Maternal Immune Activation and Dietary Soy Isoflavone Supplementation Influence Pig Immune Function but not Muscle Fiber Formation

Analysis of Maternal and Fetal Oxidative Stress During Delivery with Epidural Analgesia

Childbirth is a stressful event for mothers, and labor epidural analgesia (LEA) may reduce mental stress. Mental stressors include labor pain, fear, and anxiety, which induce oxidative stress. In this study, we focused on oxidative stress during delivery and conducted a cross-sectional analysis of maternal and fetal oxidative stress. The participants included 15 women who received LEA (LEA group) and 15 who did not (No LEA group). Participants with a gestational age of < 37 weeks, BMI of ≥ 35 kg/m2, cerebrovascular or cardiovascular complications, multiple pregnancies, gestational hypertension, gestational diabetes, chronic hypertension, thyroid disease, birth weight of < 2,500 g, emergency cesarean section, or cases in which epidural anesthesia was re-administered during delivery were excluded from the study. Maternal blood was collected on admission, and immediately after delivery, and umbilical artery blood was collected from the fetus. The oxidative stress status was assessed by measuring diacron-reactive oxygen metabolite (an index of the degree of lipid peroxide oxidation), biological antioxidant potential (an index of antioxidant capacity) and calculating the ratio of BAP/d-ROMs (an index of the oxidative stress). The results showed that maternal oxidative stress immediately after delivery was lower in the LEA group than in the No LEA group. Moreover, the fetuses experienced less oxidative stress in the LEA group than in the No LEA group. Taken together, these results suggest that LEA may reduce maternal and fetal oxidative stress associated with childbirth.

The effect of chronic, non-pathogenic maternal immune activation on offspring postnatal muscle and immune outcomes

The objective was to determine the effects of maternal inflammation on offspring muscle development and postnatal innate immune response. Sixteen first-parity gilts were randomly allotted to repeated intravenous injections with lipopolysaccharide (LPS; n = 8, treatment code INFLAM) or comparable volume of phosphate buffered saline (CON, n = 8). Injections took place every other day from gestational day (GD) 70 to GD 84 with an initial dose of 10 μg LPS/kg body weight (BW) increasing by 12% each time to prevent endotoxin tolerance. On GD 70, 76, and 84, blood was collected at 0 and 4 h postinjection via jugular or ear venipuncture to determine tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β concentrations. After farrowing, litter mortality was recorded, and the pig closest to litter BW average was used for dissection and muscle fiber characterization. On weaning (postnatal day [PND] 21), pigs were weighed individually and 2 barrows closest to litter BW average were selected for another study. The third barrow closest to litter BW average was selected for the postnatal LPS challenge. On PND 52, pigs were given 5 μg LPS/kg BW via intraperitoneal injection, and blood was collected at 0, 4, and 8 h postinjection to determine TNF-α concentration. INFLAM gilt TNF-α concentration increased (P < 0.01) 4 h postinjection compared to 0 h postinjection, while CON gilt TNF-α concentration did not differ between time points. INFLAM gilt IL-6 and IL-1β concentrations increased (P = 0.03) 4 h postinjection compared to 0 h postinjection on GD 70, but did not differ between time points on GD 76 and 84. There were no differences between INFLAM and CON gilts litter mortality outcomes (P ≥ 0.13), but INFLAM pigs were smaller (P = 0.04) at birth and tended (P = 0.09) to be smaller at weaning. Muscle and organ weights did not differ (P ≥ 0.17) between treatments, with the exception of semitendinosus, which was smaller (P < 0.01) in INFLAM pigs. INFLAM pigs tended (P = 0.06) to have larger type I fibers. INFLAM pig TNF-α concentration did not differ across time, while CON pig TNF-α concentration peaked (P = 0.01) 4 h postinjection. TNF-α concentration did not differ between treatments at 0 and 8 h postinjection, but CON pigs had increased (P = 0.01) TNF-α compared to INFLAM pigs 4 h postinjection. Overall, maternal immune activation did not alter pig muscle development, but resulted in suppressed innate immune activation.

A review on the effect of soy bioactive components on growth and health outcomes in pigs and broiler chickens

While soy products have long been included in animal diets for their macronutrient fractions, more recent work has focused on the immunomodulatory potential of bioactive components of this feedstuff. This comprehensive review aims to identify the current state of knowledge on minor soy fractions and their impact on the health and growth of pigs and broiler chickens to better direct future research. A total of 7,683 publications were screened, yet only 151 were included in the review after exclusion criteria were applied, with the majority (n = 87) of these studies conducted in pigs. In both species, antinutritional factors and carbohydrates, like stachyose and raffinose, were the most frequently studied categories of bioactive components. For both categories, most publications were evaluating ways to decrease the prevalence of the examined components in soy products, especially when fed at earlier ages. Overall, most studies evaluated the effect of the bioactive component on performance-related outcomes (n = 137), followed by microbial analysis (n = 38) and intestinal structure and integrity measures (n = 37). As they were analyzed in the majority of publications, antinutritional factors were also the most frequently investigated category in relation to each specific outcome. This trend did not hold true for microbiota- or antioxidant-associated outcomes, which were most often studied with carbohydrates or polyphenols, respectively. Changes to the host microbiota have the potential to modulate the immune system, feed intake, and social behaviors through the microbiota-gut-brain axis, though few publications measured behavior and brain characteristics as an outcome. Other identified gaps in research included the study of soy saponins, as most research focused on saponins derived from other plants, the study of phytosterols outside of their role in cardiovascular or reproductive outcomes, and the general examination of bioactive peptides. Overall, given soy's popularity as a current constituent of animal feed, additional research into these bioactive components may serve to define the value of soy products through their potential ability to support the productivity, health, and well-being of animals.

