Viable Pig Research Articles

PSV-10 Evaluation of a Nutritional Feed Supplement (Furst Protect™) on Growth Performance in Nursery Pigs

Abstract Furst Protect is a combination of monoglycerides, fatty acids, and phytonutrients. Research has shown that Furst Protect improved growth and reduced mortality in nursery pigs during a multi-viral challenged infection. Thus, the response of Furst Protect was evaluated during the first 21 d of nursery phase. A total of 551 (DNA x DNA 600 sired) weaned, commercial pigs (21 d of age, average 5.58 kg (P = 0.38); 9-10 reps; 29 pigs/pen) were blocked by body weight. There were 2 treatments: standard nursery feed without antibiotics, control (CON); 2) CON + 8 lb per ton of Furst Protect (FP) for 21 d. FANCOM feeding system was used to deliver feed. Pens of pigs were weighed and feed disappearances were recorded on d 0 and 21. Data were used to calculate ADG and ADFI. To simulate commercial practice, pigs were treated with injectable antibiotic if required, and those that did not respond were removed and placed in sick pens. At the end of 21 d, the number of dead (% mortality) and viable pigs (% morbidity) were calculated. Data were analyzed as a randomized complete block design using the GLM procedure in Minitab with Fisher’s t-test determining differences between treatments. For d 0-21, no differences (P ≥ 0.23) were observed for BW or ADFI. But, pigs were numerically 0.5 kg heavier on the FP. Pigs fed FP tended (P 0.06; 188 g vs 202 g) to have a higher ADG and improved (P 0.02; 0.54 vs 0.58) G:F. No differences were observed for mortality or morbidity; however, the FP treatment had a 62.5% reduction in mortality. Furst Protect is a nutritional feed supplement that improved the growth and helped improve livability during the first 21 d of nursery. More research is needed to evaluate the carryover effects in late nursery and to market.

PSV-11 Evaluation of a Supplement (ATPsorb) on Growth Performance in Nursery Pigs

Abstract ATPsorb is a unique combination of Lipidol Ultra (a source of lysophospholipids) and Endo-power Beta (a source of several NSP enzymes). Thus, the response of ATPsorb was evaluated in nursery pigs. A total of 551 (DNA x DNA 600 sired) weaned, commercial pigs (21 d of age, average 5.61 kg (P = 0.38); 9-10 reps; 29 pigs/pen) were blocked by body weight. There were 2 treatments: standard nursery feed without antibiotics, control (CON); 2) CON + 2 lb per ton of ATPsorb for 21 d (ATP). FANCOM feeding system was used to deliver feed. Pens of pigs were weighed and feed disappearances were recorded on d 0 and 21. Data were used to calculate ADG and ADFI. To simulate commercial practice, pigs were treated with injectable antibiotic if required, and those that did not respond were removed and placed in sick pens. At the end of 21 d, the number of dead (% mortality) and viable pigs (% morbidity) were calculated. Data were analyzed as a randomized complete block design using the GLM procedure in Minitab with Fisher’s t-test determining differences between treatments. For d 0-21, there were no differences (P ≥ 0.61) observed for BW, ADG or ADFI. There was a 6.6% improvement (P = 0.05; 0.55 vs. 0.59) in G:F. No differences (P ≥ 0.33) were observed for morbidity or mortality. These data suggests that ATPsorb is capable of providing better nutrient utilization and absorption during the first 21 d in the nursery phase. Further testing is needed to evaluate lifetime performance.

Physiological state and reproductive qualities of sows when using probiotic preparations A2 and Immunoflor

The paper provides research and practice rationale for feasibility of using the complex probiotic preparations A2 and Immunoflor in the pig production and growing technology with the aim of improving reproductive qualities of sows through increasing nonspecific resistance of the organism. The probiotic preparations were given with the feed twice, at the beginning of pregnancy and 14 days before farrow, A2 in the amount of 1.62 g per animal in Experimental Group 1 and “Immunoflor” in the amount of 0.05 g per animal in Experimental Group 2. It was established that pig production from sows of both Experimental Groups 1 and 2 was 7.2 and 10.3 % higher, comparing that in the Control Group. At that, the number of healthy and viable pigs obtained from sows of the given experimental groups was reliably 8.5 and 12.5 % greater than in the Control Group (P < 0.01). The new complex probiotic agents A2 and Immunoflor, having significant antagonistic activity against putrefactive bacteria, decreased the mortinatality of pigs 1.4 and 2.1 times, respectively, increased litter size by 11.4 and 3.6 % and the milkability of sows by 4.2 kg and 4.7 kg.

