• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.375-382
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• 2015

In the present study, offsprings of 14 sows were used to evaluate the effect of fermented milk substituted for creep feed to analyze its effect on growth performance, diarrhea score and blood profiles. The piglets of sows were randomly allocated into 1 of 2 treatments (1 treatment separated piglets of 7 sows). The dietary treatments includes: CF (creep feed) and FM (fermented milk). The CP and FM diets were given from 3 d after piglets were born to the day of weaning (21 d after piglets were born). No significant difference (P>0.05) were observed in number of born piglets, weaning pigs, survival rate, body weight of piglets at d 0, 7, 14, and 21, ADG and ADFI. At d 21, piglets fed with CP had a higher (P<0.05) IgG compared with piglets fed with FM. No significant difference (P>0.05) was observed in WBC among the treatments at d 21. At d 6, piglets fed with CP had a lower (P<0.05) number of diarrhea piglets compared to piglets fed with FM. In conclusion, FM substituted for CP had no adverse effect on growth performance in lactating piglets.

• Korean Journal of Veterinary Service
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• v.21 no.2
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• pp.141-148
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• 1998

Eighteen strains of Clostpidium perfringens were isolated from the piglets with hemorrhagic enteritis. The characteristics of the outbreaks, clinical signs and lesions were examined. The biochemical properties, type of toxins and susceptibility to antimicrobial agents against the isolates were investigated. 1. The incidence of diarrhea was appeared in 97(22.4%) of 432 piglets examined. 2. The isolation rate of Cl perfingens from the 97 diarrheal faeces were 18.5%(18 strains) 3. The population of Cl perfingens in feces were ranged $10^{8-9}$cfu/g in 5(32.5%) and $10^{3-7}$cfu/g in 13(67.4%) of 18 samples. 4. The toxin type of the 18 isolates investigated by mouse inoculation test was all type C strains of Cl perfringens. 5. As a results of antimicrobial susceptibility test, 18 isolates were higly susceptible to cephalothin, tetracycline and penicillin.

• Korean Journal of Veterinary Research
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• v.60 no.3
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• pp.163-171
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• 2020

This study examined the prevalence of adherence factors, toxin genes, antimicrobial resistance phenotypes, and resistance genes in Escherichia coli (E. coli) isolated from piglets with diarrhea before and after the ban on antibiotic growth promoters (AGPs) in Korea from 2007 to 2018. In this period, pathogenic 474 E. coli isolates were obtained from diarrheic piglets. The virulence factors and antimicrobial resistance genes were assayed using a polymerase chain reaction, and the susceptibility to antibiotics was tested according to the Clinical and Laboratory Standards Institute guidelines. After the ban on AGPs, the frequency of F4 (12.5% to 32.7%) increased significantly, and LT (31.9% to 20.3%) and EAST-I (46.5% to 35.2%) decreased significantly. In addition, the resistance to streptomycin (45.8% to 67.9%), cephalothin (34.0% to 59.4%), and cefazlin (10.4% to 28.8%) increased significantly. Colistin resistance plasmid-mediated genes, mcr-1 and mcr-3, were detected after the ban on AGPs. The results of this study can provide useful data for analyzing the impact of the ban on AGPs on the virulence profiles and antimicrobial resistance of E. coli isolated from piglets with diarrhea in Korea.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.113-128
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• 2008

The purpose of this study was to investigate the protective effects against porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) in suckling piglets by oral administration of the IgY. The piglets were divided into two groups: test and control group. The former (n=10) were administered orally with IgY for three days from one-day-old and experimentally challenged with PEDV and TGEV at four-day-old. The latter (n=10) were administered with saline solution and challenged with same methods. Several tests were studied and summarized as follows; In clinical signs, the piglets of the control group showed the typical signs such as severe watery diarrhea, depression and anorexia but those of the test group recovered progressively. Control group showed 20% in mortality, but there were no death in the other. The gross lesions in the test were milder than those in the control, and there were typical findings as like congestion and distension of lumen in the control group. In histopathological study, the piglets of the control group had shortened and fused intestinal villi and a marked loss of epithelium, whereas the others showed milder changes. It could be concluded that oral administration of IgY, specific yolk-antibody against PEDV and TGEV is effective to prevent PEDV and TGEV infection in suckling piglets.

