Pregnant Sows Research Articles

Rotavirus A Inoculation and Oral Vitamin A Supplementation of Vitamin A Deficient Pregnant Sows Enhances Maternal Adaptive Immunity and Passive Protection of Piglets against Virulent Rotavirus A.

The aim of this study was to determine the impact of vitamin A deficiency (VAD)/supplementation (±VA) and group A RV (RVA) maternal immunization of RVA seropositive multiparous pregnant sows, on their immune responses (anamnestic response) and on passive protection of their piglets against RVA challenge. Our results showed that VAD- mock sows had increased RVA RNA shedding at 1-5 days post piglet RVA challenge, and their litters had increased RVA shedding and diarrhea frequency throughout the experiment. VAD decreased memory B cell frequencies while VA supplementation increased RVA specific IgA/IgG antibody (Ab) secreting cell (ASC) numbers in blood, milk, and tissues of RVA inoculated VAD sows. The increased numbers of RVA specific IgA/IgG ASCs in blood, milk/colostrum, intestinal contents, and tissues in VA supplemented VAD sows, suggest a role of VA in B cell immunity and trafficking to tissues. We also observed that RVA inoculated sows had the highest viral neutralizing Ab titers in serum and milk while VA supplementation of VAD sows and RVA inoculation increased IgA+ B cell frequencies in sow colostrum. In summary, we demonstrated that daily oral VA-supplementation (2nd trimester-throughout lactation) to RVA inoculated VAD sows improved the function of their gut-mammary-IgA immunological axis, reducing viral RNA shedding, diarrhea, and increasing weight gain in suckling piglets.

Environmental enrichment for primiparous and multiparous pregnant sows and its effect on cortisol and behavior at farrowing and production parameters at weaning

The study evaluated the effect of environmental enrichment (EE) during gestation of primiparous and multiparous sows on the concentrations of cortisol, behavior at farrowing, and production parameters of sows and their piglets. Primiparous (n = 20) and multiparous (n = 20) sows were included. Half of the sows received EE from Week 6 to Week 14 of gestation, while the remaining sows received no EE. The concentrations of hair cortisol on Weeks 6 and 15 of gestation, the behavior of the sows before, during, and after parturition, and some production parameters of the sows and their piglets at birth and weaning were compared among groups. Cortisol increased from Week 6 through Week 15 in all the sows and it was greater in those with no EE. Before, during, and after parturition the primiparous sows that received EE showed behavioral patterns suggestive of better dealing with stress and pain, in comparison mainly with primiparous sows that received no EE. The number of piglets born alive, the total of piglets born, and the weight at birth by litter were similar (P > 0.05) in all groups. The weight at weaning by litter was greater (P < 0.05) for piglets of primiparous sows with EE and less (P < 0.05) for piglets of primiparous sows with no EE. In conclusion, providing sows, particularly gilts, with EE during gestation reduced their stress and pain during parturition, and improved the weight gain in their piglets.

Gut microbiota involved in desulfation of sulfated progesterone metabolites: A potential regulation pathway of maternal bile acid homeostasis during pregnancy.