Viable pigs after simultaneous inactivation of porcine MHC class I and three xenoreactive antigen genes GGTA1, CMAH and B4GALNT2.

Cell surface carbohydrate antigens play a major role in the rejection of porcine xenografts. The most important for human recipients are α-1,3 Gal (Galactose-alpha-1,3-galactose) causing hyperacute rejection, also Neu5Gc (N-glycolylneuraminic acid) and Sd(a) blood group antigens both of which are likely to elicit acute vascular rejection given the known human immune status. Porcine cells with knockouts of the three genes responsible, GGTA1, CMAH and B4GALNT2, revealed minimal xenoreactive antibody binding after incubation with human serum. However, human leucocyte antigen (HLA) antibodies cross-reacted with swine leucocyte antigen class I (SLA-I). We previously demonstrated efficient generation of pigs with multiple xeno-transgenes placed at a single genomic locus. Here we wished to assess whether key xenoreactive antigen genes can be simultaneously inactivated and if combination with the multi-transgenic background further reduces antibody deposition and complement activation. Multiplex CRISPR/Cas9 gene editing and somatic cell nuclear transfer were used to generate pigs carrying functional knockouts of GGTA1, CMAH, B4GALNT2 and SLA class I. Fibroblasts derived from one- to four-fold knockout animals, and from multi-transgenic cells (human CD46, CD55, CD59, HO1 and A20) with the four-fold knockout were used to examine the effects on human IgG and IgM binding or complement activation in vitro. Pigs were generated carrying four-fold knockouts of important xenoreactive genes. In vitro assays revealed that combination of all four gene knockouts reduced human IgG and IgM binding to porcine kidney cells more effectively than single or double knockouts. The multi-transgenic background combined with GGTA1 knockout alone reduced C3b/c and C4b/c complement activation to such an extent that further knockouts had no significant additional effect. We showed that pigs carrying several xenoprotective transgenes and knockouts of xenoreactive antigens can be readily generated and these modifications will have significant effects on xenograft survival.

P5999Heart failure rescue by high fat diet in a porcine model of hibernated myocardium

Abstract Background Extensive coronary artery disease without revascularization options results in ischemic hibernated myocardium and ultimately heart failure (HF). A metabolic reprogramming of the heart characterized by a shift from fatty acids (FFA) to glucose as the preferential metabolic substrate is frequent in HF and hibernated myocardium. Previous studies in mouse models of HF have shown that high fat diet (HFD) is able to reverse the metabolic reprogramming of the heart and improve cardiac function. Here we used a translational large animal model of ischemic HF evaluated by state-of-the-art imaging modalities Methods IHM was generated in Yucatan minipigs (N=50) by progressive stenosis of the proximal left anterior descending (LAD) after surgical insertion of a casein ameroid around the artery. Pigs underwent a serial multimodality imaging study including magnetic resonance imaging (MRI), multi-tracer PET/CT (18FDG &amp; 14(R,S)-[18F]Fluoro-6-thia-heptadecanoic acid (18F-FTHA) 19F-palmitate in-house synthetized), and invasive coronary angiography (ICA). Once hibernated myocardium with metabolic switch was documented (complete occlusion of LAD, LVEF&lt;50% on MRI, viable myocardium with dobutamine/MRI- evaluated contractile reserve, and metabolic substrate utilization shift towards glucose on PET/CT), animals were randomized to HFD or regular diet for 3 months Results The first part of the study was dedicated to establish the model in 42 pigs. Pigs were followed-up for 170±24 days with monthly ICA, MRI and PET/CT. Severe LAD stenosis was documented in all pigs 3–4 weeks after surgery. Mortality during follow-up was 57% (n=24) (15 peri-procedure, 2 between day 1 and 7, seven between day 7 and 45). Among those surviving beyond the sixth week, 90% (16/18) developed hibernated myocardium (mean LVEF 36±10%, absence of transmural delayed enhancement, contractile reserve and metabolic switch on PET/CT). In the second part of the study, 5 long-term survivors were allocated to receive HFD (20% extra lard), while 3 pigs served as controls. Mean LVEF before HFD initiation was 35±8%, and 36±5% in controls. Three months HFD was associated with a LVEF improvement in all treated animals (mean LVEF at the end of follow-up was 45±9%). Control animals on regular diet did not show any change in LVEF (35±5% at the end of follow-up) Conclusions We present a large animal model of HF due hibernated myocardium by placing an ameroid around the LAD. Mortality of this model is high (approx. 55%) but long-term survivors resemble all features seen in patients: LAD progressive stenosis with final occlusion but viable myocardium, LVEF deterioration and metabolic switch Feeding pigs with HFD to force cardiac reutilization of FFA, results in a consistent and large LVEF improvement in all animals Cardiac metabolic switch might be implicated in the pathogenesis of systolic dysfunction in hibernated myocardium and is a potential target for nutritional approaches

