.05) backfat thickness by 18%. IUGR pigs had lower (P < 0.05) concentrations of glycine in plasma (-45%), liver (-25%), jejunum (-19%), longissimus dorsi muscle (-23%), gastrocnemius muscle (-26%), kidney (-15%), and pancreas (-6%), as compared to NBW pigs. In addition, dietary glycine supplementation increased (P < 0.05) concentrations of glycine in plasma and all analyzed tissues. Thus, supplementing 1% of glycine to corn-soybean meal-based diets improves the growth performance, feed efficiency, and meat quality of IUGR pigs.

About 15­20% of pigs are born naturally with low birth weights (<1.1 kg) due to intrauterine growth restriction (IUGR). These pigs are often culled after birth because they have lower growth performance and feed efficiency during the production period from weaning to market weight, compared with litter mates with normal birth weights (NBW). In many countries and regions (including North America, South America, and Asia), postweaning pigs are generally fed corn- and soybean meal-based diets that contain relatively a low amount of glycine. Glycine is the most abundant amino acid in the plasma and tissue proteins of pigs but may not be formed adequately from other amino acids in the body, particularly IUGR pigs that are now known to have an impaired ability for glycine synthesis. Results of the present study indicate that IUGR pigs fed conventional corn-SBM-based diets had lower concentrations of glycine in plasma and tissues (including skeletal muscle), compared with NBW litter mates. Dietary supplementation with 1% glycine improved the growth performance, feed efficiency, and meat quality of IUGR pigs. This simple nutritional means is expected to enhance the productivity of the global swine industry.

Dietary ferulic acid supplementation improves antioxidant capacity and lipid metabolism in liver of piglets with intrauterine growth retardation.

Intrauterine growth retardation (IUGR) can result in early liver oxidative damage and abnormal lipid metabolism in neonatal piglets. Ferulic acid (FA), a phenolic compound widely found in plants, has many biological functions, such as anti-inflammation and anti-oxidation. Thus, we explored the effects of dietary FA supplementation on antioxidant capacity and lipid metabolism in newborn piglets with IUGR. In the study, 24 7-day-old piglets were divided into three groups: normal birth weight (NBW), IUGR, and IUGR + FA. The NBW and IUGR groups were fed formula milk as a basal diet, while the IUGR + FA group was fed a basal diet supplemented with 100 mg/kg FA. The trial lasted 21 days. The results showed that IUGR decreased absolute liver weight, increased transaminase activity, reduced antioxidant capacity, and disrupted lipid metabolism in piglets. Dietary FA supplementation enhanced absolute liver weight, reduced serum MDA level and ROS concentrations in serum and liver, markedly increased serum and liver GSH-PX and T-SOD activities, decreased serum HDL-C and LDL-C and liver NEFA, and increased TG content and HL activity in the liver. The mRNA expression related to the Nrf2-Keap1 signaling pathway and lipid metabolism in liver were affected by IUGR. Supplementing FA improved the antioxidant capacity of liver by down-regulating Keap1 and up-regulating the mRNA expression of SOD1 and CAT, and regulated lipid metabolism by increasing the mRNA expression level of Fasn, Pparα, LPL, and CD36. In conclusion, the study suggests that FA supplementation can improve antioxidant capacity and alleviate lipid metabolism disorders in IUGR piglets.

Seasonal and temporal variation in the placenta during melatonin supplementation in a bovine compromised pregnancy model.

