A comparative evaluation of methods for estimating the colostrum quality in sows / Avaliação comparativa de métodos para estimar a qualidade do colostro em porcas

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.(AU)

O colostro é a principal fonte de imunoglobulinas (Ig) para leitões recém-nascidos e desempenha um papel crucial na saúde e no crescimento dos leitões. Atualmente, na suinocultura, ainda não existem métodos amplamente utilizados na prática de produção para medir a concentração de imunoglobulinas no colostro suíno. Avaliou-se a concentração de IgG no colostro de porcas usando refratômetros Brix óptico e digital, e o desempenho foi comparado com ELISA e citometria de fluxo. As concentrações de IgG e IgA no colostro foram 74,05 ± 21,37mg/mL e 20,2 ± 5,32mg/mL, respectivamente. A percentagem de Brix média das amostras de colostro para o refratômetro óptico foi 26,32%, e para o digital foi 28,32%. As medições dos refratômetros de Brix apresentaram elevada correlação com a concentrações de IgG medidas por ELISA (óptico=0,74, digital=0,87; P<0,001). Considerando a imunofenotipagem, os valores dos linfoblastos IgG e IgA apresentaram alta correlação com o ELISA (IgG=0,77, IgA=0,84; P<0,001). O refratômetro Brix pode ser considerado uma ferramenta útil para ser incluída em um programa de monitoramento de colostro para melhorar a saúde neonatal. Além disso, foi demonstrado que a citometria de fluxo pode ser uma ferramenta importante para analisar e caracterizar o potencial imunológico do colostro de porcas.(AU)

Effects of supplementing sow diets during late gestation with Pennisetum purpureum on antioxidant indices, immune parameters and faecal microbiota.

The purpose of this study was to investigate the effects of adding Pennisetum purpureum (P. purpureum, also known as Napier grass or elephant grass) to the diets of late gestation on the antioxidant indexes, immune indexes and faecal microbiota of sows. At the 90 days of gestation, 300 healthy sows were randomly divided into three groups, and they received the basic commercial diet or added 5% P. purpureum and 10% P. purpureum, respectively. The experiment started from 90 days of gestation to parturition. The results showed that the total antioxidant capacity, immunoglobulins and serum equol concentrations of sows on 100 days of gestation and at parturition increased linearly (p < .05) with the increase of the content of P. purpureum in the gestation diet. The 5% P. purpureum increased the relative abundance of Bacteroidetes (p = .027) and Actinobacteria (p < .001) at phylum level, Coriobacteriaceae (p < .001) at family level and Prevotellaceae_UCG_001 (p = .004) at genus level, and decreased the relative abundance of Escherichia_Shigella (p < .001) at genus level. In summary, this study shows that the additive of P. purpureum can increase the concentration of serum equol, improve the antioxidant capacity and immune function of sow in late gestation. In addition, the additive of 5% P. purpureum in the diet might change the composition of intestinal microbiota of sows, particularly the relative abundance of Coriobacteriaceae (p < .001) increased.

Effects of tea tree oil supplementation on growth performance, antioxidant capacity, immune status and microbial community in weaned pigs.

The objective of this study was to determine whether dietary tea tree oil (TTO) supplementation could effectively replace the antibiotics through modulating the antioxidant capacity and intestinal microbiota profile, and then decreasing the diarrhoea incidence and improving the growth performance of weaned pigs. A total of 216 weaned pigs with initial body weights (BW) of 9.19 ± 1.86 kg were randomly allocated to three dietary treatments in a completely randomised design. The dietary treatments included a corn-soybean meal basal diet (CON) without any antibiotics, and two experimental diets formulated by adding 75 mg/kg aureomycin (AGP) or 100 mg/kg TTO into the basal diet, respectively. Pigs fed the TTO diet showed greater gain to feed ratio (p < 0.05) than those fed CON and AGP diets during d 0-14 and d 14-28. Both dietary TTO and AGP supplementation tended to increase the average daily gain of weaned pigs during d 14-28 (p = 0.06) and the overall 28-d period (p = 0.07), and significantly reduced (p < 0.05) the diarrhoea incidence during d 0-14 compared with the CON treatment. In addition, dietary TTO supplementation improved the apparent total tract digestibility of dry matter and ether extract (p < 0.05), and increased (p < 0.05) the propionate and butyrate concentrations in faecal samples of weaned pigs. Moreover, pigs fed the TTO diet showed greater total antioxidant capacity, greater superoxide dismutase and interleukin-10 concentrations, and lower malondialdehyde concentration in serum than those fed the CON diet (p < 0.05). Furthermore, pigs fed the TTO diet demonstrated greater relative abundance of Clostridiaceae_1, while those fed the AGP diet exhibited greater relative abundance of Lactobacillaceae at family level. In conclusion, dietary TTO supplementation could improve growth performance in weaned pigs, which could be mainly attributed to the benefits on nutrient digestibility, antioxidative capacity and microbial community profile.

