Pregnant Sows Research Articles

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 post-weaning 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 h 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.

Maternal Supplementation Spermidine During Gestation Improves Placental Angiogenesis and Reproductive Performance of High Prolific Sows.

Spermidine (SPD) is a widely recognized polyamine compound found in mammalian cells and plays a key role in various cellular processes. We propose that SPD may enhance placental vascular development in pregnant sows, leading to increased birth weight of piglets. Six hundred and nine sows at 60 days of gestation were randomly assigned into a basal diet (CON group), basal diet supplemented 10 mg/kg of SPD (SPD1 group), and basal diet supplemented 20 mg/kg of SPD (SPD2 group), respectively. Compared with the CON, SPD1 significantly increased the average number of healthy piglets per litter and the placental efficiency (P < 0.05), while the average number of mummified fetus per litter and the percentage of weak piglets significantly decreased (P < 0.05). In the plasma metabolomics, SPD content in plasma of sows (P = 0.075) and umbilical cord plasma of piglets (P = 0.078) had an increasing trend in response to SPD1. Furthermore, SPD1 increased the expression of the vascular endothelial cell marker protein, platelet endothelial cell adhesionmolecule-1 (PECAM-1/CD31) and the density of placental stromal vessels (P < 0.05). Moreover, as compared to CON, SPD2 significantly decreased the average number of mummified fetus per litter (P < 0.05), while the placental efficiency and the expression of amino acid transporter solute carrier (SLC) family 7, member7 (SLC7A7) and glucose transporters SLC2A2) and SLC5A4 in placental tissue significantly increased (P < 0.05). These results suggest that maternal supplementation of SPD during pregnancy increased healthy litter number, and promoted placental tissue development. Our findings provide evidence that maternal SPD has the potential to improve the production performance of sows.

Genetic characteristics and pathogenicity of variant porcine parvovirus 1 in northern China

Porcine parvovirus type 1 (PPV1) can lead to reproductive disorders in pregnant sows, including stillbirth, mummification, embryonic death, and infertility (SMEDI syndrome). In this study, we isolated and identified 10 PPV1 strains in northern China, with genomes around 5 kb long and minor deletions in the 127-nt repeat region. The sequence analysis results showed that compared with strain NADL-2 (Reference strain), eight amino acid substitutions on the NS1 protein and fourteen amino acid substitutions on the VP2 protein were found in the ten isolates. Because the JX strain exhibited reduced neutralizing activity induced by commercially available vaccines in vitro, it was selected for challenge experiments in sows at 35 days of gestation. Mutant strain JX not only caused viremia, but also mild edema and mild inflammation in the trachea, lungs, lymph nodes, reproductive organs, and some intestines of the pregnant sows. Strain JX also caused fetal congestion and organ infection after penetrating the placental barrier. In conclusion, this study focused on the variation and evolution of PPV1 in northern China, screened a strain with reduced neutralizing activity, and determined that it has a certain degree of pathogenicity.

Evaluating the Net Energy Requirements for Maintenance Based on Indirect Calorimetry and Heart Rate Monitoring in Gestating Sows

The objectives of this study were (1) to determine the net energy requirements for the maintenance of gestating sows based on indirect calorimetry, and (2) to explore the feasibility of predicting the net energy requirements for the maintenance of gestating sows based on daily heart rate monitoring. In Exp. 1, six Landrace × Yorkshire crossbred reproductive sows with an initial body weight of 229.5 ± 14.9 kg at d 56 of gestation were randomly assigned to six diverse energy feeding levels using a 6 × 6 Latin square design. The experimental diet was formulated using corn, soybean meal, and wheat bran as major ingredients, and the six feeding levels were set as 1.2, 1.4, 1.6, 1.8, 2.0, and 2.2 times metabolizable energy for maintenance (100 kcal ME/kg BW0.75·d−1), respectively. The animal trial lasted for six periods with 9 days per period, encompassing 5 days of adaptation, 3 days of calorimetry in fed state, and 1 day of calorimetry in fasting state. In Exp. 2, six Landrace × Yorkshire crossbred pregnant sows with an initial body weight of 232.5 ± 12.5 kg at d 64 were fed a corn–soybean meal diet. All sows were tested in a respiratory calorimetry chamber for a 4 day calorimetry test. The heat production of the gestation sows was measured every 5 min using indirect calorimetry, and the heart rate of the gestating sows was recorded every minute using a belt-shape monitor. The results showed that the net energy requirements for the maintenance of gestating sows significant increased as the gestational stage progressed (p &lt; 0.05), and a linear regression model revealed the average net energy requirement for the maintenance of gestating sows was 410 kJ/BW0.75 d−1 during late gestation (days 70–110). Moreover, the average heart rate of the gestating sows was 84 bpm, and the mathematical model developed to predict the net energy requirements for the maintenance of gestating sows was NEm(kcal/h)=19901+exp⁡[136−HR(bpm)43]. In conclusion, the average net energy requirement for the maintenance of sows during late gestation was 410 kJ/BW0.75 d−1, and the utilization of the heart rate monitoring method was found to provide a relevant, accurate prediction for the net energy requirements of sows.