Compromised pregnancies result in a poorly functioning placenta restricting the amount of oxygen and nutrient supply to the fetus resulting in intrauterine growth restriction (IUGR). Supplementing dietary melatonin during a compromised pregnancy increased uteroplacental blood flow and prevented IUGR in a seasonal-dependent manner. The objectives were to evaluate seasonal melatonin-mediated changes in temporal alterations of the bovine placental vascularity and transcript abundance of clock genes, angiogenic factors, and nutrient sensing genes in 54 underfed pregnant Brangus heifers (Fall, n = 29; Summer, n = 25). At day 160 of gestation, heifers were assigned to treatments consisting of adequately fed (ADQ-CON; 100% NRC; n = 13), nutrient restricted (RES-CON; 60% NRC; n = 13), and ADQ or RES supplemented with 20 mg/d of melatonin (ADQ-MEL, n = 13; RES-MEL, n = 15). The animals were fed daily at 0900 hours until day 240 where Cesarean sections were performed in the morning (0500 hours) or afternoon (1300 hours) for placentome collections. In both seasons, we observed a temporal alteration of the core clock genes in the cotyledonary tissue in a season-dependent manner. In the fall, ARNTL, CLOCK, NR1D1, and RORA transcript abundance were decreased (P ≤ 0.05) in the afternoon compared to the morning; whereas in the summer, ARNTL, PER2, and RORA expression were increased (P ≤ 0.05) in the afternoon. Interestingly, in both seasons, there was a concomitant temporal increase (P ≤ 0.05) of cotyledonary blood vessel perfusion and caruncular melatonin receptor 1A transcript abundance. Melatonin supplementation did not alter the melatonin receptor 1A transcript abundance (P > 0.05), however, in the summer, melatonin supplementation increased cotyledonary VEGFA, CRY1, and RORA (P ≤ 0.05) transcript abundance. In addition, during the summer the placentomes from underfed dams had increased average capillary size and HIF1α transcript abundance compared to those adequately fed (P ≤ 0.05). In conclusion, these data indicate increased cotyledonary blood vessel size and blood distribution after feeding to better facilitate nutrient transport. Interestingly, the maternal nutritional plane appears to play a crucial role in regulating the bovine placental circadian clock. Based on these findings, the regulation of angiogenic factors and clock genes in the bovine placenta appears to be an underlying mechanism of the therapeutic effect of dietary melatonin supplementation in the summer.

Maternal nutrient restriction during the last trimester of pregnancy impairs the fetal development, increases morbidity and mortality, and reduces its performance in adult life. Animals with compromised pregnancies exhibit a reduction in uterine blood flow thereby limiting the nutrients available for the fetus to grow and develop. Melatonin, a hormone that many people use as a sleep aid, could be a solution as a potential therapeutic in cattle since it has antioxidant properties and has been shown to regulate blood flow and rescue fetal weight during compromised pregnancies. In the current study, we examined the changes in placental vascularity and gene expression when supplementing underfed dams with dietary melatonin during late gestation in a group of fall-calving and spring-calving heifers. Contrary to our hypothesis melatonin did not control the placental circadian clock gene network, while maternal nutrient restriction disrupted the gene expression in the placenta. Furthermore, this study found that gene expression in the placenta is seasonally dependent.

Curcumin reduces oxidative stress and fat deposition in longissimus dorsi muscle of intrauterine growth-retarded finishing pigs.

Dietary curcumin possessing multiple biological activities may be an effective way to alleviate oxidative damage and fat deposition in intrauterine growth retardation (IUGR) finishing pigs. Therefore, this study was conducted to evaluate effects of dietary curcumin on meat quality, antioxidant capacity, and fat deposition of longissimus dorsi muscle in IUGR finishing pigs. Twelve normal birth weight (NBW) and 24 IUGR female piglets at 26 days of age were divided into 3 dietary groups: NBW (basal diet), IUGR (basal diet), and IUGR + Cur (basal diet supplemented with 200 mg/kg curcumin). The trial lasted for 169 days. Results showed that IUGR increased concentrations of malondialdehyde (MDA) and protein carbonyls (PC) and fat deposition in longissimus dorsi muscle. However, curcumin decreased the intramuscular fat content and the levels of MDA and PC and improved meat quality in IUGR pigs. Furthermore, curcumin inhibited the decrease of nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression and decreased peroxisome pro liferator-activated receptors γ (PPARγ) expression in IUGR pigs. These findings suggested that dietary addition of 200 mg/kg curcumin could improve meat quality, alleviate oxidative stress through activating Nrf2 signaling pathway, and reduce fat deposition via inhibiting PPARγ expression in longissimus dorsi muscle of IUGR finishing pigs.

Effects of ferulic acid on the growth performance, antioxidant capacity, and intestinal development of piglets with intrauterine growth retardation.

Neonates with intrauterine growth retardation (IUGR) are prone to suffer from delayed postnatal growth and development during the early stages of life. Ferulic acid (FA) is a phenolic compound that is abundantly present in fruits and vegetables and has various health benefits. Hence, we explored whether FA supplementation could favorably affect the growth performance, antioxidant capacity, and intestinal development of piglets with IUGR. In total, eight normal-birth-weight (NBW) piglets and 16 piglets with IUGR (age, 7 d) were assigned to be fed either basic formula milk (NBW and IUGR groups, respectively) or basic formula milk supplemented with 100 mg/kg FA (IUGR + FA group) for 21 d. At necropsy, the serum and intestinal tissues were collected. FA supplementation increased (P < 0.05) the feed conversion ratio and serum total superoxide dismutase and catalase activities in piglets with IUGR. Moreover, FA supplementation elevated (P < 0.05) the duodenal lactase and maltase activities, jejunal villus height and jejunal maltase activity but reduced (P < 0.05) the duodenal crypt depth and duodenal and jejunal cell apoptosis, cleaved cysteinyl aspartic acid protease-3 (caspase-3) content and cleaved caspase-9 content in piglets with IUGR. In summary, FA supplementation could elevate antioxidant capacity and facilitate intestinal development, thus resulting in increased feed efficiency in piglets with IUGR.

