Early Weaning Of Piglets Research Articles

Evaluation of oral supplementation of free and nanoencapsulated Minthostachys verticillata essential oil on immunological, biochemical and antioxidants parameters and gut microbiota in weaned piglets.

Early weaning is an important stressor that impairs the piglet´s health, and essential oils appear as promising candidates to improve it instead of antibiotics. The aim of this study was to evaluate the effect of oral supplementation of free and nanoencapsulated Minthostachys verticillata essential oil (EO and NEO, respectively) on immunological, biochemical and antioxidants parameters as well as on gut microbiota in weaned piglets. EO was extracted by hydrodistillation and nanoencapsulation was performed by high-energy method using Tween 80 and Span 60 as surfactants. EO and NEO were chemically analyzed by gas chromatography-mass spectrometry (GC-MS). The cytotoxic effects of both EO and NEO was evaluated on Caco-2 cell line. For in vivo assay, male weaned piglets (age: 28 days, mean initial body weight: 11.63 ± 0.37kg) were randomly distributed in six groups of six animals each (n = 6) and received orally EO (10.0mg/kg/day) or NEO (2.5, 5.0 and 10.0mg/kg/day), named hereinafter as EO-10, NEO-2.5, NEO-5 and NEO-10, for 30 consecutive days. Animals not treated or treated with surfactants mixture were evaluated as control and vehicle control. Subsequently, histological, hematological and biochemical parameters, cytokines production, oxidative markers, CD4+/CD8+ T cells and gut microbiota were evaluated. GC-MS analysis was similar in both EO and NEO. The NEO was more toxic on Caco-2 cells than EO. Oral supplementation of EO-10 or NEO-10 improved growth performance compared to control group NEO-2.5 or NEO-5 (p < 0.05) groups. NEO-2.5, NEO-5 and NEO-10 did not alter the morpho-physiology of digestive organs and decreased malondialdehyde (MDA) levels in liver compared to control (p < 0.05) or EO-10 groups (p < 0.05, p < 0.01). In addition, NEO-10 showed an increase in CD4+/CD8+ T cells ratio (p < 0.001), and induced the highest serum levels of IL-10 (p < 0.01). Serum triglycerides levels were significantly lower in animals treated with EO-10 or NEO-2.5, NEO-5 and NEO-10 compared to control group (p < 0.001). Gut microbiota analysis showed that NEO-10 favor the development of beneficial intestinal microorganisms to improve parameters related to early weaning of piglets. In conclusion, EO and NEO improved parameters altered by early weaning in piglets however, NEO was safer and powerful. Therefore, NEO should be further studied to be applied in swine health.

Remodeling of Hepatic Glucose Metabolism in Response to Early Weaning in Piglets.

This study aimed to investigate the dynamic changes in hepatic glucose metabolism in response to early weaning. A total of 60 piglets were randomly selected and weaned at 21 days old. Six piglets were slaughtered on the weaning day (d0) and at 1 (d1), 4 (d4), 7 (d7), and 14 (d14) days postweaning. The results illustrated that body weight significantly increased from d4 to d14 (p < 0.001). Serum glucose fell sharply after weaning and then remained at a low level from d1 to d14 (p < 0.001). Serum insulin decreased from d4 (p < 0.001), which caused hepatic glycogen to be broken down (p = 0.007). The glucose-6-phosphatase activity increased from d0 to d4 and then decreased from d4 to d14 (p = 0.039). The pyruvate carboxylase activity presented a significant sustained increase from d0 to d14 (p < 0.001). The succinate (p = 0.006) and oxaloacetate (p = 0.003) content on d4 was lower than that on d0. The succinate dehydrogenase activity (p = 0.008) and ATP (p = 0.016) production decreased significantly on d4 compared to that on d0. Taken together, these findings reveal the dynamic changes of metabolites and enzymes related to hepatic glycometabolism and the TCA (tricarboxylic acid) cycle in piglets after weaning. Our findings enrich weaning stress theory and might provide a reference for dietary intervention.

Dietary Taurine Improves Growth Performance and Intestine Health via the GSH/GSSG Antioxidant System and Nrf2/ARE Signaling Pathway in Weaned Piglets.