Abnormally raised circulating bile acids (BA) during pregnancy threat fetal and offspring health. Our previous study has identified sulfated progesterone metabolites (PMSs) in part account for dysregulation of maternal BA homeostasis during pregnancy, however, limited intervention strategies to remedy increased serum BA through PMSs during pregnancy are available. The purpose of this study is to test the feasibility of manipulating BA homeostasis and progesterone metabolism through steering gut microbiota. A total of 19 pregnant sows were randomly treated with standard diet or vancomycin-supplemented diet, to investigate the intercorrelation of PMSs, intestinal microbiota, and maternal BA metabolism from day 60 of gestation (G60) until farrowing (L0). Pregnant mice orally gavaged with epiallopregnanolone sulfate (PM5S) or vehicle and nonpregnant mice were sampled and further analyzed to verify the effect of PM5S on maternal BA metabolism. The present study revealed that oral vancomycin reduced maternal fasting serum total BA (TBA) levels and postprandial serum TBA levels at day 90 of gestation (G90). BA profile analysis showed the decreased TBA after vancomycin treatment was attributed to the decrease of primary BA and secondary BA, especially hyodeoxycholic acid (HDCA). By using newly developed UPLC-MS/MS methods, we found vancomycin increased fecal excretion of allopregnanolone sulfate (PM4S) and PM5S during late gestation and thus maintaining the relative stability of serum PM4S and PM5S, which play an important role in BA metabolism. Further study in mice showed that pregnant mice have higher serum and liver TBA levels compared with nonpregnant mice, and PM5S administration induced higher gallbladder TBA levels and TBA pool in pregnant mice. In addition, after oral vancomycin, the continuously decreased Parabacteroides genus, potentially enriched with genes encoding steroids sulfatase, may explain the increased fecal PMSs excretion in pregnant sows. Taken together, our study provides the evidence that pregnancy-induced elevation of BA levels in sow is likely regulated by manipulation of gut microbiota, which offer new insights into the prevention and treatment of disrupted BA homeostasis during pregnancy by targeting specific microbiota.

Heat wave exposure impairs reproductive performance in primiparous sows and gilts in a tropical environment.

We studied the effects of heat waves (HW), defined as three consecutive days with an ambient temperature ≥ 25°C and a temperature and humidity index (THI) > 74, on the reproductive performance of sows. Meteorological data were obtained from the National Institute of Meteorology and reproductive data from a commercial farm with 51,578 inseminations and 49,103 pregnancies from September 5, 2013, to July 12, 2019. Sows were divided into the following groups according to the parity order: group 1 (sows that did not experience HW on the day of insemination) and group 2 (sows exposed to HW on the day of insemination). The percentage of days that pregnant sows were exposed to HW was calculated as 0 to 25% (1), 26 to 50% (2), 51 to 75% (3), and > 75% (4). Out of a total of 2137days, there were 160 HW and more than 10 HW per month, except in May, June, and July. Gilts in group 2 showed a decrease in the percentage of gestation (98.21% and 98.78%, respectively, P = 0.0267) and the percentage of births compared with those in group 1 (95.53% and 96.61, respectively, P = 0.0065). Primiparous sows in group 2 had a higher percentage of abortions than gilts in group 1 (3.20% and 2.42%, respectively; P = 0.0334). Sows exposed to more than 50% HW during gestation produced more mummified piglets than sows exposed to less than 50% HW. The number of stillborn piglets was higher in sows exposed to temperatures above 25% HW during gestation. The occurrence of heat waves in gilts and primiparous sows impairs reproductive performance.

Genetic characterization of porcine reproductive and respiratory syndrome virus from Eastern China during 2017-2022.

Porcine reproductive and respiratory syndrome (PRRS) is an immunosuppressive disease caused by PRSS virus (PRRSV). PRRSV mainly causes reproductive disorders in pregnant sows and respiratory diseases in piglets. Recently, it has emerged as one of the most important diseases of the pig industry across the globe. In this study, we have collected 231 samples from differently sized pig farms in Eastern China from 2017 to 2022 to investigate the epidemic characteristics of the disease. All samples were screened by RT-PCR and analyzed further using Nsp2 and ORF5 genes. The result showed that the positive rate of PRRSV was 24% (54/231). Phylogenetic analysis (13 positive samples) revealed that all isolates belonged to genotype 2, and they were mainly distributed in four lineages (i.e., lineage 1, 3, 5, and 8). Nsp2 is the most variable protein among all PRRSV NSPs, several isolates from this study had amino acid deletions within Nsp2 compared to that of strain VR-2332. The major structural protein glycoprotein (GP5) protein is encoded by ORF5. Epitope analysis of the 13 isolated strains and additional reference strains revealed that all 13 strains had some mutations on the decoy epitope, the primary neutralizing epitope, T cell epitopes, and B cell epitopes. This study showed that the prevalent PRRSV strain in Eastern China was still HP-PRRSV, while the proportion of NADC30-like and NADC34-like strains have increased. This study further enriches the epidemiological data of PRRS in Eastern China and provides a theoretical basis for vaccine development and prevention and control of the disease across the region.