Effects of organic and inorganic selenium mixes in pregnant sows on piglet growth, selenium levels in serum and milk, and selenium deposition in newborn piglet tissues.

This study was conducted to evaluate the effects of organic and inorganic selenium mixes in pregnant sows on piglet growth, selenium levels in serum and milk, and selenium deposition in newborn piglet tissues. A total of 44 multiparous sows (Yorkshire×Landrace) with average body weight (BW), backfat thickness, and parity were assigned to one of the three treatments with 14 or 15 sows per treatment in a completely randomized design. The treatments were as follows: i) Control, corn-soybean meal-based diet with no addition of selenium premix; ii) ISOS(mixed inorganic selenium and organic selenium) 30, a basal diet supplemented with 0.15 ppm of inorganic Se and 0.15 ppm of organic Se; iii) ISOS50, a basal diet supplemented with 0.25 ppm of inorganic Se and 0.25 ppm of organic Se. At day 21 of lactation, supplementing a high level of mixed Se at 0.50 ppm resulted in higher piglet BW and weight gain than adding a low level of mixed Se at 0.30 ppm (p<0.05). Selenium concentration of colostrum in sows fed ISOS50 diet was significantly higher than those in sows fed ISOS30 diet (p<0.05). Selenium concentrations in the serum at days 90 and 110 of gestation and 24 hours postpartum were highest when sows were fed ISOS50 diet (p<0.05). Additionally, increasing levels of mixed Se led to an increase in piglet serum Se concentration at 24 hours postpartum (p<0.05). Before ingesting colostrum, piglets from sows fed a mixed selenium (Se) diet had significantly higher kidney Se concentrations compared to those from the control group, with the ISOS50 treatment showing the most significant difference (p<0.05). Supplementation of the gestation diet with 0.5 ppm of mixed Se may improve piglet growth performance, increase Se concentrations in milk, and enhance Se status in the serum of sows, as well as in the serum and tissues of their offspring.

Monoclonal Antibody against Porcine LAG3 Inhibits Porcine Reproductive and Respiratory Syndrome Virus Infection

Lymphocyte activation gene 3 (LAG3) is an inhibitory receptor and the interaction between fibrinogen-like protein 1 and LAG3 can inhibit the anti-tumor effect of T cells both in vivo and in vitro, which was regarded as a new immune evasion mechanism. Porcine reproductive and respiratory syndrome (PRRS), caused by PRRSV, is an infectious disease characterized by reproductive disorders in pregnant sows and gilts and respiratory problems in pigs of all ages, seriously impacting the pig industry worldwide. In this study, monoclonal antibodies (mAbs) against porcine LAG3 (pLAG3) were developed, and one mAb (1C2) showed good reactivity with pLAG3 on PHA-activated porcine peripheral blood lymphocytes. Epitope mapping showed the epitope recognized by mAb 1C2 was located at amino acid residues 214–435 of pLAG3. LAG3 expression in the tissues of PRRSV-infected pigs was detected, using mAb 1C2 as the primary antibody, and the results revealed that PRRSV infection caused a marked increase in LAG3 expression compared to the control group. Interference of LAG3 expression on PHA-activated lymphocytes promoted PRRSV replication in the co-culture system of monocyte-derived dendritic cells and lymphocytes, whereas overexpression of LAG3 or blocking of the LAG3 signal with mAb 1C2 inhibited PRRSV replication, indicating that PRRSV infection activates the LAG3-signaling pathway, suggesting that this pathway plays an important role in PRRSV pathogenesis. The results obtained lay the foundation for subsequent research on the role of LAG3 in PRRS and other diseases with persistent infection characteristics.

