The acquisition of passive immunity in the new-born piglet

Maternal resveratrol improves the intestinal health and weight gain of suckling piglets during high summer temperatures: The involvement of exosome-derived microRNAs and immunoglobin in colostrum

Previous studies have shown that maternal resveratrol improved growth performance and altered the microbial composition of suckling piglets under hot summer conditions. However, it remains unclear how maternal resveratrol improves growth performance of suckling piglets during high summer temperatures. A total of 20 sows (Landrace × Large White; three parity) were randomly assigned to 2 groups (with or without 300 mg/kg resveratrol) from d 75 of gestation to d 21 of lactation during high ambient temperatures (from 27 to 30 °C). The results showed that maternal resveratrol supplementation increased total daily weight gain of piglets under hot summer conditions, which is consistent with previous studies. Furthermore, we found that maternal resveratrol improved the intestinal morphology and intestinal epithelial proliferation in suckling piglets. Dietary resveratrol supplementation affected the characteristics of exosome-derived microRNAs (miRNAs) in sow colostrum, as well as the genes targeted by differentially produced miRNAs. MiRNAs are concentrated in the tight junction pathway. As a result, the expression of intestinal tight junction proteins was increased in suckling piglets (P < 0.05). Notably, maternal resveratrol increased the intestinal secretory immunoglobulin A (sIgA) levels of suckling piglets via colostrum immunoglobin (P < 0.05), which could increase the abundance of beneficial microbiota to further increase the concentration of short chain fatty acids (SCFA) in suckling piglets' intestine (P < 0.05). Finally, our correlation analysis further demonstrated the positive associations between significantly differential intestinal microbiota, intestinal sIgA production and SCFA concentrations, as well as the positive relation between total daily weight gain and intestinal health of suckling piglets. Taken together, our findings suggested that maternal resveratrol could promote intestinal health to improve piglet growth during high summer temperatures, which might be associated with the immunoglobin and exosome-derived miRNAs in sows' colostrum.

Developing Next-Generation Live Attenuated Vaccines for Porcine Epidemic Diarrhea Using Reverse Genetic Techniques

Porcine epidemic diarrhea virus (PEDV) is the etiology of porcine epidemic diarrhea (PED), a highly contagious digestive disease in pigs and especially in neonatal piglets, in which a mortality rate of up to 100% will be induced. Immunizing pregnant sows remains the most promising and effective strategy for protecting their neonatal offspring from PEDV. Although half a century has passed since its first report in Europe and several prophylactic vaccines (inactivated or live attenuated) have been developed, PED still poses a significant economic concern to the swine industry worldwide. Hence, there is an urgent need for novel vaccines in clinical practice, especially live attenuated vaccines (LAVs) that can induce a strong protective lactogenic immune response in pregnant sows. Reverse genetic techniques provide a robust tool for virological research from the function of viral proteins to the generation of rationally designed vaccines. In this review, after systematically summarizing the research progress on virulence-related viral proteins, we reviewed reverse genetics techniques for PEDV and their application in the development of PED LAVs. Then, we probed into the potential methods for generating safe, effective, and genetically stable PED LAV candidates, aiming to provide new ideas for the rational design of PED LAVs.

Large litters have a detrimental impact on litter performance and postpartum maternal behaviour in primiparous sows

BACKGROUND

Our previous study confirmed that large litter size adversely affects prepartum maternal hormones and behaviour, concurrently with heightened oxidative stress in primiparous sows. The purpose of this study was to examine the effect of large litter size on litter performance, postpartum maternal behaviour, salivary cortisol levels, and colostral immunoglobulin levels in sows, as well as investigate their correlations with the levels of oxidative stress parameters.

RESULTS

A total of 24 primiparous sows (Landrace[Formula: see text]Large white) and their offspring were categorised into two groups based on litter size: NORMAL (n = 8) with litter size ranging from 7 to 14 (mean 11.5[Formula: see text]2.7), and LARGE (n=16) with litter size ranging from 15 to 20 (mean 15.9[Formula: see text]1.4). All sows were housed in a group housing system during gestation and transitioned to an adaptable loose housing system (2.4[Formula: see text]2.3 m) during the farrowing and lactation periods. The nursing and carefulness behaviour of the sows was monitored over a 24-h period between 72 and 96 h after parturition. Saliva samples were collected for cortisol assay on 35, 21, and 7 days before parturition (D-35, D-21, and D-7, respectively), as well as on days 1, 7, and 28 after parturition (D1, D7, and D28, respectively). On D1, higher piglet mortality rates were observed among the LARGE group compared to the NORMAL group (p<0.01). The total and successful nursing behaviours of the sows were less frequent in the LARGE group than in the NORMAL group (p<0.05, for both), and the carefulness score of the LARGE group was also lower than that of the NORMAL group (p< 0.01). On D1, cortisol levels in LARGE sows were higher than those in NORMAL sows (p< 0.05), and for other time points (D-21, D-7, D7, and D28), cortisol levels in LARGE sows tended to be higher than those in NORMAL sows (p < 0.10, for all). Successful nursing behaviour displayed negative correlations with levels of salivary cortisol and certain oxidative stress parameters measured on D1.

CONCLUSIONS

These findings suggest that the strategy for alleviating physiological and oxidative stress during the peripartum periods could benefit potential postpartum maternal behaviour and litter performance in the sows with large litters.

The influence of parity, body condition, litter size and carbetocin administration on colostrum production and immunoglobulin levels in highly productive sows within a tropical environment

The aim of this study was to explore the factors contributing to colostrum production and the levels of colostrum immunoglobulins (IgG and IgA) in contemporary highly productive sows within a tropical climate. We focused on variables such as parity number, litter size, sow body condition score (BCS), the timing of sample collection following the commencement of farrowing and the use of carbetocin during the birthing process. A total of 100 colostrum samples were collected from a group of 50 Danish Landrace × Yorkshire crossbred sows. These samples were taken at two distinct time intervals: right after farrowing (0 h) and 6 h later. The colostrum samples were classified according to the sows' parity numbers, with 33 samples originating from primiparous sows and 67 from multiparous ones. Additionally, the number of live-born piglets were categorized into three groups: 7-13, 14-17 and ≥ 18 piglets per litter. Moreover, the samples were categorized based on the use of carbetocin during the birthing process, with 34 sows experiencing natural farrowing and 66 sows receiving carbetocin. The sow's BCS was assessed through visual evaluation and palpation. The piglet colostrum consumption and the amount of colostrum produced by the sows were determined. The concentrations of IgG and IgA were determined by using the enzyme-linked immunosorbent assay (ELISA) technique. On average, the colostrum production averaged 5.5 ± 1.7 kg, with IgG and IgA concentrations averaging 54.9 ± 24.6 mg/ml and 7.6 ± 3.5 mg/ml, respectively. Primiparous sows exhibited a significant 25.2% decrease in IgG concentration within 6 h of parturition (P < 0.05), whereas no such decline was observed in multiparous sows. Furthermore, multiparous sows displayed higher colostrum yields (6.2 ± 1.5 kg and 4.3 ± 1.5 kg, respectively, P < 0.001) and IgA concentrations compared to primiparous sows (8.3 ± 3.8 mg/ml and 6.3 ± 2.6 mg/ml, respectively, P = 0.002). Furthermore, a positive correlation was observed between IgA concentrations in colostrum and the sow's BCS at both the 0-h and 6-h post-farrowing time points (r = 0.425, P = 0.002 and r = 0.315, P = 0.031, respectively). The administration of carbetocin did not yield a significant impact on the concentrations of IgG and IgA in the sows' colostrum (P > 0.05). In conclusion, during the initial 6 h after birth, colostrum IgA levels remained stable, whereas there was a noticeable decline in IgG levels, particularly among primiparous sows. The production volume of colostrum and the concentration of IgA in sows within tropical conditions were influenced by both parity number and body condition score.

The impact of the interval between the last meal and the onset of farrowing on the duration of farrowing, stillbirth rates, and colostrum production in highly productive sows in a tropical climate

The present study investigated impact of the interval between the last meal and the onset of farrowing on the duration of farrowing, stillbirth rates, and colostrum production in highly productive sows in a tropical climate. The study involved a total of 92 Danish Landrace x Yorkshire sows (herd A) and 114 French Landrace × Yorkshire sows (herd B). In herd B, a total of 61 sows had their blood samples collected within 1 hr after the onset of farrowing to evaluate their blood glucose levels. The interval between the last meal and the onset of farrowing averaged 5.9 ± 4.5 and 5.4 ± 4.1 hr in herds A and B, respectively. Neither the duration of farrowing nor the occurrence of stillborn piglets in both herds was affected by the time gap between the last meal and the onset of farrowing. At the onset of farrowing, the average blood glucose level in sows was 77.1 ± 19.3 mg/dL, with a range of 27 to 115 mg/dL. There was a positive correlation observed between the blood glucose concentration and the colostrum yield of the sows (r=0.261, P=0.042). In conclusion, the time interval between the last meal and the onset of farrowing did not have any impact on the farrowing performance of sows. However, a higher concentration of blood glucose at the onset of farrowing was associated with an improvement in the colostrum yield of the sows.