Abstract 3706: The CRISPR-Cas9 minipig: A transgenic toolbox pig to produce specific genome editing in designated tissues

Abstract The aim of the project is to generate a toolbox pig model. This is being done because the pig probably is the best non-primate model in translational medicine. Unfortunately, pig models have proven difficult to produce. The two main complications have been the cloning of viable pigs and that just a few genes are altered, which often is not sufficient to induce the desired disease. Especially, models based on multiple genetic modifications of the pig genome, e.g. cancer, are challenging to generate. This was changed with the development of the CRISPR-Cas9 technology, which made it possible to perform multiple in vivo gene editing. We have cloned an inducible Cas9 expressing minipig and have obtained healthy F1 offspring. Activation of the Cas9 expression is attained by transduction with adeno-associated virus that delivers both the recombinase and the guide RNA to the designated tissue. This design provides spatial and temporal control of the activation. The Cas9 expression is mediated by a ubiquitous promotor, which also co-expresses fluorescent proteins for expression analysis. Transgenic Cas9 expression is observed in all major organs with strong expression in the epithelia, muscles and hepatocytes. Successful in vitro gene editing has been conducted in primary keratinocytes and fibroblast obtained from the transgenic pigs, which confirms the genetic design. By delivery of our construct by adeno-associated virus to the skin of the pigs, In vivo activation of the transgenic construct has been achieved. To validate the model, lung cancer has been induced in nine pigs by alteration a panel of cancer related genes including STK11, TP53, PTEN, and KRAS, all key drivers of human lung cancer. To obtain the constitutive active KRAS-G12D isoform of the KRAS oncogene a repair template was supplied. The pigs are being followed by PET/CT scanning in combination with 18F-FDG as a tracer. Preliminary data indicates abnormalities/cancer initiation in the pigs eight months after induction. In conclusion, an inducible Cas9 expressing minipig allows rapid gene editing to study different scenarios of human cancer in a pig model. The development of the Cas9 pig will extend the variety of pig disease models, both to generate a model of lung cancer as proposed but also models for other cancers. Citation Format: Martin F. Berthelsen, Maria Riedel, Mikkel H. Vendelbo, Aage K. Alstrup, Frederik Dagnæs-Hansen, Yonglun Luo, Simone S. Møller, Henrik Callesen, Jannik E. Jakobsen, Martin K. Thomsen. The CRISPR-Cas9 minipig: A transgenic toolbox pig to produce specific genome editing in designated tissues [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3706.

Lipid peroxidation impairs growth and viability of nursery pigs reared under commercial conditions1.