Heat stress of gilts around farrowing causes oxygen insufficiency in the umbilical cord and reduces piglet survival

Late gestating sows are susceptible to high ambient temperatures, possibly causing farrowing complications and reducing piglet survival. This experiment aimed to quantify in the days leading up to farrowing the impact of sow heat stress (HS) on farrowing physiology and survival of the piglets. Pregnant primiparous sows (gilts) were allocated to either thermoneutral control (CON, n = 8; constant 20 °C) or cyclical HS conditions (n = 8; 0900 h to 1700 h, 30 °C; 1700 h to 0900 h, 28 °C) from d 110 of gestation until farrowing completion. Gilt respiration rate, skin temperature and rectal temperature were recorded daily, and farrowing duration was quantified by video analyses. Blood samples were collected from the piglet umbilical vein at birth. At 48 h of age, piglet growth was quantified by morphometric analyses. The thermal exposure model induced HS and respiratory alkalosis in the gilts, as indicated by increased respiration rate, rectal temperature, skin temperature (all P < 0.001), plasma cortisol (P = 0.01) and blood pH (P < 0.001). Heat-stressed gilts took longer to start expelling placentae (P = 0.003), although the active farrowing duration was not significantly different between treatments. Stillbirth rates were higher in the HS group (P < 0.001), with surviving piglets at birth having lower umbilical vein partial pressure of oxygen (P = 0.04), oxygen saturation rate (P = 0.03) and tending to have increased lactate concentrations (P = 0.07). At birth, piglet skin meconium staining scores were greater in the HS group (P = 0.022). At 48 h of age, piglets from the HS group had reduced small intestinal length (P = 0.02), reduced jejunal crypt depth (P = 0.02) and lighter absolute brain weight (P = 0.001). In contrast, piglet BW, growth rate, relative organ weight and small intestinal mucosal barrier function did not change between treatments. Collectively, these findings demonstrated gilt HS during late gestation caused farrowing complications and reduced the umbilical oxygen supply to the piglets at parturition, leading to increased risks of piglet stillbirth with implications on impaired neonatal survivability and development.

Perinatal exposure to glyphosate-based herbicides impairs progeny health and placental angiogenesis by disturbing mitochondrial function

Glyphosate-based herbicides (GBHs) are the most widely used pesticide worldwide and can provoke placental injury. However, whether and how GBHs damage angiogenesis in the placenta is not yet known. This work evaluated the safety of glyphosate on pregnant sows based on the limit level by governments and investigated the effects and mechanism of Low-GBHs (20 mg/kg) and High-GBHs (100 mg/kg) exposure on placental angiogenesis. Results showed that gestational exposure to GBHs decreased placental vessel density and cell multiplication by interfering with the expression of VEGFA, PLGF, VEGFr2 and Hand2 (indicators of angiogenesis), which may be in relation to oxidative stress-induced disorders of mitochondrial fission and fusion as well as the impaired function of the mitochondrial respiratory chain. Additionally, GBHs destroyed barrier function and nutrient transport in the placenta, and was accompanied by jejunum oxidative stress in newborn piglets. However, GBHs exposure had no significant differences on sow reproductive performance. As a natural antioxidant, betaine treatment protected placenta and newborn piglets against GBHs-induced damage. In conclusion, GBHs impaired placental angiogenesis and function and further damaged the health of postnatal progeny, these effects may be linked to mitochondrial dysfunction. Betaine treatment following glyphosate exposure provided modest relief.

Maternal obesity: new placental paradigms unfolded.

The prevalence of maternal obesity is increasing at an alarming rate, and is providing a major challenge for obstetric practice. Adverse effects on maternal and fetal health are mediated by complex interactions between metabolic, inflammatory, and oxidative stress signaling in the placenta. Endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) are common downstream pathways of cell stress, and there is evidence that this conserved homeostatic response may be a key mediator in the pathogenesis of placental dysfunction. We summarize the current literature on the placental cellular and molecular changes that occur in obese women. A special focus is cast onto placental ER stress in obese pregnancy, which may provide a novel link for future investigation.