Effects of supplementing cultured Cordyceps militaris mushroom mycelia in the pregnant sow s diet on the health and performance of the mothers and their suckling piglets

Present study aimed to evaluate the effects of supplementing cultured Cordyceps mushroom mycelia (CMM) in the diets of pregnant sows on the productivity of the mothers and their suckling piglets during their first week of age. A total of 30 pregnant F1 (Landrace x Yorkshire) sows were randomly allocated to 5 dietary treatments with 6 replicates each: Control (sows fed the basal diet), and T30, T50, T100, and T200, where sows were fed the basal diet supplemented with 30, 50, 100, and 200 g of dried CMM, respectively. The animals were individually housed and fed twice daily. The performance and health status of the sows and their piglets were recorded accordingly. The results showed that the inclusion of CMM in the diets of pregnant and lactating sows affected the performance and health status of both the mothers and their piglets. For the piglets, the total number of piglets born and alive was higher in the T50, T100, and T200 groups compared to the control and T30 groups, but there was no effect on the survival rate at 7 days old. Daily gains per piglet were higher in the T30, T50, and T100 groups compared to T200 (P&lt;0.05). For the sows, daily feed intake was lower in the T30 group compared to the other treatments (P&lt;0.05). The values of gross energy in the milk produced by the sows were higher in the control, T30, T50, and T100 groups compared to T200 (P&lt;0.05). Both the piglets and the sows on diets supplemented with CMM experienced fewer health problems than those on the Control diet (P&lt;0.05). In conclusion, the supplementation of 50 and 100 g of CMM per day in the diets of pregnant and lactating sows improved litter size and health status but did not affect the performance of either the mothers or their piglets.

The ileal, total tract and postileal digestibility of compound feeds either rich in wheat or rye in an ileo-caecal fistulated minipig model

ABSTRACT Environmental issues and concerns about animal welfare display current challenges in animal husbandry and feeding. Rye, a cereal that has scarcely been used in animal feed in recent decades, could help address some of the challenges in pig feeding as a climate friendly and health promoting feed ingredient. Distinct constituents of rye – especially its non-starch-polysaccharides (NSP) – are fermented in the large intestine while short chain fatty acids (SCFA) are produced in that process. This can promote gut health and the feeling of satiety in pigs. To examine the site of the digestion of rye within the digestive tract in comparison to wheat as a widely used ingredient in pig diets, two diets with high shares of either wheat or rye (each 69.0%) were fed to ileo-caecally fistulated, adult minipigs. Ileal digesta and faeces were collected and ileal, total tract and postileal digestibility rates were calculated. In the apparent ileal digestibility (AID), significant differences were only found for organic matter (OM) and Nitrogen-free extract (NfE) with lower values for the rye-rich diets (77.2 ± 2.00 vs. 73.8 ± 2.01% and 79.8 ± 2.56 vs. 75.3 ± 2.61%, respectively). These differences could not be recovered for the total tract digestibility (ATTD − 90.2 ± 2.16 vs. 89.8 ± 1.94% and 93.0 ± 1.69 vs. 92.8 ± 1.37%, respectively), resulting in an elevated postileal digestibility which was significant for NfE (13.2 ± 2.42 vs. 17.5 ± 2.77%). Therefore, rye can be used to promote hindgut fill and fermentation in pig feeding, especially in restrictively fed animals such as pregnant sows.