Intrauterine growth retardation (IUGR) impairs postnatal growth and development in neonatal piglets. Ferulic acid (FA) is a ubiquitous phenolic compound that is present in numerous fruits and vegetables and possesses various biological activities. However, little is known about whether FA supplementation has beneficial effects on the growth performance, antioxidant capacity, and intestinal development of piglets with IUGR. Our findings provide important implications for treating piglets with IUGR after birth by stimulating intestinal development with FA supplementation.

Leucine alters blood parameters and regulates hepatic protein synthesis via mammalian/mechanistic target of rapamycin activation in intrauterine growth-restricted piglets.

Neonatal piglets often suffer low birth weights and poor growth performance accompanied by the disruption of protein metabolism, when intrauterine growth restriction (IUGR) takes place during pregnancy, leading to a higher mortality and bigger economic loss than expected. Leucine has been proposed to function as a nutritional signal-regulating protein synthesis in numerous studies. The aim of this study was to determine the effect of dietary leucine supplementation on the blood parameters and hepatic protein metabolism in IUGR piglets. Weaned piglets were assigned to one of four treatments in a 2 × 2 factorial arrangement: 1) piglets fed a basal diet with normal birth weight, 2) piglets fed a basal diet plus 0.35% l-leucine with normal birth weight, 3) IUGR piglets fed a basal diet with low birth weight, and 4) IUGR piglets fed a basal diet plus 0.35% l-leucine with low birth weight. The results showed that IUGR decreased serum aspartate aminotransferase and alkaline phosphatase activities and increased serum cortisol and prostaglandin E2 levels at 35 d of age (P < 0.05), suggesting the occurrence of liver dysfunction and stress response. Leucine supplementation increased serum alkaline phosphatase activity and decreased serum cortisol levels at 35 d of age (P < 0.05). IUGR decreased the lysozyme activity and complement 3 level in serum (P < 0.05), which were prevented by dietary leucine supplementation. IUGR piglets showed increased hepatic DNA contents while showing a reduced RNA/DNA ratio (P < 0.05). Piglets supplied with leucine had decreased RNA/DNA ratio in the liver (P < 0.05). Leucine supplementation stimulated hepatic protein anabolism through upregulating protein synthesis-related genes expression and activating the phosphorylation of mammalian/mechanistic target of rapamycin (mTOR) (P < 0.05). Moreover, IUGR inhibited the mRNA expression of hepatic protein degradation-related genes, indicating a compensatory mechanism for the metabolic response. Dietary leucine supplementation attenuated the suppression of the protein catabolism induced by IUGR in the liver. These results demonstrate that dietary leucine supplementation could alter the blood parameters and alleviated the disrupted protein metabolism induced by IUGR via enhanced mTOR phosphorylation to promote protein synthesis in weaned piglets.

Intrauterine growth restriction (IUGR) produces a notable disturbance of protein metabolism in piglets, leading to lower birth weights and economic loss. Leucine supplementation positively regulates protein metabolism in animals and has the potential to recover the impaired balance between protein synthesis and degradation. Our study showed that leucine supplementation alleviated the abnormal changes in blood parameters and stimulated protein synthesis through the mammalian/mechanistic target of rapamycin signal pathway in the liver. Leucine supplementation attenuated the suppression of protein degradation induced by IUGR, which might be involved in a hepatic compensatory mechanism contributing to health status.

Review: Improving the performance of neonatal piglets.