Dietary supplementation of beta-glucan-rich molasses yeast powder on antibody response to swine fever virus and hematology of starter-grower pigs.

This research investigated the impact of dietary beta-glucan-rich molasses yeast powder (MYP) supplementation on the antibody response to swine fever virus (Titer) and hematology of starter-grower pig. Sixteen cross pigs (30 kg body weight) were equally split into four groups; each group with four replicates and fed four dietary treatments that consisted of basal diets (control) and the basal diets added with 2.5, 5.0, and 7.5% MYP. Feed and water were consumed ad libitum for 44 days. Feed intake (FI), MYP intake (MYPI), beta-glucan intake (BGI), and Mannan-oligosaccharide intake (MOSI) were recorded daily. Titer was evaluated after 15 (Titer15) and 30 (Titer30) days after vaccination, while hematology was analyzed at the end of the experiment. The results indicated that it was unchangeable for ADFI (P > 0.05). No impacts were observed on hematological variables and Titer15 in MYP fed pigs (P > 0.05). However, supplementation with 7.5% MYP increased platelet count (PC) and Titer30 (P < 0.01), but decreased hematocrit (Hct) (P < 0.05). Titer 30 and titer 15 were linked to MYPI, BGI, and MOSI (P < 0.05). Based on the study, feeding starter-grower pigs diets supplemented with 7.5% MYP might enhance the antibody response to swine fever virus 30 days after vaccination, and it has a potential role in the application in prevention of swine fever virus disease.

Effect of Folic Acid Supplementation and Dietary Protein Level on Growth Performance, Serum Chemistry and Immune Response in Weanling Piglets Fed Differing Concentrations of Aflatoxin.

Effects of folic acid and protein levels on growth and serum chemistry in pigs fed aflatoxin were determined in two experiments. Increasing aflatoxin (250 to 800 ppb) decreased (P < 0.05) weight gain and feed intake for both of the 35-day trials. In Experiment 1, increasing aflatoxin (0, 250, 500 ppb), increased linearly (P < 0.05) aspartate aminotransferase (AST), alkaline phosphatase (ALKP) and ɣ-glutamyl transferase (GGT). Folic acid (0, 2.0, 5.0, 12.5 ppm) increased linearly (P < 0.05) serum K, Ca, P, Mg, and AST with the largest effect observed at 12.5 ppm. Folic acid decreased (P < 0.05) blood urea nitrogen (BUN): creatinine and Na:K. In Experiment 2, aflatoxin (800 ppb) increased (P < 0.05) glucose and GGT, and decreased (P < 0.05) Na:K and albumin:globulin. Increasing protein from 15 to 18% elevated BUN: creatinine (P < 0.05), albumin: globulin (P < 0.05), albumin (P < 0.05) and ALKP (P < 0.05). Folic acid (2 ppm) elevated (P < 0.05) BUN, and interacted with both aflatoxin (P < 0.10) and protein (P < 0.05) on BUN. Adding folic acid to aflatoxin contaminated diets improved some measures of clinical chemistry in Experiment 1 but not traditional growth performance measures. The higher protein level reduced the effects of aflatoxicosis on growth.

Effects of soybean hulls and lignocellulose on performance, nutrient digestibility, microbial metabolites and immune response in piglets.