Weaning transition, but not the administration of probiotic candidate Kazachstania slooffiae, shaped the gastrointestinal bacterial and fungal communities in nursery piglets

As in-feed antibiotics are phased out of swine production, producers are seeking alternatives to facilitate improvements in growth typically seen from this previously common feed additive. Kazachstania slooffiae is a prominent commensal fungus in the swine gut that peaks in relative abundance shortly after weaning and has beneficial interactions with other bacteriome members important for piglet health. In this study, piglets were supplemented with K. slooffiae to characterize responses in piglet health as well as fungal and bacterial components of the microbiome both spatially (along the entire gastrointestinal tract and feces) and temporally (before, during, and after weaning). Litters were assigned to one of four treatments: no K. slooffiae (CONT); one dose of K. slooffiae 7 days before weaning (day 14; PRE); one dose of K. slooffiae at weaning (day 21; POST); or one dose of K. slooffiae 7 days before weaning and one dose at weaning (PREPOST). The bacteriome and mycobiome were analyzed from fecal samples collected from all piglets at day 14, day 21, and day 49, and from organ samples along the gastrointestinal (GI) tract at day 21 and day 49. Blood samples were taken at day 14 and day 49 for cytokine analysis, and fecal samples were assayed for antimicrobial resistance. While some regional shifts were seen in response to K. slooffiae administration in the mycobiome of the GI tract, no remarkable changes in weight gain or health of the animals were observed, and changes were more likely due to sow and the environment. Ultimately, the combined microbiome changed most considerably following the transition from suckling to nursery diets. This work describes the mycobiome along the piglet GI tract through the weaning transition for the first time. Based on these findings, K. slooffiae administered at this concentration may not be an effective tool to hasten colonization of K. slooffiae in the piglet GI tract around the weaning transition nor support piglet growth, microbial gut health, or immunity. However, diet and environment greatly influence microbial community development.

Nutritional Strategies to Mitigate Post-Weaning Challenges in Pigs: A Focus on Glucans, Vitamin D, and Selenium

This review examines the challenges faced by the pig industry, with a specific focus on improving the health and growth of weaned pigs. It emphasizes the immediate necessity of investigating alternative approaches to managing pig nutrition and health due to restrictions on the use of antibiotics and the prohibition of zinc oxide in weaned pig diets. The weaning phase is identified as a critical stage in piglet development, characterized by stressors that affect their gastrointestinal health, immune responses, and overall physiology. The primary challenge during weaning arises from transitioning piglets from a digestible milk-based diet to a less digestible cereal-based feed, causing nutritional stress. This manifests as reduced feed intake, leading to gastrointestinal disturbances, intestinal inflammation, and adverse effects on intestinal structure and microbiota. To address these challenges and optimize piglet development, various nutritional strategies have been explored. Notably, glucans, particularly β-glucans from fungi, cereals, algae, and yeast, show promise in alleviating weaning-related issues. Furthermore, it is important to highlight the critical roles played by Vitamin D and selenium in piglet nutrition. These essential nutrients can be sourced naturally from enriched mushrooms that are specifically enriched with Vitamin D and selenium, providing a sustainable dietary option. In conclusion, effective nutritional strategies, including glucans, Vitamin D, selenium, and enriched mushrooms, are beneficial for addressing weaning-related challenges.

A Comparison of Haematological and Biochemical Profiles between Intrauterine Growth Restriction and Normal Piglets at 72 Hours Postpartum

Intrauterine growth restriction in piglets has been a problem in the pig industry due to genetic selection based on hyperprolificacy. This has led to an increase in the number of underweight piglets and a worsening of the survival rate. The goal of this study was to enhance the knowledge of differences between normal and IUGR piglets a few hours after birth in terms of haematological variables, biochemical parameters, and immunoglobulin levels. Two groups of 20 piglets each were assessed. The control group (N) was made up of piglets with weights greater than 1500 g, and the IUGR group consisted of piglets weighing 500-1000 g and with at least two IUGR features. Blood samples were collected 72 h after birth for analysis of the red and white blood cell parameters, reticulocyte indices, platelet indices, biochemical parameters, and immunoglobulin levels. Alterations in red blood cells and reticulocytes, a lower lymphocyte count, hyperinsulinemia, and high oxidative stress were observed in IUGR piglets (p < 0.05). In contrast, differences were not observed (p > 0.05) in the serum immunoglobulin level. It can be concluded that the haematological and biochemical differences in IUGR piglets with respect to normal-weight piglets are present at birth indicating possible alterations in immunity, metabolism, and redox status; therefore, IUGR piglets could be more vulnerable to illness and future disorders, such as metabolic syndrome.

Associations between Surface and Rectal Temperature Profiles of Low-Birth-Weight Piglets

The use of infrared cameras to record surface temperature has shown some promise in older pigs, but neonatal piglets are metabolically less mature and experience rapid temperature changes during their first 24 h. The present experiment aimed to compare rectal temperature to surface temperature at the base of the ear, measured using an infrared camera, for piglets of different birth weights. During farrowing, 48 multiparous sows were monitored, and rectal and surface temperatures were recorded for their lower-birth-weight (≤1.2 kg) piglets within 3 min of birth and at 0.25, 0.50, 0.75, 1, 1.25, 1.50, 2, 3, 4, and 24 h. Piglet birth weights were assigned to one of three categories (BWC): BWC1 (≤0.80 kg), BWC2 (0.81 to 1.10 kg), or BWC3 (1.11 to 1.20 kg). Piglet rectal temperatures at 1.25 h after birth were assigned to one of three categories: RC1 (≤32.0 °C), RC2 (32.1 to 35.0 °C), or RC3 (≥35.1 °C). Surface temperatures showed a similar recovery pattern to rectal temperatures in the first 24 h across all piglet birth weights, although large and variable differences seen in the current study militate against surface temperature being an appropriate replacement for neonatal rectal temperature for use in production.

The Effect of Maternal Probiotic or Synbiotic Supplementation on Sow and Offspring Gastrointestinal Microbiota, Health, and Performance

The increasing prevalence of antimicrobial-resistant pathogens has prompted the reduction in antibiotic and antimicrobial use in commercial pig production. This has led to increased research efforts to identify alternative dietary interventions to support the health and development of the pig. The crucial role of the GIT microbiota in animal health and performance is becoming increasingly evident. Hence, promoting an improved GIT microbiota, particularly the pioneer microbiota in the young pig, is a fundamental focus. Recent research has indicated that the sow's GIT microbiota is a significant contributor to the development of the offspring's microbiota. Thus, dietary manipulation of the sow's microbiota with probiotics or synbiotics, before farrowing and during lactation, is a compelling area of exploration. This review aims to identify the potential health benefits of maternal probiotic or synbiotic supplementation to both the sow and her offspring and to explore their possible modes of action. Finally, the results of maternal sow probiotic and synbiotic supplementation studies are collated and summarized. Maternal probiotic or synbiotic supplementation offers an effective strategy to modulate the sow's microbiota and thereby enhance the formation of a health-promoting pioneer microbiota in the offspring. In addition, this strategy can potentially reduce oxidative stress and inflammation in the sow and her offspring, enhance the immune potential of the milk, the immune system development in the offspring, and the sow's feed intake during lactation. Although many studies have used probiotics in the maternal sow diet, the most effective probiotic or probiotic blends remain unclear. To this extent, further direct comparative investigations using different probiotics are warranted to advance the current understanding in this area. Moreover, the number of investigations supplementing synbiotics in the maternal sow diet is limited and is an area where further exploration is warranted.