N-Carbamylglutamate Improves Reproductive Performance and Alters Fecal Microbiota and Serum Metabolites of Primiparous Sows during Gestation after Fixed-Time Artificial Insemination.

Simple SummaryLarger litter size (born alive) and higher uniformity of piglets’ birth weight are the most desired characteristics in pig production. Application of N-carbamylglutamate (NCG) was shown to increase litter size and decrease the coefficient of variation of piglets’ birth weight from sows after conventional artificial insemination. In this study, we report that, in sows after fixed-time artificial insemination (FTAI), NCG improved the number of piglets born alive and the coefficient of variation of birth weight through direct effects (increased serum NCG levels) and indirect effects (altered intestinal microbiome and serum metabolites). These findings indicate that NCG can improve reproductive performance by improving both the number of piglets born alive and the uniformity of piglets’ birth weight in sows after FTAI.N-carbamylglutamate (NCG) supplementation during gestation improves reproductive performance in sows after conventional artificial insemination. However, whether NCG can improve reproductive performance and change fecal microbiota and serum metabolite levels during pregnancy in sows after fixed-time artificial insemination (FTAI) remains unclear. Two hundred multiparous sows were assigned a diet from mating until farrowing: control (corn–soybean meal) or NCG supplementation (0.05% NCG). At days 30, 70, and 110 of gestation and after farrowing, maternal microbial diversity and serum metabolites were studied. Supplementation of NCG increased the number of piglets born alive and the litter weight (all p < 0.05) and altered the fetal microbial community during gestation. Some genera were particularly abundant at different time points during gestation and after farrowing, but none were commonly abundant across all four time points. Metabolic analysis revealed that NCG supplementation significantly increased the serum concentrations of NCG, ferulic acid, cinnamoylglycine, 3-phenyllactic acid, and gamma-glutamylglutamic acid in the NCG group compared with levels in the control group. Our results reveal that NCG supplementation during gestation improves reproductive performance in sows after FTAI, exerting both direct (increased serum NCG levels) and indirect effects (altered intestinal microbiome and serum metabolites) on sow reproduction and, ultimately, improving placental and fetal development.

Characterization and Pathogenicity of Two Novel PRRSVs Recombined by NADC30-like and NADC34-like Strains in China.

Porcine reproductive and respiratory syndrome viruses (PRRSVs) pose a serious threat to the swine industry in China, which has caused great difficulties for porcine reproductive and respiratory syndrome (PRRS) immune prevention and control, due to its easily mutable and recombinant nature. In this study, two novel PRRSV strains, which were named GD-H1 and GD-F1, were isolated and fully sequenced from pig farms in Guangdong province, China. The phylogenetic analysis and recombination analysis revealed that the GD-H1 and GD-F1 were generated by the recombination of NADC30-like and NADC34-like strains which were different from the previously prevalent strain. Further pathogenic studies on piglets and sows found that the recombinant strains could cause piglets high fever, loss of appetite and lung lesions, but no piglets died. However, the recombinant strains could cause acute death and abortion in pregnant sow infection models together with average survival rates of 62.5% and 37.5% abortion rates, respectively. These findings indicated that the recombinant strains were extremely pathogenic to sows. Therefore, we report two clinical novel recombinant strains of PRRSV that are different from the traditional epidemic strains in China, which may provide early warning and support for PRRS immune prevention and control.

Exposure of a single wild boar population in North Rhine-Westphalia (Germany) to perfluoroalkyl acids

Perfluoroalkyl acids (PFAA) are among the leading chemical pollutants in the twenty-first century. Of these, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) have been widely detected in a large number of animal and environmental samples. Wild boars accumulate PFAA in their livers, but it has not yet been clarified to what extent wild boars of the same population accumulate different PFAA in their livers or whether any conclusions can be drawn from any differences found in regard to environmental contamination. In this study, liver samples from wild boars killed during driven hunts in 2019 and 2020 from a defined forest area in North Rhine-Westfalia, Germany were analyzed for 13 different PFAA. A mean load of 493 µg/kg (± 168 µg/kg) PFAA was measured in 2020. Perfluorosulfonic acids accounted for 87% of the total load in both years, with PFOS dominating this group. These results were similar to those of 14 liver samples collected from other regions of Germany for comparison. In addition, the livers of hunted pregnant sows and fetuses were examined. The load of short-chain perfluorocarboxylic acids (< C8) in the fetus liver was as high as that of the sows, whereas the concentrations of long-chain perfluorocarboxylic acids (≥ C8) were lower than in the dams. This result shows for the first time that fetuses take up PFAA from their mothers in utero. Our study shows that PFAA content in wild boar livers is comparably high in all animals in a local population and indicates a need for further research regarding a nationwide background exposure to PFAA in wild boars and their surrounding environment.

