Maternal malnutrition and offspring sex determine juvenile obesity and metabolic disorders in a swine model of leptin resistance

Maternal dietary fat during lactation shapes single nucleus transcriptomic profile of postnatal offspring hypothalamus in a sexually dimorphic manner in mice

Maternal overnutrition during lactation predisposes offspring to develop metabolic diseases and exacerbates the relevant syndromes in males more than females in later life. The hypothalamus is a heterogenous brain region that regulates energy balance. Here we combined metabolic trait quantification of mother and offspring mice under low and high fat diet (HFD) feeding during lactation, with single nucleus transcriptomic profiling of their offspring hypothalamus at peak lacation to understand the cellular and molecular alterations in response to maternal dietary pertubation. We found significant expansion in neuronal subpopulations including histaminergic (Hdc), arginine vasopressin/retinoic acid receptor-related orphan receptor β (Avp/Rorb) and agouti-related peptide/neuropeptide Y (AgRP/Npy) in male offspring when their mothers were fed HFD, and increased Npy-astrocyte interactions in offspring responding to maternal overnutrition. Our study provides a comprehensive offspring hypothalamus map at the peak lactation and reveals how the cellular subpopulations respond to maternal dietary fat in a sex-specific manner during development.

Gestational Caloric Restriction Alters Adipose Tissue Methylome and Offspring's Metabolic Profile in a Swine Model

Limited nutrient supply to the fetus results in physiologic and metabolic adaptations that have unfavorable consequences in the offspring. In a swine animal model, we aimed to study the effects of gestational caloric restriction and early postnatal metformin administration on offspring's adipose tissue epigenetics and their association with morphometric and metabolic variables. Sows were either underfed (30% restriction of total food) or kept under standard diet during gestation, and piglets were randomly assigned at birth to receive metformin (n = 16 per group) or vehicle treatment (n = 16 per group) throughout lactation. DNA methylation and gene expression were assessed in the retroperitoneal adipose tissue of piglets at weaning. Results showed that gestational caloric restriction had a negative effect on the metabolic profile of the piglets, increased the expression of inflammatory markers in the adipose tissue, and changed the methylation of several genes related to metabolism. Metformin treatment resulted in positive changes in the adipocyte morphology and regulated the methylation of several genes related to atherosclerosis, insulin, and fatty acids signaling pathways. The methylation and gene expression of the differentially methylated FASN, SLC5A10, COL5A1, and PRKCZ genes in adipose tissue associated with the metabolic profile in the piglets born to underfed sows. In conclusion, our swine model showed that caloric restriction during pregnancy was associated with impaired inflammatory and DNA methylation markers in the offspring's adipose tissue that could predispose the offspring to later metabolic abnormalities. Early metformin administration could modulate the size of adipocytes and the DNA methylation changes.

Proteomic changes associated with maternal dietary low ω6:ω3 ratio in piglets supplemented with seaweed. Part I: Serum proteomes

This study examines whether maternal low ω6:ω3 ratio diet and offspring SW supplementation can improve offspring immunity and performance by elucidating the effects on piglet serum proteome. A total of 16 sows were given either a standard (CR, 13:1) or low ω6:ω3 ratio diet (LR, 4:1) during pregnancy and lactation and their male weaned piglets were supplemented with SW powder (4 g/kg, SW) or not (CT) in a 21-day post-weaning (PW) diet. Four PW piglet groups were then identified based on dam and piglet treatment, namely CRCT, CRSW, LRCT, and LRSW (n = 10 each). Piglet serum collected at weaning and d21 PW were analysed (n = 5 each) using TMT-based quantitative proteomics and validated by appropriate assays. The differentially abundant proteins (n = 122) displayed positive effects of maternal LR diet on anti-inflammatory properties and innate immune stimulation. Progeny SW diet activated the innate immunity and enhance the host defence during inflammation. These data demonstrate the value of decreasing ω6:ω3 ratio in maternal diet and SW supplementation in PW piglet's diet to boost their immunity and anti-inflammation properties. SIGNIFICANCE: This novel proteomic study in post-weaned piglets addresses the interplay between maternal and offspring nutritional interventions in a context of rapid and dynamic alterations in piglet metabolic status around weaning. Decreasing ω6:ω3 ratio in maternal diet and SW supplementation in PW piglet's diet can boost their immunity and anti-inflammation properties. This study also provides new insights into piglet serum proteome regulation during post-weaning, a critical development period in swine.

Obesity and Metabolic Traits after High-Fat Diet in Iberian Pigs with Low Birth Weight of Placental Origin

Intrauterine growth restriction (IUGR) and later obesity and metabolic disorders have classically been associated with maternal malnutrition, but most cases of IUGR are related to placental insufficiency. The current study, using a swine model for IUGR and obesity, aimed to determine the interaction of birth weight (categorized as low birth weight [LBW] or normal birth-weight [NBW]) and postnatal diet (categorized as maintenance diet [MD] or fattening diet [FD]) on body weight, adiposity and metabolic traits. FD induced higher body weight and adiposity (both p < 0.0001), with higher fructosamine levels (p < 0.005) and a trend toward higher HOMA-β index (p = 0.05). NBW pigs remained heavier than LBW pigs during the early juvenile period (p < 0.005), but there were no differences at later stages. There were no differences in metabolic traits during juvenile development, but there were differences in adulthood, when LBW pigs showed higher glucose and lower insulin levels than NBW pigs (both p < 0.05). These results suggest that (a) FD allows LBW offspring to achieve similar obesity in adulthood as NBW offspring, and (b) glucose metabolism is more compromised in obese LBW than obese NBW pigs. The comparison of our data with previous studies highlights significant differences between offspring with LBW induced by maternal malnutrition or placental insufficiency, which should be considered when studying the condition.