The objective of this study was to investigate the impact of lipid peroxidation in a dose-dependent manner on growth, health, and oxidative stress status of nursery pigs. A total of 2,200 weaned pigs (5.95 ± 0.20 kg BW) were housed in 100 pens (22 pigs per pen) in a randomized complete block design based on initial BW and sex. Pigs were randomly assigned within blocks to 5 dietary treatments, consisting of a corn-soybean meal-based diet supplemented with 5% of either control corn oil (iodine value = 118, FFA = 0.06%, anisidine value = 3, peroxide value = 3 mEq/kg oil) or peroxidized corn oil (iodine value = 120, FFA = 0.35%, anisidine value = 30, peroxide value = 163 mEq/kg oil). These 2 diets were blended to obtain 5 levels of peroxidation with final treatments designated as 0 (diet with 5% control oil), 25%, 50%, 75%, and 100% (diet with peroxidized corn oil) peroxidation. Diets were fed ad libitum for 43 d. Blood samples were collected on d 33 from 20 pigs per treatment to determine serum oxidative stress markers and vitamin E concentrations and again on d 43 (14 d after vaccination) to determine immune response to porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (Mhyo). Gain:feed ratio decreased linearly (P = 0.023) with increasing peroxidation, but pen ADG and ADFI were not affected. Number of pigs removed for medical treatment, total number medically treated, pigs culled for low end weight, and mortality increased, and full-value pigs linearly decreased (P < 0.04) with increasing peroxidation. Consequently, total pen gain (weight of viable pigs that remained in test pens at the end of the study minus weight of pigs placed) decreased linearly (P < 0.01) with increasing peroxidation. Antibody titers to Mhyo and PCV2 increased postvaccination (P < 0.001), but did not differ due to dietary treatment. Serum concentrations of malondialdehyde, 8-hydroxy-2'-deoxyguanosine, and protein carbonyl were not affected by peroxidation. Total antioxidant capacity and serum vitamin E concentrations decreased (P = 0.01) linearly with increasing peroxidation. Data show a dose-dependent negative impact of lipid peroxidation on pig productivity when determined under field population conditions, being primarily manifested by increased mortality, number of pigs medically treated, and number of culled pigs (≤13.6 kg BW). Results underscore the importance of proper assessment of lipid peroxidation as part of quality control to prevent oxidative stress and performance losses in weaned pigs.

Beneficial Effects of Human Mesenchymal Stromal Cells on Porcine Hepatocyte Viability and Albumin Secretion

Aim Porcine hepatocytes transplanted during acute liver failure might support metabolic functions until the diseased liver recovers its function. Here, we isolated high numbers of viable pig hepatocytes and evaluated hepatocyte functionality after encapsulation. We further investigated whether co-culture and co-encapsulation of hepatocytes with human multipotent mesenchymal stromal cells (MSC) is beneficial on hepatocyte function. Methods Livers from 10kg pigs (n=9) were harvested and hepatocytes were isolated from liver suspensions for microencapsulation using alginate and poly(ethylene-glycol)(PEG)-grafted alginate polymeric hydrogels, either alone or in combination with MSC. Results Viability, albumin secretion and diazepam catabolism of hepatocytes were measured for one week. 9.2±3.6x109 hepatocytes with 95.2±3.1% viability were obtained after isolation. At day 3, free hepatocytes displayed 99% viability, whereas microencapsulation in alginate and PEG-grafted alginate decreased viability to 62% and 48%, respectively. Albumin secretion and diazepam catabolism occurred in free and microencapsulated hepatocytes. Co-encapsulation of hepatocytes with MSC significantly improved viability and albumin secretion at days 4 and 8 (p<0.05). Co-culture with MSC significantly increased and prolonged albumin secretion. Conclusions In conclusion, we established a protocol for isolation and microencapsulation of high numbers of viable pig hepatocytes and demonstrated that the presence of MSC are beneficial for viability and function of porcine hepatocytes.

Beneficial Effects of Human Mesenchymal Stromal Cells on Porcine Hepatocyte Viability and Albumin Secretion.

Porcine hepatocytes transplanted during acute liver failure might support metabolic functions until the diseased liver recovers its function. Here, we isolated high numbers of viable pig hepatocytes and evaluated hepatocyte functionality after encapsulation. We further investigated whether coculture and coencapsulation of hepatocytes with human multipotent mesenchymal stromal cells (MSC) are beneficial on hepatocyte function. Livers from 10 kg pigs (n = 9) were harvested, and hepatocytes were isolated from liver suspensions for microencapsulation using alginate and poly(ethylene-glycol)- (PEG-) grafted alginate hydrogels, either alone or in combination with MSC. Viability, albumin secretion, and diazepam catabolism of hepatocytes were measured for one week. 9.2 ± 3.6 × 109 hepatocytes with 95.2 ± 3.1% viability were obtained after isolation. At day 3, free hepatocytes displayed 99% viability, whereas microencapsulation in alginate and PEG-grafted alginate decreased viability to 62% and 48%, respectively. Albumin secretion and diazepam catabolism occurred in free and microencapsulated hepatocytes. Coencapsulation of hepatocytes with MSC significantly improved viability and albumin secretion at days 4 and 8 (p < 0.05). Coculture with MSC significantly increased and prolonged albumin secretion. In conclusion, we established a protocol for isolation and microencapsulation of high numbers of viable pig hepatocytes and demonstrated that the presence of MSC is beneficial for the viability and function of porcine hepatocytes.