PSXIII-B-19 The Effect of Maternal Melatonin Supplementation During mid to Late Gestation on Fetal Piglet Hepatic Gene Expression

Abstract Using melatonin as a gestational therapeutic due to its antioxidant and vasodilative properties increases fetal morphometric measurements in ruminant models, however its effects on gestating swine and fetal circadian regulation remain unknown. This study evaluated the effects of dietary melatonin supplementation during gestation on fetal hepatic circadian regulatory and metabolic gene expression. Twenty-four pregnant sows were randomly assigned to either melatonin (20mg/d; MEL) or control (CON) and 0500h (AM) or 1700h (PM) harvest timepoint across fall and spring replicates. The fall replicate occurred from gestational day 38±1 to 99±1, while spring was days 41 to 106±1. At harvest small, medium, and large piglets were identified by body weight and their livers were collected. Data were analyzed using a linear mixed model by the MIXED procedure of SAS. Cry1 expression tended to increase (P=0.0575) in large fetuses compared to small during the fall, while large fetuses had the greatest expression, medium intermediary, and small least during the spring (P=0.0056). Cry2 was reduced (P&amp;lt; 0.001) in MEL offspring compared to CON in the fall. There was a Treatment × Class interaction (P=0.0104) for Cry2 expression during spring wherein, CON-AM was reduced compared to CON-PM, however no differences between MEL groups. A Treatment × Class interaction (P=0.0511) of Per2 expression was present in the fall, where expression of small control fetuses was reduced compared to remaining controls. Spring Per2 expression increased (P=0.0122) in large fetuses compared to other sizes, Per2 also increased (P=0.0039) in PM compared to AM. Fall IGF1 expression increased (P=0.0366) in large fetuses compared to medium and small, and spring IGF1 expression increased (P=0.0067) in large fetuses compared to small. These findings suggest that maternal melatonin supplementation during gestation modulates expression of hepatic circadian regulatory and metabolic genes which may impact growth and developmental efficiency postnatally in a seasonal manner.

Impact of dietary supplementation with N-carbamoyl-aspartic acid on serum metabolites and intestinal microflora of sows.

N-Carbamoyl-aspartic acid (NCA) is a critical precursor for de novo biosynthesis of pyrimidine nucleotides. To investigate the cumulative effects of maternal supplementation with NCA on the productive performance, serum metabolites and intestinal microbiota of sows, 40 pregnant sows (∼day 80) were assigned into two groups: (1) the control (CON) and (2) treatment (NCA, 50 gt-1 NCA). Results showed that piglets from the NCA group had heavier birth weight than those in the CON group (P < 0.05). In addition, maternal supplementation with NCA decreased the backfat loss of sows during lactation (P < 0.05). Furthermore,16S-rRNA sequencing results revealed that maternal NCA supplementation decreased the abundance of Cellulosilyticum, Fournierella, Anaerovibrio, and Oribacterium genera of sows during late pregnancy (P < 0.05). Similarly, on the 14th day of lactation, maternal supplementation with NCA reduced the diversity of fecal microbes of sows as evidenced by significantly lower observed species, Chao1, and Ace indexes, and decreased the abundance of Lachnospire, Faecalibacterium, and Anaerovorax genera, while enriched the abundance of Catenisphaera (P < 0.05). Untargeted metabolomics showed that a total of 48 differentially abundant biomarkers were identified, which were mainly involved in metabolic pathways of arginine/proline metabolism, phenylalanine/tyrosine metabolism, and fatty acid biosynthesis, etc. CONCLUSION: Overall, the results indicated that NCA supplementation regulated intestinal microbial composition of sows and serum differential metabolites related to arginine, proline, phenylalanine, tyrosine, and fatty acids metabolism that may contribute to regulating the backfat loss of sows, and the birth weight and diarrhea rate of piglets. © 2022 Society of Chemical Industry.