Effects of maternal inflammation on growth performance, carcass characteristics, and meat quality of offspring pigs

The objective of this research was to determine the effects of mid-gestational maternal inflammation on performance, carcass characteristics, and meat quality of offspring. Pregnant gilts were administered either lipopolysaccharide (LPS; n = 7) or saline (CON, n = 7) from days 70 to 84 of gestation. Gilts assigned to the LPS treatment were administered an intravenous injection of reconstituted LPS every other day with a beginning dose of 10 μg LPS/kg body weight and subsequent doses increasing by 12%, while CON gilts received intravenous injections of comparable volumes of saline. Gilts farrowed naturally, and at day 66 of age, a total of 59 pigs, both barrows and gilts began a 3-phase feeding regimen designed to meet or exceed nutrient requirements for growing-finishing pigs. Pigs were weighed on days 0, 35, 70, and 105 of the finishing trial to determine average daily gain, average daily feed intake, and gain-to-feed ratio (G:F). On day 106, pigs were slaughtered under the supervision of the U.S. Department of Agriculture Food Safety Inspection Service. Ending live weight, hot carcass weight, and dressing percentage were determined. The left side of carcasses was weighed and fabricated to determine carcass cutting yields. The semitendinosus was collected for histological samples. Fresh belly characteristics and loin quality were measured. Two chops were collected for Warner-Bratzler shear force and proximate analysis. No differences (P ≥ 0.13) between LPS and CON pigs were observed for growth performance in phases 1, 2, 3, or overall (days 0 to 105) performance with the exception of overall G:F reduced in CON pigs compared with LPS pigs (P = 0.03). There was a tendency for carcass yield to be reduced (P = 0.06; 0.82% units) in LPS pigs compared with CON pigs. Additionally, longissimus muscle area tended to be reduced (P = 0.10) 2.27 cm2 in LPS compared with CON pigs. Loin chop quality traits including instrumental color, subjective color, marbling, firmness, pH, and drip loss were not different (P ≥ 0.09) between LPS and CON pigs. Fresh belly characteristics were not different (P ≥ 0.22) between LPS and CON pigs. There were no differences in primal and subprimal weights, except that LPS pigs tended to have a reduction (P ≥ 0.07) in tenderloin and Canadian back weights compared with CON pigs. Furthermore, LPS pigs had no differences (P ≥ 0.25) in muscle fiber composition or size; however, LPS pigs tended (P = 0.10) to have a 13% reduction in estimated muscle fibers number compared with CON pigs. In summary, mid-gestational inflammation did not result in reduced meat quality, growth performance, or carcass yields of offspring.

A pre- and postnatal immune challenge influences muscle growth and metabolism in weaned pigs

The in utero environment is key to both fetal and postnatal growth and development. The objective of this study was to determine if administration of an acute low-dose lipopolysaccharide (LPS) to gestating sows during mid to late gestation and postweaning would alter the offsprings metabolomic profile of the longissimus dorsi (LD) and muscle ultrastructure. Pregnant Camborough sows were randomly assigned to receive LPS (LPS; n = 7) at a dose of 2.5 µg/kg or saline (CON; n = 7) on 78 ± 1.8 d of gestation. At weaning (21 ± 1.3 d of age), barrows (CON n = 17; LPS n = 17) from each treatment were selected to receive a secondary LPS. Barrows were administered the secondary LPS challenge at a dose of 10 µg/kg 7 d post weaning. Twenty-four hours after the postnatal LPS dose, barrows (31 ± 1.3 d of age) were euthanized, and each LD was removed. The left LD was utilized for morphometric measurements. Two samples from the medial section of the right LD were preserved for immunohistochemical measurements and metabolomic analyses. Mass spectral data were deconvoluted, aligned, and annotated using MS-DIAL. Univariate and multivariate analyses were conducted using MetaboAnalyst. Pathway analysis was conducted and compared to the Homo sapiens pathway library. Morphometric and immunohistochemical measurements were analyzed using the MIXED procedure of SAS version 9.4. Significance for all analyses was declared at P ≤ 0.05 and tendencies were considered at P ≤ 0.10. Average diameter of myosin heavy chain (MHC) type I and IIB/X fibers was increased (P ≤ 0.048) in LPS offspring compared with CON. Average cross-sectional area was increased (P = 0.030) in MHC IIB/X fibers and tended to be increased (P = 0.080) in MHC I fibers of LPS offspring. There were no differences (P = 0.186) between treatment groups for total nuclei or nuclei positive for MYF5, PAX7, or MYF5 and PAX7 nuclei. Metabolomic analyses identified 14 differentially expressed (P < 0.05) metabolites in the LD between treatment groups. There were 10 metabolites within the LD that tended (P ≤ 0.096) to differ between treatment groups. Thus, this study shows that in utero immune stimulation using LPS in gestating sows and a subsequent LPS challenge postnatally alters the metabolomic profile and muscle ultrastructure of the LD in weaned pigs.