A feeding trial with 96 piglets was performed to investigate the effect of added soluble (SDF) and insoluble dietary fibre (IDF) sources on performance, apparent total tract digestibility (ATTD), concentration of microbial metabolites and pro-inflammatory marker genes as indicators for immune response. Piglets were allotted to four treatments (T): T1 control, T2 with soybean hulls (IDF/SDF: 8.35) and T3 and T4 with two different kinds of lignocellulose (IDF/SDF: >70). Diets were isofibrous for their value of total dietary fibre to underline the particular physicochemical properties of fibre sources. No differences were observed regarding average daily feed intake, average daily gain (ADG), feed conversion ratio and body weight, while T2 expressed higher ADG in the grower phase (day 14-54) vs. T3. Soybean hulls (T2) resulted in higher ATTD of dry matter and organic matter vs. T4; ether extract vs. T1 and neutral detergent fibre vs. T1, T2 and T3. The concentration of short chain fatty acids did not differ among treatments. Ileal digesta in T2 generated higher amounts of cadaverine vs. T3 and T4, likewise T1 vs. T4. Finally, no impact on immune response was detected. In conclusion, soybean hulls affected ATTD positively and lignocellulose prevented the formation of cadaverine, no overall direct response of SDF nor of IDF for the inclusion level  were observed.

Increased vitamin supplement to sows, piglets and finishers and the effect in productivity.

With still limited information on vitamin requirements and considering that many commercial practices adopt dietary vitamin levels above the values suggested by nutritional tables, this study aimed to assess the effect of administering vitamin supplementation to sows in gestation and lactation and to their litters on the reproductive performance and body condition of the sows and on the performance and immune profile of the litters until slaughter. The trial was split into two phases. The first phase used 104 sows, assigned to be randomized to blocks according to parity, submitted until 21 days of lactation to two treatments: control-standard (standard levels of vitamins) and test-elevated (elevated levels of vitamins). Each sow and its respective farrow were considered an experimental unit. The sows underwent evaluations of body condition score, back fat thickness and reproductive performance. In the second phase, 60 barrows and 60 gilts at 21 days of age and mean initial weight of 5.33 ± 1.5 kg until slaughter at 164 days of age. The piglets were assigned to randomized blocks according to the weight and sex of the animals in a 2 × 2 factorial model, with 10 replicates per treatment, where a pen with three animals represented the experimental unit. Following the same treatments of the first phase, the piglets were evaluated for daily weight gain, daily feed intake, feed conversion, mortality rate and humoral immune response. Vitamin supplementation had no positive effects on the reproductive parameters or body composition of sows. However, it positively impacted the performance of the litters in the early nursery stage, but did not lead to superior effects on the immune responses to vaccination against circovirus or mycoplasma.

Dose-dependent effects of two inulin types differing in chain length on the small intestinal morphology, contractility and proinflammatory cytokine gene expression in piglets.

Inulin is a linear fructose polymer which may affect small intestinal physiology. The effects of dietary level of two inulin types on morphology, contractility and proinflammatory cytokine gene expression in the small intestine of piglets were investigated. Fifty six piglets were divided into seven groups fed diets without inulin addition or with 1%, 2% or 3% of inulin with an average degree of polymerisation of 10 (IN10) or 23 (IN23). All diets were offered from day 10 of life for 40 d. Feeding IN10 diets did not affect villous height to crypt depth ratio in the duodenum, while in the jejunum the 2% IN10 diet increased it as compared to other groups. Jejunal muscle contractions induced by electrical field stimulation were impaired by the 2% and 3% IN10 diets. The ileal expression of interleukin-12p40 was decreased by the 2% IN10 diet. There was no effect of IN23 level on villous height to crypt depth ratio in any segment of the small intestine as well as on jejunal motility. The 2% and 3% IN23 diets decreased the jejunal expression of tumour necrosis factor-α. In conclusion, IN10 is more active in the small intestine than IN23. At the 2% dietary level, it increases absorptive area in the jejunum, but may slightly impair smooth muscle contractions.

Oral vitamin A supplementation of porcine epidemic diarrhea virus infected gilts enhances IgA and lactogenic immune protection of nursing piglets.