Early weaning of piglets was prone to increase reactive oxygen species, disrupt the redox balance, decrease antioxidant capacity, cause oxidative stress and intestinal oxidative damage, and lead to diarrhea in piglets. This research aimed to study dietary taurine (Tau) supplementation at a level relieving intestinal oxidative damage in early-weaned piglets. A total of 48 piglets were assigned to four groups of 12 individuals and fed a basal diet with 0.0% Tau (CON), 0.2% Tau (L-Tau), 0.3% Tau (M-Tau), or 0.4% Tau (H-Tau), respectively. The animal experiment lasted 30 days. The final weight, weight gain, average daily gain, and feed conversion rate increased with the increase in dietary Tau (Linear, p < 0.05; Quadratic p < 0.05), while the diarrhea index of piglets decreased with the increase in dietary Tau (Linear, p < 0.05). Serum malondialdehyde, nitric oxide (NO), D-lactose, and oxidized glutathione (GSSG) concentrations decreased with the increase in dietary Tau (Linear, p < 0.05). The O2•- and •OH clearance rate in serum, liver, and jejunum mucosa increased with the increase in dietary Tau (Linear, p < 0.05). Serum superoxide dismutase (SOD) activity, glutathione peroxidase (GPX) activity, catalase (CAT) activity, and peroxidase (POD) activity and total antioxidant capacity increased with the increase in dietary Tau (Linear, p < 0.05). The serum glutathione (GSH) concentration and the ratio of GSH to GSSG increased with the increase in dietary Tau (Linear, p < 0.05). The POD and glutathione synthase activity in the liver and jejunum mucosa increased with the increase in dietary Tau (Linear, p < 0.05). The mRNA abundances of HO-1 and GPX1 in the H-Tau group were higher than that in the L-Tau, M-Tau, and CON groups (p < 0.05). The mRNA abundances of SOD1 and Nrf2 in the M-Tau and H-Tau groups were higher than in the L-Tau and CON groups (p < 0.05). The mRNA abundance of SOD2 in the L-Tau, M-Tau, and H-Tau groups was higher than in the CON group (p < 0.05). The VH and the ratio of VH to CD of jejunum and ileum increased with the increase in dietary Tau (Linear, p < 0.05). The mRNA abundances of occludens 1 and claudin 1 in the H-Tau group were higher than that in the CON, L-Tau, and M-Tau (p < 0.05). The mRNA abundance of occludin in the L-Tau, M-Tau, and H-Tau groups was higher than that in CON (p < 0.05). The abundance of Firmicutes increased with the increase in dietary Tau (Linear, p < 0.05), while Proteobacteria and Spirochaetota decreased with the increase in dietary Tau (Linear, p < 0.05). Collectively, dietary supplementation of 0.3% and 0.4% Tau in feed could significantly improve the growth performance and enhance the antioxidant capacity of piglets.

Morphological characteristics of the duodenum of piglets fed with various feed additives

Early weaning of piglets from the sow and a sharp transition to granular feeding usually leads to the development of feed stress. As a consequence, changes occur in the small intestine epithelium, which are associated with desquamation of the epithelium of the villi, crypt hyperplasia and atrophy of the villi, colonization of pathogenic microflora, which leads to a decrease in digestion and absorption of nutrients. Hence the aim of this study was to evaluate the effect of various feed additives on the morphofunctional state of the duodenal mucosa of piglets in the pre-weaning period. Forty piglets of the same age were involved in the experiment, which were divided into four groups of 10 head each. The first group of piglets was a control one and received a standard diet and free access to water from the 7th day of life. Additionally to their standard diet, the piglets of group II were given a drug which included a combination of live yeast of the genus Saccharomyces and a complex of 6 enzymes (proteases, cellulases, xylanases, α-amylases, β-glucanases and phytases) in the amount of 0.5 kg/t of feed. Piglets of group III received 0.2 kg/t of a feed additive consisting of a mixture of essential oils from plant extracts. Piglets of group IV were given a supplement with dry yeast and egg powder enriched with immunoglobulins. Piglets had constant access to feed and water. On the 14th and 28th day of the experiment, three piglets from each group were euthanized in compliance with ethical standards for animals used in experiments. According to the results of histological studies, it was established that the duodenum mucous membrane in piglets of all experimental groups was characterized by insignificant variability. Mostly, the villi had a leaf-like or finger-like shape. The crypts were mostly closely adjacent to each other. The muscle layer was well developed, represented by smooth muscles that diverged in the places where the excretory ducts of Brunner's glands pass. The lamina of the mucous membrane was represented by a loose connective tissue made of collagen fibers and, to a lesser extent, elastic fibers and small capillaries between which lymphoid cellular elements were located. The enterocytes of the apical surface of the villi had a well-defined brush border and elongated nuclei that occupied a third of the cytoplasm. Morphometric studies showed that, compared to the control group of piglets, the addition of feed additives with a mixture of essential oils increased the taste and smell of the feed, contributing to its better consumption, thus having a positive effect on the condition of the mucous membrane. On the 14th and 28th day, a significant increase in the height and width of the villi was noted. In piglets that received feed supplements with a combination of live yeast, positive dynamics were also observed in terms of increasing the ratio of villi height to crypt depth. Summarizing the experiment results, we can note that various feed additives had a positive effect on the condition of the duodenum mucous membrane, but the feed additive containing a mixture of essential oils from plant extracts was more effective.