Maternal Supplementation with Polyphenols and Omega-3 Fatty Acids during Pregnancy: Prenatal Effects on Fetal Fatty Acid Composition in the Iberian Pig

Simple Summary

The present study aimed to determine the effects of maternal dietary supplementation combining hydroxytyrosol and n3 polyunsaturated fatty acids (n3-PUFA) from day 35 to day 100 of gestation on the fatty acid (FA) composition of the offspring tissues of the Iberian pig. No effects were found in the plasma FA composition of the dams but higher levels of n3-PUFA were found in the plasma and different tissues (muscle, liver, and brain) of the supplemented fetuses. These findings may have important implications for piglets’ health and may offer guidance for achieving human dietary n3-PUFA recommendations.

Abstract

Intrauterine Growth Restriction (IUGR) is a major problem in pig production and different strategies, mainly maternal supplementation with different agents, are currently being studied. The combination of hydroxytyrosol and n3-PUFA seems to be a promising treatment to counteract IUGR, since the combination may help improve n3-PUFA composition and lower the inflammatory status of IUGR piglets. The aim of the present study is to determine the effects of a maternal supplementation, from day 35 to day 100 of pregnancy, with linseed oil and hydroxytyrosol on the fetal FA composition. The results showed higher n3 levels, including eicosapentaenoic and docosahexaenoic FA in the offspring from treated gilts, which showed lower n6-PUFA/n3-PUFA (n6/n3) ratios. Saturated and monounsaturated fatty acids were also affected by treatment, especially in the muscle and brain. Thus, a maternal supplementation with linseed oil and hydroxytyrosol affected the fetal FA tissue composition, which could have implications in pig production due to the improvement of the piglets’ health status.

High-fidelity porcine models of metabolic syndrome: a contemporary synthesis

This review aims to describe and compare porcine models of metabolic syndrome. This syndrome and its associated secondary comorbidities are set to become the greatest challenge to healthcare providers and policy makers in the coming century. However, an incomplete understanding of the pathogenesis has left significant knowledge gaps in terms of efficacious therapeutics. To further our comprehension and, in turn, management of metabolic syndrome, appropriate high-fidelity models of the disease complex are of great importance. In this context, our review aims to assess the most promising porcine models of metabolic syndrome currently available for their similarity to the human phenotype. In addition, we aim to highlight the strengths and shortcomings of each model in an attempt to identify the most appropriate application of each. Although no porcine model perfectly recapitulates the human metabolic syndrome, several pose satisfactory approximations. The Ossabaw miniature swine in particular represents a highly translatable model that develops each of the core parameters of the syndrome with many of the associated secondary comorbidities. Future high-fidelity porcine models of metabolic syndrome need to focus on secondary sequelae replication, which may require extended induction period to reveal.

Use of Agriculturally Important Animals as Models in Biomedical Research

Livestock have contributed significantly to advances in biomedicine and offer unique advantages over rodent models. The human is the ideal biomedical model; however, ethical reasons limit the testing of hypotheses and treatments in humans. Rodent models are frequently used as alternatives to humans due to size, low cost, and ease of genetic manipulation, and have contributed tremendously to our understanding of human health and disease. However, the use of rodents in translational research pose challenges for researchers due to physiological differences to humans. The use of livestock species as biomedical models can address these challenges as livestock have several similarities to human anatomy, physiology, genetics, and metabolism and their larger size permits collection of more frequent and often larger samples. Additionally, recent advances in genetics in livestock species allow for studies in genomics, proteomics, and metabolomics, which have the added benefit of applications to both humans in biomedical research and livestock in improving production. In this review, we provide an overview of scientific findings using livestock and benefits of each model to the livestock industry and to biomedical research.

The Role of Offspring Genotype-By-Sex Interactions, Independently of Environmental Cues, on the Phenotype Traits of an Obese Swine Model

Simple Summary

The present study, comparing the postnatal development of purebred Iberian and crossbreds Iberian × Large White littermates born from purebred Iberian sows, allows us to discern phenotype traits driven by the genotype from features imposed by pre- and postnatal environment. The results obtained in this study support the well-known relevance of genotype but also evidence a paramount role of the interaction sex-by-genotype, with differential effects depending on the offspring genotype and sex.

Abstract

The present study aimed to assess the importance of offspring genotype on postnatal development, independently of confounding factors related to prenatal environment and postnatal lifestyle, using a translational model of obesity and metabolic syndrome (the Iberian pig). Hence, we compared two genotypes (purebred Iberian and crossbreds Iberian × Large White), produced in one single maternal environment (pure Iberian mothers) through artificial insemination of Iberian sows with Iberian and Large White heterospermic semen and maintained in the same conditions during postnatal development. The results indicate that, under same pre- and postnatal environments, the interaction genotype-by-sex has a determinant role on offspring phenotype (i.e., growth and development, metabolic and antioxidant status and fatty acid composition of different tissues). These results may set the basis for future preclinical and clinical research on the differences in the metabolic phenotype among genotypes.

