• 대한수의학회지
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• 제47권2호
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• pp.175-185
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• 2007

This study was carried out to investigate the pathogenesis and pathogenicity of the porcine circovirus type 2 (PCV2) Korean isolate from weaned pigs. Twenty four weaned pigs, PCV2, porcine reproductive and respiratory syndrome virus (PRRSV) and porcine parvovirus (PPV) antibodies free, were allocated to 4 groups (n = 6). Six pigs were inoculated intranasally with PCV2 alone, 6 with PCV2 and PRRSV, 6 with the combined PCV2/PRRSV/PPV inoculum, and 6 were remained as a uninoculated negative control. Pigs were killed 3 and 6 weeks after inoculation and tissue samples examined for gross and microscopic lesions and for the presence of PCV2 antigens and nucleic acids. Experimentally inoculated pigs were evaluated for 3 considerations: 1. development of postweaning multisystemic wasting syndrome (PMWS), 2. distribution of viral antigens by immunohistochemistry and polymerase chain reaction (PCR), and 3. cytokine mRNA levels in lymph nodes. Pigs inoculated with PCV2/PRRSV/PPV showed typical clinical signs, gross findings, and histopathologic characteristics of PMWS. In the PCV2/PRRSV/PPV inoculated group, the PCV2 antigen was widely distributed in various parenchymal organs such as brain, spinal cord, tonsil, lymph nodes, lung, heart, liver, kidney, spleen, and peyer's patch. Lymph node mRNA expression of IL-$1{\alpha}$, IL-2R and IL-8 was determined by real-time PCR. The pigs of PCV2/PRRSV and PCV2/PRRSV/PPV inoculation group, the mRNA expression was characterized by a decrease of IL-$1{\alpha}$, IL-2R and IL-8. The decrease of cytokine mRNA represent the state of T cell immuno-suppression in pig, and nicely support the evidence for the impairment of immune system in pigs with PMWS. In conclusion, PCV2 infection and some additional infectious causes such as PRRSV and/or PPV are warranted for the presence of PMWS in weaned pigs in Korea.

• Animal Bioscience
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• 제35권8호
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• pp.1235-1249
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• 2022

Objective: The purpose of this study was to evaluate the protection of glutamate (GLU) against the impairment in intestinal barrier function induced by lipopolysaccharide (LPS) stress in weaned pigs. Methods: Twenty-four weaned pigs were divided into four treatments containing: i) non-challenged control, ii) LPS-challenged control, iii) LPS+1.0% GLU, and iv) LPS+2.0% GLU. On day 28, pigs were treated with LPS or saline. Blood samples were collected at 0, 2, and 4 h post-injection. After blood samples collection at 4 h, all pigs were slaughtered, and spleen, mesenteric lymph nodes, liver and intestinal samples were obtained. Results: Dietary GLU supplementation inhibited the LPS-induced oxidative stress in pigs, as demonstrated by reduced malondialdehyde level and increased glutathione level in jejunum. Diets supplemented with GLU enhanced villus height, villus height/crypt depth and claudin-1 expression, attenuated intestinal histology and ultrastructure impairment induced by LPS. Moreover, GLU supplementation reversed intestinal intraepithelial lymphocyte number decrease and mast cell number increase induced by LPS stress. GLU reduced serum cortisol concentration at 4 h after LPS stress and downregulated the mRNA expression of intestinal corticotropin-releasing factor signal (corticotrophin-releasing factor [CRF], CRF receptor 1 [CRFR1], glucocorticoid receptor, tryptase, nerve growth factor, tyrosine kinase receptor A), and prevented mast cell activation. GLU upregulated the mRNA expression of intestinal transforming growth factor β. Conclusion: These findings indicate that GLU attenuates LPS-induced intestinal mucosal barrier injury, which is associated with modulating CRF signaling pathway.

• 한국동물위생학회지
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• 제45권2호
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• pp.71-77
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• 2022