The Role of Probiotics in Alleviating Postweaning Diarrhea in Piglets From the Perspective of Intestinal Barriers.

Early weaning of piglets is an important strategy for improving the production efficiency of sows in modern intensive farming systems. However, due to multiple stressors such as physiological, environmental and social challenges, postweaning syndrome in piglets often occurs during early weaning period, and postweaning diarrhea (PWD) is a serious threat to piglet health, resulting in high mortality. Early weaning disrupts the intestinal barrier function of piglets, disturbs the homeostasis of gut microbiota, and destroys the intestinal chemical, mechanical and immunological barriers, which is one of the main causes of PWD in piglets. The traditional method of preventing PWD is to supplement piglet diet with antibiotics. However, the long-term overuse of antibiotics led to bacterial resistance, and antibiotics residues in animal products, threatening human health while causing dysbiosis of gut microbiota and superinfection of piglets. Antibiotic supplementation in livestock diets is prohibited in many countries and regions. Regarding this context, finding antibiotic alternatives to maintain piglet health at the critical weaning period becomes a real emergency. More and more studies showed that probiotics can prevent and treat PWD by regulating the intestinal barriers in recent years. Here, we review the research status of PWD-preventing and treating probiotics and discuss its potential mechanisms from the perspective of intestinal barriers (the intestinal microbial barrier, the intestinal chemical barrier, the intestinal mechanical barrier and the intestinal immunological barrier) in piglets.

Porcine cytomegalovirus: A very unwelcome stowaway.

The announcement of the first pig-to-human heart transplantation early this year was the culmination of a very long and arduous path. The groundbreaking first life-sustaining pig-to man heart transplantation by the team of University of Maryland at Baltimore under the lead of Professor Griffith provided the long-awaited proof that it can work–even if survival was cut short by a hitherto still to be defined process. In a fascinating webinar, Professor Griffith described in detail the course of the patient.1 One potential element in the deterioration was the increase of porcine cytomegalovirus (PCMV) DNAemia, detected in the blood of the patient. The exact role of PCMV in the sequence of events is unclear and currently analyzed in detail, and will undoubtedly increase our knowledge. As a young researcher in the laboratory of Jay Fishman, I had the privilege to play a small role in early pig-to-baboon xenotransplantation experiments done in the Transplantation Biology Research Center at MGH, headed by Professor David Sachs. Organ- and recipient survival was short in the early 2000s, and reasons were explored on many different angles. From the experience in human-to-human solid organ transplantation, one avenue was to look for activation or primary infection of latent viruses, primarily from the herpesvirus family. PCMV had been identified as a potential zoonotic agent before.2 Using quantitative PCR assays, we demonstrated activation of PCMV and baboon cytomegalovirus (BCMV) in a series of pig-to primate organ kidney xenotransplantations. High copy numbers of PCMV DNAemia were detected in recipient baboon tissue and particularly in the transplanted porcine graft tissues.3, 4 In a model of primary porcine aortic endothelial cells infected in vitro with PCMV, an increase in porcine tissue factor was observed, and we hypothesized that this was a potential cofactor in the development of an often fatal consumptive coagulopathy observed in pig-to baboon kidney xenotransplantation.5 Using PCMV-free pig donors, which was achieved by early weaning of piglets, consumptive coagulopathy was prevented in pig-to-baboon heart transplantation, resulting in an improved graft survival.6 Given the many modifications in the protocols over time, it was not possible to establish PCMV as the sole cause of this coagulopathy. Nevertheless, at this point elimination of PCMV was the clear goal given the harmful potential of this virus.7 Eradication protocols were developed and successfully tested.8 This was all the more important, as ganciclovir failed to control PCMV activation.9 BCMV activation in the recipient baboons, on the other hand, by then was controlled by prophylactic use of ganciclovir in the majority of recipients and had become part of all protocols. The most comprehensive study on the role of PCMV was recently published by Denner et al. in 2020. In a series of orthotopic pig-to-baboon heart transplantations, transmission of PCMV was observed from PCMV-positive donor pigs in some but not all baboon recipients, whereas no transmission events occurred for a number of other potentially harmful latent porcine viruses tested, including porcine lymphotropic herpesviruses, and porcine endogenous retroviruses. In baboons transplanted with a heart from a PCMV-positive donor pig, survival was reduced, inflammatory cytokines such as IL-6 and TNF-α were increased and tPA-PAI-1 complexes circulated in high concentrations in the recipients, pointing to substantial alterations of the coagulation system. This detailed report provided additional evidence for the deleterious effects of PCMV, and reiterated the need for elimination of PCMV from the pig donor.10 Why then are PCMV-positive donor pigs still an issue? Breeding pathogen-free pigs was shown to be feasible, but the effort to achieve this is considerable. In a publication on virus prevalence in different minipig breeds in 2021, PCMV was still detected in some but not all breeds.11 Recent work did primarily focus on porcine endogenous retroviruses, as elimination of these viruses is incomparably more challenging than that of traditional latent viruses. Testing for elimination requires not only the use of PCR for detection PCMV DNAemia, but also by serology, as PCR can be negative in swabs from a healthy swine. Validated serological assays for PCMV are not readily available. Efforts did understandably concentrate on the genetic modifications of donor pigs. Given the potential unfavorable role in the first human case of orthotopic heart transplantation, the focus must be redirected to the elimination of PCMV. It is a feasible and necessary step. The amazing initial clinical course of the patient is a huge incentive to keep the momentum going and continue on this path.

