Global per capita consumption of protein is rising, while infertility is becoming prevailing. Here we found that mouse primordial follicle activation, the first step of folliculogenesis, was reduced by restricted protein intake and was accelerated by excessive protein intake, in an ovarian mTORC1 signaling-dependent manner. Furthermore, restricted or excessive protein intake resulted in an augmentation or decline of oocyte number and fertility at older age, respectively. Liver-specific ablation of fibroblast growth factor 21 (FGF21), which resulted in a reduction of 87% in circulating FGF21, abrogated the preserving effect of low-protein intake on primordial follicle pool. Interestingly, FGF21 had no direct effect on the activation of primordial follicles, but instead required an adipokine adiponectin. Moreover, AdipoRon, an oral adiponectin receptor agonist, prevented the over-activation effect of excessive protein intake on primordial follicle activation. Collectively, dietary protein consumption controlled ovarian primordial follicle reserve and fertility, which required coordination between FGF21 and adiponectin.Funding Statement: This study was funded in part by National Natural Science Foundation of China (Grant 31772616). Declaration of Interests: None of the authors have a conflict of interests to declare. Ethics Approval Statement: All animal procedures in this study were handled in accordance with Guide for the Care and Use of Laboratory Animals (National Research Council, Bethesda, MD, USA), and the Institutional Animal Care and Research Committee of Sichuan Agricultural University (SICAU-2015-034).
Dietary fiber is a substance that cannot be digested by endogenous digestive enzymes but can be digested by the cellulolytic enzymes produced by intestinal microorganisms. In the past, dietary fiber was considered an anti-nutrient component in diets because it could resist digestion by endogenous enzymes secreted by the intestine and has a negative effect on the digestion of energy-producing nutrients. However, due to its functional properties, potential health benefits to animals, and innate fermentability, it has attracted increasing attention in recent years. There are a plethora of studies on dietary fiber. Evidence suggests that dietary fiber can provide energy for pigs through intestinal microbial fermentation and improve sow welfare, reproductive performance, intestinal flora, and immunity. This is a brief overview of the composition and classification of dietary fiber, the mechanism of action and effects of dietary fiber on reproductive performance, intestinal microorganisms, and the immune index of the sow. This review also provides scientific guidance for the application of dietary fiber in sow production.
This study examined the effects of soluble fiber (SF) supplementation (0.8%), containing 17.4% rhamnose, 4.1% fucose, 11.1% arabinose, 30.6% xylose, and 16.4% galactose during the prepubescent phase on the subsequent performance from the second to fifth parities. After the first parity, 56 and 55 post-weaning sows in the control (CON) and SF groups had their reproductive performance monitored in succeeding parities. Circulating concentrations of anti-mullerian hormone (AMH) were greater in the SF group than in the CON group at 205 d of age and the first post-weaning day ( p < 0.05). The SF treatment at the prepubescent phase resulted in an enhanced reproductive performance from parities three to five. In Parity three, the SF sows had 1.32 total born ( p = 0.044), 1.43 born alive ( p = 0.023) and 1.40 born effective, which was significantly more than in the CON group ( p = 0.022). In Parity four, the SF sows had 1.1 total born ( p = 0.058), 1.28 born alive ( p = 0.019), and 1.06 born effective, significantly more than in the CON group ( p = 0.049). In Parity five, the SF gilts had 1.43 total born ( p = 0.075), 1.53 born alive ( p = 0.067) and 1.65 born effective, significantly more than in the CON group ( p = 0.020). No effects were observed for the removal of sows and backfat thickness at the mating in each parity between groups ( p > 0.05). Collectively, gilts that received an extra 0.8% SF during the prepubescent phase increased their subsequent litter size as breeding sows. These results showed that nutritional decisions at the replacement phase could influence lifetime fertility.
The effects of maternal addition of yeast cultures on offspring gut development and intestinal microorganisms are not yet known, so the aim of this study was to investigate the effects of maternal addition of yeast cultures to the diet of sows during late gestation and lactation on growth performance, antioxidant properties and intestinal microorganisms of offspring weaned piglets.40 Landrace × Yorkshire sows (3-7 of parity) with similar backfat were randomly divided into two treatment groups: control diet (CON) and control diet +2.0 g/kg yeast culture (XPC), and the trial started on day 90 of gestation and ended on day 21 of lactation.The results showed that maternal addition of yeast culture significantly increased weaned piglet weight and mean daily gain (p < 0.05), with a tendency to increase litter weight gain (p = 0.083) and liver weight (p = 0.076) compared to the control group. The content of thymus malondialdehyde (MDA) was significantly higher (p < 0.05) and the content of colon total antioxidant capacity (T-AOC) was significantly lower (p < 0.05) in the offspring weaned piglets of the XPC group compared to the control group. The expression of thymus SOD1 and SOD2, spleen SOD1, jejunum SOD2, and colon GPX1, SOD1, and SOD2 were significantly downregulated in the XPC group of offspring weaned piglets compared with the control group (p < 0.05). The intestinal morphology and the content of short-chain fatty acids in colonic chyme did not differ between the two groups (p > 0.05). Compared with the control group, the XPC group significantly increased the relative abundance of colonic chyme Bacteroidetes (p < 0.05), tended to decrease the relative abundance of Lactobacillus (p = 0.078), and tended to increase the relative abundance of Alloprevotella (p = 0.055). The XPC group significantly upregulated Blautia and Fournierella (p < 0.05) and significantly downregulated Candidatus_Competibacter, Nitrospira, Dechloromonas, Haliangium, and Oscillospira (p < 0.05).In conclusion, maternal addition of yeast cultures improved the growth performance of offspring weaned piglets and changed the intestinal microbial community, but did not improve their antioxidant performance.