Chaperonin CCT5 binding with porcine parvovirus NS1 promotes the interaction of NS1 and COPƐ to facilitate viral replication

Porcine parvovirus (PPV) is an important pathogen causing reproductive disorders in first pregnant sows. The non-structure protein NS1 of PPV is a multifunctional protein playing a key role in viral replication. Chaperonin-containing T-complex polypeptide complex (CCT), containing CCT1-CCT8 subunits, belongs to the type II chaperones that interact with proteins to help in folding and maintaining. In this study, CCT5, for the first time, was found to be one of the host interacting proteins of PPV NS1, and CCT5 was directly bound with NS1. Interference of CCT5 expression by specific siRNA and knockout of CCT5 expression by CRISPR/Cas9 suppressed PPV replication, while overexpression of CCT5 promoted PPV replication in PK-15 cells. The interaction of CCT5 and PPV NS1 was dependent on the 36–42 aa motif at the N-terminal end of NS1. More importantly, CCT5 was also found interacting with COPƐ, which has previously been demonstrated to promote PPV replication by regulating type I interferon. Interference and knockout of CCT5 expression significantly reduced the interaction of PPV NS1 and host protein COPƐ, and promoted the IFN-β expression. These results show that CCT5 mediates the interaction of PPV NS1 and COPƐ to regulate viral replication, providing new insight into the mechanism of PPV replication.

The nutritive value of soybean meal from different sources for sows during mid- and late gestation.

A precise understanding of the nutritive value of soybean meal (SBM) for pregnant sow is required for accurate feeding. Hence, we evaluated the nutritive value of 11 SBM samples from different sources for sows during mid and late gestation. In total, 24 mid-gestating sows (parity three; 230.3 ± 12.0 kg on day 37 of gestation) and 24 late-gestating sows (parity three; 238.8 ± 20.9 kg on day 72 of gestation) were assigned to a replicated 12 × 3 Youden square design with 12 diets and 3 periods. The 12 diets included a corn-based diet and 11 diets containing 25.50% SBMs from different sources. After 5-d adaptation, urine and feces were collected for 5 d. Although the chemical characteristics of SBM varied between samples, no differences were observed in digestible energy (DE), metabolizable energy (ME), apparent total tract digestibility (ATTD) of dry matter, gross energy, crude fiber, and neutral detergent fiber values in SBMs fed to both animal groups. However, de-hulled SBM 4 from Brazil displayed greater ATTD for nitrogen (N) in late-gestating sows (P < 0.05); animals displayed significantly (P < 0.01) greater ME, ME:DE ratio, and N net utilization values when compared with mid-gestating sows. The chemical composition of SBMs can be used to predict DE and ME values. In conclusion, ME, ME:DE ratio, and N net utilization SBM values for late-gestating sows were greater than in mid-gestating sows. Therefore, we should consider differences in ME values for SBMs when formulating diets for sows in mid and late gestation periods.

Expressions of ghrelin and GHSR-1a in the corpus luteum and the stimulatory effect of ghrelin on luteal function of pregnant sows