Productive and metabolomic consequences of arginine supplementation in sows during different gestation periods in two different seasons

BackgroundThe prolificacy of sows (litter size at birth) has markedly increased, leading to higher post-natal mortality. Heat stress can exacerbate this issue. Arginine plays an important role in several physiological pathways; its effect on gestating sows can depend on the period of supplementation. This study evaluated the effects of arginine supplementation on the productive performance and physiological status of sows during different gestation periods and seasons, using a multi-omics approach.MethodsA total of 320 sows were divided into 4 groups over 2 seasons (warm/cold); a control group (CO) received a standard diet (including 16.5 g/d of arginine) and 3 other groups received the standard diet supplemented with 21.8 g/d of arginine (38.3 g/d of arginine) either during the first 35 d (Early35), the last 45 d (Late45) or throughout the entire gestation period (COM). The colostrum was analyzed for nutritional composition, immunoglobulins and metabolomic profile. Urine and feces were analyzed on d 35 and 106 for the metabolomic and microbial profiles. Piglet body weight and mortality were recorded at birth, d 6, d 26, and on d 14 post-weaning.ResultsInteractions between arginine and season were never significant. The Early35 group had a lower percentage of stillborn (P < 0.001), mummified (P = 0.002) and low birthweight (LBW) piglets (P = 0.02) than the CO group. The Late45 group had a lower percentage of stillborn piglets (P = 0.029) and a higher percentage of high birthweight piglets (HBW; P < 0.001) than the CO group. The COM group had a higher percentage of LBW (P = 0.004) and crushed piglets (P < 0.001) than the CO group. Arginine supplementation modifies the metabolome characterization of colostrum, urine, and feces. Creatine and nitric oxide pathways, as well as metabolites related to microbial activity, were influenced in all matrices. A slight trend in the beta diversity index was observed in the microbiome profile on d 35 (P = 0.064).ConclusionsArginine supplementation during early gestation reduced the percentage of stillborn and LBW piglets, while in the last third of pregnancy, it favored the percentage of HBW pigs and reduced the percentage of stillbirths, showing that arginine plays a significant role in the physiology of pregnant sows.

Effect of Dietary Sugarcane Bagasse on Reproductive Performance, Constipation, and Gut Microbiota of Gestational Sows.

This experiment aimed to evaluate the effects of using sugarcane bagasse (SB) as a substitute for soybean hulls and wheat bran in the diet of pregnant sows on their reproductive performance and gut microbiota. A total of seventy-two primiparous sows were randomly divided into four treatment groups, with eighteen replicates of one sow each. The sows were fed a basal diet supplemented with 0% (CON), 5%, 10%, and 15% SB to replace soybean hulls from day 57 of gestation until the day of the end of the gestation period. The results showed that SB contains higher levels of crude fiber (42.1%) and neutral detergent fiber (81.3%) than soybean hulls, and it also exhibited the highest volumetric expansion when soaked in water (50 g expanding to 389.8 mL) compared to the other six materials we tested (vegetable scraps, soybean hulls, wheat bran, rice bran meal, rice bran, and corn DDGS). Compared with the CON, 5% SB significantly increased the litter birth weight of piglets. Meanwhile, 10% and 15% SB significantly increased the rates of constipation and reduced the contents of isobutyric acid and isovaleric acid in feces. Furthermore, 10% and 15% SB significantly disturbed gut microbial diversity with increasing Streptococcus and decreasing Prevotellaceae_NK3B31-group and Christensenellaceae_R-7-group genera in feces. Interestingly, Streptococcus had a significant negative correlation with isobutyric acid, isovaleric acid, and fecal score, while Prevotellaceae_NK3B31-group and Christensenellaceae_R-7-group had a positive correlation with them. In conclusion, our study indicates that 5% SB can be used as an equivalent substitute for soybean hulls to improve the reproductive performance of sows without affecting their gut microbiota.

Genomic and pathogenicity analysis of two novel highly pathogenic recombinant NADC30-like PRRSV strains in China, in 2023.