Unraveling molecular mechanisms involved in the development of leptin resistance using the pig as a model

The increase in obesity worldwide underlines the need for research concerning its metabolic and genetic determinants. One of the most intriguing mechanisms regarding obesity involves leptin and its signaling cascade. Leptin is a key regulator contributing to the fine-tuned crosstalk between nutrient availability and appetite signaling in the central nervous system. Owing to ethical concerns, many human tissues are not readily available and pigs can serve as a good animal model owing to their comparable anatomy, metabolism and genetics. In the present study, we utilized the pig to investigate the possible impact of increased adiposity on the development of alterations within the leptin signaling pathway. Two divergent groups of pigs (High and Low) were defined based on a high and low amount of mesenteric fat. Cortex, cerebellum, hypothalamus, mesenteric, subcutaneous and retroperitoneal fat tissues were used to study changes in expression levels of 94 mRNA transcripts related to the leptin signaling pathway using the qPCR approach. No significant differences were found at the central nervous system, whereas the expression level of STAT1 was reduced in mesenteric fat and leptin (LEP) and interleukin 6 (IL6) were shown to be consistently increased in all analyzed fat compartments from pigs with a high amount of mesenteric fat. These results could imply the onset of leptin and pro-inflammatory cytokine overexpression at early stages of obesity in the analyzed pigs without affecting any key components in the central nervous system. Thus, these pigs showing a unique leptin deregulation in adipose tissues could be a useful translational resource for studies of obesity and leptin resistance phenotypes.

The Effects of Maternal Metformin Treatment on Late Prenatal and Early Postnatal Development of the Offspring Are Modulated by Sex

Metformin is currently used to improve pregnancy outcome in women affected by polycystic ovary syndrome (PCOS) or diabetes. However, metformin may also be useful in pregnancies at risk of intrauterine growth restriction (IUGR) since it improves placental efficiency and the fetuses' developmental competence. There is no data on the duration of the effect of this treatment from the prenatal up to the postnatal stages. Therefore, the present trial aimed at determining the impact of metformin treatment on the offspring neonatal traits and early postnatal development (i.e., during lactation) using an in vivo swine model. The results support that maternal metformin treatment during pregnancy induces protective changes in body shape and composition of the progeny (i.e., larger head size and body length at birth and higher total viscera weight at weaning). However, there were also major effects of the offspring sex (smaller corpulence in females and lower relative weight of main viscerae in males), which should be considered for further preclinical studies and when even the current clinical application in women affected by PCOS or diabetes is implemented.

Maternal Supplementation with Polyphenols and Omega-3 Fatty Acids during Pregnancy: Effects on Growth, Metabolism, and Body Composition of the Offspring

Simple Summary

The present study aimed to determine benefits and risks of a dietary supplementation combining hydroxytyrosol and n3 polyunsaturated fatty acids (PUFA) on developmental patterns and metabolic traits of offspring in swine, a model of intrauterine growth restricted (IUGR) pregnancies. There were no deleterious effects on the reproductive traits of the sows and the postnatal features of the piglets. Piglets from the supplemented sows, in spite of a lower mean weight and corpulence at birth, showed higher average daily weight gain and fractional growth rate afterwards. Consequently, they reached higher weight and corpulence with increased muscle development and better lipidemic and fatty acids profiles than control offspring at juvenile stages.

Abstract

Maternal supplementation with antioxidants and n3 PUFAs may be a promising strategy to reduce the risk of intrauterine growth restriction and preterm delivery, which may diminish the appearance of low-birth-weight neonates. The present study aimed to determine benefits and risks of a dietary supplementation combining hydroxytyrosol, a polyphenol from olive leaves and fruits, and n3 PUFAs, from linseed oil, on developmental patterns and metabolic traits of offspring in swine, a model of IUGR pregnancies. The results obtained indicate that maternal supplementation with hydroxytyrosol and n-3 fatty acids during pregnancy has no deleterious effects on the reproductive traits of the sows (prolificacy, homogeneity of the litter, and percentage of stillborns and low-birth-weight, LBW, piglets) and the postnatal features of the piglets (growth patterns, adiposity, and metabolic traits). Conversely, in spite of a lower mean weight and corpulence at birth, piglets from the supplemented sows showed higher average daily weight gain and fractional growth rate. Thus, at juvenile stages afterwards, the offspring from the treated group reached higher weight and corpulence, with increased muscle development and better lipidemic and fatty acid profiles, in spite of similar adiposity, than offspring in the control group. However, much caution and more research are still needed before practical recommendation and use in human pregnancies.