Vitamin A (VA) has pleiotropic effects on the immune system and is critical for mucosal immune function and intestinal lymphocyte trafficking. We hypothesized that oral VA supplementation of porcine epidemic diarrhea virus (PEDV)-infected pregnant gilts would enhance the gut-mammary gland-secretory IgA axis to boost lactogenic immunity and passive protection of nursing piglets against PEDV challenge. Gilts received daily oral retinyl acetate (30 000 IU) starting at gestation day 76 throughout lactation. At 3-4 weeks pre-partum, VA-supplemented (PEDV + VA) and non-supplemented (PEDV) gilts were PEDV or mock inoculated (mock + VA and mock, respectively). PEDV + VA gilts had decreased mean PEDV RNA shedding titers and diarrhea scores. To determine if lactogenic immunity correlated with protection, all piglets were PEDV-challenged at 3-5 days post-partum. The survival rate of PEDV + VA litters was 74.2% compared with 55.9% in PEDV litters. Mock and mock + VA litter survival rates were 5.7% and 8.3%, respectively. PEDV + VA gilts had increased PEDV IgA antibody secreting cells and PEDV IgA antibodies in serum pre-partum and IgA+ß7+ (gut homing) cells in milk post piglet challenge compared with PEDV gilts. Our findings suggest that oral VA supplementation may act as an adjuvant during pregnancy, enhancing maternal IgA and lactogenic immune protection in nursing piglets.

Microalgae supplementation to late gestation sows and its effects on the health status of weaned piglets fed diets containing high- or low-quality protein sources.

Maternal stress, such as a bacterial infection occurring in late gestation, may predispose offspring to a variety of diseases later in life. It may also alter programming of developing systems within the fetus, such as the hypothalamic-pituitary-adrenal (HPA) axis and immune system. Dietary supplementation during the last trimester of pregnancy with immune-modulating compounds may be a means of reducing potential adverse effects of maternal stress on the developing fetus. Essential omega-3 polyunsaturated fatty acids (n-3 PUFA) such as docosahexanoic acid (DHA) and eicosapentanoic acid are well-known for their immune-modulating and anti-inflammatory properties. Sources of these n-3 PUFA include fish products such as fish oil and microalgae, which may be a suitable alternative to fish-based products. The aim of this study was to determine the effect of supplementing gestating sow diets with n-3 PUFA and inducing an immune stress challenge in late gestation on piglet growth and immune responsiveness when placed on either a high- or low-quality protein diet after weaning. Forty-eight sows were fed gestation diets containing either 3.12% microalgae, 3.1% fish oil or a corn oil control diet containing 1.89% corn oil starting on gestation day (gd) 75. On gd112, half the sows in each treatment were immune stress challenged with bacterial lipopolysaccharide (LPS) endotoxin (10 µg/kg administered i.m). After farrowing, piglet BW gain was monitored weekly during lactation and pigs were weaned at 21 days of age. One week after weaning, four piglets per sow were immune stress challenged with LPS (40 µg/kg administered i.m.). At the same time, four piglets per sow were vaccinated with the novel antigens chicken ovalbumin (OVA) and Candida cellular antigen (CAA) and received booster vaccinations two weeks later. Four weeks after the initial vaccination, a transdermal hypersensitivity immune challenge was performed using the same antigens. Blood samples were also collected to quantify IgG antibody responses to both antigens. PUFA enrichment in sow blood and piglet brain was detected after sows were on feed for 40 days. Piglet growth was increased in pigs fed a high-quality diet in nursery phase 1. Concentrations of the cytokines IL-1ra, IL-6 and IL-10 were elevated in pigs fed a high-quality protein diet following LPS immune challenge. Overall, it appears that in the current study piglet nursery diet quality was more important for determining piglet health and growth than maternal diet and immune stress.

Effects of dietary 25-hydroxyvitamin D3 supplementation on growth performance, immune function and antioxidative capacity in weaned piglets.