Newborn piglets have a high incidence of preweaning mortality that is not only associated with low birth weights but also with the presence of intra-uterine growth-restricted (IUGR) piglets. Such IUGR piglets are commonly seen in litters from hyperprolific sows as a result of insufficient placental transfer of nutrients. Nutritional strategies can be used prior to and during gestation to enhance foetal development and can also be implemented in the transition period to reduce the duration of farrowing and increase colostrum yield. Recent findings showed that the energy status of sows at the onset of farrowing is crucial to diminish stillbirth rate. Newborn piglets often fail to consume enough colostrum to promote thermostability and subsequent growth, and this is particularly problematic in very large litters when there are fewer available teats than the number of suckling piglets. One injection of 75 IU of oxytocin approximately 14 h after farrowing can prolong the colostral phase, hence increasing the supply of immunoglobulins to piglets. Nevertheless, assistance must be provided to piglets after birth in order to increase their chance of survival. Various approaches can be used, such as: (1) optimising the farrowing environment, (2) supervising farrowing and assisting newborn piglets, (3) using cross-fostering techniques, (4) providing nurse sows, and 5) providing artificial milk. Although research advances have been made in developing feeding and management strategies for sows that increase performance of their newborn piglets, much work still remains to be done to ensure that maximal outcomes are achieved.

Dietary dimethylglycine sodium salt supplementation improves growth performance, redox status, and skeletal muscle function of intrauterine growth-restricted weaned piglets.

Few studies have focused on the role of dimethylglycine sodium (DMG-Na) salt in protecting the redox status of skeletal muscle, although it is reported to be beneficial in animal husbandry. This study investigated the beneficial effects of DMG-Na salt on the growth performance, longissimus dorsi muscle (LM) redox status, and mitochondrial function in weaning piglets that were intrauterine growth restricted (IUGR). Ten normal birth weight (NBW) newborn piglets (1.53 ± 0.04 kg) and 20 IUGR newborn piglets (0.76 ± 0.06 kg) from 10 sows were obtained. All piglets were weaned at 21 d of age and allocated to the three groups with 10 replicates per group: NBW weaned piglets fed a common basal diet (N); IUGR weaned piglets fed a common basal diet (I); IUGR weaned piglets fed a common basal diet supplemented with 0.1% DMG-Na (ID). They were slaughtered at 49 d of age to collect the serum and LM samples. Compared with the N group, the growth performance, LM structure, serum, and, within the LM, mitochondrial redox status, mitochondrial respiratory chain complex activity, energy metabolites, redox status-related, cell adhesion-related, and mitochondrial function-related gene expression, and protein expression deteriorated in group I (P < 0.05). The ID group showed improved growth performance, LM structure, serum, and, within the LM, mitochondrial redox status, mitochondrial respiratory chain complex activity, energy metabolites, redox status-related, cell adhesion-related, and mitochondrial function-related gene expression, and protein expression compared with those in the I group (P < 0.05). The above results indicated that the DMG-Na salt treatment could improve the LM redox status and mitochondrial function in IUGR weaned piglets via the nuclear factor erythroid 2-related factor 2/sirtuin 1/peroxisome proliferator-activated receptorγcoactivator-1α network, thus improving their growth performance.

Effects of dietary dihydroartemisinin supplementation on growth performance, hepatic inflammation, and lipid metabolism in weaned piglets with intrauterine growth retardation.

The aims of this study were to investigate the effects of dietary supplementation with dihydroartemisinin (DHA) on growth performance, hepatic inflammation, and lipid metabolism in intrauterine growth retardation (IUGR)-affected weaned piglets. Eight piglets with normal birth weight (NBW) and 16 IUGR-affected piglets were selected and fed either a basal diet (NBW and IUGR groups) or the basal diet supplemented with 80 mg/kg DHA (IUGR-DHA group) from 21 to 49 day of age. Blood and liver samples were collected on day 49. DHA supplementation significantly alleviated the compromised growth performance and liver damage in IUGR-affected piglets. Additionally, DHA supplementation decreased the activities of alanine aminotransferase and aspartate aminotransferase, as well as the serum levels of non-esterified fatty acids (NEFA), very-low-density lipoprotein, and total cholesterol. In the liver, the concentrations of interleukin 1 beta, interleukin 6, tumor necrosis factor alpha, triglycerides, and NEFA were decreased. Fatty acid synthesis was decreased by DHA supplementation, whereas the activities of lipoprotein lipase, hepatic lipase, and total lipase were increased. Dietary DHA supplementation led to upregulation of the expression of AMPK/SIRT1 signaling pathway-related genes, whereas that of inflammatory factor-related genes were downregulated. In conclusion, dietary inclusion of 80 mg/kg DHA can alleviate IUGR-induced impairments in piglets.

Flaxseed oil supplementation improves intestinal function and immunity, associated with altered intestinal microbiome and fatty acid profile in pigs with intrauterine growth retardation.