Enhancement of protective vaccine-induced antibody titer to swine diseases and growth performance by Amino-Zn, yucca extract, and β-mannanase feed additive in wean-finishing pigs

The primary purpose of this research is to determine the effect of Amino-Zn (AZn), Yucca schidigera extract (YE), and β-mannanase enzyme supplementation on growth performance, nutrient digestibility, fecal gas emission, and immune response in pigs. A total of 180 crossbred pigs (6.57 ± 1 kg) were randomly assigned to one of three dietary treatments: CON-corn soybean meal (basal diet); TRT1-CON +1,000 ppm AZn + 0.07% yucca extract (YE) + 0.05% β-mannanase; and TRT2-CON +2,000 ppm AZn + 0.07% YE+ 0.05% β-mannanase for 22 weeks. Each treatment had 12 replicates with 5 pigs per pen. Pigs fed a diet supplemented with AZn, YE, and β-mannanase linearly increased (p < 0.05) BW and average daily gain at weeks 6, 12, 17, and 18. In contrast, the gain-to-feed ratio showed a linear increase (p < 0.05) from weeks 6 to 17 and the overall trial period. Moreover, the inclusion of experimental diets linearly decreased (p > 0.05) noxious gas emissions such as ammonia, hydrogen sulfide, acetic acid, carbon dioxide, and methyl mercaptans. The dietary inclusion of AZn, YE, and β-mannanase significantly increased the serological immune responses to Mycoplasma hyopneumoniae (MH) and foot-and-mouth disease virus (FMDV-O type) at the end of week 6 and porcine circovirus-2 (PCV-2) at week 19. Based on this result, we infer that the combination of AZn, YE, and β-mannanase supplement would serve as a novel in-feed additive to enhance growth performance and act as a boosting agent and immune stimulatory to increase the efficacy of swine vaccinations.

Porcine epidemic diarrhea virus: an update overview of virus epidemiology, vaccines, and control strategies in South Korea

Porcine epidemic diarrhea virus (PEDV) has posed significant financial threats to the domestic pig industry over the last three decades in South Korea. PEDV infection will mostly result in endemic persistence in the affected farrow-to-finish (FTF) herds, leading to endemic porcine epidemic diarrhea (PED) followed by year-round recurrent outbreaks. This review aims to encourage collaboration among swine producers, veterinarians, and researchers to offer answers that strengthen our understanding of PEDV in efforts to prevent and control endemic PED and to prepare for the next epidemics or pandemics. We found that collaboratively implementing a PED risk assessment and customized four-pillar-based control measures is vital to interrupt the chain of endemic PED in affected herds: the former can identify on-farm risk factors while the latter aims to compensate for or improve weaknesses via herd immunity stabilization and virus elimination. Under endemic PED, long-term virus survival in slurry and asymptomatically infected gilts ("Trojan Pigs") that can transmit the virus to farrowing houses are key challenges for PEDV eradication in FTF farms and highlight the necessity for active monitoring and surveillance of the virus in herds and their environments. This paper underlines the current knowledge of molecular epidemiology and commercially available vaccines, as well as the risk assessment and customized strategies to control PEDV. The intervention measures for stabilizing herd immunity and eliminating virus circulation may be the cornerstone of establishing regional or national PED eradication programs.

Offspring of hyper prolific sows: Immunity, birthweight, and heterogeneous litters

In Europe, in the last 3 decades, there has been a constant increase in litter size due to the use of superior maternal line genetics. Those sows giving birth to more piglets than their average number of functional teats are identified as hyperprolific sows (HPS). The large number of piglets born within a litter implies not only a challenge for their access to vital resources like colostrum and milk but has a direct effect on their average birth weight and heterogeneity. These conditions are detrimental to piglets' vitality in the first hours of life and also to their immunity development. An exceptionally large number of growing fetuses in HPS leads to intrauterine crowding and consequently to an increased number of piglets suffering from intrauterine growth retardation (IUGR), which put piglets at a high risk of mortality after birth and up to later stages of life. Increased heterogeneity of birth weight within large litters increases the competition for colostrum intake, with the smaller piglets being less competitive and vital, and therefore affecting negatively their immunity. Low birth weight, long interval to reach the udder, and long duration of farrowing, all have negative effects on piglets' immunoglobulin absorption. In HPS litters, colostrum management should be focused on low birth weight piglets, anticipating their impaired capabilities associated with ingesting adequate colostrum, by shortening the time to reach the udder and reducing competition among piglets. The vitality of neonate piglets, especially low in birth weight or affected by IUGR should be enhanced to improve their body temperature and their early life stage energy metabolism.

The impact of birth weight, birth order, birth asphyxia, and colostrum intake per se on growth and immunity of the suckling piglets

Colostrum is the only source of passive immunity and the major source of nutrients and is crucial for thermoregulation of newborn piglets in their early life. However, the amount of colostrum obtained by each piglet [colostrum intake (CI)] differs considerably in large litters as born by contemporary hyperprolific sow lines. This experiment aimed to investigate the impact of the following individual characteristics of piglets; birth weight, birth order and neonatal asphyxia at birth on CI, and further to determine the relationship between the CI and the passive immunity transfer, and the growth performance of piglets prior to weaning. Twenty-four Danbred sows of the second-parity and their progeny (n = 460) were used. As main inputs in the prediction model to assess individual piglet CI were piglet birth weight, their weight gain, and the duration of colostrum suckling of the piglets. The asphyxia (state of oxygen deprivation) was assessed by measuring blood lactate concentration immediately after birth, and piglets sampled at d 3 of age for determination of blood plasma concentrations of immunoglobulins (Ig) G, A, and M. Piglets' CI was negatively associated with asphyxia (P = 0.003), birth order (P = 0.005) and low birth weight have compromised the individual CI (P < 0.001). Average daily gain during the suckling period was greater among piglets with high CI (P = 0.001) and birth weight (P < 0.001). Body weight at weaning (d 24 of age) was positively associated with CI (P = 0.0004) and birth weight (P < 0.001). The probability of weaning was positively associated with CI and birth weight (P < 0.001) of the piglets. Concentrations of IgG (P = 0.02), IgA (P = 0.0007), and IgM (P = 0.04) in piglets' plasma at d 3 of age were positively associated with CI, and were negatively associated with birth order (P < 0.001). The present study demonstrated that piglets' individual characteristics at birth (birth weight, birth order, state of oxygen deprivation) have considerable effects on their CI. The knowledge gained from the results of this study gives a scientific base for development and implementation of more effective techniques in practice aimed to improve the piglets' robustness during the suckling period.

Effects of Dietary Probiotics and Acidifiers on the Production Performance, Colostrum Components, Serum Antioxidant Activity and Hormone Levels, and Gene Expression in Mammary Tissue of Lactating Sows

The aims of this study were to test the effects of dietary probiotics and acidifiers on the production performance, colostrum components, serum antioxidant activity and hormone levels, and gene expression in the mammary tissue of lactating sows. Four treatments were administered with six replicates to 24 lactating sows. The control group (GC) received a basal diet, while the experimental groups received a basal diet with 200 mL/d probiotics (GP), 0.5% acidifiers (GA), and 200 mL/d probiotics + 0.5% acidifiers (GM), respectively. Compared with the GC, (1) the average weight of the piglets on the 21st day of lactation in the GM was higher (p < 0.05); (2) the colostrum fat ratio increased significantly (p < 0.05); (3) the malondialdehyde levels in GP and GM were lower (p < 0.05) on the 11th day; (4) on the 1st, 11th, and 21st days, the prolactin in GP and GM increased (p < 0.05); (5) on the 21st day, the relative expression levels of the prolactin receptor and fatty acid synthase were increased (p < 0.05). In summary, the basal diet mixed with 200 mL/d probiotics + 0.5% acidifiers could improve the production performance, colostrum components, serum antioxidant activity, and hormone levels of lactating sows.

Gut Health and Influencing Factors in Pigs

The gastrointestinal tract (GIT) is a complex, dynamic, and critical part of the body, which plays an important role in the digestion and absorption of ingested nutrients and excreting waste products of digestion. In addition, GIT also plays a vital role in preventing the entry of harmful substances and potential pathogens into the bloodstream. The gastrointestinal tract hosts a significant number of microbes, which throughout their metabolites, directly interact with the hosts. In modern intensive animal farming, many factors can disrupt GIT functions. As dietary nutrients and biologically active substances play important roles in maintaining homeostasis and eubiosis in the GIT, this review aims to summarize the current status of our knowledge on the most important areas.