The study evaluated the effects of different doses of 25-hydroxyvitamin D3 (25(OH)D3) on growth performance, immune function and antioxidative capacity in piglets. In a 21-d trial, 35 weaned pigs were divided into five groups and diets were supplemented with 5.5 (control), 43.0, 80.5, 118.0 and 155.5 µg 25(OH)D3/kg, respectively. No treatment effects were observed for average daily gain, average daily feed intake and feed to gain ratio. Increasing dietary 25(OH)D3 levels increased serum 25(OH)D3 concentrations linearly (p < 0.01), decreased the frequency of CD3+CD4+ and CD3+CD8+ T cells (p < 0.01), and the serum level of complement component 3 (p < 0.05). Supplementation of 80.5 and 118.0 µg 25(OH)D3/kg enhanced the activity of serum glutathione peroxidase (p < 0.05) and addition of 43.0 µg 25(OH)D3/kg increased the malondialdehyde concentration (p < 0.05). Overall, feeding high-dose 25(OH)D3 to weaned pigs partly improved immune functions and the antioxidative capacity.

The effects of superoxide dismutase-rich melon pulp concentrate on inflammation, antioxidant status and growth performance of challenged post-weaning piglets.

Piglets can often suffer impaired antioxidant status and poor immune response during post-weaning, especially when chronic inflammation takes place, leading to lower growth rates than expected. Oral administration of dietary antioxidant compounds during this period could be a feasible way to balance oxidation processes and increase health and growth performance. The aim of the trial was to study the effects of an antioxidant feed supplement (melon pulp concentrate) that contains high concentration of the antioxidant superoxide dismutase (SOD) on inflammation, antioxidant status and growth performance of lipopolysaccharide (LPS) challenged weaned piglets. In total, 48 weaned piglets were individually allocated to four experimental groups in a 2×2 factorial design for 29 days. Two different dietary treatments were adopted: (a) control (CTR), fed a basal diet, (b) treatment (MPC), fed the basal diet plus 30 g/ton of melon pulp concentrate. On days 19, 21, 23 and 25 half of the animals within CTR and MPC groups were subjected to a challenge with intramuscular injections of an increasing dosage of LPS from Escherichia coli (serotype 0.55:B5) (+) or were injected with an equal amount of PBS solution (-). Blood samples were collected at the beginning of the trial and under the challenge period for interleukin 1ß, interleukin 6, tumour necrosis factor α, haptoglobin, plasma SOD activity, total antioxidant capacity, reactive oxygen species, red blood cells and plasma resistance to haemolysis, and 8-oxo-7, 8-dihydro-2'-deoxyguanosine. Growth performance was evaluated weekly. A positive effect of melon pulp concentrate was evidenced on total antioxidant capacity, half-haemolysis time of red blood cells, average daily gain (ADG) and feed intake, while LPS challenge increased pro-inflammatory cytokines and haptoglobin serum concentrations, with a reduced feed intake and gain : feed (G : F). The obtained results show that oral SOD supplementation with melon pulp concentrate ameliorates the total antioxidant capacity and the half-haemolysis time in red blood cell of post-weaning piglets, with positive results on growing performance.

The effects of zinc amino acid complex supplementation on the porcine host response to Lawsonia intracellularis infection.

Lawsonia intracellularis is among the most important enteric pathogens of swine and antibiotic alternatives are needed to help mitigate the negative effects of infection. Zinc is an essential trace mineral known to be crucial for maintaining intestinal barrier function and proper immune response. In this study, we investigated the porcine host response to L. intracellularis infection when supplemented with a zinc-amino acid complex, a form of zinc that can lead to greater bioavailability when compared to traditional inorganic forms of zinc. Our results show that a zinc-amino acid complex supplementation with a final concentration of 125 ppm of zinc in feed significantly (p < 0.05) decreased the number of animals with lesions and severity of lesions caused by L. intracellularis. Animals supplemented with the zinc-amino acid complex also exhibited a significantly (p < 0.05) earlier onset of seroconversion as well as an increased number of T cells in infected and non-infected intestinal tissue. This study demonstrated that this zinc-amino acid complex aids the host in responding to L. intracellularis infection and may be a new approach to help minimize negative effects of disease.

Characterisation of the porcine cytokines which activate the CD131ßc common sub-unit, for potential immune-augmentation.