Flaxseed oil (FO), enriched in n-3 polyunsaturated fatty acids (PUFAs), is an important oil source for intestinal development and health. We aimed to study the different effects of FO versus soybean oil (SO) on growth, intestinal health and immune function of neonates with intrauterine growth retardation (IUGR) using a weaned piglet model. Forty pairs of male IUGR and normal birth weight piglets, weaned at 21 ± 1 d, were fed diets containing either 4% FO or SO for 3 weeks consecutively. Growth performance, nutrient digestibility and intestinal function parameters, immunology and microbiota composition were determined. IUGR led to a poor growth rate, nutrient digestibility and abnormal immunology variables, whereas feeding FO diet improved systemic and gut immunity, as indicated by increased plasma concentration of immunoglobulin G and decreased CD3+CD8+ T lymphocytes, and down-regulated intestinal expression of genes (MyD88, NF-κB, TNF-α, IL-10). Although IUGR tended to decrease villous height, feeding FO diet tended to increase the villi-crypt ratio and up-regulated expressions of tight junction genes (Claudin-1 and ZO-1), together with increased mucosa contents of n-3 PUFAs and a lower Σn-6/Σn-3 ratio. Besides, FO diet decreased the abundance of pathogenic bacteria Spirochaetes, and increased phylum Actinobacteria, and genera Blautia and Bifidobacterium in colonic digesta. Our findings indicate that IUGR impairs growth rate, nutrient digestibility, and partly immunology variables, whereas feeding FO-supplemented diet could improve intestinal function and immunity of both IUGR and NBW pigs, associated with the altered gut microbiome and mucosal fatty acid profile.

N-carbamylglutamate and l-arginine promote intestinal function in suckling lambs with intrauterine growth restriction by regulating antioxidant capacity via a nitric oxide-dependent pathway.

Data indicate that intrauterine growth restriction (IUGR) in newborns can be partly alleviated through the supply of l-arginine (Arg) and N-carbamylglutamate (NCG). The current work aimed to explore whether Arg and NCG promote intestinal function by regulating antioxidant capacity in suckling lambs with IUGR via a nitric oxide (NO)-dependent pathway. Forty eight newly born Hu lambs with normal weights at birth (CON) or suffering from IUGR were randomly divided into 4 groups (n = 12 per group), namely, the CON, IUGR, IUGR + 1% Arg, and IUGR + 0.1% NCG groups. The animals were used for experiments from the age of day 7 to 28. Compared with the lambs in the IUGR group, the lambs in the Arg or NCG group had higher (P < 0.05) final body weights. The plasma insulin, NO, and NO synthase (NOS) concentrations in the IUGR group were higher (P < 0.05) compared with those in IUGR + 1% Arg or IUGR + 0.1% NCG. The jejunal level of the tumor necrosis factor α (TNF-α) in the IUGR lambs was greater (P < 0.05) compared with that in IUGR + 1% Arg or IUGR + 0.1% NCG. The plasma and jejunal total antioxidant capacity (T-AOC) values for the IUGR + 1% Arg or IUGR + 0.1% NCG group were greater (P < 0.05) compared with those for the IUGR group. Compared with the IUGR + 1% Arg or IUGR + 0.1% NCG lambs, the IUGR lambs had lower (P < 0.05) abundance of mRNA and protein abundance of glutathione peroxidase 1 (GPx1), catalase (CAT), superoxide dismutase 2 (SOD2), nuclear factor erythroid 2-related factor 2 (Nrf2), quinone oxidoreductase 1 (NQO1), heme oxygenase (HO-1), zonula occludens-1 (ZO-1), occludin, inducible NOS (iNOS), and epithelial NOS (eNOS). Overall, the data suggest that the Arg or NCG supplementation to suckling lambs with IUGR enhances the intestinal function by regulating the oxidant status via the NO-dependent pathway.

Effects of dietary methionine supplementation on growth performance, intestinal morphology, antioxidant capacity and immune function in intra-uterine growth-retarded suckling piglets.