Immune status of piglets during the first week of life: Current knowledge, significance and assessment

The immune system of neonate piglets differs from adult pigs in structure and competence. Although piglets are born immunocompetent, they are genuinely immunologically defenceless. To survive in the environment, piglets need passive protection provided by sow’s colostrum and milk when constantly exposed to numerous pathogens. Early assessment of piglets’ immune status may enable rapid intervention in case of detection of any deficiencies or disorders. Moreover, awareness of the piglets’ immunocompetence and the level of maternally-derived antibodies (MDA) may allow the creation of a proper vaccine schedule. Hence, extending knowledge of prenatal ontogeny of the porcine immune system, the immune status of neonate piglets’ and the immunological components of porcine colostrum is crucial. Since animal welfare has become a more critical element of animal production, new, non-invasive sampling methodologies are highly desirable for the evaluation of piglets’ immune status.

Two-Stage Fermented Feather Meal-Soybean Meal Product Improves the Performance and Immunity of Lactating Sows and Piglets

This study aimed to investigate the effects of a two-stage fermented feather meal-soybean meal product (TSFP) on the performance, clinical blood biochemistry, and immunity of sows and piglets. TSFP was fermented by Saccharomyces cerevisiae Y10 for three days in the second stage, which showed similar results to the five-day fermentation of B. coagulans (p > 0.05). Fifty hybrid sows (Duroc × KHAPS black pig) were randomly assigned into dietary supplementation groups of 2% fish meal or different levels of TSFP at 0%, 1%, 2%, or 3%. The results showed that body weight gain and feed conversion ratio of 2% and 3% TSFP groups were better than the control group and fish meal group during the gestation period (d 80–114) (p < 0.05). During the lactation period, the 3% TSFP group showed the best weaning litter weight (p < 0.05). In sows, interferon-γ and immunoglobulin G (IgG) of 2% and 3% TSFP groups were higher than the control group and fish meal group (p < 0.05). In piglets, in groups of 2% and 3% TSFP blood urea decreased (p < 0.05). The IgG of fermented groups was superior to the control group (p < 0.05). The oxidative burst of phagocytes in the 3% TSFP was higher than those of the control and fish meal groups (p < 0.05). In conclusion, TSFP supplementation exhibits the advantages of performance and immunity of lactating sows and piglets. Furthermore, adding 3% TSFP in the feed showed the best performance.

Investigating the effects of jute nesting material and enriched piglet mats on sow welfare and piglet survival

Domesticated sows are motivated to perform nesting behavior prior to farrowing, and nesting material can reduce piglet cold stress. However, nesting material may not be practical in most production systems due to the potential for clogging slurry systems. Therefore, the study objectives were to assess an alternative nesting material provided prior to farrowing on sow welfare and piglet survival, and to investigate the effect of the entire nesting environment on piglet survival and growth performance. We hypothesized that the provision of jute nesting material would decrease sow stress and farrowing duration, and that nesting mat provision would allow piglets to remain euthermic and improve survival and growth. Sows (N = 20) were randomly assigned to one of two treatments: a farrowing crate with three pieces of 40.6 × 21.6 cm jute nesting material (Nest; n = 10) and two enriched piglet mats made from an acrylic board (28.0 × 86.4 cm) covered with a microfiber material, or a farrowing crate without nesting material (Control; n = 10) and one standard plastic piglet mat (28.0 × 86.4 cm). Jute pieces were attached to the front of the crate to prevent substrate from falling through the slatted floors. Saliva samples were collected to measure cortisol and immunoglobulin A (IgA), on days -1, 0, 1, and 2 relative to farrowing, and a final sample was collected at weaning (day 16.9 ± 0.18). Blood was collected from four piglets per litter to measure immunoglobulin G (IgG) at 48 h, day 7, and weaning. Piglet skin temperature (TS) was measured on two piglets per litter using an infrared camera for 3 d after birth at 0800, 1200, 1600, and 2000 h. One piglet was randomly chosen from the heat lamp and nonheat lamp side of the crate to measure TS. Video was continuously coded for observations of jute- and crate-directed interactions. Data were analyzed as a mixed model analysis of variance in SAS 9.4. Nest sows performed less crate-directed behavior than Control sows (P = 0.02). Cortisol tended to be reduced in Nest sows (P = 0.08) when compared to Controls, but no differences in IgA concentrations (P > 0.40) were detected. Nest piglets tended to be heavier on day 7 (P < 0.10), had greater IgG concentrations (P = 0.03), and had greater TS (P = 0.02) versus Controls. No farrowing duration or number of stillbirth differences were observed (P > 0.70). The jute material and piglet nests positively impacted sow welfare and piglet measures but did not translate into improved piglet survival.

Immunogenicity of a recombinant hemagglutinin neuraminidase-Porcine rubulavirus produced by Escherichia coli of Porcine rubulavirus gives protective immunity of litter after challenge

Porcine rubulavirus (PRV) is a contagious virus that affects the Mexican swine industry. This work aimed to evaluate the immunogenicity of an recombinant hemagglutinin neuraminidase-Porcine rubulavirus (rHN-PorPV) candidate vaccine on pregnant sows, and the protective efficacy afforded to their 7-day-old suckling piglets against PRV lethal challenge. Three sows were immunized with rHN-PorPV formulated with immune-stimulating complex (ISCOMs) and two sows with rHN-PorPV protein alone as well as a mock-immunized pregnant sow (negative control). Quantitative ELISA detected a high concentration of anti-rHN-PorPV Immunoglobulin G (IgG) antibodies in sow sera after the second dose of vaccine administered on day 14 until farrowing, showing viral-neutralizing and cross-neutralization activity against different variants of PRV. Sera samples from piglets of immunized sows (with or without adjuvant), showed high concentrations of IgG antibodies. As expected, piglets from the negative control sow (n=5), exhibited severe signs of disease and 100% of mortality after PRV challenge study. Conversely, 75% and 87.5% of the piglets born from the rHN-PorPV and the rHN-PorPV-ISCOMs-immunized sows (n=8), survived, respectively, showing milder PRV clinical signs. Our data indicate that rHN-PorPV candidate vaccine produced in Escherichia coli induces efficient humoral response in pregnant sows and that the maternally derived immunity provides high protection to suckling piglets against PRV lethal challenge.

Effects of freezing storage on the stability of maternal cellular and humoral immune components in porcine colostrum

The placental structure of sows is epitheliochorial and prevents maternal serum immunoglobulin transfer to the fetus; therefore, the piglet relies on the ingestion of colostrum to acquire passive immunity. Colostral antibody-mediated and cell-mediated immunity contribute to immunity in piglets. However, little is known about the effects of freezing at -20 °C on colostral immune components during short-term storage, whether this will somehow compromise the acquisition of passive immunity of newborn piglets fed with this colostrum and the humoral immunity in porcine colostrum, and to possible shifts in immunological levels in colostrum collections during the colostral period. Based on the average concentration of immunoglobulin, frozen and fresh colostrum did not differ significantly. Overall, there were no storage differences in total macrophages, granulocytes, and NK cells. However, the frozen colostrum presented T lymphocyte subsets and B lymphocytes significantly lower than the fresh colostrum (p ≤ 0.05). Therefore, to sustain higher piglet survival rates, B cells may be a selective strategy to ensure immune defense to neonatal piglets. According to our findings, colostrum can be stored by freezing at -20 °C for up to 30 days and surplus porcine colostrum can be collected from the sow up to eight hours after the start of farrowing.

Implications of placentation type on species-specific colostrum properties in mammals

Maternal care is essential to optimally support survival of the offspring. During evolution of mammalian species, different phenotypes have evolved in relation to gestation length, number, size, and maturation stage of the offspring at parturition, as well as colostrum and milk composition. The aim of the present review is to describe relationships between placental function and colostrum and milk composition in different mammalian species. Species covered in this article include humans, rabbits, rodents (rat and mouse), carnivores (cats and dogs), and a variety of ungulate species (cattle, sheep, goats, pigs, and horses). Species-specific aspects are elucidated with a special focus on the transfer of passive immunity. In this regard, the structure and thus the capability of the placenta to transport immunoglobulins from maternal to fetal circulation in utero dictates the necessity of the passive transfer of immunity via colostrum. Consequently, species with exclusive postpartal transfer of immunity such as in all ungulate species have greater immunoglobulin G concentrations in colostrum than species with a prepartal transfer in utero, where especially immunoglobulin A with its local immune function in the gastrointestinal tract is present in colostrum (e.g., rabbit and human). In terms of the nutritional purpose, suckling frequency is an important factor determining the gross composition of colostrum as well as in the mature milk of these species. Milk of nidicolous animals with long intervals in-between suckling events contains more fat than milk of nidifugous animals with constant access to their mother. However, the importance of colostrum and milk consumption for newborn animals and human babies goes beyond nutrition and the transfer of immunity. Numerous bioactive components such as growth factors, hormones, and oligosaccharides are enriched in colostrum and transition milk, which support the development of the intestinal tract and local immune system.