Abstract This study set out to determine the apparent total tract digestibility (ATTD) of the nutrients and energy in six cottonseed meal (CSM) feedstuffs fed to pregnant and non-pregnant sows. The six types of CSM were: two expelled CSMs with crude protein (CP) levels of 40.67% and 44.64%, and four solvent-extracted CSMs with CP levels of 45.18%, 51.16%, 56.44%, and 59.63%. Fourteen gestating sows (at the fourth parity with body weights of 220.6 ± 18.4 kg at days 30 of gestation) and 14 non-pregnant sows (after the third parity with body weights of 219 ± 14.6 kg) were assigned to a replicated 7 × 3 Youden square design with seven diets and three periods. The seven diets included an entirely corn-based diet and six diets each containing 20.0% of the six CSMs tested. Each period included a 5-d acclimation to the experimental diets, followed by a 5-d period during which urine and feces were collected. Significant differences were found among the six CSM diets, regardless of reproductive stage, regarding 1) the ATTD of neutral detergent fiber (NDF) (P < 0.05) and 2) the ATTD of dry matter (DM), organic matter (OM), and CP and the gross energy (GE) (P < 0.01). Non-pregnant sows had a greater ATTD of OM and CP (P < 0.01) compared with gestating sows. The digestible energy (DE) and metabolizable energy (ME) of the six CSM samples ranged from 12.48 to 17.15 MJ/kg and 11.35 to 15.88 MJ/kg, respectively, for non-pregnant sows, and from 12.86 to 16.41 MJ/kg and 12.43 to 14.72 MJ/kg, respectively, for gestating sows. However, the DE, ME, and ME:DE ratios of each CSM were similar between gestating and non-pregnant sows. DE and ME were negatively correlated with NDF and ADF, respectively, but were positively corrected with CP level (P < 0.01). Collectively, the DE, ME, and nutrient digestibility of CSM varied greatly according to the chemical compositions, and CSMs with higher protein and lower fiber levels had greater DE and ME levels.
Dietary oxidized fat contains harmful materials such as hydrogen peroxide and malondialdehyde (MDA). Excessive oxidized fat intake during pregnancy and lactation not only leads to maternal body injury but also damages offspring health. Our previous study demonstrated that vitamin D (VD) had antioxidative capability in sows. This study was conducted to investigate the effect of maternal VD and inulin supplementation in oxidized oil diet on the growth performance and oxidative stress of their offspring. Sixty 5-month-old C57BL/6N female mice were randomly divided into five groups: Control group (basal diet, n = 12), OF group (oxidized-soybean-oil-replaced diet, n = 12), OFV group (oxidized-soybean-oil-replaced diet + 7000 IU/kg VD, n = 12), OFI group (oxidized-soybean-oil-replaced diet + 5% inulin, n = 12) and OFVI group (oxidized-soybean-oil-replaced diet + 7000 IU/kg VD + 5% inulin, n = 12). Mice were fed with the respective diet during pregnancy and lactation. The offspring were then slaughtered on day 21 of age at weaning. Results showed that a maternal oxidized oil diet impaired body weight and liver weight gain of offspring during lactation compared to the control group, while maternal VD, inulin or VD and inulin mixture supplementation reversed this effect. In addition, the activity of T-AOC in the liver of offspring was lower in the OF group than that in the control group, but could be restored by maternal VD and inulin mixture supplementation. Furthermore, the gene expression of both proinflammatory and anti-inflammatory cytokines, such as Il-6, Tnfα and Il-10, in offspring liver were downregulated by a maternal oxidized oil diet compared with the control group, but they were restored by maternal VD or VD and inulin mixture supplementation. The expressions of Vdr and Cyp27a1 were decreased by a maternal oxidized oil diet compared with the control group, while they could be increased by VD or VD and inulin mixture supplementation. Conclusion: maternal oxidized oil diet intake could impair the growth performance by inducing oxidative stress, but this can be relieved by maternal VD and inulin supplementation.