Porcine reproductive and respiratory syndrome viruses (PRRSVs) exhibit high mutability and recombination, posing challenges to their immunization and control. This study isolated two new PRRSV strains, GD-7 and GX-3, from samples collected in Guangdong and Guangxi in 2023. Whole-genome sequencing, along with phylogenetic and recombination analyses, confirmed that GD-7 and GX-3 are natural novel recombinant strains of NADC30 PRRSV. Moreover, we established a pathogenicity model for piglets and sows based on the two isolates. The results of piglet pathogenicity revealed that both GD-7 and GX-3 caused clinical symptoms such as fever, loss of appetite, depression, and slow weight gain. Moreover, we observed that the mortality rate of GD-7-inoculated group piglets was 33.3%, which was similar to that of piglets infected with other highly pathogenic PRRSV strains and exceeded the mortality rate of most NADC30-like PRRSV. In pregnant sow models, the survival rate of sows in the GD-7 group was 75%, in contrast to the GX-3 group, where no sow mortality was observed, and both strains resulted in abortion, mummified fetuses, and stillbirths. These results highlight the elevated pathogenicity of these recombinant strains in sows, with GD-7 mainly causing sows to abort, and GX-3 mainly causing sows to give birth to mummified fetuses. This study introduces two distinct clinical recombinant PRRSV strains that differ from the prevalent strains in China. This research furthers our understanding of the epidemiology of PRRSV and underscores the significance of ongoing monitoring and research in the face of evolving virus strains. Moreover, these discoveries act as early warnings, underscoring the necessity for active control and immunization against PRRSV.IMPORTANCESince the discovery of NADC30-like PRRSV in China in 2013, it has gradually become the dominant strain of PRRSV in China. NADC30-like PRRSV exhibits high recombination characteristics, constantly recombining with different strains, leading to the emergence of numerous novel strains. Of particular importance is the observation that NADC30-like PRRSV with different recombination patterns exhibits varying pathogenicity, which has a significant impact on the pig farming industry. This emphasizes the necessity of monitoring and responding to evolving PRRSV strains to develop effective immunization and control strategies. In this paper, we conducted pathogenicity studies on the isolated NADC30-like PRRSV and analyzed the differences in the genomes and pathogenicity of the different strains by recording clinical symptoms, temperature changes, detoxification tests, and changes in viremia and histopathology in infected pigs. This was done to provide a theoretical basis for the epidemiological situation and epidemic prevention and control of PRRSV.

Detection of sow pregnancy in day-20 urine samples using monoclonal antibody against synthesized porcine early pregnancy factor: Preliminary results

Early diagnosis of pregnancy is directly related to cost-effective livestock production. We produced a rat monoclonal antibody (mAb) against synthesized porcine early pregnancy factor (pEPF) using conventional hybridoma technology and used it as a tool for the detection of early pregnancy in Duroc sows. The rat pEPF-mAb showed reactivity to uterine tissues of pregnant sows 20 or 30 days post-mating (day 0 defined as the day of mating) and non-pregnant sows (confirmed signs of estrus) in western blotting. Immunohistochemical analysis confirmed that pEPF was located in the stromal and grand epithelial tissues of pregnant sows 20 or 30 days post-mating. In the enzyme-linked immunosorbent assay, pEPF expression in urine and blood showed similar results, with the highest expression observed in pregnant sows 20 days post-mating, whereas there was no significant difference in expression levels between non-pregnant sows and pregnant sows 30 days post-mating. The pEPF-mAb-based pregnancy diagnostic kit can be applied to pig urine samples non-invasively collected at 20 days post-mating with 70 % accuracy. Further improvements to the kit's diagnostic performance may lead to substantial benefits for the swine industry, facilitating more efficient and accurate reproductive management.