Maternal nucleotide supplementation improves the intestinal morphology and immune function in lipopolysaccharide-challenged newborn piglets

This study aimed to evaluate the effects of maternal nucleotide (NT) supplementation on intestinal morphology and immune function in lipopolysaccharide-challenged newborn piglets. At 85 d gestation, 12 sows were selected and assigned to two groups: the CON group (basal diet, n = 6) and the NT group (basal diet with 1 g/kg NT mixture, n = 6). After parturition, newborn piglets were collected without suckling. Piglets from the CON group were intraperitoneally injected with sterile saline or lipopolysaccharide (LPS, 10 mg/kg body weight), and divided into the C-CON (n = 6) and C-LPS groups (n = 6). Piglets from the NT group received the same treatment and were divided into the N-CON (n = 6) and N-LPS groups (n = 6). The blood and small intestinal samples of piglets were collected 1 h after injection. The results showed that: (1) maternal NT supplementation increased the concentrations of serum complement C3 and C4 (P < 0.05), and suppressed the increase in serum hypersensitive C-reactive protein in LPS-challenged newborn piglets (P < 0.05); (2) maternal NT supplementation increased the villus height and the ratio of villus height to crypt depth in the duodenum of newborn piglets (P < 0.05) and inhibited the LPS-induced decrease in the villus height in the jejunum and ileum (P < 0.05). (3) The LPS-induced increased levels of interleukin-6 in the jejunum and tumor necrosis factor-α in the ileum of newborn piglets were suppressed by maternal NT supplementation (P < 0.05). (4) In the jejunum of newborn piglets, maternal NT supplementation inhibited the LPS-induced increase in toll-like receptor 4 (TLR4) mRNA and protein expression (P < 0.05) and the decrease of nuclear factor-κB inhibitor α (IκBα) protein expression (P < 0.05). In the ileum, piglets had a lower nuclear factor-κB (NFκB) mRNA expression in the NT groups than the CON groups (P < 0.05), and maternal NT supplementation suppressed the decrease of IκBα mRNA in LPS-treated piglets (P < 0.05). In conclusion, maternal NT supplementation could promote the intestinal development and immune function of newborn piglets, and may improve LPS-induced intestinal inflammatory responses via the TLR4/IκBα/NFκB pathway.

Formulating Diets for Improved Health Status of Pigs: Current Knowledge and Perspectives

Our understanding of nutrition has been evolving to support both performance and immune status of pigs, particularly in disease-challenged animals which experience repartitioning of nutrients from growth towards the immune response. In this sense, it is critical to understand how stress may impact nutrient metabolism and the effects of nutritional interventions able to modulate organ (e.g., gastrointestinal tract) functionality and health. This will be pivotal in the development of effective diet formulation strategies in the context of improved animal performance and health. Therefore, this review will address qualitative and quantitative effects of immune system stimulation on voluntary feed intake and growth performance measurements in pigs. Due to the known repartitioning of nutrients, the effects of stimulating the immune system on nutrient requirements, stratified according to different challenge models, will be explored. Finally, different nutritional strategies (i.e., low protein, amino acid-supplemented diets; functional amino acid supplementation; dietary fiber level and source; diet complexity; organic acids; plant secondary metabolites) will be presented and discussed in the context of their possible role in enhancing the immune response and animal performance.

On the influence of the source of porcine colostrum in the development of early immune ontogeny in piglets

The effects on the ontogeny of serum cytokines and immune cells caused by feeding suckling piglets with sow/gilt colostrum and milk replacer was assessed in the present study. After farrowing, the piglets born were randomized into six groups: GG and SS (n = 10/group): piglets were kept with their dam; GS (n = 10): piglets were changed from gilts to sows; SG (n = 10): piglets were changed from sows to gilts; GMR (n = 6) and SMR (n = 8): piglets from either gilts or sows were isolated from the dams and were bottle-fed ad libitum with commercial formula milk replacer. The piglets remained in the groups during the first 24 h of life and were later returned to their respective mothers. Serum immunoglobulin concentration and lymphocyte proliferation from the blood, spleen, thymus, and mesenteric lymph node of the piglets were assessed at 24 h and at 28 days of age. Serum cytokine concentrations were measured through a cytokine multiplex assay at 24 h. Overall, piglets suckling on sows (SS and GS) had a higher concentration of serum immunoglobulin at 24 h, which was also associated with a rise in plasma cytokine concentration and greater ability of B and T cells from lymphatic organs and blood mononuclear cells to respond to mitogens. We suggest a bias towards Th1-, Th2-, and Th17-cell polarizing and cytokines during the suckling period, which may be influenced by maternal immunological factors in the colostrum, such as dam parity. All findings suggest sow parity having a possible role, which may contribute to exerting a modulating action on immune response development.

Characteristics of thermal images of the mammary gland and of performance in sows differing in health status and parity

Precision livestock farming can combine sensors and complex data to provide a simple score of meaningful productivity, pig welfare, and farm sustainability, which are the main drivers of modern pig production. Examples include using infrared thermography to monitor the temperature of sows to detect the early stages of the disease. To take account of these drivers, we assigned 697 hybrid (BHZP db. Viktoria) sows to four parity groups. In addition, by pooling clinical findings from every sow and their piglets, sows were classified into three groups for the annotation: healthy, clinically suspicious, and diseased. Besides, the udder was thermographed, and performance data were documented. Results showed that the piglets of diseased sows with eighth or higher parity had the lowest daily weight gain [healthy; 192 g ± 31.2, clinically suspicious; 191 g ± 31.3, diseased; 148 g ± 50.3 (p < 0.05)] and the highest number of stillborn piglets (healthy; 2.2 ± 2.39, clinically suspicious; 2.0 ± 1.62, diseased; 3.91 ± 4.93). Moreover, all diseased sows showed higher maximal skin temperatures by infrared thermography of the udder (p < 0.05). Thus, thermography coupled with Artificial Intelligence (AI) systems can help identify and orient the diagnosis of symptomatic animals to prompt adequate reaction at the earliest time.

Effect of Porcine Colostral Exosomes on T Cells in the Peripheral Blood of Suckling Piglets

Simple Summary

Exosomes in porcine colostrum have gained attention as the possible key compounds involved in the growth and/or development of suckling piglets. In this study, peripheral blood mononuclear cells (PBMCs) from suckling piglets were cultured with or without milk-derived exosomes (control) in vitro. Porcine colostral exosomes increased the proportion of cytotoxic T (Tc) cells, while this phenomenon was not observed in PBMC whose endocytosis was inhibited. Moreover, exosome-treated PBMCs had a higher cytokine IL-2 concentration in the culture supernatant than the control. The present study demonstrated that porcine colostral exosomes could increase the Tc cell proportion in the peripheral blood of a suckling piglet, with the underlying mechanism believed to be the stimulation of IL-2 production in PBMCs via endocytosis.

Abstract

Growing evidence indicates that porcine colostral exosomes may contribute to the healthy development of piglets. Here, we evaluated in vitro the effect of porcine milk-derived exosomes, in particular colostral exosomes, on T cells in the peripheral blood of suckling piglets. A total of seven sows and thirteen suckling piglets were used. Peripheral blood mononuclear cells (PBMCs) from suckling piglets were cultured with or without milk-derived exosomes (control). Using flow cytometry, the proportion of each T cell subset in cultured PBMCs was analyzed three days post-incubation. PBMCs cultured with porcine colostral exosomes had a higher proportion of CD3⁺CD4⁻CD8⁺ T cells (cytotoxic T cells; Tc) than the control. However, exosomes induced no increase in the Tc cell population in PBMC whose endocytosis was inhibited. We further measured the concentrations of cytokines in the culture supernatant. Exosome-treated PBMCs had a higher cytokine IL-2 concentration than the control. The present study demonstrated that porcine colostral exosomes could increase the Tc cell proportion in the peripheral blood of suckling piglets, with the underlying mechanism believed to be the stimulation of IL-2 production in PBMCs via endocytosis. Moreover, our results suggested that porcine colostral exosomes were involved in the development of cellular immunity in suckling piglets.