Studies have shown that ghrelin played direct actions in ovarian function, but the direct role of ghrelin in corpus luteum (CL) of pregnant sows has remained obscure. The study aimed to examine the expressions of ghrelin and its functional receptor (GHSR-1a) in the CL of sows during pregnancy, and evaluate the role of ghrelin in CL function of pregnant sows. Immunohistochemistry analysis showed that ghrelin and GHSR-1a are both predominantly localized in the luteal cells of pregnant sows CL. Strong immunoreactivity for ghrelin and GHSR-1a is detected at days 20 (early) and 50 (middle), but weak immunoreactivity is observed at days 90 (late) post mating. Similarly, there is a significant effect of pregnant phase on the expression (mRNA and protein) of ghrelin and GHSR-1a in the CL, with higher levels at days 20 (early) and 50 (middle), and lower values at 90 (late) post mating. In vitro, treatments of luteal cells with ghrelin (from 0.01 to 10 ng/mL) are promoted cell viability and P4 secretion in a dose-dependent manner. Ghrelin is also accelerated the LH-induced P4 secretion in luteal cells. Moreover, ghrelin is induced the release and mRNA expression of LH, and increased the release of prostaglandin (PG)E2, but reduced the secretion of PGF2α in luteal cells. In conclusion, the presences of ghrelin and GHSR-1a in the porcine CL during pregnancy, and the stimulatory effect of ghrelin on luteal cells suggest positive regulation by ghrelin in CL function of pregnant sows.

Dietary silymarin ameliorating reproductive and lactation performance of sows via regulating body antioxidant and metabolism

ObjectiveThe experiment was conducted to explore the effects of silymarin on reproductive and lactation performance, serum antioxidants, and body metabolism of sows. MethodsSixty pregnant sows (85 d, Large × Landrace) with similar genetic background, body condition, and parity were randomly divided into three groups, and each group has 20 individually housed sows. The sows in the control group (CG) were fed with basal diet, and those in the experimental group A (EGA) and B (EGB) were fed with basal diet containing 250 and 500 mg/kg silymarin, respectively. The experiment lasted 46 days from day 85 of gestation to the end of lactation (weaning on day 17 ).The milk composition and serum biochemical parameters were determined by a milk composition analyzer and a blood biochemical analyzer, respectively. Serum antioxidant indexes and plasma hormone levels were measured using the biochemical kits. The gas chromatograph was applied to detect the fecal short chain fatty acids. ResultsCompared with the CG, the total feed intake (TFI) and average daily feed intake (ADFI) were significantly increased (P < 0.01), and the urea content in regular milk tended to increase (P = 0.095) in the EG. The serum malondialdehyde (MDA) contents were decreased on day 90 of gestation and the day of farrowing (P < 0.01), and the serum contents of total antioxidant capacity (T-AOC) tended to increase on day 17 of lactation (P = 0.099) compared with the CG. Compared with the CG, the serum triglyceride (TG) concentrations in the EG tended to increase on day 90 of gestation (P = 0.062), and the content of serum total protein (TP) and albumin (ALB) reduced on day 17 of lactation (P < 0.01). Compared with the CG, plasm D-lactic acid content was decreased (P < 0.05), and the plasma prostaglandin (PG) level tended to increase (P = 0.088) in the EG on the day of farrowing and day 17 of lactation. Compared with the CG, fecal isobutyric acid concentration in the EG significantly decreased on the day of farrowing ( P < 0.05). ConclusionAdding 250 – 500 mg/kg silymarin to diets from the late gestation to the end of lactation could improve reproductive and lactation performance of sows via the regulation of nutrient metabolism and serum antioxidant.

Non-contact detection method of pregnant sows backfat thickness based on two-dimensional images.

Since sow backfat thickness (BFT) is highly correlated with its service life and reproductive effectiveness, dynamic monitoring of BFT is a critical component of large-scale sow farm productivity. Existing contact measures of sow BFT have their problems including, high measurement intensity and sows' stress reaction, low biological safety, and difficulty in meeting the requirements for multiple measurements. This article presents a two-dimensional (2D) image-based approach for determining the BFT of pregnant sows when combined with the backfat growth rate (BGR). The 2D image features of sows extracted by convolutional neural networks (CNN) and the artificially defined phenotypic features of sows such as hip width, hip height, body length, hip height-width ratio, length-width ratio, and waist-hip ratio, were used respectively, combined with BGR, to construct a prediction model for sow BFT using support vector regression (SVR). Following testing and comparison, it was shown that using CNN to extract features from images could effectively replace artificially defined features, BGR contributed to the model's accuracy improvement. The CNN-BGR-SVR model performed the best, with R2 of 0.72 and mean absolute error of 1.21 mm, and root mean square error of 1.50 mm, and mean absolute percentage error of 7.57%. The results demonstrated that the CNN-BGR-SVR model based on 2D images was capable of detecting sow BFT, establishing a new reference for non-contact sow BFT detection technology.