African swine fever (ASF) is a fatal viral disease in pigs, with a short incubation period and causing immediate death. Few studies exist on the Asian epidemic ASF virus (ASFV) challenge in older pigs, including growing and fattening pigs and sows. We aimed to investigate clinical outcomes, pathomorphological lesions, and viral distribution in organs of 3-month-old growing pigs that were inoculated with the ASFV isolated in Vietnam. The clinical outcomes were recorded daily, and the dead or euthanized pigs immediately underwent necropsy. Viral loads were determined in 10 major organs using quantitative polymerase chain reaction. The average incubation period in growing pigs was more delayed (5.2±0.9 dpi) than that in weaned pigs, and the clinical signs were milder in growing pigs than in weaned pigs. The digestive and respiratory clinical signs in growing pigs showed at the end period of life, but these were observed at an early stage of infection in weaned pigs. The pathomorphological features were severe and nonspecific with hemorrhagic lesions in various organs. The viral loads in organs from growing pigs were higher than those from piglets, and the number of viral copies was related to gross lesions in the tonsil and intestine. In the absence of vaccines against ASF, early clinical detection is important for preventing the spread of the virus. Our findings elucidated that the clinical signs and gross lesions in growing pigs differed from those in weaned pigs, which provide valuable information for diagnosis of pigs with suspected ASF infection.

• Asian-Australasian Journal of Animal Sciences
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• 제24권6호
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• pp.834-843
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• 2011

Bacterial diversity was studied using PCR-DGGE, cloning and sequencing. DNA was isolated from digesta samples from stomach, ileum and colon of 28 weaned piglets (Large White${\times}$Mong Cai) fed dry control feed, naturally fermented liquid feed (FE) and a liquid diet with inclusion of rice distiller's residue feed. General bacterial diversity was described using DGGE analysis of the V3 region of 16S rDNA. The microbial populations in the stomach and the ileum were considerably influenced by the diet, while only marginal effects were observed in the colon. There was a large variation of the microbial flora in the stomach between individuals fed non-fermented diets. In contrast, animals fed diet FE had a more uniform microbial flora in the stomach and the ileum compared to the other diets. In total 47 bands from the DGGE profiles were cloned. In stomach, most frequently lactic acid bacteria were found. Feeding diet FE resulted in the occurrence of Pediococcus species in stomach and ileum. In pigs fed the other diets, Lactobacillus gallinarum, Lactobacillus johnsonii and Lactobacillus fermentum were found in stomach and ileum. Most of the sequences of bands isolated from colon samples and several from ileum matched to unknown bacteria, which often grouped within Prevotellaceae, Enterobacteriaceae, Bacteroidaceae and Erysipelotrichaceae. This study demonstrates that fermented liquid feed affects bacterial diversity and the specific microflora in stomach and ileum, which provides a potential to modulate the gut microflora with dietary means to increase the abundance of beneficial bacteria and improve piglets' health.

• Asian-Australasian Journal of Animal Sciences
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• 제12권8호
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• pp.1263-1272
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• 1999

The effects of carnitine in diets with or without added fat (5% lard or soybean oil) were evaluated in 72 Large White ${\times}$ Landrace ${\times}$ Duroc pigs weaned at 35 days of age. Pigs were fed a 1.30% lysine corn-soybean basal diet+15% dried whey+4% fish meal with carnitine at 0 or 50 mg/kg and either 0% added fat, 5% soybean oil or 5% lard for 6 weeks in a $2{\times}3$ factorial trial (6 treatments, 3 pens per treatment, 4 pigs per pen). Addition of carnitine increased average daily gain (ADG) and average daily feed intake (ADFI) in the second two weeks of the six-week trial and overall, but had no significant effect on feed per gain (F/G). Lard alone depressed ADG (p<0.05) in the last two weeks of the trial and overall, but the ADG for pigs fed lard+carnitine was similar to the control. Lard reduced feed intake in the first two weeks of the trial (p<0.05). Carnitine reduced the percentage of pigs with poor (ADG<375 g/d) growth (15 vs 40%; p<0.05). The greater uniformity of growth was most evident in low-weaning-weight pigs in the second period (16 vs 62%, p<0.005). Addition of fat did not produce any positive effect on uniformity and had no interaction with carnitine on uniformity. Carnitine addition increased serum total carnitione and short-chain acyl-carnitine levels (p<0.05), but did not modify free carnitine levels. Serum carnitine levels were lower at weaning than at 14, 28, or 39 days after weaning (p<0.05). Carnitine increased serum protein levels on day 14 (p<0.05). Addition of fat in the form of soybean oil or lard did not improve piglet growth performance. Addition of 50 mg/kg of carnitine to the diet of weanling pigs enhanced postweaning performance.

• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1326-1331
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• 2003

The aim of the study was to assess the efficacy of Toyocerin, a probiotic containing Bacillus toyoi spores, on the health status and productivity of pigs, during nursery, growing and finishing phases. On a commercial farrow-to-finish farm in Greece, 3 experimental groups were formed, each of 72 weaned piglets. The pigs of the first group (T1 group; negative controls) received normal feed with no antimicrobials or probiotics, the pigs of the second group (T2 group) received the same type of feed but supplemented with 1.0${\times}$10$^9$, 0.5${\times}$10$^9$ and 0.2${\times}$10$^9$ spores per kg of feed at weaning, growing and finishing stage, respectively, and the pigs of the third group (T3 group) were fed with Toyocerin at the dose of 1.0${\times}$10$^9$ spores per kg of feed during the entire fattening period (weaning, growing and finishing stages). The results have shown that, compared to the controls, Toyocerin treated pigs had reduced incidence of postweaning diarrhoea (p<0.05). Enterotoxigenic strains of Escherichia coli were detected in faecal samples of 0% to 25% of pigs of the treated groups, but in 33.5% to 50% of pigs of the non-treated group (p<0.05). Over the negative controls, a significant improvement of weight gain (4.5% and 8.3% for T2 and T3 groups, respectively), and of feed conversion ratio (6.6% and 13.0% for T2 and T3 groups, respectively) was observed. The 76.5% of the carcasses of the T3 group was classified in the top three categories of the EUROP scale (S, E and U), whilst the respective figures were 47.8% for T2 group and only 10.5% for T1 group (p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제31권12호
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• pp.1852-1862
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• 2018

Objective: The purpose of this study was to investigate a single step genome-wide association study (ssGWAS) for identifying genomic regions affecting reproductive traits in Landrace and Large White pigs. Methods: The traits included the number of pigs weaned per sow per year (PWSY), the number of litters per sow per year (LSY), pigs weaned per litters (PWL), born alive per litters (BAL), non-productive day (NPD) and wean to conception interval per litters (W2CL). A total of 321 animals (140 Landrace and 181 Large White pigs) were genotyped with the Illumina Porcine SNP 60k BeadChip, containing 61,177 single nucleotide polymorphisms (SNPs), while multiple traits single-step genomic BLUP method was used to calculate variances of 5 SNP windows for 11,048 Landrace and 13,985 Large White data records. Results: The outcome of ssGWAS on the reproductive traits identified twenty-five and twenty-two SNPs associated with reproductive traits in Landrace and Large White, respectively. Three known genes were identified to be candidate genes in Landrace pigs including retinol binding protein 7, and ubiquitination factor E4B genes for PWL, BAL, W2CL, and PWSY and one gene, solute carrier organic anion transporter family member 6A1, for LSY and NPD. Meanwhile, five genes were identified to be candidate genes in Large White, two of which, aldehyde dehydrogenase 1 family member A3 and leucine rich repeat kinase 1, associated with all of six reproduction traits and three genes; retrotransposon Gag like 4, transient receptor potential cation channel subfamily C member 5, and LHFPL tetraspan subfamily member 1 for five traits except W2CL. Conclusion: The genomic regions identified in this study provided a start-up point for marker assisted selection and estimating genomic breeding values for improving reproductive traits in commercial pig populations.

• Animal Bioscience
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• 제34권3_spc호
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• pp.405-416
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• 2021

Objective: This study evaluated the effects of feeding diets naturally contaminated with deoxynivalenol (supplemental 2 mg/kg) on health, growth, and the effects of a mycotoxin-detoxifying additive in newly-weaned pigs. Methods: Thirty-six pigs (27 day-old) were housed individually and assigned to 3 treatments for 5 weeks: CON (diet containing minimal deoxynivalenol), MT (diet with supplemental 1.9 mg/kg of deoxynivalenol), and MT+D (MT + mycotoxin-detoxifying additive, 0.2%, MegaFix, ICC, São Paulo, Brazil). The mycotoxin-detoxifying additive included bentonite, algae, enzymes, and yeast. Blood was taken at week 2 and 5. Jejunal tissue were taken at week 5. Data were analyzed using the MIXED procedure of SAS. Results: Pigs fed MT+D tended to have decreased (p = 0.056) averaged daily feed intake during week 1 than MT. At week 2, serum aspartate aminotransferase/alanine aminotransferase in MT tended to be lower (p = 0.059) than CON, whereas it was increased (p<0.05) for MT+D than MT, indicating hepatic damages in MT and recovery in MT+D. Pigs fed MT had lower (p<0.05) blood urea nitrogen/creatinine than CON, supporting hepatic damage. At week 5, pigs fed MT tended to have reduced (p = 0.079) glucose than CON, whereas it was increased (p<0.05) for MT+D than MT, indicating impaired intestinal glucose absorption in MT, which was improved in MT+D. Pigs fed CON tended to have increased (p = 0.057) total glutathione in jejunum than MT, indicating oxidative stress in MT. Pigs fed MT+D had a reduced (p<0.05) proportion of Ki-67-positive cells in jejunum than MT, indicating lower enterocyte proliferation in MT+D. Conclusion: Feeding supplemental 1.9 mg/kg of deoxynivalenol reduced growth and debilitated hepatic health of pigs, as seen in leakage of hepatic enzymes, impaired nitrogen metabolism, and increase in oxidative stress. The mycotoxin-detoxifying enhanced hepatic health and glucose levels, and attenuated gut damage in pigs fed deoxynivalenol contaminated diets.