Short-Term Effects of Early Menopause on Adiposity, Fatty Acids Profile and Insulin Sensitivity of a Swine Model of Female Obesity

Menopause strongly increases incidence and consequences of obesity and non-communicable diseases in women, with recent research suggesting a very early onset of changes in lipid accumulation, dyslipidemia, and insulin resistance. However, there is a lack of adequate preclinical models for its study. The present trial evaluated the usefulness of an alternative method to surgical ovariectomy, the administration of two doses of a GnRH analogue-protein conjugate (Vacsincel^®), for inducing ovarian inactivity in sows used as preclinical models of obesity and menopause. All the sows treated with the compound developed ovarian stoppage after the second dose and, when exposed to obesogenic diets during the following three months, showed changes in the patterns of fat deposition, in the fatty acids profiles at the different tissues and in the plasma concentrations of fructosamine, urea, β-hydroxibutirate, and haptoglobin when compared to obese fed with the same diet but maintaining ovarian activity. Altogether, these results indicate that menopause early augments the deleterious effects induced by overfeeding and obesity on metabolic traits, paving the way for future research on physiopathology of these conditions and possible therapeutic targets using the swine model.

Metformin Alleviates Obesity and Systemic Oxidative Stress in Obese Young Swine

The present study assessed the relationship between obesity induced by lifestyle and systemic oxidative stress and possible modulations by oral metformin treatments in young individuals, by using a translational swine model of obesity and associated cardiometabolic disorders (Iberian pig). The results indicate the existence of an age-related increase in both adiposity and systemic oxidative stress (using hydrogen peroxide as a marker), which is higher in individuals with obesogenic lifestyle and increased weight and obesity. Such effect was not found in individuals treated with metformin. The translation of these results suggests that childhood obesity increases production of reactive oxygen species (ROS), and therefore systemic oxidative stress. Treatment with metformin would improve such oxidative status.

Differential Effects of Litter Size and Within-Litter Birthweight on Postnatal Traits of Fatty Pigs

Simple Summary

The current work evaluated the relative effects of the number of piglets in the litter of origin (high vs. low litter size) and the birthweight (low (LBW) vs. normal (NBW) in large litters) on postnatal performance and quality of carcasses and meat in purebred Iberian pigs. The results indicated that NBW piglets born in large litters had disparities in developmental patterns in weight and size, back-fat deposition, and fatty acid composition of viscerae compared to NBW piglets from small litters, which again were different from those found in LBW piglets when compared to their NBW counterparts. However, both growth patterns were altered and might indicate previous phases of metabolic disorders.

Abstract

Fatty pigs are characterized by a thrifty genotype, adapted to harsh environments based on changes in metabolism and energy saving. Thus, we hypothesized that feto-maternal energy partitioning in large litters might have postnatal effects that might be independent of intrauterine growth restriction (IUGR) processes. Hence, the current work reported the influence of two effects on postnatal performance and carcass and meat quality of purebred Iberian pigs: (a) the effects of the number of piglets in the litter (high vs. low litter size), and (b) the effects of birthweight (low (LBW) vs. normal (NBW)) in large litters. The results confirmed that NBW piglets born in large litters had differences in developmental patterns of weight, back-fat deposition, and fatty acid (FA) composition when compared to NBW piglets from small litters. These results were different from those found in LBW piglets when compared to their NBW counterparts, which showed an initial asymmetrical growth and altered muscle FA composition at slaughtering. The assessment of FA composition indicated better metabolic status in NBW piglets from large litters than in LBW piglets. These data support the concept that the prenatal environment, even when the individual may cope with it, inescapably affects postnatal life.

Piglet birthweight and sex affect growth performance and fatty acid composition in fatty pigs

This study aimed to determine the effects of piglet birthweight (BIW) and sex, and within-litter BIW variation, on postnatal growth traits and meat quality in fatty breeds of pig. In total, 406 crossbred piglets (half male, half female) born to Iberian sows were studied during their postnatal development until slaughter. After birth, piglets were classified into four BIW categories: very low, low, medium and high. There was a negative effect of low BIW on growth patterns and fatty acid (FA) composition, but effects of litter size and within-litter BIW variation were not found. The very low BIW piglets underwent a period of significant catch-up growth (P &lt; 0.005) relative to high BIW piglets during the early postnatal phase, but also showed a higher feed conversion rate and lower average daily weight gain (P &lt; 0.05 for both measures) throughout the study period. BIW affected development during the entire productive life, and the sex effect increased with age. As a result, the period to reach market weight was longer in very low BIW piglets, by 43 days for females and 15 days for males, compared with their high BIW counterparts. BIW and sex also influenced amount of intramuscular fat, n-3 FA content and monounsaturated FA composition. The study indicates that BIW, modulated by sex, is a critical point for productive traits in fatty pigs. These results provide a basis for future strategies to enhance productive efficiency and meat quality of traditional swine breeds.

The Iberian pig fed with high-fat diet: a model of renal disease in obesity and metabolic syndrome

BACKGROUND

The pathogenesis of renal disease in the context of overweight/obesity, metabolic syndrome, and insulin resistance is not completely understood. This may be due to the lack of a definitive animal model of disease, which limits our understanding of obesity-induced renal damage. We evaluated the changes in renal histology and lipid deposits induced by obesity in a model of insulin resistance: the Iberian swine fed with fat-enriched food.

METHODS

Twenty-eight female sows were randomized to standard (SD) or high-fat diet (HFD: 6.8% of saturated fat) for 100 days. Weight, adiposity, analytics, oral glucose tolerance tests, and measured renal function were determined. Renal histology and lipid deposits in renal tissue were analyzed.