Can we further reduce the time pregnant sows spend in gestation stalls?

There is growing societal pressure to eliminate close confinement of farm animals. However, under current EU legislation, sows can be kept in gestation stalls for up to 28 days post-service. Pregnant sows fight to establish a dominance hierarchy at mixing. This poses welfare and productivity concerns particularly if sows are mixed in early pregnancy when the pregnancy is less well established and they are still recovering from the demands of lactation. The aim of this study was to compare the effects of day of mixing (PEN4D:4 days or PEN28D:28 days post-insemination) on measures of animal welfare (skin lesion and cortisol concentrations) collected at mixing, 3 and 7 days after and on body condition (back fat thickness), reproductive performance (pregnancy and farrowing rate) and litter size. Sows included in the study (n=144) were of mixed parity (parities 2-7) and they were all weaned 4 weeks after farrowing and moved from farrowing to the breeding area where they were placed into individual stalls. Once inseminated, sows were assigned according to parity order and genetics to one of the two experimental treatments (PEN4D and PEN28D) and they were maintained as a static group until 1 week before farrowing. The group size was 21, and sows were housed on solid concrete floor, with a slope to convey manure in a drain, and with a floor space allowance of 2.25 m2/head. One block of wood on chain and one chain were provided as enrichments. Feed was distributed manually, spreading it in a wide clean area of the pen floor and in the troughs in the individual stall.There were no treatment effects on salivary cortisol concentrations or on the number of fresh skin injuries. For the old scratches score, a significant effect of treatment was observed only at three days after mixing, where PEN28D sows had a higher anterior lesion score than PEN4D sows (P=0.005). Furthermore, there were no treatment effects on backfat thickness, reproductive performance or litter size. Results of this experiment indicate that mixing sows into groups early after insemination (within 4 days post AI) rather than 28 d after has no effect on reproductive and welfare indicators measured in the short term after mixing.

Pathogenicity of a novel classical swine fever LOM vaccine-derived virus isolated on Jeju Island, South Korea.

Reemergent local outbreaks of classical swine fever (CSF) occurred simultaneously in multiple pig farms on CSF-free Jeju Island, South Korea, in 2014 because of inadvertent injection of a commercial CSF (LOM) vaccine into pregnant sows. The LOM virus has since spread across the island and has become endemic in Jeju herds, raising concern about possible reversion to the virulence of the LOM vaccine. We previously isolated LOM-derived field CSF virus (CSFV) strains with unique insertion-deletion (INDEL) mutations in the 3'-untranslated region (UTR), designated LOM-derived Jeju 3'-UTR INDEL variants, from CSF-recurrent swine farms on Jeju Island in 2019. The present study conducted animal experiments to investigate whether a 2019 emergent LOM 3'-UTR INDEL variant, KNU-1905, has reverted to a pathogenic form in conventional pigs (n = 10). Experimental animal infection showed that pigs inoculated with the commercial LOM vaccine strain developed no adverse effects compared to the sham-infected pigs. However, KNU-1905 displayed pathogenic characteristics in pigs, including clinical symptoms (e.g., lethargy, conjunctivitis, nasal discharge, and diarrhoea), weight loss, and gross lesions. Moreover, viremia, virus shedding in faeces and nasal fluids, and viral loads in various tissues of all the KNU-1905-infected pigs were highly significant, in contrast to those of the LOM-infected group in which CSFV RNA was detected only in the serum, nasal, and tonsil samples of one identical pig. Overall, the LOM-derived field isolate with molecular variations induced clinical adverse events in pigs, which commonly shed considerable amounts of CSFV. This study provides evidence that the genetic evolution of the LOM-derived CSFV circulating on Jeju Island might have allowed the LOM vaccine to recover its primary prototype and that these variants might have induced chronic or persistent infection in pigs that can shed CSFV in field farms leading to a risk of transmission among pigs or farms in this former CSF-free region.