Early acting cytokines and growth factors such as those of the CD131 ßc subunit, may offer an alternative method to the current use of antibiotics and chemicals such as anthelmintics in maintaining Porcine (Po) health. Thus far, the recombinant Po (rPo) Granulocyte-macrophage colony-stimulating factor (GM-CSF), rPo interleukin-3 (IL-3) and rPo interleukin-5 (IL-5) proteins have been identified and cloned and the biological activity of each cytokine has been confirmed in vitro, however, in vivo immune system regulation and hematopoietic stem cell (HSC) augmentation are regulated by numerous cytokines and cellular signals within the bone marrow (BM) niche. In order to quantify the use of recombinant cytokines in augmenting the immune response, it is necessary to determine the stages of hematopoiesis induced by each cytokine and possible areas of synergy requiring further investigation. Here we used the chemotherapeutic agent 5-fluorouracil (5-FU), to chemically induce a state of myelosuppression in young pigs. This allowed for the monitoring of both the autologous BM reconstitution and recombinant cytokine induced BM repopulation, precursor cell proliferation and cellular differentiation. The recombinant cytokines PoGM-CSF, PoIL-3 and PoIL-5 were administered by intramuscular injections (i.m.) following confirmation of 5-FU induced leukocytopenia. Blood and BM samples were collected and then analysed for cell composition. Statistically significant results were observed in several blood cell populations including eosinophils for animals treated with rPoIL-5, rPoGM-CSF and basophils for animals treated with rPoIL-3. BM analysis of CD90+ and CD172a+ cells confirmed myelosuppression in week one with significant results observed between rPoIL-3 and the 5-FU control group in week two and for the rPoGM-CSF group in week three. These results have demonstrated the effects of each of these rPo cytokines within the hematopoietic processes of the pig and may demonstrate similar outcomes in other mammalian models including human.

The microbial community of the gut differs between piglets fed sow milk, milk replacer or bovine colostrum.

The aim of this study was to characterise the gut microbiota composition of piglets fed bovine colostrum (BC), milk replacer (MR) or sow milk (SM) in the post-weaning period. Piglets (n 36), 23-d old, were randomly allocated to the three diets. Faecal samples were collected at 23, 25, 27 and 30 d of age. Digesta from the stomach, ileum, caecum and mid-colon was collected at 30 d of age. Bacterial DNA from all samples was subjected to amplicon sequencing of the 16S rRNA gene. Bacterial enumerations by culture and SCFA analysis were conducted as well. BC-piglets had the highest abundance of Lactococcus in the stomach (P<0·0001) and ileal (P<0·0001) digesta, whereas SM-piglets had the highest abundance of Lactobacillus in the stomach digesta (P<0·0001). MR-piglets had a high abundance of Enterobacteriaceae in the ileal digesta (P<0·0001) and a higher number of haemolytic bacteria in ileal (P=0·0002) and mid-colon (P=0·001) digesta than SM-piglets. BC-piglets showed the highest colonic concentration of iso-butyric and iso-valeric acid (P=0·02). Sequencing and culture showed that MR-piglets were colonised by a higher number of Enterobacteriaceae, whereas the gut microbiota of BC-piglets was characterised by a change in lactic acid bacteria genera when compared with SM-piglets. We conclude that especially the ileal microbiota of BC-piglets had a closer resemblance to that of SM-piglets in regard to the abundance of potential enteric pathogens than did MR-piglets. The results indicate that BC may be a useful substitute for regular milk replacers, and as a feeding supplement in the immediate post-weaning period.

Renal xenotransplantation: experimental progress and clinical prospects.

There are >100,000 patients waiting for kidney transplants in the United States and a vast need worldwide. Xenotransplantation, in the form of the transplantation of kidneys from genetically engineered pigs, offers the possibility of overcoming the chronic shortage of deceased and living human donors. These genetic manipulations can take the form of (i) knockout of pig genes that are responsible for the expression of antigens against which the primate (human or nonhuman primate) has natural "preformed" antibodies that bind and initiate complement-mediated destruction or (ii) the insertion of human transgenes that provide protection against the human complement, coagulation, or inflammatory responses. Between 1989 and 2015, pig kidney graft survival in nonhuman primates increased from 23 days to almost 10 months. There appear to be no clinically significant physiological incompatibilities in renal function between pigs and primates. The organ-source pigs will be housed in a biosecure environment, and thus the risk of transferring an exogenous potentially pathogenic microorganism will be less than that after allotransplantation. Although the risk associated with porcine endogenous retroviruses is considered small, techniques are now available whereby they could potentially be excluded from the pig. The US Food and Drug Administration suggests that xenotransplantation should be restricted to "patients with serious or life-threatening diseases for whom adequately safe and effective alternative therapies are not available." These might include those with (i) a high degree of allosensitization to human leukocyte antigens or (ii) rapid recurrence of primary disease in previous allografts. The potential psychosocial, regulatory, and legal aspects of clinical xenotransplantation are briefly discussed.