RESULTS

Animals on HFD developed obesity, hypertension, high levels of LDL cholesterol, triglycerides, insulin resistance, and glomerular hyperfiltration. No animal developed overt diabetes. Animals on HFD showed "diabetoid changes", including mesangial expansion [21.40% ± 4 vs.13.20% ± 4.0, p < 0.0001], nodular glomerulosclerosis [7.40% ± 7, 0.75 vs. 2.40% ± 4.7, p = 0.02], and glomerulomegaly (18% vs. 10%, p = 0.010) than those on SD. Tubular atrophy, interstitial fibrosis, inflammation, arteriolar hyalinosis, or fibrointimal thickening were mild and similar between groups. Triglyceride content in renal tissue was higher in animals on HFD than in SD (15.4% ± 0.5 vs. 12.7% ± 0.7; p < 0.01).

CONCLUSIONS

Iberian pigs fed with fat-enriched food showed diabetoid changes and glomerulomegaly as observed in obese humans making this model suitable to study obesity-induced renal disease.

Polyphenols and IUGR Pregnancies: Effects of Maternal Hydroxytyrosol Supplementation on Hepatic Fat Accretion and Energy and Fatty Acids Profile of Fetal Tissues

Maternal supplementation with hydroxytyrosol, a polyphenol present in olive leaves and fruits, is a highly promising strategy to improve the oxidative and metabolic status of fetuses at risk of intrauterine growth restriction, which may diminish the appearance of low-birth-weight neonates. The present study aimed to determine whether hydroxytyrosol, by preventing lipid peroxidation, may influence the fat accretion and energy homeostasis in the liver, as well as the fatty acid composition in the liver and muscle. The results indicate that hydroxytyrosol treatment significantly decreased the energy content of the fetal liver, without affecting fat accretion, and caused significant changes in the availability of fatty acids. There were significant increases in the amount of total polyunsaturated fatty acids, omega-3 and omega-6, which are highly important for adequate fetal tissue development. However, there were increases in the omega-6/omega-3 ratio and the desaturation index, which make further studies necessary to determine possible effects on the pro/anti-inflammatory status of the fetuses.

Effects of Dietary Taurine Supplementation to Gilts during Late Gestation and Lactation on Offspring Growth and Oxidative Stress

Simple Summary

Previous studies showed that gilts had elevated oxidative stress during late gestation and lactation, and could affect offspring growth. Taurine (Tau) is an important regulator of oxidative stress and possesses growth-enhancing properties. Our results suggested that taurine supplementation during late gestation and lactation of gilts increased growth performance in piglets through improved milk quality of gilts and intestinal morphology and barrier function of offspring.

Abstract

Birth is one of the most important events of animal production agriculture, as newborns are abruptly forced to adapt to environmental and nutritional disruptions that can lead to oxidative damage and delay in growth. Taurine (Tau) is an important regulator of oxidative stress and possesses growth-enhancing properties. In the present study, we investigated the effects of dietary Tau supplementation in gilts during late gestation and lactation on the growth performance of piglets by assessing intestinal morphology and barrier function, and oxidative stress status. Sixteen gilts were randomly allocated to the Con (basal diet) and Tau (basal diet with 1% Tau) groups from 75 d of gestation to weaning. Maternal dietary Tau supplementation significantly increased weaning weight and average daily gain weight in piglets. Piglets in the Tau group had higher villus height and villus height-to-crypt depth ratio (VCR), ZO-1 protein expression, and secretory immunoglobulin A (sIgA) content in the jejunum. Meanwhile, Tau bebeficial affected the milk quality of gilts, as indicated by decreased malondialdehyde (MDA) concentration and increased total superoxide dismutase (T-SOD), total antioxidative capability (T-AOC), glutathione peroxidase (GPx), and catalase (CAT) activity. Furthermore, Tau supplementation increased T-SOD activity in plasma and SOD2 protein expression in the jejunum in the piglets. In conclusion, this study provides evidence that dietary Tau supplementation to gilts improves growth performance in piglets, owing to improved intestinal morphology and barrier function, as well as inhibition of oxidative stress.

Antioxidant homeostasis is disturbed in fetuses with leptin-resistant genotypes: A cross-sectional study

BACKGROUND

Leptin resistance is associated with lower reproductive efficiency, with deficiencies in embryo viability and growth leading to low prolificacy and high incidence of intrauterine growth restriction.

OBJECTIVE

We aimed to investigate the underlying mechanisms of the leptin-resistance, evaluating the antioxidant homeostasis of leptin-resistant and lean swine fetuses.

MATERIALS AND METHODS

The study included 70 plasma samples from fetuses at day 62 of gestation (mid-pregnancy), from breeds with (Iberian breed; n=35) and without leptin resistance (25% Large White x 25% Landrace x 50% Pietrain; n=35). The antioxidant status of the plasma samples was determined by photoinduced chemiluminescence whilst systemic oxidative stress was assessed determining plasma hydrogen peroxide concentration by enzimoimmunoassay.

RESULTS

Plasma total antioxidant capacity was significantly lower in leptin-resistant fetuses (p=0.003), whilst systemic oxidative stress was increased (p=0.02).

CONCLUSION

Our results indicate key differences in the antioxidant status in pregnancies affected by leptin resistance.