Animal board invited review: Factors affecting the early growth and development of gilt progeny compared to sow progeny

Progeny born to primiparous sows farrowing their first litter, often called gilt progeny (GP), are typically characterised by their poorer overall production performance than progeny from multiparous sows (sow progeny; SP). Gilt progeny consistently grow slower, are born and weaned lighter, and have higher postweaning illness and mortality rates than SP. Collectively, their poorer performance culminates in a long time to reach market weight and, ultimately, reduced revenue. Due to the high replacement rates of sows, the primiparous sow and her progeny represent a large proportion of the herd resulting in a significant loss for the pig industry. While the reasons for poorer performance are complex and multifaceted, they may largely be attributed to the immature age at which gilts are often mated and the significant impact of this on their metabolism during gestation and lactation. As a result, this can have negative consequences on the piglet itself. To improve GP performance, it is crucial to understand the biological basis for differences between GP and SP. The purpose of this review is to summarise published literature investigating differences in growth performance and health status between GP and SP. It also examines the primiparous sow during gestation and lactation and how the young sow must support her own growth while supporting the metabolic demands of her pregnancy and the growth and development of her litter. Finally, the underlying physiology of GP is discussed in terms of growth and development in utero, the neonatal period, and the early development of the gastrointestinal tract. The present review concludes that there are a number of interplaying factors relating to the anatomy and physiology of the primiparous sow and of GP themselves. The studies presented herein strongly suggest that poor support of piglet growth in utero and reduced colostrum and milk production and consumption are largely responsible for the underperformance of GP. It is therefore recommended that future management strategies focus on supporting the primiparous sow during gestation and lactation, increasing the preweaning growth of GP to improve their ability to cope with the stressors of weaning, selection of reproductive traits such as uterine capacity to improve birth weights and ultimately GP performance, and finally, increase the longevity of sows to reduce the proportion of GP entering the herd.

Modification of Gut Microbiota and Immune Responses via Dietary Protease in Soybean Meal-Based Protein Diets

Plant-based protein sources such as soybean meal have low digestibility and are generally promoted accumulation of undigested proteins into the intestine by enzymatic treatments. Moreover, potential intestinal pathogens ferment undigested proteins, producing harmful substances, such as ammonia, amines and phenols, leading to an overactive immune response and diarrhea in weaned pigs. As a solution, dietary proteases hydrolyze soybean-based antinutritive factors, which negatively affect immune responses and gut microbiota. In this study, we investigated the effects of dietary proteases (PRO) in a low-crude protein (CP) commercial diet on the immune responses and gut microbiota of weaned pigs. The experimental design consisted of three dietary treatments: a commercial diet as a positive control (PC; phase1 CP = 23.71%; phase 2 CP: 22.36%), a lower CP diet than PC as negative control (NC; 0.61% less CP than PC), and NC diet supplement with 0.02% PRO. We found that PRO tended to decrease the frequency of diarrhea in the first two weeks after weaning compared with PC and NC. In addition, pigs fed PRO showed decreased TNF-α and TGF-β1 levels compared with those fed PC and NC. The PRO group had a higher relative proportion of the genus Lactobacillus and lower levels of the genus Streptococcus than the PC and NC groups. In conclusion, the addition of PRO to a low CP commercial weaned diet attenuated inflammatory responses and modified gut microbiota in weaned pigs.

Environment and Offspring Surveillance in Porcine Brucellosis

Porcine brucellosis, caused by Brucella suis (B. suis), is a notifiable disease causing significant economic losses in production systems. Most infected pigs may act as carriers and shed B. suis even if asymptomatic. This can contribute to environmental persistence, thus hindering control efforts. Here, the environment and the offspring were investigated during and after a B. suis outbreak at a sow breeding farm. The diagnosis of B. suis in sows (n = 1,140) was performed by culture and polymerase chain reaction (PCR) from vaginal swabs, indirect enzyme-linked immunosorbent assay (I-ELISA) from sera, and brucellin skin test (BST). B. suis diagnosis in post-weaning pigs (n = 899) was performed by I-ELISA in sera and BST. The environmental surveillance programme was implemented by placing gauze sponges (n = 175) pre-hydrated in a surfactant and inactivating liquid for Brucella DNA detection by PCR in different farm areas. Our results showed that the offspring of infected sows reacted to in vivo techniques for B. suis. Furthermore, the offspring born during the outbreak displayed higher seropositivity (I-ELISA) and reactivity (BST) than those pigs born after. Brucella DNA was detected in pregnant sow areas, boxes, boots, and post-weaning pig areas. In addition, Brucella DNA environmental detection was higher during the B. suis outbreak than the post B. suis outbreak. The environmental approach has proven to be a simple, practical, valuable, and safe method to detect and monitor B. suis. These results suggest a role of the environment and the offspring that should be considered in porcine brucellosis surveillance and control programmes.

Importance of Breed, Parity and Sow Colostrum Components on Litter Performance and Health

The aims of this study were to investigate the effect of breed and parity on colostrum components, and to associate sow breed, parity, and colostrum components with survival, growth, and the occurrence of diarrhoea of their litters. In Experiment 1, 64 sows (Duroc = 13; Landrace = 17 and Large White = 34) were included. In Experiment 2, 71 sows with different parities (1 = 10; 2 = 16; 3 = 13; 4 = 12; ≥5 = 20) were included. The number (N) of live piglets, litter body weight (Experiment 1), and the occurrence of diarrhoea (Experiment 1) were recorded at farrowing, at 2−3 days of age, and at weaning. Colostrum was analysed for proximate composition, immunoglobulins (Igs), and somatic cell count (SCC). Stepwise regressions and ANOVA models were used to associate breed, parity, and colostrum components with litter performance. The Duroc breed had the highest IgG and IgA (p < 0.005). Gilts had a higher fat% and SCC (p< 0.0001); these compounds were positively correlated (r = 0.45). Increased IgA tended to increase the N of weaned piglets (p = 0.058) and reduce litter diarrhoea (p = 0.021). The SCC increased the N of weaned piglets (p = 0.031). Overall, this study confirmed that breed and parity can influence the colostrum composition and highlighted the key role of Igs and somatic cells in piglet health.

Effect pf Fermented Rapeseed Meal as a Feed Component on the Redox and Immune System of Pregnant Sows and their Offspring

The aim of the study was to assess the effect of dried fermented rapeseed meal (FRSM) in diets for sows on blood redox and immunological parameters, taking into account the physiological period (pregnancy or lactation) and age (primiparous vs multiparous sows). The experiment also aimed to determine how FRSM administered to pregnant sows, affects the antioxidant and immune systems of piglets. The animals were divided into 4 groups of 15 animals each. Control groups of primiparous (CG) and multiparous sows (CS) received a standard diet for pregnant or lactating sows. Experimental groups of primiparous (EG) and multiparous sows (ES) received feed with a 4% share of FRSM in place of soybean meal up to day 100 of gestation, 9% share of FRSM from day 100 of gestation to day 7 of lactation, and then again 4% share of FRSM until the end of lactation. In the blood plasma of pregnant sows fed diet with FRSM addition, higher FRAP value and vitamin C, uric acid (UA), immunoglobulin IgG content, lymphocytes (LYM) count and a lower content of malondialdehyde (MDA), lipid hydroperoxides (LOH), immunoglobulin IgM was noted than in the blood plasma of control sows. Both primiparous and multiparous lactation sows whose feed included FRSM had higher catalase (CAT) activity, higher FRAP, vitamin C, immunoglobulin IgG and IL-6 content, and lower UA content than the control sows. Piglets born to sows fed diet with FRSM addition had significantly higher FRAP values, vitamin C, IgG, and IL-6 content and white blood cells (WBC) count and lower MDA and UA content in the blood plasma than piglets born to sows from control group. Multiparous sows compared to primiparous sows had higher CAT activity, and higher vitamin C, LOH, creatinine (CREAT), and IgM content. Elevated FRAP, and CREAT levels and reduced MDA content were also observed in the plasma of the multiparous sows compared to primiparous sows during lactation. Multiparous lactation sows compared to primiparous sows had lower WBC count, and IgG and IgM content. Piglets born to multiparous sows had higher FRAP values, LOH content and IgA content while lower MDA content compared to piglets born to primiparous sows. The inclusion of dried fermented rapeseed meal in feed for sows significantly stimulates antioxidant processes in primiparous and multiparous sows and in their piglets. The inclusion of dried fermented rapeseed meal in the diet of sows stimulates antioxidant processes in primiparous and multiparous sows and in their piglets. This is responsible for stimulation of the immune system (increased LYM counts and IgG titres in the blood plasma). The improved antioxidant status in the plasma suggests that dried fermented rapeseed meal stimulated the immune system of pregnant and lactating sows and their newborn offspring.