Skin absorption of actinides: influence of solvents or chelates on skin penetration ex vivo

Purpose: To evaluate skin penetration and retention of americium (Am) and plutonium (Pu), in different chemical forms relevant to the nuclear industry and to treatment by chelation.Materials and methods: Percutaneous penetration of different Am and Pu forms were evaluated using viable pig skin with the Franz cell diffusion system. The behavior of the complex Pu-tributyl phosphate (Pu-TBP), Am or Pu complexed to the chelator Diethylene triamine pentaacetic acid (DTPA) and the effect of dimethyl sulfoxide (DMSO) was assessed. Radioactivity was measured in skin and receiver compartments. Three approaches were used to visualize activity in skin including the recent iQID technique for quantification.Results: Transfer of Am was 24-fold greater than Pu and Pu-TBP complex penetration was enhanced by 500-fold. Actinide-DTPA transfer was greater than the Am or Pu alone (17-fold and 148-fold, respectively). The stratum corneum retained the majority of activity in all cases and both DMSO and TBP enhanced skin retention of Am and Pu, respectively. Histological and bioimaging data confirmed these results and the iQID camera allowed the quantification of skin activity.Conclusions: Skin penetration and fixation profiles are different depending on the chemical actinide form. Altered behavior of Pu-TBP and actinide-DTPA complexes reinforces the need to address decontamination protocols.

203 Performance responses of weaned pigs when fermented soybean meal (NF8) was replaced with a modified grain by-product (Gold Pro)

The objective of this study was to determine in a commercial research environment if performance could be maintained when fermented soybean meal was replaced as a protein source, with a modified, fermented corn by-product (Gold Pro), at graded levels in the diet: 10% NF8 (NONE), 5% NF8 + 5% Gold Pro (PARTIAL) and 10% of Gold Pro (COMPLETE). The experiment involved 472 weaned pigs (21 d of age, 6.6 kg) that were allocated to either NONE, PARTIAL or COMPLETE replacement treatment diet, allocated by weight and weaning age, and blocked within the barn. A commercial wean to finish barn was used (29 pigs per pen, 4–6 pens per treatment) with a FANCOM feed system. To test the immediate postweaning effect of the protein replacement, pigs were placed immediately onto treatments on arrival; there was no adaptation period. Pens of pigs were weighed and feed disappearances were recorded on d 0, 7, and 21, which were used to calculate ADG, ADFI, and FCR. To replicate commercial production as closely as possible, pigs that did not respond to treatment with injectable antibiotic were tagged and removed to sick pens. At the end of the trial it was determined if pigs that were removed from trial had died (% mortality), or remained as viable pigs (% morbidity). Medical treatments were recorded daily. Data were analyzed as a randomized complete block design using GLM procedure in Minitab with Tukey's test to determine differences between dietary treatments. There were no differences for (P > 0.10) for d 0–21 ADG, ADFI, or FCR. There were no differences (P > 0.10) observed for % morbidity/pen. However, pigs fed the PARTIAL and COMPLETE feed had a lower % mortality/pen (P < 0.01) in contrast with pigs fed the NONE treatment. There was a trend (P < 0.10) for pigs fed the NONE treatment to have more medical treatments/pen compared to pigs fed the PARTIAL and COMPLETE treatments. In conclusion, Gold Pro can be used as an alternative protein ingredient to replace fermented soybean meal in weaned pig starter rations without loss of growth performance, and may have benefits on health. Summary of Performance Day 0 to 21 Summary of Performance Day 0 to 21

Viable pigs with a conditionally-activated oncogenic KRAS mutation.

Oncogenic mutations of KRAS play a major role in human carcinogenesis. Here we describe viable gene-targeted pigs carrying a latent KRAS (G12D) mutant allele that can be activated by Cre recombination. These have been produced as part of a program to model human cancers in pigs by replicating genetic lesions known to initiate and drive human disease. Cre-activated KRAS (G12D) animals add to a growing set of gene-targeted pigs that includes a Cre-activated oncogenic mutant TP53, a Cre-responsive dual fluorescent reporter and two truncating mutations of APC (adenomatous polyposis coli). These alleles can be combined and activated in various tissues to produce new models for cancer research.