The level of products of lipid peroxidation in the blood of piglets at the action feed additive “Sylimevit”

Intensive pig breeding has been reported in the literature to suggest that early weaning of piglets from sows is an extreme stimulus that reduces the protective and adaptive responses of piglets. That is why the aim of the study was to study the effect of the feed additive “Sylimevit” on the level of lipid peroxidation products of piglets after weaning. Two groups of piglets were formed – control and experimental in the amount of 10 individuals in each group, selected on the principle of analogs – age, breed and body weight. During the weaning period, the piglets were kept under the sow in special machines, had constant access to the mother, and from the age of 5 days – free access to concentrated feed. While feeding of animals was carried out in accordance with the norms for a given age of pigs. Prior to the study, a clinical and physiological examination of the piglets was performed. Their general condition and activity when eating food were taken into account. On the 28th day of life, the piglets were weaned from the sow and regrouped from different nests in order to be further maintained during the period of fattening and rearing with a change in the structure of the diet, which served as technological stress for the animals. From the age of 5 days, piglets of all groups were fed pre-starter feed. Piglets of the experimental group, from 21 to 40 days of age, were additionally fed the feed supplement “Sylimevit” at a dose of 100 mg/kg body weight per day. The technological stress of weaning piglets from sows is accompanied by a gradual probable intensification of lipid peroxidation processes. Feeding Sylimevit feed to piglets after weaning helped to reduce the content of intermediate and final products of lipid peroxidation: lipid hydroperoxides – by 52 % (P &lt; 0.001) and TBA-active products – by 22.5 % (P &lt; 0.01). Thus, feeding the piglets of the experimental group of the feed additive “Sylimevit” helped to suppress the processes of lipid peroxidation in animals. Thus, the results of the use of feed additive “Sylimevit” in weaned piglets showed a pronounced antioxidant effect. The components of the feed additive directly interacted with reactive oxygen species and free radicals, preventing the development of oxidative stress.

N-Acetyl-D-glucosamine improves the intestinal development and nutrient absorption of weaned piglets via regulating the activity of intestinal stem cells.

Early weaning in piglets can cause a series of negative effects. This causes serious losses to the livestock industry. N-Acetyl-D-glucosamine (D-GlcNAc) plays an important role in regulating the homeostasis of the intestine. This study aimed to investigate the effects of D-GlcNAc on the growth performance and intestinal function of weaned piglets. Twenty-four weaned piglets ([Yorkshire × Landrace] × Duroc, 6.58 ± 0.15 kg, n = 8) at 21 d old were fed 3 diets supplemented with 0 (control), 1 and 3 g/kg D-GlcNAc. The intestinal organoid model was used to verify the regulatory mechanism of D-GlcNAc on intestinal epithelial cells. On the whole, supplementation of D-GlcNAc in the piglet diet has no significant effect on the growth performance and diarrhoea of weaned piglets (P > 0.05). The apparent digestibility of nutrients and mRNA abundance of nutrient transporters in the 1 g/kg D-GlcNAc group were increased significantly (P < 0.05). D-GlcNAc did not affect villus height (VH) and crypt depth (CD) but resulted in a numerically shorter VH and shallower CD, which lead to an increase in ileal VH:CD ratio (P < 0.05). Cell shedding rates in the ileum villi increased (P < 0.05). The relative length and weight of the small intestine of weaned piglets increased (P < 0.05). In vitro studies found that the budding rates of organoids treated with 0.1 mmol/L D-GlcNAc increased on the d 3 and 5 (P < 0.05). The average budding numbers per budding organoid treated with 0.1 and 10 mmol/L D-GlcNAc increased on d 3 (P < 0.05). D-GlcNAc upregulated leucine rich repeat containing G protein-coupled receptor 5 (Lgr5+) and Chromogranin A mRNA abundance in organoids (P < 0.05). Mucin 2 (Muc2) expression increased when treated with 1 and 10 mmol/L D-GlcNAc (P < 0.05). In conclusion, dietary D-GlcNAc cannot improve the growth performance of weaned piglets. However, it can promote the growth and development of the intestinal tract and improve the digestion and absorption capacity of the intestine, which is achieved by affecting the activity of intestinal stem cells.