Maternal Nutrition During Late Gestation and Lactation: Association With Immunity and the Inflammatory Response in the Offspring

The immature immune system at birth and environmental stress increase the risk of infection in nursing pigs. Severe infection subsequently induces intestinal and respiratory diseases and even cause death of pigs. The nutritional and physiological conditions of sows directly affect the growth, development and disease resistance of the fetus and newborn. Many studies have shown that providing sows with nutrients such as functional oligosaccharides, oils, antioxidants, and trace elements could regulate immunity and the inflammatory response of piglets. Here, we reviewed the positive effects of certain nutrients on milk quality, immunoglobulin inflammatory response, oxidative stress, and intestinal microflora of sows, and further discuss the effects of these nutrients on immunity and the inflammatory response in the offspring.

Piglet Viability: A Review of Identification and Pre-Weaning Management Strategies

Simple Summary

Neonatal piglet viability is decreasing in concert with the selection for ever-greater numbers of piglets born per sow per year. Their survival depends on the early intervention and management strategies used by production staff. This paper will review current and novel methods used to identify these piglets, some of the factors affecting their viability, and management strategies commonly used within production systems to improve their survival.

Abstract

Increased attention on the effects of the global push for a larger litter size has focused on the increased occurrence of piglets with decreased viability, which have lighter birthweights and a reduced ability to thrive in early life. To improve their odds of survival, interventions must be timely and targeted. This requires the early identification of low-viability pigs and appropriate strategies to manage them. Using novel measures such as abdominal circumference and crown to the rump length in conjunction with birth weight may provide an improved protocol for the identification of those at most risk of preweaning mortality. Further, identifying these at-risk piglets allows interventions to increase their colostrum intake and heat provisions shortly following birth. The appropriate management of the pre- and post-partum sows will improve the chances of decreasing the number of piglets born with lower viability. However, this outcome is constrained by limitations in resources such as technology and staffing. If these challenges can be overcome, it will allow for greater control and increased effectiveness in the implementation of current and new management strategies.

A comparative evaluation of methods for estimating the colostrum quality in sows

ABSTRACT Colostrum is the main source of immunoglobulins (Ig) for neonate piglets and plays a crucial role within the health and growth of the piglet. Currently in pig farming, there are still no widespread practical methods for measuring the Ig concentration in colostrum at herd level. We evaluated sows’ colostrum IgG concentration using an optical and a digital Brix refractometer and their performance was correlated to an IgG ELISA test, and flow cytometry. Colostrum concentrations of IgG and IgA averaged 74.05 ± 21.37mg/mL and 20.2 ± 5.32mg/mL respectively. The mean value of the Brix percentages for optical refractometer was 26.32%, and for digital was 28.32%. The Brix refractometer measurements of colostrum samples presented high correlation for IgG content analyzed by ELISA (Optical = 0.74, Digital = 0.87; P <0.001). Considering the immunophenotyping, the values for IgG and IgA lymphoblasts indicated a highly significant relationship to ELISA (IgG=0.77, IgA=0.84; P<0.001). The Brix refractometer can be considered a useful tool to be included in a colostrum monitoring program to improve potentially neonatal health. In addition, we demonstrated that flow cytometry can be an important tool to analyze and characterize the immunological potential of sow colostrum.

Stochastic Assessment of the Economic Impact of Streptococcus suis-Associated Disease in German, Dutch and Spanish Swine Farms

The economic assessment of animal diseases is essential for decision-making, including the allocation of resources for disease control. However, that assessment is usually hampered by the lack of reliable data on disease incidence, or treatment and control measures, and that is particularly true for swine production diseases, such as infections caused by Streptococcus suis. Therefore, we deployed a questionnaire survey of clinical swine veterinarians to obtain the input data needed for a stochastic model to calculate the costs caused by S. suis, which was implemented in three of the main swine producing countries in Europe: Germany, the Netherlands and Spain. S. suis-associated disease is endemic in those countries in all production phases, though nursery was the phase most severely impacted. In affected nursery units, between 3.3 and 4.0% of pigs had S. suis-associated disease and the mortalities ranged from 0.5 to 0.9%. In Germany, the average cost of S. suis per pig (summed across all production phases) was 1.30 euros (90% CI: 0.53-2.28), in the Netherlands 0.96 euros (90% CI: 0.27-1.54), and in Spain 0.60 euros (90% CI: 0.29-0.96). In Germany, that cost was essentially influenced by the expenditure in early metaphylaxis in nursery and in autogenous vaccines in sows and nursery pigs; in the Netherlands, by expenditure on autogenous vaccines in sows and nursery pigs; and in Spain, by the expenditures in early metaphylaxis and to a lesser extent by the mortality in nursery pigs. Therefore, the differences in costs between countries can be explained to a great extent by the measures to control S. suis implemented in each country. In Spain and in Germany, use of antimicrobials, predominantly beta-lactams, is still crucial for the control of the disease.

Serum protein electrophoretic pattern in piglets during the early postnatal period

The pattern of serum proteins, the typical features of the electrophoretogram in newborn piglets and during their postnatal development is not completely described. Therefore, the aim of this study was to characterize the changes in serum protein electrophoretic pattern and features of the electrophoretograms during the early postnatal period. Significant changes during the monitored period were found in all evaluated parameters (P < 0.001). The most marked changes were observed mainly in the period before weaning. The concentrations of total proteins, albumin and γ-globulins were before colostrum intake low, γ-globulins represented the smallest proportion of protein fractions. The proportion of α1-globulins was after birth a dominant protein fraction. Significant increase of total proteins, α2-, β- and γ-globulins and decrease of α1-globulins was found 2 days after colostrum intake. The albumin and A/G values increased after birth gradually until weaning. After weaning a significant changes were found in absolute concentrations of total protein and albumin, and in relative values of β-globulin fractions. Presented results showed marked developmental alterations in the serum protein pattern in piglets along with the age. The study also brings new knowledge in the field of description of typical features of electrophoretograms in the observed period of piglet's life.

Supplementing Colostrum from Multiparous Sows: Effects on Performance and Health in Piglets from Gilts in Farm Conditions

Simple Summary

Colostrum intake is essential for piglets. Gilt litters may not receive the same quantity and quality of colostrum as the litters from sows do. An extra dose of 30 mL divided into two doses (20 min apart, using a gastric tube) of colostrum from multiparous sows was administered to piglets born from gilts to ascertain its effects on piglets’ performance and health in farm conditions, with a special interest in the smallest piglets (under quartile 1, Q1). Quartiles for birth weight were Q1 = 1.100 kg, Q2 = 1.300 kg, and Q3 = 1.500 kg (n = 401). The control group (CON) consisted of 200 piglets from 18 gilts (50 smallest piglets), and 201 piglets from 16 gilts (52 smallest piglets) formed the supplemented group (SUP). Colostrum supplementation increased the homogeneity of weight and average daily gain (ADG) and decreased the use of antibiotics and mortality by diarrhoea. Immune response improved among SUP piglets for the diseases evaluated. In the smallest piglets, colostrum supplementation had significant effects on mean weight and ADG in the first days of life. The smallest piglets had a reduced use of antibiotics when supplemented. The time and labour invested in colostrum supplementation could be compensated by the improvement of piglets’ productive parameters and health.

Abstract

Gilts produce less colostrum with lower immunoglobulin G concentration than multiparous sows do. An extra dose of colostrum (30 mL) from multiparous sows was administered to piglets from gilts to ascertain its effects on performance and health in farm conditions, especially in the smallest piglets (birth weight < 1.100 kg; Q1). The control group (CON) consisted of 200 piglets from 18 gilts (50 smallest piglets) and 201 piglets from 16 gilts (52 smallest piglets) formed the supplemented group (SUP). Colostrum supplementation increased the homogeneity of weight (days 21 and 60) and average daily gain (ADG; days 0–10, 0–21, and 0–60) and a decreased use of antibiotics and mortality by diarrhoea (p < 0.05). SUP piglets showed better immune response (presence of antibodies, p = 0.033) against Mycoplasma hyopneumoniae (day 21), porcine reproductive and respiratory syndrome (PRRS; day 60), and influenza (day 60). In the smallest piglets, colostrum supplementation had important effects on mean weight in the first day of life (p = 0.009) and ADG until day 21 (p < 0.05). The smallest piglets had decreased the use of antibiotic treatment use when supplemented (p < 0.05). Colostrum supplementation can improve piglets´ performance and health, although doing so requires increased time and labour in maternity.