Effects of fetal genotype and sex on developmental response to maternal malnutrition

The present study aimed to determine whether developmental patterns, adiposity level and fatty-acid composition of fetuses exposed to maternal malnutrition are driven by their sex or their genotype, or both, as these may modulate the adaptive response to the intrauterine environment independently of the maternal genotype. We used a single maternal genotype (purebred Iberian (IB) sows), which was inseminated with heterospermic semen (obtained by mixing semen from Iberian and Large White (LW) boars), to obtain four different subsets of fetuses (male and female, purebred (IB×IB) and crossbred (IB×LW)) in Iberian purebred sows. Analysis of fetal phenotypes indicated a better adaptive response of the female offspring, which was modulated by their genotype. When faced with prenatal undernutrition, females prioritised the growth of vital organs (brain, liver, lungs, kidneys and intestine) at the expense of bone and muscle. Moreover, the analysis of fat composition showed a higher availability of essential fatty acids in the female sex than in their male counterparts and also in the Iberian genotype than in crossbred fetuses. These results are of high translational value for understanding ethnic differences in prenatal programming of postnatal health and disease status, and show evidence that prenatal development and metabolic traits are primarily determined by fetal sex and strongly modulated by fetal genotype.

Maternal undernutrition and offspring sex determine birth-weight, postnatal development and meat characteristics in traditional swine breeds

Background

The aim of this study was to determine how maternal undernutrition during pregnancy and offspring birth-weight can affect the postnatal development of offspring under farm conditions, which may lead to consequences in its meat and carcass quality. The current study involved a total of 80 litters from Iberian sows fed a diet fulfilling daily requirements (n = 47; control) or providing 70% daily requirements (n = 33; underfed) from d 38 to d 90 of gestation when fetal tissue development begins. After birth, piglets born live were classified as low birth-weight (LBW; < 1 kg) and normal birth-weight (NBW; ≥1 kg). During the growing phase, 240 control and 230 underfed pigs (50% males and females) distributed by BW category and sex were studied until the slaughter.

Results

At birth and weaning, there were significant differences in all morphological measures and weight between NBW and LBW piglets as expected (P < 0.0005), but few effects of the gestational feed restriction. During the growing phase, NBW pigs continued with higher weight than LBW pigs on all the days of evaluation (P < 0.05), even though control-LBW-females and LBW-males showed a catch-up growth. However, underfed pigs showed slower growth and higher feed conversion ratio than control pigs (P < 0.0001) at 215 days old. Moreover, the average daily weight gain (ADWG) for the overall period was greater for NBW, male and control pigs than for their LBW, female and underfed pigs (P < 0.0001, P< 0.0005 and P< 0.05, respectively) and NBW pigs were slaughtered at a younger age than LBW pigs (P < 0.0001). After slaughtering, control pigs also had higher carcass yield and backfat depth than underfed pigs (P < 0.0005) and the maternal nutritional effect caused main changes in the polar lipid fraction of liver and loin. The fatty acid composition of loin in control pigs had higher C18:1n-9 and n-3 FA concentrations, as well as lower ∑n-6/∑n-3 ratio, than in underfed pigs (P < 0.005).

Conclusions

In brief, results showed that the effects of maternal nutritional restriction appeared and increased with offspring age, causing worse developmental patterns for underfed pigs than for control pigs.

Electronic supplementary material

The online version of this article (10.1186/s40104-018-0240-6) contains supplementary material, which is available to authorized users.

Characterization of Ageing- and Diet-Related Swine Models of Sarcopenia and Sarcopenic Obesity

Sarcopenia and sarcopenic obesity are currently considered major global threats for health and well-being. However, there is a lack of adequate preclinical models for their study. The present trial evaluated the suitability of aged swine by determining changes in adiposity, fatty acids composition, antioxidant status and lipid peroxidation, development of metabolic disturbances and structural changes in tissues and organs. Iberian sows with clinical evidence of aging-related sarcopenia were fed a standard diet fulfilling their maintenance requirements or an obesogenic diet for 100 days. Aging and sarcopenia were related to increased lipid accumulation and cellular dysfunction at both adipose tissue and non-adipose ectopic tissues (liver and pancreas). Obesity concomitant to sarcopenia aggravates the condition by increasing visceral adiposity and causing dyslipidemia, insulin resistance and lipotoxicity in non-adipose tissues. These results support that the Iberian swine model represents certain features of sarcopenia and sarcopenic obesity in humans, paving the way for future research on physiopathology of these conditions and possible therapeutic targets.

The Risks of Overweight, Obesity and Abdominal Obesity in Middle Age after Exposure to Famine in Early Life: Evidence from the China's 1959-1961 Famine

OBJECTIVE

Several studies have revealed that exposure to famine in early life was associated with higher body mass index(BMI) and waist circumference, and most of them used data from cross-sectional studies and defined those born before or after the famine period as non-exposed participants, which ignored the effects caused by age. Our objective was to study the effects of undernutrition in early life on overweight, obesity and abdominal obesity in those aged 54-56.

METHODS

This was a retrospective cohort study with the status at age of 54-56 as outcomes. 1092 participants born between 1959 and 1961 from 2015 wave of China Health and Retirement Longitudinal Study (CHARLS) were defined as exposed and 1616 born between 1955 and 1957 from 2011 wave of CHARLS were defined as control. We used the prevalence odds ratios(ORs) to estimate the risks of overweight, obesity, abdominal obesity, and stratified by famine severity and sex separately for comparisons.