Chemical Compound Chemical Treatment in Animal Husbandry

The acidulant is widely used in the production of animal husbandry, and its use is affected by many factors, including environmental factors, dosage, diet composition, and animal’s own factors, so only the correct use of the acidulant can bring good results in animal production and financial income. This article takes acidifier as an example to study the application of compound chemical treatment in livestock farms. In this paper, the effect of using acidulant in the first 1 to 3 weeks after early weaning of piglets is obvious through this experimental study. The effect gradually decreases after 3 weeks and basically has no effect after 4 weeks. Experimental studies have found that the combination of organic acids, antibiotics, and high copper is the most effective. These three have different functions and have complementary or additive effects. Under harsh feeding conditions, especially when the environmental sanitation and environmental conditions are relatively poor, the effect of acidulants is better than good feeding conditions. Experimental data show that fulvic acid depletes milk’s somatic cells in a short period of time and then quickly activates immune function, which is indicated by the increase in lymphocytes in the blood. When a large number of somatic cells migrate to the breast, the somatic cells in milk will also increase, thereby improving the immunity mediated by human cells. The experimental results show that the BFA formula added 1% to the cattle feed. After the research control of this experiment, the milk output increased by 9–17%, and the quality milk output increased by 19.12%, so the use of acidulant increased feed compensation and reduces gastrointestinal diseases and the reproduction of microorganisms in the rumen of dairy cows.

Influenza A virus in swine breeding herds: Combination of vaccination and biosecurity practices can reduce likelihood of endemic piglet reservoir

Recent modelling and empirical work on influenza A virus (IAV) suggests that piglets play an important role as an endemic reservoir. The objective of this study is to test intervention strategies aimed at reducing the incidence of IAV in piglets and ideally, preventing piglets from becoming exposed in the first place. These interventions include biosecurity measures, vaccination, and management options that swine producers may employ individually or jointly to control IAV in their herds. We have developed a stochastic Susceptible-Exposed-Infectious-Recovered-Vaccinated (SEIRV) model that reflects the spatial organization of a standard breeding herd and accounts for the different production classes of pigs therein. Notably, this model allows for loss of immunity for vaccinated and recovered animals, and for vaccinated animals to have different latency and infectious periods from unvaccinated animals as suggested by the literature. The interventions tested include: (1) varied timing of gilt introductions to the breeding herd, (2) gilt separation (no indirect transmission to or from the gilt development unit), (3) gilt vaccination upon arrival to the farm, (4) early weaning, and (5) vaccination strategies of sows with different timing (mass and pre-farrow) and efficacy (homologous vs. heterologous). We conducted a Latin Hypercube Sampling and Partial Rank Correlation Coefficient (LHS-PRCC) analysis combined with a random forest analysis to assess the relative importance of each epidemiological parameter in determining epidemic outcomes. In concert, mass vaccination, early weaning of piglets (removal 0–7days after birth), gilt separation, gilt vaccination, and longer periods between introductions of gilts (6 months) were the most effective at reducing prevalence. Endemic prevalence overall was reduced by 51% relative to the null case; endemic prevalence in piglets was reduced by 74%; and IAV was eliminated completely from the herd in 23% of all simulations. Importantly, elimination of IAV was most likely to occur within the first few days of an epidemic. The latency period, infectious period, duration of immunity, and transmission rate for piglets with maternal immunity had the highest correlation with three separate measures of IAV prevalence; therefore, these are parameters that warrant increased attention for obtaining empirical estimates. Our findings support other studies suggesting that piglets play a key role in maintaining IAV in breeding herds. We recommend biosecurity measures in combination with targeted homologous vaccination or vaccines that provide wider cross-protective immunity to prevent incursions of virus to the farm and subsequent establishment of an infected piglet reservoir.