Effect of a post-weaning diet supplemented with functional feed additives on ileal transcriptome activity and serum cytokines in piglets challenged with lipopolysaccharide.

This study evaluated the potential of a weanling diet supplemented with trace minerals, vitamins, prebiotics, essential oils, antioxidants and bovine colostrum (BC) to modulate the inflammatory response of low-weight (LW) and high-weight (HW) piglets challenged with lipopolysaccharide (LPS). At weaning (20±1 d), litters from 32 sows were assigned to four groups: control diet (CTL), CTL plus dietary supplements (DS) or the antibiotic chlortetracycline (ATB), or DS plus BC in place of plasma proteins in the weanling diet (DS+BC). At 37 d (T0), two LW and two HW piglets were bled to evaluate ex vivo cytokine production by LPS activated peripheral blood mononuclear cells (PBMCs). In parallel, LW and HW piglets received intraperitoneal LPS and were bled at slaughter at 4h (T4) or 18h (T18) post-injection. Ileal tissues from these piglets and two unchallenged medium weight (MW) piglets per treatment were excised and analyzed by microarray. At T0, cytokine production of LPS-activated PBMCs was not affected by dietary treatments. At T4 after LPS challenge, serum concentrations of TNF-α, IL-6, IL-8, and IL-10 were increased in all piglets (P<0.01). Interestingly, the LW piglets had a higher TNF-α level than the HW piglets did (P=0.05). Dietary treatments had no effect on the piglet serum concentration of these cytokines neither at T4 nor at T18. Microarray data and QPCR analysis reveal that several genes were differentially expressed in the LPS-challenged piglets in comparison with the two control MW piglets (P<0.001). However, the dietary treatments had a slight effect on the ileal gene expression of the T4 and T18 LPS-challenged piglets when all piglets were included in the analysis. But when body weight (LW and HW) was considered as a fixed effect, the microarray analysis showed that the expression of 54 genes was differentially modulated by the dietary treatments in the T4 and T18 LPS-challenged LW piglets (P<0.05) while in HW piglets no difference was observed. QPCR analyses confirm that the level expression of several genes was reduced in LW piglets fed DS or DS+BC diet compared with ATB piglets. In conclusion, LPS challenge induced a transitional inflammation in weanling piglets that was characterized by increased blood-circulating cytokines and gut transcriptome activity. Results also suggest that the weanling diet supplemented with feed additives attenuated the ileal gene response to the LPS challenge, an effect that was more pronounced in the LW piglets.

Effects of dietary addition of heat-killed Mycobacterium phlei on growth performance, immune status and anti-oxidative capacity in early weaned piglets.

The contradiction between high susceptibility of early weaned piglets to enteric pathogens and rigid restriction of antibiotic use in the diet is still prominent in the livestock production industry. To address this issue, the study was designed to replace dietary antibiotics partly or completely by an immunostimulant, namely heat-killed Mycobacterium phlei (M. phlei). Piglets (n = 192) were randomly assigned to one of the four groups: (1) basal diet (Group A), (2) basal diet + a mixture of antibiotics (80 mg/kg diet, Group B), (3) basal diet + a mixture of antibiotics (same as in Group B, but 40 mg/kg diet) + heat-killed M. phlei (1.5 g/kg diet) (Group C) and (4) basal diet + heat-killed M. phlei (3 g/kg diet) (Group D). All piglets received the respective diets from days 21 to 51 of age and were weaned at the age of 28 d. Compared with the Control (Group A), in all other groups the average daily gain, average daily feed intake, small intestinal villus height:crypt depth ratio and protein levels of occludin and ZO-1 in the jejunal mucosa were increased. A decreased incidence of diarrhoea in conjunction with an increased sIgA concentration in the intestinal mucosa and serum IL-12 and IFN-γ concentrations was found in groups supplemented with heat-killed M. phlei (Groups C and D), but not in Group B. Groups C and D also showed decreased IL-2 concentrations in the intestinal mucosa with lower TLR4 and phosphor-IκB protein levels. The antioxidant capacity was reinforced in Groups C and D, as evidenced by the reduction in malondialdehyde and enhanced activities of antioxidant enzymes in serum. These data indicate that heat-killed M. phlei is a promising alternative to antibiotic use for early weaned piglets via induction of protective immune responses.