RESULTS

Exposed group had higher risks of overweight (OR 1.357, 95%CI 1.067,1.727) and obesity (OR 1.356, 95%CI 1.001,1.836) in women, not in men. Participants in exposed group were more likely to have abdominal obesity (OR 1.362, 95%CI 1.139,1.629), regardless of famine severity and gender.

CONCLUSION

Undernutrition in early life increased the risks of overweight and obesity in women not in men. And the risk of abdominal obesity was increased with the experience of undernutrition at early age both in men and women.

Physiological and metabolic control of diet selection

The fact that most farm animals have no dietary choice under commercial practices translates the dietary decisions to the carers. Thus, a lack of understanding of the principles of dietary choices is likely to result in a high toll for the feed industry. In healthy animals, diet selection and, ultimately, feed intake is the result of factoring together the preference for the feed available with the motivation to eat. Both are dynamic states and integrate transient stimulus derived from the nutritional status, environmental and social determinants of the animal with hard-wired genetic mechanisms. Peripheral senses are the primary inputs that determine feed preferences. Some of the sensory aspects of feed, such as taste, are innate and genetically driven, keeping the hedonic value of feed strictly associated with a nutritional frame. Sweet, umami and fat tastes are all highly appetitive. They stimulate reward responses from the brain and reinforce dietary choices related to essential nutrients. In contrast, aroma (smell) recognition is a plastic trait and preferences are driven mostly by learned experience. Maternal transfer through perinatal conditioning and the individual’s own innate behaviour to try or to avoid novel feed (often termed as neophobia) are known mechanisms where the learning process strongly affects preferences. In addtition, the motivation to eat responds to episodic events fluctuating in harmony with the eating patterns. These signals are driven mainly by gastrointestinal hormones (such as cholecystokinin [CCK] and glucagon-like peptide 1 [GLP-1]) and load. In addition, long-term events generate mechanisms for a sustainable nutritional homeostasis managed by tonic signals from tissue stores (i.e. leptin and insulin). Insulin and leptin are known to affect appetite by modulating peripheral sensory inputs. The study of chemosensory mechanisms related to the nutritional status of the animal offers novel tools to understand the dynamic states of feed choices so as to meet nutritional and hedonic needs. Finally, a significant body of literature exists regarding appetite driven by energy and amino acids in farm animals. However, it is surprising that there is scarcity of knowledge regarding what and how specific dietary nutrients may affect satiety. Thus, a better understanding on how bitter compounds and excess dietary nutrients (i.e. amino acids) play a role in no-choice animal feeding is an urgent topic to be addressed so that right choices can be made on the animal’s behalf.

Developmental Origins of Health and Disease in swine: implications for animal production and biomedical research

The concept of Developmental Origins of Health and Disease (DOHaD) addresses, from a large set of epidemiological evidences in human beings and translational studies in animal models, both the importance of genetic predisposition and the determinant role of maternal nutrition during pregnancy on adult morphomics and homeostasis. Compelling evidences suggest that both overnutrition and undernutrition may modify the intrauterine environment of the conceptus and may alter the expression of its genome and therefore its phenotype during prenatal and postnatal life. In fact, the DOHaD concept is an extreme shift in the vision of the factors conditioning adult phenotype and supposes a drastic change from a gene-centric perspective, only modified by lifestyle and nutritional strategies during juvenile development and adulthood, to a more holistic approach in which environmental, parental, and prenatal conditions are strongly determining postnatal development and homeostasis. The implications of DOHaD are profound in all the mammalian species and the present review summarizes current knowledge on causes and consequences of DOHaD in pigs, both for meat production and as a well-recognized model for biomedicine research.

Fetal Sex Modulates Developmental Response to Maternal Malnutrition

The incidence of obesity and metabolic diseases is dramatically high in rapidly developing countries. Causes have been related to intrinsic ethnic features with development of a thrifty genotype for adapting to food scarcity, prenatal programming by undernutrition, and postnatal exposure to obesogenic lifestyle. Observational studies in humans and experimental studies in animal models evidence that the adaptive responses of the offspring may be modulated by their sex. In the contemporary context of world globalization, the new question arising is the existence and extent of sex-related differences in developmental and metabolic traits in case of mixed-race. Hence, in the current study, using a swine model, we compared male and female fetuses that were crossbred from mothers with thrifty genotype and fathers without thrifty genotype. Female conceptuses evidence stronger protective strategies for their adequate growth and postnatal survival. In brief, both male and female fetuses developed a brain-sparing effect but female fetuses were still able to maintain the development of other viscerae than the brain (mainly liver, intestine and kidneys) at the expense of carcass development. Furthermore, these morphometric differences were reinforced by differences in nutrient availability (glucose and cholesterol) favoring female fetuses with severe developmental predicament. These findings set the basis for further studies aiming to increase the knowledge on the interaction between genetic and environmental factors in the determination of adult phenotype

Non-invasive methods for the determination of body and carcass composition in livestock: dual-energy X-ray absorptiometry, computed tomography, magnetic resonance imaging and ultrasound: invited review