Влияние теплового стресса на оплодотворяемость и многоплодие свиноматок

Abstract. The study of the effect of heat stress on the reproductive parameters of pigs is an urgent problem all over the world. Knowing the degree of influence of heat stress on pigs of different breeds will allow you to choose economically sound solutions to this problem in specific conditions. The propose is to study the effect of heat stress on some indicators of reproduction of sows of different breeds (large white, landrace, duroc, MAXGRO). Methods. The study was conducted on a large pig breeding complex. The material for the analysis was data on changes in air temperature in the breeding farm in the period from June to August (13 weeks) and data on the fertilization and duration of pregnancy of sows fertilized during this period and the size of the offspring obtained from them. Scientific novelty. For the first time, a comparative analysis of the effect of heat stress on fertilization, duration of pregnancy and the size of the offspring of sows of four breeds – large white, landrace, duroc, MAXGRO – was carried out on a wide population of pigs. Different sensitivity of sows to heat stress was revealed. Results. From the 4th to the 6th week of the experiment, the sows were in a state of increasing heat stress – the average daily temperature during this period increased to 27.68 ± 1.36 °C. The negative effect of hyperthermia on fertilization was recorded with a delay of 1–3 weeks, depending on the breed. The most sensitive to heat stress were sows of the duroc breed – fertilization decreased by 25.00 % compared to the pre-stress period, the least – sows of the large white breed – fertilization decreased by 9.82 %. The duration of pregnancy was not affected by heat stress. As well as fertilization, heat stress had a negative effect on the size of the litter. The most sensitive were sows of duroc and MAXGRO breeds – the litter size decreased by 3.77 and 3.61 heads compared to the pre-stress period, the least – sows of the large white breed, the size of the litter decreased by 0.38 heads. duroc sows are the most sensitive to heat stress, then, according to sensitivity reduction, MAXGRO, landrace and large white.

Determination and prediction of the net energy content of wheat bran for pregnant sow

ABSTRACT Two experiments were conducted to determine net energy (NE) values of wheat bran ingredients and develop a prediction equation for NE of wheat bran. In each experiment, 12 multiparous pregnant sows were allocated to two 3 × 6 Youden squares with three consecutive periods and six diets in each square. The study consisted of six diets, including a corn-soybean meal basal diet and five diets formulated with 29.2% wheat bran. Each period lasted for 10 d, with 5 d allocated for adaptation and followed by 5 d for heat production measurement. Sows were provided feed at 604 kJ/kg BW0.75·d−1. On day 10, sows underwent fasting to measure fasting heat production. Results indicated that the inclusion of wheat bran in the diets significantly reduced digestibility of energy and nutrients in (p < 0.05). The average net energy (NE) content of wheat bran was determined to be 8.8 MJ/kg DM. A regress equation NE = 7.968 + 0.28 × CP + 0.607 × EE − 0.782 × ash − 0.05 × hemicellulose (R2 = 0.98, p < 0.01) was found to accurately predit the NE value when feeding pregnant sows with wheat bran-based diets. In conclusion, the net energy content of wheat bran fed to pregnant sows ranged from 7.24 to 10.67 MJ/kg DM and can be effectively estimated using proximate analysis methods.

106. Effects of using a sound signal as a call to feeding on the behaviour and welfare of pregnant sows

106. Effects of using a sound signal as a call to feeding on the behaviour and welfare of pregnant sows

105. Comparison of methods for estimating the activity level of pregnant sows from video recordings

105. Comparison of methods for estimating the activity level of pregnant sows from video recordings

FlagT4G Vaccine Prevents Transplacental Transmission of Highly Virulent Classical Swine Fever Virus after Single Vaccination in Pregnant Sows.

The transplacental transmission of CSFV and the resulting persistent congenital infection in newborn piglets have been abundantly discussed in pregnant sows suffering from virus infection. Importantly, the availability of safe commercial vaccines with proven efficacy to prevent the generation of congenital and postnatal persistent infections in pregnant sows are critical tools for controlling the disease in CSF endemic areas. Here, we demonstrate the high efficacy of a single dose of the recombinant FlagT4G vaccine to provide solid protection in pregnant sows against transplacental transmission of a highly virulent CSFV. Pregnant sows vaccinated with FlagT4G at 44 days of gestation elicited a strong CSFV-specific antibody response, with neutralizing antibody levels above those required for protection against CSFV. Importantly, after the challenge with a highly virulent CSFV, all foetuses from FlagT4G-vaccinated sows lacked CSF macroscopic lesions and showed a complete absence of the challenge virus in their internal organs at day 79 of gestation. Therefore, pregnant sows safely vaccinated with FlagT4G without affecting reproductive efficacy are efficaciously protected, along with their foetuses, against the infection and disease caused by a CSFV virulent field strain.