Effect of bovine colostrum feeding in comparison with milk replacer and natural feeding on the immune responses and colonisation of enterotoxigenic Escherichia coli in the intestinal tissue of piglets.

The present study investigated the effect of feeding bovine colostrum (BC) to piglets in comparison with feeding a milk replacer (MR) and conventional rearing by the sow on the intestinal immune system and number of enterotoxigenic Escherichia coli (ETEC) colonising the intestinal tissue. Piglets (23-d-old) were allocated to one of the following four groups: (1) killed at the beginning of the experiment (Base); (2) separated from the sow and fed BC (BC-fed); (3) separated from the sow and fed a MR (MR-fed); (4) kept with the sow (Sow-Milk). Blood was sampled on days 1 and 8, and faecal samples were collected on days 1, 3, 5 and 8. On day 8, piglets were killed and gastrointestinal digesta and intestinal segments were collected. The frequency of diarrhoea was found to be higher (P≤ 0·019) in MR-fed piglets than in BC-fed and Sow-Milk piglets. Piglets from the MR-fed group had the lowest lactic acid bacteria:haemolytic E. coli ratio (P(treat)= 0·064) in the faeces. The number of E. coli colonising the intestinal tissue was higher (P< 0·001) in piglets from the MR-fed group than in those from the BC-fed and Sow-Milk groups. Piglets from the Sow-Milk group had a higher (P= 0·020) mucosal IgG concentration than those from the MR-fed group, but did not exhibit any difference when compared with piglets from the Base and BC-fed groups. Piglets from the BC-fed group exhibited a reduced (P≤ 0·037) expression level of Toll-like receptor-4 in the intestinal mucosa when compared with those from the MR-fed and Sow-Milk groups. The expression level of IL-2 was higher (P≤ 0·051) in piglets from the MR-fed group than in those from the other treatment groups. In conclusion, feeding BC rather than MR to the piglets reduced the colonisation of intestine by ETEC and modulated the intestinal immune system, whereas no differences were observed in piglets fed BC and conventionally reared by the sows.

Induced lung inflammation and dietary protein supply affect nitrogen retention and amino acid metabolism in growing pigs.

It is hypothesised that during immune system activation, there is a competition for amino acids (AA) between body protein deposition and immune system functioning. The aim of the present study was to quantify the effect of immune system activation on N retention and AA metabolism in growing pigs, depending on dietary protein supply. A total of sixteen barrows received an adequate (Ad) or restricted (Res) amount of dietary protein, and were challenged at day 0 with intravenous complete Freund's adjuvant (CFA). At days - 5, 3 and 8, an irreversible loss rate (ILR) of eight AA was determined. CFA successfully activated the immune system, as indicated by a 2- to 4-fold increase in serum concentrations of acute-phase proteins (APP). Pre-challenge C-reactive protein concentrations were lower (P< 0·05) and pre- and post-challenge albumin tended to be lower in Res-pigs. These findings indicate that a restricted protein supply can limit the acute-phase response. CFA increased urinary N losses (P= 0·04) and tended to reduce N retention in Ad-pigs, but not in Res-pigs (P= 0·07). The ILR for Val was lower (P= 0·05) at day 8 than at day 3 in the post-challenge period. The ILR of most AA, except for Trp, were strongly affected by dietary protein supply and positively correlated with N retention. The correlations between the ILR and APP indices were absent or negative, indicating that changes in AA utilisation for APP synthesis were either not substantial or more likely outweighed by a decrease in muscle protein synthesis during immune system activation in growing pigs.