Effect of artificial suckling devices on behaviour, adaptation pattern and growth performance of early weaned piglets

Eighteen Large White Yorkshire piglets weaned at 10 ±2 days were divided randomly into three groups (n=6) and each group was allotted to circular (T1), horizontal (T2) device and control (T3). Piglets in T3 were reared with sow through natural suckling. Piglets were acclimatised for 5 days; during this period milk was given at the rate 25 ml per piglets four times daily. Further, during first, second, third and forth fortnights feeding continued at the rate of 100, 150 and 200 ml for four, three and two times daily in T1 and T2 devices respectively. Piglets were observed for behaviour, adaptation pattern and average milk consumption time daily, while body weight gained was recorded fortnightly. 100% of piglets in T3 showed non-nutritive suckling, belly nosing, massaging and teat order behaviours, but no such observations were recorded in T1 and T2. Adaptation pattern of piglets in T1 was 66.7 % and 100% in T2 and T3. Effects of suckling devices on average milk consumption time were 10.09 % and 13.79 % lower (Pe″0.05) in T1 and T2 device respectively compared to T3. Mean body weight gain in T1 and T2 devices were 5.12% and 16.89 % higher than T3. Horizontal suckling device (T2) performed better than T1 and T3 (control). Hence it can be recommended for early weaning in piglets.

Oral administration of putrescine and proline during the suckling period improves epithelial restitution after early weaning in piglets.

Polyamines are necessary for normal integrity and the restitution after injury of the gastrointestinal epithelium. The objective of this study was to investigate the effects of oral administration of putrescine and proline during the suckling period on epithelial restitution after early weaning in piglets. Eighteen neonatal piglets (Duroc × Landrace × Large Yorkshire) from 3 litters (6 piglets per litter) were assigned to 3 groups, representing oral administration with an equal volume of saline (control), putrescine (5 mg/kg BW), and proline (25 mg/kg BW) twice daily from d 1 to weaning at 14 d of age. Plasma and intestinal samples were obtained 3 d after weaning. The results showed that oral administration of putrescine or proline increased the final BW and ADG of piglets compared with the control (P < 0.05). Proline treatment decreased plasma D-lactate concentration but increased the villus height in the jejunum and ileum, as well as the percentage of proliferating cell nuclear antigen (PCNA) positive cells and alkaline phosphatase (AKP) activity in the jejunal mucosa (P < 0.05). The protein expressions for zonula occludens (ZO-1), occludin, and claudin-3 (P < 0.05) but not mRNA were increased in the jejunum of putrescine- and proline-treated piglets compared with those of control piglets. The voltage-gated K+ channel (Kv) 1.1 protein expression in the jejunum of piglets administrated with putrescine and the Kv1.5 mRNA and Kv1.1 protein levels in the ileum of piglets administrated with proline were greater than those in control piglets (P < 0.05). These findings indicate that polyamine or its precursor could improve mucosal proliferation, intestinal morphology, as well as tight junction and potassium channel protein expressions in early-weaned piglets, with implications for epithelial restitution and barrier function after stress injury.

日粮蛋白质水平对早期断奶仔猪生产性能的影响

仔猪早期断奶已成为规模化养殖生产中采取的一项重要手段。早期断奶技术可提高母猪生产性能，也有利于提高仔猪的成活率。饲粮蛋白质是制约早期断奶仔猪生产成绩的主要因素。仔猪适宜的蛋白质水平是保证仔猪健康生长的必要条件。日粮蛋白水平对早期断奶仔猪生产性能有重要影响。由试验结果可知，日粮蛋白质水平在14%~20%的范围内，平均日增重、平均日采食量都逐渐增加，料重比与腹泻率都逐渐降低。在蛋白质为20%条件下，平均日增重与平均日采食量达到最大，料重比与腹泻率都达到最小。蛋白质水平继续升高各指标趋势相反。 Early weaning of piglets has already become an important means of intensive and mass breeding production. Early weaning technique not only may improve the sow production performance, but also improve the survival rates of piglets. Fodder protein is the main restricted factor of early weaned piglets’ production results. An appropriate protein level is the necessary condition to guarantee the health growth of piglets. Different protein level diets have an important influence on production performance of the early weaned piglets. By test results, when the protein level is in 14 percent to 20 percent range, the daily gain and average daily intake are gradually increased. Feed weight ratio and diarrhea rate are gradually reduced. Under the condition of the protein level in 20%, the daily gain and average daily intake achieve the maximum, feed weight ratio and diarrhea rate achieve the minimum. Protein level continues to rise and each index trends to the contrary.