• Journal of Animal Science and Technology
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• 제64권2호
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• pp.302-311
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• 2022

This study investigated the effect of a synergistic blend of free and buffered organic acid (FMP) on the performance of piglets born to sows supplemented with a blend of short- and medium-chain organic acids (SGG) during the late gestation and lactation period. A total of 150 multiparous sows (n = 50/treatment, Landrace × Yorkshire) were blocked (2.4 parity) and assigned to 1 of 3 dietary treatments: CON - corn-soybean meal-based basal diet, SGG-Low - CON+ 1.5 kg/ton SGG, and SGG-High - CON + 3kg/ton SGG. During weaning, 600 piglets (6.72 ± 0.5kg) which weaned from sows supplemented with 3 levels of SGG were allocated to 2 weaner diets (Control and FMP - 3kg/ton) following 3 × 2 factorial arrangement. Supplemental effects on performance were measured at d0-d21 and d 21-42, and the entire period. Pigs fed with FMP and born to sows supplemented with SGG-High gained more weight and ate more (p < 0.05) compared with those in the CON group in both phases, and with SGG-Low in the second phase. Over the entire post-weaning period, piglets born to sows supplemented with SGG-Low and SGG-High had a higher average daily gain (ADG) and body weight (BW) (p < 0.05). Regardless of sow treatment, pigs fed with an FMP diet had higher ADG (p < 0.001), BW (p = 0.045), and a lower feed conversion ratio (p = 0.033). Also, feeding FMP diets reduced the fecal Escherichia coli and Clostridium perfringens counts at d42. The current study indicates that sows fed SGG supplement had a positive carry-over effect on the post-weaning growth rate, and FMP supplement enhances the growth performance and reduced the number of C. perfringens and E. coli. Thus, the application of 3 kg/ton of SGG in sows' diet and subsequent feeding of piglets with FMP would be an effective strategy to improve growth rate and reduce pathogenic bacteria in post-weaned piglets.

• Animal Bioscience
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• 제35권3호
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• pp.434-443
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• 2022

Objective: The study was conducted to investigate the impact of boron supplementation on nutrient digestibility, inflammatory responses, blood metabolites and diarrhea index, and their relevance to growth performance in weaned pigs housed in good and poor sanitary environments for 14 days after weaning. Methods: A total of 108 male pigs (Duroc×[Yorkshire×Landrace]) weaned at 21 days of age were used in a randomized complete block design with 2×3 factorial arrangement. Pigs were assigned to three boron treatments (0, 5, and 10 mg/kg) under two environments (good and poor sanitary) to give six replicates per treatment (3 pigs per replicate). On 0, 7, and 14 days, one pig per replicate was euthanized to collect, ileum tissue samples, and rectal fecal samples. Results: Boron supplementation quadratically influenced (p<0.001) feed intake and weight gain in pigs housed in good sanitary conditions from 1 to 14 days post-weaning where pigs offered 5 mg/kg boron optimized weight gain and feed intake. There is a quadratic interaction (p = 0.019) on feed intake for 1 to 14 days post-weaning where 5 mg/kg boron increased feed intake in good sanitary conditions. Pigs housed in the poor sanitary environment decreased (p<0.001) villus height and crypt depth in ileum at days 7 and 14. On day 7 and 14, crude protein digestibility was quadratically influenced (p<0.05) by boron supplementation. Boron supplementation linearly increased (p<0.05) plasma calcium and cholesterol levels whilst linearly (p = 0.005) reducing plasma triglyceride concentrations. Diarrhea index was quadratically influenced (p<0.05) by boron supplementations regardless of sanitary conditions where 5 mg/kg boron inclusion achieved the lowest diarrhea index. Conclusion: Pigs offered 5 mg/kg of boron increased weight gain which may be deduced by improved dry matter, crude protein, and energy digestibility regardless of the sanitary conditions.