Long-Term IgG Response to Porcine Neu5Gc Antigens without Transmission of PERV in Burn Patients Treated with Porcine Skin Xenografts

Acellular materials of xenogenic origin are used worldwide as xenografts, and phase I trials of viable pig pancreatic islets are currently being performed. However, limited information is available on transmission of porcine endogenous retrovirus (PERV) after xenotransplantation and on the long-term immune response of recipients to xenoantigens. We analyzed the blood of burn patients who had received living pig-skin dressings for up to 8 wk for the presence of PERV as well as for the level and nature of their long term (maximum, 34 y) immune response against pig Ags. Although no evidence of PERV genomic material or anti-PERV Ab response was found, we observed a moderate increase in anti-αGal Abs and a high and sustained anti-non-αGal IgG response in those patients. Abs against the nonhuman sialic acid Neu5Gc constituted the anti-non-αGal response with the recognition pattern on a sialoglycan array differing from that of burn patients treated without pig skin. These data suggest that anti-Neu5Gc Abs represent a barrier for long-term acceptance of porcine xenografts. Because anti-Neu5Gc Abs can promote chronic inflammation, the long-term safety of living and acellular pig tissue implants in recipients warrants further evaluation.

Rib Butterfly Fractures as a Possible Indicator of Blast Trauma

Forensic anthropologists have become increasingly involved in the interpretation of skeletal trauma caused by exploding ordnance. This study examines the cause and significance of butterfly fractures observed in a recent study investigating skeletal blast trauma by Christensen et al. Fractured ribs resulting from blast events carried out in the original study were re-examined revealing that rib butterfly fractures with the tensile indicator on the visceral surface were present in 100% of viable pig specimens. Additionally, manual fracture testing was performed on 46 pig ribs to simulate the bending force believed to have been sustained in the original blast events. Fracture testing resulted in 93% of specimens presenting butterfly fractures with the tensile indicator on the visceral surface. This fracture pattern differs significantly from that normally observed in association with other types of trauma events and may aid forensic anthropologists and other investigators in the identification and interpretation of blast events.

Viability, maturation and embryo development in vitro of immature porcine and ovine oocytes vitrified in different devices

This study was designed to evaluate the effects of vitrification on immature porcine and ovine oocytes, collected at a slaughterhouse, by performing vitrification in devices with different volumes. Viability was evaluated both before and after vitrification and maturation. Immediately after warming, the percentage of viable pig oocytes was 81% regardless the type of device, while in the control (after oocyte selection) was 95%. The viability of matured pig oocytes after warming, vitrified in beveled edge open straws (BES) was 6%, in small-open-pulled-straw (SOPS) was 17% and in cryotop was 4%, while the viability of the control group was 86%. The viability and maturation results were similar with all devices. Embryo development (ED) was observed in fresh porcine oocytes with 15% 2–8 cell embryos, 7% morulae and 3% blastocysts, and non-embryo cleavage was observed in warmed oocytes. The viability of sheep oocytes immediately after warming averaged 90% in all devices, while that of the control (after oocyte selection) averaged 95%. The viability of warmed oocytes after maturation was: BES 21%, SOPS 30%, cryotop 21% and control group 86%; while maturation values were 11, 21, 34 and 70%, respectively. After vitrification, the highest ED was achieved with ovine oocytes vitrified in SOPS, with 17% morulae development and it was the only device in which blastocysts developed. A direct relationship was observed between viability and actin filament integrity in both species.

Viable skin efficiently absorbs and metabolizes bisphenol A

Skin contact has been hypothesized to contribute to human exposure to bisphenol A (BPA). We examined the diffusion and metabolism of BPA using viable skin models: human skin explants and short-term cultures of pig ear skin, an alternative model for the study of the fate of xenobiotics following contact exposure. 14C-BPA [50–800 nmol] was applied on the surface of skin models. Radioactivity distribution was measured in all skin compartments and in the diffusion cells of static cells diffusion systems. BPA and metabolites were further quantified by radio-HPLC. BPA was efficiently absorbed in short-term cultures, with no major difference between the models used in the study [viable pig ear skin: 65%; viable human explants: 46%; non-viable (previously frozen) pig skin: 58%]. BPA was extensively metabolized in viable systems only. Major BPA metabolites produced by the skin were BPA mono-glucuronide and BPA mono-sulfate, accounting together for 73% and 27% of the dose, in pig and human, respectively. In conclusion, experiments with viable skin models unequivocally demonstrate that BPA is readily absorbed and metabolized by the skin. The trans-dermal route is expected to contribute substantially to BPA exposure in human, when direct contact with BPA (free monomer) occurs.