Development of an antioxidant system after early weaning in piglets2

The objective of this experiment was to investigate oxidative injury and the development of an antioxidant system after early weaning in piglets. A total of 40 piglets (Landrace× Large White, weaned at 14 d after birth) were randomly slaughtered 0 (w0d), 1 (w1d), 3 (w3d), 5 (w5d), or 7 d (w7d; n = 8) after weaning. Concentrations of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), and protein carbonyl and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase were measured in plasma. Gene expressions of antioxidant enzymes were determined by quantitative reverse transcription PCR analysis. The mediation of transcription factor 65 (p65) and the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways by oxidative stress was determined by Western blot analysis. Results showed that the plasma MDA level was significantly higher at 3 d (P < 0.05) and that the protein carbonyl level increased at 1, 3, and 5 d (P < 0.05) compared with w0d. In addition, early weaning suppressed the plasma activity of SOD at 1 d (P < 0.05) and reduced the GSH-Px activity at 3 d (P < 0.05). The expression results in the jejunum indicate that the genes related to antioxidant enzymes were downregulated (P < 0.05) at 3 and 5 d after weaning. Uncoupling protein 2 (Ucp2), which is considered to be a feedback regulation on reactive oxygen species generation, tended to decrease in the ileum (P < 0.05) after weaning. Tumor protein 53 (p53), which regulates reactive oxygen species generation, was enhanced (P < 0.05) in the jejunum after weaning. Meanwhile, early weaning suppressed p65 (at 3, 5, and 7 d; P < 0.05) and Nrf2 (at 5 and 7 d; P < 0.05) signals in the jejunum, which might feedback-regulate antioxidant gene expression and promote the development of the antioxidant system. Therefore, we speculate that weaning disrupted oxidative balance and caused oxidative injury in piglets, and this imbalance can recover with the development of an antioxidant system via feedback regulation.

Nutritional management of gut health in pigs around weaning

Early weaning of piglets is often accompanied by a severe growth check and diarrhoea. It is well established that this process is multi-factorial and that post-weaning anorexia and undernutrition are major aetiological factors. Gastrointestinal disturbances include alterations in small intestine architecture and enzyme activities. Recent data indicate transiently-increased mucosal permeability, disturbed absorptive-secretory electrolyte balance and altered local inflammatory cytokine patterns after weaning. These responses appear to operate according to two distinct temporal patterns, an acute response followed by a long-lasting adaptation response. Pigs coexist with a diverse and dense commensal microbiota in their gastrointestinal tract. Most of these microbes are beneficial, providing necessary nutrients or protection against harmful pathogens for the host. The microbial colonisation of the porcine intestine begins at birth and follows a rapid succession during the neonatal and weaning period. Following the withdrawal of sow's milk the young piglets are highly susceptible to enteric diseases partly as a result of the altered balance between developing beneficial microbiota and the establishment of intestinal bacterial pathogens. The intestinal immune system of the newborn piglet is poorly developed at birth and undergoes a rapid period of expansion and specialisation that is not achieved before early (commercial) weaning. Here, new insights on the interactions between feed components, the commensal microbiota and the physiology and immunology of the host gastrointestinal tract are highlighted, and some novel dietary strategies are outlined that are focused on improving gut health. Prebiotics and probiotics are clear nutritional options, while convincing evidence is still lacking for other bioactive substances of vegetable origin.

Three-Day Enteral Exposure to a Red Kidney Bean Lectin Preparation Enhances the Pancreatic Response to CCK Stimulation in Suckling Pigs

Background: A reason for the digestive problems that often occur around early weaning in piglets could be that the pancreas is not yet fully developed and the enzymes required for degradation of the solid food are not secreted in enough amounts. Objectives: The aim of the study was to investigate the possibility of inducing pancreas maturation with enhanced enzyme secretion. Methods: 10-day-old suckling pigs were gavage fed with a red kidney bean lectin preparation for 3 days, and the pancreatic response to intravenous infusion of CCK-33 was measured in the anaesthetized animals fitted with pancreatic duct catheters. Results: The pancreatic fluid secretion, protein output, and the trypsin and amylase outputs were significantly increased in response to CCK stimulation after the lectin treatment, as compared to those of the control littermates (p ≤ 0.05). In addition, the plasma insulin basal levels and those observed during CCK-33 stimulation were lower in the lectin-treated piglets. Conclusion: The results suggested that the lectin treatment led to an increase in the capacity for pancreatic enzyme secretion in the suckling piglets. An enhanced pancreatic function might help to ameliorate the problems that may appear in modern pig production which are associated with weaning.