This study investigated the effects of dietary supplementation with L -methionine (L -Met), DL -methionine (DL -Met) and calcium salt of the methionine hydroxyl analog (MHA-Ca) on growth performance, intestinal morphology, antioxidant capacity and immune function in intra-uterine growth-retarded (IUGR) suckling piglets. Six normal birthweight (NBW) female piglets and 24 same-sex IUGR piglets were selected at birth. Piglets were fed nutrient adequate basal diet supplemented with 0.08% L -alanine (NBW-CON), 0.08% L -alanine (IUGR-CON), 0.12% L -Met (IUGR-LM), 0.12% DL -Met (IUGR-DLM) and 0.16% MHA-Ca (IUGR-MHA-Ca) from 7 to 21 days of age respectively (n = 6). The results indicated that IUGR decreased average daily milk (dry matter) intake and average daily gain and increased feed conversion ratio of suckling piglets (p < 0.05). Compared with the NBW-CON piglets, IUGR also impaired villus morphology and reduced antioxidant capacity and immune homeostasis in the intestine of IUGR-CON piglets (p < 0.05). Supplementation with L -Met enhanced jejunal villus height (VH) and villus area and ileal VH of IUGR piglets compared with IUGR-CON piglets (p < 0.05). Similarly, DL -Met supplementation increased VH and the ratio of VH to crypt depth in the jejunum compared with IUGR-CON pigs (p < 0.05). Supplementation with L -Met and DL -Met (0.12%) tended to increase reduced glutathione content and reduced glutathione: oxidized glutathione ratio and decrease protein carbonyl concentration in the jejunum of piglets when compared with the IUGR-CON group (p < 0.10). However, supplementation with MHA-Ca had no effect on the intestinal redox status of IUGR piglets (p > 0.10). In conclusion, supplementation with either L -Met or DL -Met has a beneficial effect on the intestinal morphology and antioxidant capacity of IUGR suckling piglets.

Effects of Dietary l-Arginine and N-Carbamylglutamate Supplementation on Intestinal Integrity, Immune Function, and Oxidative Status in Intrauterine-Growth-Retarded Suckling Lambs.

This study investigated the effects of dietary l-arginine (Arg) and N-carbamylglutamate (NCG) supplementation on intestinal integrity, immune function, and oxidative status in intrauterine-growth-retarded (IUGR) suckling lambs. A total of 48 newborn Hu lambs of normal birth weight (CON) and IUGR were allocated randomly into four groups of 12 animals each: CON, IUGR, IUGR + 1% Arg, or IUGR + 0.1% NCG. All lambs were raised for a period of 21 days from 7 to 28 days after birth. The Arg or NCG group exhibited improved ( p < 0.05) final body weights compared to that of the IUGR group. In comparison to the IUGR lambs, the apoptotic percentage was lower ( p < 0.05) in the ileum of IUGR lambs supplemented with Arg and NCG. In addition, in comparison to IUGR, the concentrations of protein carbonyl and malondialdehyde were lower ( p < 0.05) and the reduced glutathione (GSH) concentration and ratio of GSH/oxidized glutathione were greater ( p < 0.05) in the jejunum, duodenum, and ileum of IUGR + 1% Arg or 0.1% NCG lambs. In comparison to the IUGR group, the mRNA abundance of myeloid differentiation factor 88, toll-like receptor 9, toll-like receptor 4, interleukin 6, and fuclear factor-κB was lower ( p < 0.05) and the mRNA abundance of superoxide dismutase 1, B-cell lymphoma/leukaemia 2, zonula occludens-1 (ZO-1), and occludin was greater in the ileum of the IUGR lambs supplemented with Arg or NCG. Furthermore, the protein abundance of ZO-1 and claudin-1 in the ileum was greater ( p < 0.05) in the IUGR + 1% Arg or 0.1% NCG lambs. The results show that Arg or NCG supplementation improves the growth, intestinal integrity, immune function, and oxidative status in IUGR Hu suckling lambs.

Innate differences and colostrum-induced alterations of jejunal mucosal proteins in piglets with intra-uterine growth restriction.

Mammalian neonates undergo rapid transitions from a sterile uterine environment with a continuous intravenous supply of nutrients to a microbe-rich environment with intermittent ingesting of colostrum/milk via the gut. Currently, little is known about the colostrum-induced alterations of intestinal mucosal proteins in piglets with intra-uterine growth restriction (IUGR). In this study, we sought to investigate the innate differences and effects of colostrum on alterations in small-intestinal proteomes of IUGR piglets. Two IUGR (approximately 0·9 kg) and two normal-birth weight (NBW; approximately 1·3 kg) piglets were obtained from each of six sows at birth. One half (n 12; 6 IUGR v. 6 NBW) of the selected newborn piglets were killed to obtain jejunum samples, and the other half (n 12; 6 IUGR v. 6 NBW) of the newborn piglets were allowed to suckle colostrum from their own mothers for 24 h before jejunum sample collection. On the basis of proteomic analysis, we identified thirty-one differentially expressed proteins in the jejunal mucosa between IUGR and normal neonates before or after colostrum consumption. The intestinal proteins altered by colostrum feeding play important roles in the following: (1) increasing intestinal integrity, transport of nutrients, energy metabolism, protein synthesis, immune response and, therefore, cell proliferation; and (2) decreasing oxidative stress, and therefore cell apoptosis, in IUGR neonates. However, colostrum only partially ameliorated the inferior status of the jejunal mucosa in IUGR neonates. These findings provide the first evidence in intestinal protein alterations of IUGR neonates in response to colostrum ingestion, and thus render new insights into the mechanisms responsible for impaired growth in IUGR neonates and into new nutritional intervention strategies.