Gestational diabetes mellitus (GDM) is associated with increased inflammation in adipose tissues. Fibroblast growth factor 21 (FGF21) is an endocrine hormone which signals to multiple tissues to regulate metabolism. However, its role in GDM remains largely unknown. In this study, we found that impaired FGF21 signaling in GDM correlates with worsened inflammation and insulin resistance in white adipose tissues in mice. Mechanistically, the pregnancy-related upregulation of FGF21 signaling in adipocytes promotes the differentiation of regulatory T cells (Tregs), which are critical for reducing pregnancy-induced adipose tissue inflammation. The anti-inflammatory effects of FGF21 may involve linolenic acid-mediated PGE2 synthesis in adipocytes. These findings underscore FGF21's role in mediating crosstalk between mature adipocytes and immune cells in white adipose tissue and suggest that targeting FGF21 signaling and its downstream metabolites could offer a potential therapeutic approach for GDM in humans.
Abstract Background Dietary fiber (DF) is often eschewed in swine diet due to its anti-nutritional effects, but DF is attracting growing attention for its reproductive benefits. The objective of this study was to investigate the effects of DF intake level on oocyte maturation and uterine development, to determine the optimal DF intake for gilts, and gain microbial and metabolomic insight into the underlying mechanisms involved. Methods Seventy-six Landrace × Yorkshire (LY) crossbred replacement gilts of similar age (92.6 ± 0.6 d; mean ± standard deviation [SD]) and body weight (BW, 33.8 ± 3.9 kg; mean ± SD) were randomly allocated to 4 dietary treatment groups ( n = 19); a basal diet without extra DF intake (DF 1.0), and 3 dietary groups ingesting an extra 50% (DF 1.5), 75% (DF 1.75), and 100% (DF 2.0) dietary fiber mixture consisting of inulin and cellulose (1:4). Oocyte maturation and uterine development were assessed on 19 d of the 2nd oestrous cycle. Microbial diversity of faecal samples was analysed by high-throughput pyrosequencing (16S rRNA) and blood samples were subjected to untargeted metabolomics. Results The rates of oocytes showing first polar bodies after in vitro maturation for 44 h and uterine development increased linearly with increasing DF intake; DF 1.75 gilts had a 19.8% faster oocyte maturation rate and a 48.9 cm longer uterus than DF 1.0 gilts ( P < 0.05). Among the top 10 microbiota components at the phylum level, 8 increased linearly with increasing DF level, and the relative abundance of 30 of 53 microbiota components at the genus level (> 0.1%) increased linearly or quadratically with increasing DF intake. Untargeted metabolic analysis revealed significant changes in serum metabolites that were closely associated with microbiota, including serotonin, a gut-derived signal that stimulates oocyte maturation. Conclusions The findings provide evidence of the benefits of increased DF intake by supplementing inulin and cellulose on oocyte maturation and uterine development in gilts, and new microbial and metabolomic insight into the mechanisms mediating the effects of DF on reproductive performance of replacement gilts.
Intra-uterine growth restriction (IUGR) impairs postnatal growth and skeletal muscle development in neonatal infants. This study evaluated whether dietary β-hydroxy-β-methylbutyrate Ca (HMB-Ca) supplementation during the early postnatal period could improve muscle growth in IUGR neonates using piglets as a model. A total of twelve pairs of IUGR and normal-birth-weight (NBW) male piglets with average initial weights (1·85 (sem 0·36) and 2·51 (sem 0·39) kg, respectively) were randomly allotted to groups that received milk-based diets (CON) or milk-based diets supplemented with 800 mg/kg HMB-Ca (HMB) during days 7-28 after birth. Blood and longissimus dorsi (LD) samples were collected and analysed for plasma amino acid content, fibre morphology and the expression of genes related to muscle development. The results indicate that, regardless of diet, IUGR piglets had a significantly decreased average daily weight gain (ADG) compared with that of NBW piglets (P<0·05). However, IUGR piglets fed HMB-Ca had a net weight and ADG similar to that of NBW piglets fed the CON diet. Irrespective of body weight (BW), HMB-Ca supplementation markedly increased the type II fibre cross-sectional area and the mRNA expression of mammalian target of rapamycin (mTOR), insulin-like growth factor-1 and myosin heavy-chain isoform IIb in the LD of piglets (P<0·05). Moreover, there was a significant interaction between the effects of BW and HMB on mTOR expression in the LD (P<0·05). In conclusion, HMB-Ca supplementation during the early postnatal period could improve skeletal muscle growth and maturity by accelerating fast-twitch glycolytic fibre development in piglets.