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.353-358
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• 2013

A study investigated the effects of Galla Rhois (GR) on growth performance and diarrhea incidence of postweaning piglets. One hundred 28-day-old piglets were randomly assigned into five experimental groups, which were a basal diet alone (NC), chlortetracycline 0.3 g/kg feed (PC) and supplemented with GR 1.0 g/kg feed (GR 1), GR 2.0 g/kg feed (GR 2), and GR 4.0 g/kg feed (GR 3). After 28 days of administration, final body weight (BW) and feed conversion ratio of PC, GR 2 and GR 3 was significantly different compared to those of NC (p < 0.05). Additionally, the average daily gain (ADG) and average daily feed intake (ADFI) of PC and all groups treated with GR was significantly different compared to those of NC (p < 0.05). Especially, final BW, ADG, ADFI and feed conversion ratio (FCR) of GR 2 and GR 3 were not significant different compared to those of PC. In fecal scores and duration of diarrhea, PC and all groups treated with GR were significantly different compared to NC (p < 0.05). In hematogolical and serum biochemical analysis, there were no significant differences in any of the hematogolical and serum biochemical parameters examined in either NC or all groups treated with GR. The results of this study indicated that GR could be a potential candidate as feed additives for the improvement of growth performance and incidence of diarrhea in piglets.

• Journal of Animal Science and Technology
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• v.57 no.10
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• pp.33.1-33.7
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• 2015

The objective of this study was to evaluate effects of a combined use of extracts of medicinal herbs Taraxaumi mongolicum, Viola yedoensis Makino, Rhizoma coptidis, and Radix isatidis (MYCI) on porcine epidemic diarrhea (PED). Twenty-two 3-day-old piglets received an oral challenge with $3{\times}10^{3.5}$ $TCID_{50}$ of the virulent PED virus (PEDV) in PBS or PBS only and daily oral administration of 60 mg of the MYCI mixture suspended in milk replacer or the vehicle for 7 days in a $2{\times}2$ factorial arrangement of treatments. Average daily gain (ADG) increased (p < 0.05) in response to the MYCI treatment in the PEDV-challenged piglets (-18 vs. 7 g for the vehicle- vs. MYCI-administered group), but not in unchallenged animals (27 vs. 28 g). Diarrhea score and fecal PEDV shedding, however, were not influenced by the MYCI treatment. The PEDV challenge caused severe intestinal villus atrophy and crypt hyperplasia, both of which were alleviated by administration of the MYCI mixture as indicated by an increase in the villus height and a decrease in the crypt depth due to the treatment. Overall, medicinal herb extracts used in this study ameliorated impaired growth performance and intestinal lesion of newborn piglets challenged with the virulent PEDV. Therefore, our results suggest that the MYCI mixture could be used as a prophylactic or therapeutic agent against PED.

• Korean Journal of Veterinary Service
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• v.46 no.3
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• pp.193-202
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• 2023

Porcine epidemic diarrhea is an infectious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV). Especially, when suckling piglets are infected, the mortality rate is close to 100%. PEDV is classified into G1 and G2 types based on genetic differences. The G2 type PEDV outbreak in the United States in 2013 was highly pathogenic and contagious, and it has spread worldwide and caused continuous economic losses. Most commercial vaccines used are G1 type vaccines, and existing vaccines do not fully protect piglets due to genetic differences. In this study, we evaluated the safety of the newly developed G2 type attenuated HSGP vaccine strain by inoculating it into piglets and testing whether the vaccine virus spreads to the non-vaccinated, negative pigs and whether the vaccine reverts to its virulence during serial passage experiments. Each experiment lasted for 7 days for each passage, and fecal viral titers, clinical symptoms, and weight gain were measured daily. After the experiment, necropsy was performed to measure intestinal virus titer and pathological evaluation. As a result of the first passage, no transmission of the vaccine virus to negative pigs co-housed with vaccinated pigs was observed. In addition, after four consecutive passage experiments, the clinical symptoms and small intestine lesions were gradually alleviated, and no virus was detected in the feces in the fourth passage experiment. Therefore, it was concluded that the vaccine was safe without virulence reversion in accordance with the guidelines of the current licensing authority. However, further studies are needed on the genetic changes and biological characteristics of the mutant virus that occur during successive passages of the attenuated vaccine since the replication and clinical symptoms of the virus increased until the third passage during successive passages of the vaccine virus. Based on this study, it was concluded that virulence reversion and safety evaluation of attenuated vaccines through serial passage in target animals can be useful to evaluate the safety of attenuated viruses.