Early weaning of piglets fails to exclude porcine lymphotropic herpesvirus

Xenotransplantation using pigs as source species carries a risk for the activation of latent herpesviruses from the porcine donor and potential transmission to the recipient. In pig-to-baboon xenotransplantation, activation of porcine cytomegalovirus (PCMV) has been associated with xenograft injury and an increased incidence of consumptive coagulopathy and graft loss. Activation of porcine lymphotropic herpesvirus (PLHV)-1 was not observed in pig-to-baboon solid organ xenotransplantation, but was associated with a syndrome of post-transplantation lymphoproliferative disorder (PTLD) after allogeneic stem cell transplantation in pigs. Early weaning of piglets was used to try to reduce the viral burden of xenograft donors. This consisted of separating the piglets of a litter from the sow within the first 2 weeks after birth and raising them in isolation from the remaining herd. We have previously demonstrated that PCMV could be excluded from source animals by early weaning of piglets. However, early weaning failed to exclude PLHV-1 from source pigs. This disparity between PCMV and PLHV-1 reflects differing pathogenesis of infection of these herpesviruses. New approaches will be needed to exclude PLHV-1 from pig colonies.

Reduction of Consumptive Coagulopathy Using Porcine Cytomegalovirus-Free Cardiac Porcine Grafts in Pig-to-Primate Xenotransplantation

Xenotransplantation using pigs as the source species for organs carries a potential risk for transmission and activation of porcine herpesviruses. Activation of porcine cytomegalovirus (PCMV) in pig-to-baboon xenotransplantation is associated with xenograft injury and possibly an increased incidence of consumptive coagulopathy (CC). To further investigate the role of PCMV activation in the occurrence of CC, a strategy to exclude PCMV from the donor was developed. To exclude PCMV, piglets were early-weaned and raised separated from other swine. These piglets were used as donors in an experimental protocol of pig-to-baboon heart xenotransplantation. Early weaning of piglets was successful in excluding PCMV. Use of PCMV-free cardiac porcine xenografts in baboons resulted in prolonged graft survival and prevented consumptive coagulopathy in all recipients. The use of PCMV-free cardiac grafts is beneficial in reducing the direct effects of PCMV activation in the graft (tissue damage) and the indirect effects of PCMV activation in the recipient (consumptive coagulopathy).

Xenotransplantation: Infectious Risk Revisited

Xenotransplantation is a possible solution for the shortage of tissues for human transplantation. Multiple hurdles exist to clinical xenotransplantation, including immunologic barriers, metabolic differences between pigs – the source species most commonly considered – and humans, and ethical concerns. Since clinical trials were first proposed almost 10 years ago, the degree of risk for infection transmitted from the xenograft donor to the recipient has been extensively investigated. A number of potential viral pathogens have been identified including porcine endogenous retrovirus (PERV), porcine cytomegalovirus (PCMV), and porcine lymphotropic herpesvirus (PLHV). Sensitive diagnostic assays have been developed for each virus. Human-tropic PERV are exogenous recombinants between PERV-A and PERV-C sequences and are present in only a subset of swine. Porcine cytomegalovirus can be excluded from herds of source animals by early weaning of piglets. In contrast, the risks associated with PLHV remain undefined. Microbiologic studies and assays for potential xenogeneic pathogens have furthered understanding of risks associated with xenotransplantation. Thus far, clinical xenotransplantation of pig tissues has not resulted in transmission of viral infection to humans; significant risks for disease transmission from swine to humans have not been confirmed. If immunologic hurdles can be overcome, it is reasonable to initiate carefully monitored clinical trials.

Neuroendocrine consequences of very early weaning in swine

An experiment was conducted to investigate the consequences of very early weaning of piglets on neuroendocrine variables and growth. Sixty piglets from eight litters were either weaned on Postnatal Day 6 (early weaning, or EW piglets) or left with their dam until normal weaning at Day 28 (control piglets, or C). At Days 5, 7, 11, 14, and 19, urine was collected between 7:00 and 8:00 a.m. for the measurement of catecholamines, glucocorticoids, and creatinine. Compared with C, EW piglets displayed a transient increase in urinary cortisol on the day following separation from their dam (Day 7) ( P<.05). Urinary norepinephrine (NE) was three times lower in EW compared to C piglets from Day 7 until Day 14 ( P<.01) but there was no difference between the two groups on Day 19. Urinary epinephrine (EPI) did not differ between C and EW piglets on the day after weaning. Thereafter, EW piglets displayed a three times drop in urinary EPI as compared to C piglets until the end of the period ( P<.01). Weaning induced an immediate reduction in food intake and growth rate and at Day 28, the body weight of EW piglets was 1.60 kg lower than that of C piglets ( P<.0001). In conclusion, weaning of 6-day-old piglets results in a marked and prolonged suppression of the release of catecholamines. This result likely reflects physiological responses to insufficient energy intake after weaning, as reflected also by changes in thermoregulatory behavior. The transient increase in cortisol excretion in weanlings may be caused by both emotional distress and acute food deprivation.