Production and characterization of transgenic pigs expressing porcine CTLA4‐Ig

Inhibition of the T-cell-mediated immune response is a necessary component of preventing rejection following xenotransplantation with pig alpha1,3-galactosyltransferase gene-knockout (GTKO) organs. Cytotoxic T lymphocyte-associated antigen (CTLA4) is a co-stimulatory molecule that inhibits T-cell activity and may be useful in prolonging graft rejection. An expression vector was built containing the extracellular coding region of porcine (p) CTLA4 fused to the hinge and CH2/CH3 regions of human IgG1 (pCTLA4-Ig). Pigs transgenic for pCTLA4-Ig, on either a GTKO or wild-type (WT) genetic background, were produced by nuclear transfer and characterized using Western blot analysis, immunofluorescence, ELISA, and necropsy. Fifteen pCTLA4-Ig-transgenic piglets resulted from five pregnancies produced by nuclear transfer. All transgenic pigs exhibited robust expression of the pCTLA4-Ig protein and most expressed the transgene in all organs analyzed, with significant levels in the blood as well. Despite initial good health, these pigs exhibited diminished humoral immunity, and were susceptible to infection, which could be managed for a limited time with antibiotics. Viable pigs exhibiting robust and ubiquitous expression of pCTLA4-Ig were produced on both a WT and GTKO background. Expression of pCTLA4-Ig resulted in acute susceptibility to opportunistic pathogens due at least in part to a significantly compromised humoral immune status. As this molecule is known to have immunosuppressive activity, high levels of pCTLA4-Ig expression in the blood, as well as defective development related to exposure to pCTLA4-Ig in utero, may contribute to this reduced immune status. Prophylactic treatment with antibiotics may promote survival of disease-free transgenic pigs to a size optimal for organ procurement for transplantation. Additional genetic modifications and/or tightly regulated expression of pCTLA4Ig may reduce the impact of this transgene on the humoral immune system.

Evaluating animal welfare with choice experiments: an application to Swedish pig production

AbstractIn this study, the demand for animal welfare attributes when buying pork fillet is investigated among Swedish respondents. The issue is of importance in order to ensure an economically viable pig industry while applying an increasing number of animal friendly practices. In order to obtain information about consumer demand, an indirect utility function and willingness to pay (WTP) for animal welfare attributes are estimated. The attributes are solely associated with animal friendly practices. An investigation of numerous housing and managerial practices of pig production has not yet been performed. The indirect utility function is estimated using a random parameter logit model. A realistic approach when modeling consumer choice is to allow for heterogeneity in preferences. The relevance of assuming randomness of some of the parameters is evaluated by using a specification test developed by McFadden and Train (2000). The WTP is also estimated at the individual level. The results indicate that WTP for animal welfare attributes may be negative or positive. The preferences are also heterogeneous among respondents, which may be explained by a segmentation of preferences. Finally, the WTP estimates for animal welfare practices are compared with cost estimates for such production systems. [Econlit subject codes: C010, C500, Q100] © 2008 Wiley Periodicals, Inc.

Production of Viable Pigs from Fetal Somatic Stem Cells

Fetal somatic stem cells (FSSCs) are a novel type of somatic stem cells that have recently been discovered in primary fibroblast cultures from pigs and other species. The goal of the present study was to produce viable piglets from FSSCs. NT complexes were prepared from both FSSCs and porcine fetal fibroblasts (pFF) to permit comparison of these two donor cell types. FSSCs from isolated attached colonies were compared with pFF in their ability to form blastocysts upon use in NT. Fusion and cleavage rates were similar between the two groups, while blastocyst rates were significantly higher when using pFF as donor cells. FSSCs of three different size categories derived from dissociation of spheroids yielded similar results. The use of FSSCs of 15-20 microm in size yielded similar cleavage and blastocyst rates as fetal fibroblasts. In the final experiment NT complexes produced from FSSCs were transferred to foster mothers. After transfer to prepubertal gilts, three of seven recipients established pregnancies and delivered seven piglets, of which three piglets were viable and showed normal development. Results for the first time demonstrate that FSSCs are able to produce cloned embryos, and that pregnancies can be established and viable piglets can be produced.

Time and Dose-related Ultraviolet B Damage in Viable Pig Skin Explants Held in a Newly Developed Organ Culture System¶

Time and Dose-related Ultraviolet B Damage in Viable Pig Skin Explants Held in a Newly Developed Organ Culture System¶