The ability to accurately measure body or carcass composition is important for performance testing, grading and finally selection or payment of meat-producing animals. Advances especially in non-invasive techniques are mainly based on the development of electronic and computer-driven methods in order to provide objective phenotypic data. The preference for a specific technique depends on the target animal species or carcass, combined with technical and practical aspects such as accuracy, reliability, cost, portability, speed, ease of use, safety and for in vivo measurements the need for fixation or sedation. The techniques rely on specific device-driven signals, which interact with tissues in the body or carcass at the atomic or molecular level, resulting in secondary or attenuated signals detected by the instruments and analyzed quantitatively. The electromagnetic signal produced by the instrument may originate from mechanical energy such as sound waves (ultrasound - US), 'photon' radiation (X-ray-computed tomography - CT, dual-energy X-ray absorptiometry - DXA) or radio frequency waves (magnetic resonance imaging - MRI). The signals detected by the corresponding instruments are processed to measure, for example, tissue depths, areas, volumes or distributions of fat, muscle (water, protein) and partly bone or bone mineral. Among the above techniques, CT is the most accurate one followed by MRI and DXA, whereas US can be used for all sizes of farm animal species even under field conditions. CT, MRI and US can provide volume data, whereas only DXA delivers immediate whole-body composition results without (2D) image manipulation. A combination of simple US and more expensive CT, MRI or DXA might be applied for farm animal selection programs in a stepwise approach.

Epigenetic and developmental influences on the risk of obesity, diabetes, and metabolic syndrome

Metabolic syndrome is a growing cause of morbidity and mortality worldwide. Metabolic syndrome is characterized by the presence of a variety of metabolic disturbances including obesity, hyperlipidemia, hypertension, and elevated fasting blood sugar. Although the risk for metabolic syndrome has largely been attributed to adult lifestyle factors such as poor nutrition, lack of exercise, and smoking, there is now strong evidence suggesting that predisposition to the development of metabolic syndrome begins in utero. First posited by Hales and Barker in 1992, the "thrifty phenotype" hypothesis proposes that susceptibility to adult chronic diseases can occur in response to exposures in the prenatal and perinatal periods. This hypothesis has been continually supported by epidemiologic studies and studies involving animal models. In this review, we describe the structural, metabolic and epigenetic changes that occur in response to adverse intrauterine environments including prenatal and postnatal diet, maternal obesity, and pregnancy complications. Given the increasing prevalence of metabolic syndrome in both the developed and developing worlds, a greater understanding and appreciation for the role of the intrauterine environment in adult chronic disease etiology is imperative.

Effects of the use of assisted reproductive technologies and an obesogenic environment on resistance artery function and diabetes biomarkers in mice offspring

Maternal obesity affects the incidence of cardiovascular disease and diabetes in offspring. Also the use of assisted reproductive technologies (ART) has been associated with cardiovascular deficiencies in offspring. Obese women often suffer from infertility and use ART to achieve a pregnancy, but the combined effects of maternal obesity and ART on cardiovascular health and incidence of diabetes in the offspring is not known. Here, we report the effects of the use of ART within an obesogenic environment, consisting of feeding a western diet (WD) to dams and offspring, on resistance artery function and presence of diabetes biomarkers in juvenile mice offspring. Our results indicate that WD and ART interacted to induce endothelial dysfunction in mesenteric resistance arteries isolated from 7-week-old mice offspring. This was determined by presence of a reduced acetylcholine-induced dilation compared to controls. The arteries from these WD-ART mice also had greater wall cross-sectional areas and wall to lumen ratios indicative of vascular hypertrophic remodeling. Of the diabetes biomarkers measured, only resistin was affected by a WD×ART interaction. Serum resistin was significantly greater in WD-ART offspring compared to controls. Diet and sex effects were observed in other diabetes biomarkers. Our conclusion is that in mice the use of ART within an obesogenic environment interacts to favor the development of endothelial dysfunction in the resistance arteries of juvenile offspring, while having marginal effects on diabetes biomarkers.

Early-postnatal changes in adiposity and lipids profile by transgenerational developmental programming in swine with obesity/leptin resistance

Maternal malnutrition during pregnancy, both deficiency and excess, induces changes in the intrauterine environment and the metabolic status of the offspring, playing a key role in the growth, status of fitness/obesity and appearance of metabolic disorders during postnatal life. There is increasing evidence that these effects may not be only limited to the first generation of descendants, the offspring directly exposed to metabolic challenges, but to subsequent generations. This study evaluated, in a swine model of obesity/leptin resistance, the existence and extent of transgenerational developmental programming effects. Pre- and postnatal development, adiposity and metabolic features were assessed in the second generation of piglets, descendant of sows exposed to either undernutrition or overnutrition during pregnancy. The results indicated that these piglets exhibited early-postnatal increases in adiposity and disturbances in lipid profiles compatible with the early prodrome of metabolic syndrome, with liver tissue also displaying evidence of paediatric liver disease. These features indicative of early-life metabolic disorders were more evident in the males that were descended from overfed grandmothers and during the transition from milk to solid feeding. Thus, this study provides evidence supporting transgenerational developmental programming and supports the necessity for the development of strategies for avoiding the current epidemics of childhood overweight and obesity.