Maternal supplementation with a combination of wheat bran and sugar beet pulp during late gestation and lactation improves growth and intestinal functions in piglets

Maternal diet has a profound impact on growth and immune development of offspring. This study aimed to evaluate the effects of maternal supplementation with a combination of wheat bran (WB, a source of insoluble dietary fiber) and sugar beet pulp (SBP, a source of soluble dietary fiber) on growth and intestinal morphology, immunity, barrier function and microbiota in piglets. Thirty sows (Landrace × Yorkshire; 3-6 parity) were randomly allocated to 2 dietary treatments from d 85 of gestation to weaning (d 21 of lactation). The 2 dietary treatments were: a control diet (CON, a corn-soybean meal diet) and a dietary fiber diet (DF, 15% WB and 10% SBP during gestation and 7.5% WB and 5% SBP during lactation). Maternal DF supplementation improved growth, serum growth hormones and ileal morphology in piglets. Piglets fed DF showed enhanced intestinal barrier function as indicated by reduced serum concentrations of diamine oxidase and endotoxin, and increased ileal mRNA level of occludin. Maternal DF supplementation reduced pro-inflammatory cytokines in the colostrum, milk and serum of piglets. Furthermore, maternal DF supplementation decreased the colonic abundance of Subdoligranulum and Mogibacterium, and increased the colonic abundance of Lactobacillus and norank_f__Bacteroidales_S24-7_group and the colonic concentration of acetate and butyrate in piglets. In summary, maternal supplementation with a combination of SBP and WB during late gestation and lactation improved cytokines in colostrum and milk, growth, immune responses, intestinal morphology, barrier function and microbiota in piglets, which may be a potential strategy to improve offspring growth and intestinal functions.

Characterization and comparative analysis of transcriptional profiles of porcine colostrum and mature milk at different parities

BACKGROUND

Porcine milk is a complex fluid, containing a myriad of immunological, biochemical, and cellular components, made to satisfy the nutritional requirements of the neonate. Whole milk contains many different cell types, including mammary epithelial cells, neutrophils, macrophages, and lymphocytes, as well nanoparticles, such as milk exosomes. To-date, only a limited number of livestock transcriptomic studies have reported sequencing of milk. Moreover, those studies focused only on sequencing somatic cells as a proxy for the mammary gland with the goal of investigating differences in the lactation process. Recent studies have indicated that RNA originating from multiple cell types present in milk can withstand harsh environments, such as the digestive system, and transmit regulatory molecules from maternal to neonate. Transcriptomic profiling of porcine whole milk, which is reflective of the combined cell populations, could help elucidate these mechanisms. To this end, total RNA from colostrum and mature milk samples were sequenced from 65 sows at differing parities. A stringent bioinformatic pipeline was used to identify and characterize 70,841 transcripts.

RESULTS

The 70,841 identified transcripts included 42,733 previously annotated transcripts and 28,108 novel transcripts. Differential gene expression analysis was conducted using a generalized linear model coupled with the Lancaster method for P-value aggregation across transcripts. In total, 1667 differentially expressed genes (DEG) were identified for the milk type main effect, and 33 DEG were identified for the milk type x parity interaction. Several gene ontology (GO) terms related to immune response were significant for the milk type main effect, supporting the well-known fact that immunoglobulins and immune cells are transferred to the neonate via colostrum.

CONCLUSIONS

This is the first study to perform global transcriptome analysis from whole milk samples in sows from different parities. Our results provide important information and insight into synthesis of milk proteins and innate immunity and potential targets for future improvement of swine lactation and piglet development.

Transferrins Reduce Replication of Chlamydia suis in McCoy Cells

Chlamydia suis (C. suis) resides in the intestines of pigs and tetracycline-resistant strains are emerging worldwide. Intestinal infections are often subclinical. However, the gut is regarded as a C. suis reservoir and clinical infections have been associated with enteritis, conjunctivitis, pneumonia and reproductive failure. C. suis was found in boar semen and venereal transmission occurred. We studied the anti-Chlamydia suis activity of ovotransferrin (ovoTF) and bovine lactoferrin (bLF). Pre-incubation of C. suis with bLF or ovoTF had no significant effect on overall chlamydia replication (mean fluorescence area) in McCoy cells. The addition of ovoTF to the culture medium had no effect on bacterial replication, but the addition of 0.5 or 5 mg/mL of bLF significantly reduced the inclusion size by 17% and 15% respectively. Egg components are used for cryopreservation of boar semen. When inoculating an ovoTF-containing and Chlamydia suis-spiked semen sample in McCoy cells, a significant reduction in inclusion number (by 7%) and overall replication (by 11%) was observed. Thus, we showed that transferrins possess anti-chlamydial activity. Moreover, ovoTF addition to semen extenders might reduce C. suis venereal transmission. Further research is needed to unravel the mechanisms behind the observations and to enhance the effect of transferrins on C. suis.

Sow Vaccination with a Protein Fragment against Virulent Glaesserella (Haemophilus) parasuis Modulates Immunity Traits in Their Offspring

Glaesserella (Haemophilus) parasuis, an early colonizer of the nasal cavity in piglets, is a highly heterogeneous species, comprising both commensal and virulent strains. Virulent G. parasuis strains can cause fibrinous polyserositis called Glässer’s disease. Colostrum is a source of passive immunity for young piglets. When vaccinating sows, protective antibodies are transferred to their offspring through the colostrum. Here, sow vaccination was performed with a protein fragment, F4, from the outer membrane trimeric autotransporters VtaAs exclusively found in virulent G. parasuis. Piglets were allowed to suckle for 3 weeks, following which a challenge with two virulent strains of G. parasuis was performed. A group of nonvaccinated sows and their piglets were included as a control. Antibodies against F4 were confirmed using ELISA in the vaccinated sows and their offspring before the G. parasuis challenge. Compared to the control group, F4-vaccination also resulted in an increased level of serum TGF-β both in vaccinated sows and in their offspring at early time points of life. After the challenge, a lower body temperature and a higher weight were observed in the group of piglets from vaccinated sows. One piglet from the non-vaccinated group succumbed to the infection, but no other significant differences in clinical signs were noticed. At necropsy, performed 2 weeks after the virulent challenge, the level of surfactant protein D (SP-D) in bronchoalveolar lavage was higher in the piglets from vaccinated sows. Vaccination did not inhibit the nasal colonization of the piglets by the challenge strains.

FcRn is not the receptor mediating the transfer of serum IgG to colostrum in pigs

In contrast to humans or rabbits, in which maternal IgG is transmitted to offspring prenatally via the placenta or the yolk sac, large domestic animals such as pigs, cows and sheep transmit IgG exclusively through colostrum feeding after delivery. The extremely high IgG content in colostrum is absorbed by newborns via the small intestine. Although it is widely accepted that the neonatal Fc receptor, FcRn, is the receptor mediating IgG transfer across both the placenta and small intestine, it remains unclear whether FcRn also mediates serum IgG transfer across the mammary barrier to colostrum/milk, especially in large domestic animals. In this study, using a FcRn knockout pig model generated with a CRISPR-Cas9-based approach, we clearly demonstrate that FcRn is not responsible for the IgG transfer from serum to colostrum in pigs, although like in other mammals, it is involved in IgG homeostasis and mediates IgG absorption in the small intestine of newborns.

Effect of Maternal Dietary Redox Levels on Antioxidative Status and Immunity of the Suckling Off-Spring

This study investigates two levels of dietary selenium (Se) and vitamin E in combination on their status in sows and their progeny, and influence on antioxidant status and immunological responses of the piglets at weaning. Female pigs (n = 6) were provided LOW or HIGH antioxidant nutrition (Se and vitamin E) from mating until weaning of their off-spring. The HIGH treatment elevated the concentration of Se (p = 0.015) and α-tocopherol (p = 0.023) in plasma of piglets compared with piglets of the LOW treatment. Treatments also affected the concentrations of milk and sow plasma immunoglobulins. Piglets from sows on the HIGH treatment had increased (p < 0.001) activity of glutathione peroxidase, lower serum levels of C-reactive protein (p = 0.005), haptoglobin (p = 0.05) and albumin (p = 0.05), and the number of white blood cells (p = 0.023) and the ratio of NEU to LYM was lower (p = 0.025) than in piglets from sows on the LOW group. Furthermore, the dietary antioxidant level influenced responses of cytokines (interleukine (IL) 6 (p = 0.007), 12 (p = 0.01) and 18 (p = 0.01)) in piglets’ plasma. In conclusion, improved antioxidant status via dietary maternal provision improves the robustness of the offspring via immunomodulatory mechanisms.