• Korean Journal of Veterinary Research
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• v.61 no.4
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• pp.30.1-30.11
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• 2021

From April 2014 to September 2015, 153 piglets from 52 farms in Jeju were diagnosed with porcine epidemic diarrhea (PED). The major PED cases were focused on suckling piglets (144 piglets, 94.1%), particularly in 1-7-day-old piglets. Histopathologically, severe villous atrophy was observed in the small intestine, especially in the jejunum and ileum. The mean villous height to crypt depth ratios of the jejunum and ileum were 1.4:1 and 1.5:1, respectively. The major histopathologic findings of the small intestine were cytoplasmic vacuolation, cuboidalization, squamation, and exfoliation of the mucosal enterocytes in the villi. The cytoplasmic vacuolations in the enterocytes were the most prevalent lesions in the small intestine and were more severe in the ileum than in the jejunum. According to immunohistochemistry methods, the PED virus (PEDV) antigens were presented in the cytoplasms of the enterocytes, and were distributed more prevalently in the ileum than in the jejunum. PEDV antigens were also detected in the colon of 26 piglets (19.5%). Sequence comparison and phylogenetic analysis indicated that 12 PEDV had more than a 98.9% homology with each other. These PEDV strains were highly homologous with the genogroup 2 North American group.

• Korean Journal of Veterinary Research
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• v.21 no.2
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• pp.87-91
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• 1981

OK serogroups of 268 cultures of Escherichia coli isolated from piglets with colibacillary diarrhea were determined by the use of the simplified routine diagnostic procedures of Sojka. The results obtained are summarised as follows: 1. Of 268 cultures of Escherichia coli tested, 190 cultures were classified into 15 OK groups and the remaining 78(29.1%) were untypable. 2. The most frequently isolated enteropathogenic E. coli in order of prevalence were 0157 : K 'Vl7' (14.2%), 0149 : K91, K88a, c (13.7%), 064 : K 'V142' (11.6%), 08 : K87, K88a, b (10.5%) and O141 : K85a, b, K88a, b (7.9%).

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.300-307
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• 2006

In the present study, methods of the reverse transcription-polymerase chain reaction(RT-PCR) were evaluated for the rapid detection and differentiation of transmissible gastroenteritis virus(TGEV), porcine epidemic diarrhea virus(PEDV) and rotavirus in piglets suffering from diarrhea. For the purposes, the PCR conditions were first confirmed for the amplification of VP7 gene of rotavirus and N gene of TGEV and PEDV using each specific primers and their annealing temperature. Multiplex RT-PCR methods were further determined to distinguish these viral infections and the results are as follows. For the specific amplification of these viral genes, the reliable PCR condition was determined as 30 cycles of reaction consisting each 1 min of denature at $94^{\circ}C$, annealing at $42^{\circ}C$ and polymerization at $72^{\circ}C$ with 1.0 mM $MgCl_2$. It was able to differentiate these viral infections in the intestines and feces of piglets suffering from diarrhea by duplex PCR for TGEV and PEDV and single PCR for rotavirus with a primer-annealing temperature of $42^{\circ}C$. When the multiplex RT-PCR were undertaken for the field samples, 17 cases of PEDV and 5 cases of rotavirus infections were differential diagnosed in a total of 92 samples of intestines and feces of the piglets with diarrhea.