N-acetylcysteine attenuates intrauterine growth retardation-induced hepatic damage in suckling piglets by improving glutathione synthesis and cellular homeostasis.

PURPOSE: The objective of the present study was to test the hypothesis that N-acetylcysteine (NAC) may play beneficial roles against intrauterine growth retardation (IUGR)-induced hepatic damage in suckling piglets. METHODS: Fourteen IUGR and seven normal birth weight (NBW) neonatal male piglets were selected. Piglets were weaned at 7 days of postnatal age and fed the control formula milk (NBW-CON and IUGR-CON groups) or the control formula milk supplemented with 1.2 g/kg NAC (IUGR-NAC group) for 14 days (n = 7). The plasma and liver samples were analyzed for the parameters related to hepatic damage, redox status, apoptosis, and autophagy. RESULTS: Compared with the NBW-CON group, IUGR-CON group exhibited increased activities of plasma aminotransferases, increased numbers of apoptotic hepatocytes, as well as higher concentrations of protein carbonyl, malondialdehyde (MDA), microtubule-associated protein 1 light chain 3 beta, and phospholipid-conjugated form (MAP1LC3B-II), along with a decrease in the content of reduced glutathione (GSH). NAC treatment increased GSH content and GSH-to-oxidized GSH ratio in the liver of IUGR-NAC group, most likely owing to the improved activities of γ-glutamine-cysteine ligase, γ-glutamine-cysteine synthetase, and glutathione reductase. The hepatic protein carbonyl and MDA contents were decreased in the IUGR-NAC group compared with the IUGR-CON group. In addition, NAC-treated piglets had an increased content of B cell lymphoma/leukemia 2 protein, whereas a decreased expression level of MAP1LC3B-II in the liver. CONCLUSIONS: NAC may have beneficial effects in improving GSH synthesis and cellular homeostasis in the liver of IUGR suckling piglets.

Supplementing newborn intrauterine growth restricted piglets with a bolus of porcine colostrum raises rectal temperatures one degree Celsius.

Hyperprolific sows have increased litter sizes but also result in more piglets that have been exposed to intrauterine growth restriction (IUGR). These IUGR piglets are likely to have a low rectal temperature and lower blood glucose levels compared with normal piglets at birth. Therefore, we hypothesized that a colostrum bolus at birth and/or heat from an external source would have a positive effect on blood glucose levels, rectal temperatures, and growth up to 8 h postpartum. In addition, liver glycogen and blood values at 8 h were investigated. Eighty-four piglets were classified at birth (time = 0) as IUGR based on their head morphology and randomly allocated to 1 of 4 treatments ( = 21) in a 2 × 2 factorial arrangement: 1) with or without a porcine colostrum bolus (12 mL/kg BW at birth) and 2) with sow or isolated from sow with external heat. Piglets were removed from the sow before they had suckled and were numbered and dried, and initial whole-blood glucose, rectal temperature, and BW were recorded. Piglets in the 2 treatments isolated from sow were placed under a heating lamp (150 W) with a temperature range of 35 to 39°C. Rectal temperatures, glucose, and BW were measured again at 1, 2, 4, 6, and 8 h after birth, and a final plasma sample and organs (liver and brain) were removed at 8 h. There was a time × colostrum bolus interaction ( = 0.026) and a time × sow interaction ( < 0.001) for whole-blood glucose. The piglets that were given a bolus had greater glucose levels after 1 h postpartum (time = 1 h) than piglets without a bolus at birth, but from time = 2 h and onward, there was no difference ( > 0.05). There was a time × colostrum bolus interaction ( < 0.001) and a time × sow interaction ( < 0.001) on rectal temperatures. One hour after birth, the piglets with a bolus had a greater rectal temperature compared with piglets without a bolus (37.5 vs. 36.6°C; < 0.001) and the piglets that had been isolated from the sow had a greater rectal temperature compared with the 2 treatments with sows (37.8 vs. 36.3°C; < 0.001). Four hours after birth, rectal temperature was not affected by treatments. In conclusion, both heat and a colostrum bolus increased rectal temperature by 1°C an hour after birth. However, after 4 h, no differences were found between the treatments. Interventions to help IUGR piglets postpartum most likely need to be frequent to have any effect on whole-blood glucose, rectal temperatures, and BW over the first 8 h.