Use of feed additive Actigen in the production of compound feed for pregnant sows

The introduction of various innovative technologies in diff erent branches of animal husbandry involves the use of various non-traditional feed additives in animal diets, which contribute not only to the disclosure of genetic potential, but also to the removal of heavy metals from the body of animals, bees and poultry. The purpose of the research was to use the Actigen feed additive in the production of compound feed for pregnant sows. Scientifi c and economic experiment in improving the production technology of compound feed for pregnant sows was carried outunder the conditions of a compound feed plant at Agrofi rm Ariant LLC. The object of the study was compound feed, as well as pregnant sows. For the research, 2 groups of pregnant sows (control and experimental) were formed per 10 heads in each according to the principle of pairs-analogues. The sows of control group compound feed without the Actigen feed additive was given, and the sows of experimental group it was with Actigen additive. The Actigen feed additive was used at a dose of 0.5 kg per 1 ton of compound feed. The results of the experiment showed that the experimental group produced by 9 live piglets more than the control group, and the average weight of one piglet in the experimental group was0.15 kg more than in the control group. There were 4 stillborn piglets in the control group, which was 1 head or 33.3 % more than in the experimental group. The average live weight of one piglet at weaning in the experimental group was 6.00 kg, which was 0.80 kg more than in the control group. The weight of the litter at weaning in the control group was 54.08 kg, and in the experimental groupit was 69.60 kg, which was 15.52 kg more than in the control group. Thus, the Actigen feed additive at the dose of 0.5 kg per 1 ton of compound feed had a positive infl uence on the reproductive traits of sows.

A recombinant Getah Virus expressing a GFP gene for rapid neutralization testing and antiviral drug screening assay

Getah virus (GETV) is a re-emerging mosquito-borne RNA virus that induces fever, hind limb edema, swollen submandibular lymph nodes, and urticaria in horses. In pigs, the virus often results in stillbirths among pregnant sows, and neurological symptoms leading to death in piglets. Currently, there are no specific treatments or drugs available for GETV infection. The use of reporter viruses to monitor viral replication and spread in real-time within infected cells and animals provides a powerful tool for targeting antiviral drugs throughout the viral life cycle. Their fluorescence-tracked characteristics greatly facilitate virus neutralization tests (VNTs). In this study, we engineered two recombinant viruses by inserting different reporter protein genes at the 3′ end of the structural protein gene, an unreported location that can accommodate exogenous genes. The rGEEiLOV and rGEEGFP viruses demonstrated genetic stability for at least five passages and replicated at a rate similar to that of the parental virus in BHK-21 cells. The rGEEGFP virus facilitated viral neutralization testing. Additionally, we used the reporter virus rGEEGFP to confirm ivermectin, a broad-spectrum antiparasitic agent, as a potential inhibitor of GETV in vitro. Ivermectin appears to inhibit the early replication stages of the virus and can block cell-to-cell viral transmission. In conclusion, rGEEGFP holds significant potential for antiviral screening to identify specific inhibitors against GETV and for use in viral neutralization tests.

Effects of Dietary Lonicera flos and Sucutellaria baicalensis Mixed Extracts Supplementation on Reproductive Performance, Umbilical Cord Blood Parameters, Colostrum Ingredients and Immunoglobulin Contents of Late-Pregnant Sows.

The present study aimed to determine the effects of dietary Lonicera flos and Sucutellaria baicalensis mixed extract (LSE) supplementation during the late-pregnancy period on the reproductive performance, umbilical cord blood hematological parameters, umbilical cord serum biochemical parameters, immune indices, hormone levels, colostrum ingredients, and immunoglobulin contents of sows. A total of 40 hybrid pregnant sows were randomly assigned to the control group (CON; sows fed a basal diet) and LSE group (LSE; sows fed a basal diet supplemented with 500 g/t PE). The results indicated that dietary LSE supplementation significantly increased (p < 0.05) the number of alive and healthy piglets and the litter weight at birth, and significantly increased (p < 0.05) the platelet counts in umbilical cord blood. Dietary LSE supplementation significantly increased (p < 0.05) the levels of prolactin (PRL) and growth hormone (GH), and the content of interleukin 2 (IL-2) in umbilical cord serum. Moreover, immunoglobulin A (IgA) and immunoglobulin M (IgM) in the colostrum were increased with PE supplementation (p < 0.05). In conclusion, dietary LSE supplementation in late-pregnancy sows could improve reproductive performance and colostrum quality, and could also regulate the levels of reproductive hormone in umbilical cord serum.