Protective effects of leucine on redox status and mitochondrial-related gene abundance in the jejunum of intrauterine growth-retarded piglets during early weaning period.

The aim of this study was to investigate the effects of dietary supplementation with 0.35% l-leucine on redox status and gene abundance relating to mitochondrial biogenesis and function in the jejunum of intrauterine growth-retarded (IUGR) piglets during early weaning period. According to a 2 × 2 factorial arrangement, 16 IUGR and 16 normal body weight (NBW) piglets were fed a basal diet without l-leucine supplementation or a basal diet plus 0.35% l-leucine supplementation from the age of 14 to 35 d. The results showed that compared with NBW piglets, IUGR piglets had a lower (p < 0.05) jejunal DNA concentration, a reduced (p < 0.05) manganese superoxide dismutase (MnSOD) and total antioxidant capability (T-AOC) activities and mitochondrial DNA content in the jejunum. Leucine supplementation increased (p < 0.05) MnSOD and T-AOC activities and decreased (p < 0.05) the malondialdehyde content in the jejunum of IUGR piglets. The mRNA gene abundance of nuclear respiratory factor-1 (NRF1), mitochondrial transcription factor A (TFAM), ATP synthase (ATPs), cytochrome c oxidase V (CcOX V), cytochrome c and glucokinase in the jejunum of IUGR piglets was reduced (p < 0.05) compared with NBW piglets. However, NRF1, peroxisome proliferation-activated receptor gamma coactivator-1 alpha, TFAM, ATPs and CcOX I mRNA gene abundance in the jejunum of IUGR piglets were increased (p < 0.05) by diets supplemented with leucine. These data indicate that leucine supplementation has therapeutic potential for attenuating intestinal oxidative stress and mitochondrial dysfunction in IUGR piglets during the early period of life via increasing enzyme activities and up-regulating mRNA gene abundance.

Intrauterine growth-restricted piglets have similar gastric emptying rates but lower rectal temperatures and altered blood values when compared with normal-weight piglets at birth.

Intrauterine growth-restricted (IUGR) piglets have lower survival rates and are more likely to have empty stomachs 24 h after birth than normal piglets. Although hypoglycemia may result from low colostrum intake per se, it is not known if slow gastric emptying may be an additional risk factor for poor immunization and glucose absorption in IUGR piglets. It is estimated that IUGR piglets consume less colostrum per kilogram BW than normal-weight piglets within the first 24 h, which could be due to a slower gastric emptying rate and a compromised energy metabolism. Therefore, we hypothesized that the gastric emptying rate and blood glucose would be lower in IUGR piglets. We investigated gastric emptying rates in normal and IUGR piglets and blood glucose and rectal temperatures at birth and after 15, 30, 60, and 120 min. In addition, blood parameters relevant for metabolism were studied. Forty-eight piglets (24 normal and 24 IUGR) were classified at birth as either normal or IUGR on the basis of head morphology. Piglets were removed from the sow at birth before suckling, and birth weight was recorded. Pooled porcine colostrum was tube-fed to all piglets at 12 mL/kg BW as soon as possible after birth (t = 0 min). The piglets were randomly allocated to be euthanized at 15, 30, 60, and 120 min (all groups, = 6) after bolus feeding, and the weights of the stomach and its residuals were recorded. There was no difference in gastric emptying rates between normal and IUGR piglets ( = 0.129); however, gastric DM residuals tended to by greater in IUGR piglets than normal piglets ( = 0.085). Overall, IUGR piglets had lower rectal temperatures (36.2°C ± 0.2°C vs. 37.5°C ± 0.2°C; < 0.001) and plasma glucose levels (2.8 ± 0.2 vs. 4.1 ± 0.2 mmol; < 0.001) than normal piglets. Interactions between piglet classification and time were observed in plasma values for NEFA, -3-hydroxybutyrate, albumin, aspartate, and alanine amino transferase, with greater levels in normal piglets at 15 min ( < 0.05) and 30 min for bile acid ( < 0.05) compared to IUGR piglets. In conclusion, the gastric emptying rates between normal and IUGR piglets were similar, but gastric DM residuals tended to be greater in IUGR piglets. Differences were observed in blood values and rectal temperatures, with lower values in IUGR piglets. Therefore, it is likely that factors like hypothermia and possibly reduced metabolic function are more important during the first hours after birth than gastric retention per se.