• Journal of Animal Science and Technology
• /
• v.65 no.4
• /
• pp.838-855
• /
• 2023

The highly pathogenic avian influenza (HPAI) virus triggers infectious diseases, resulting in pulmonary damage and high mortality in domestic poultry worldwide. This study aimed to analyze miRNA expression profiles after infection with the HPAI H5N1 virus in resistant and susceptible lines of Ri chickens.For this purpose, resistant and susceptible lines of Vietnamese Ri chicken were used based on the A/G allele of Mx and BF2 genes. These genes are responsible for innate antiviral activity and were selected to determine differentially expressed (DE) miRNAs in HPAI-infected chicken lines using small RNA sequencing. A total of 44 miRNAs were DE after 3 days of infection with the H5N1 virus. Computational program analysis indicated the candidate target genes for DE miRNAs to possess significant functions related to cytokines, chemokines, MAPK signaling pathway, ErBb signaling pathway, and Wnt signaling pathway. Several DE miRNA-mRNA matches were suggested to play crucial roles in mediating immune functions against viral evasion. These results revealed the potential regulatory roles of miRNAs in the immune response of the two Ri chicken lines against HPAI H5N1 virus infection in the lungs.

• Korean Journal of Poultry Science
• /
• v.19 no.2
• /
• pp.107-112
• /
• 1992

Sporozoite of Eimeria tenella inoculated into the allantoic cavities of embryonating eggs completed their life-cycle in the chorioallantoic membranes (CAM ) and produced viable oocysts. And the strain continued to adapt to the CAM through the period of the passages. In embryos, the reproduction of the strain, judged by oocyst production increased, but the pathogenicity, judged by mortality of embryo decreased, with increasing numbers of passage in eggs.

• Journal of Korean Society on Water Environment
• /
• v.28 no.2
• /
• pp.305-312
• /
• 2012

Avian influenza (AI) and foot and mouth disease (FMD) are two main contagious pathogenic viruses causing massive mortality burial, as burial is a primary measure to quaranteen the causative viruse(s). Biosecurity is a set of preventive measures designed to reduce the risk of propagation of infectious diseases. Main objectives of this paper were to discuss the needs of biosecurity and develop protocol outlines for environmental management of burial sites. Pathological characteristics of contagious viruses should be considered during environmental management practices. Current practice prescribes to minimize the potential for on-farm pollution and the spread of infectious diseases, policy makers should understand robust knowledge regarding biosecurity to make informed decisions on future legislation.

• Korean Journal of Poultry Science
• /
• v.23 no.4
• /
• pp.185-191
• /
• 1996

A feeding trial was conducted to investigate the effect of skip-a-day feeding program in early growing stage of male broiler chicks on the compensatory growth, and development of visceral organs during the later realimentation period. Day-old 328 male broiler chickens( Avian x Avian) were divided into control(ad libitum feeding) and skip-a-day feeding(limited feeding) treatments. Each treatment was consisted of 4 pens( replicates) of 41 birds each. Chickens on the skip-a-day program were fasted every other day during the second wk of age(8~15 d of age). During the starter period(0~4 wk), chickens were fed a commercial crumble diet. A commercial pellet diet was fed to chickens during the finishing period( 5~8 wk). Chickens were group-weighed every week, and one bird was selected from each pen to measure carcass characteristics. The skip-a-day program delayed the growth rate of male broilers up to 4 wk of age(P

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2006.11a
• /
• pp.90-91
• /
• 2006

To reduce the economic impact and control Low pathogenic avian influenza (LPAI), vaccination with inactivated vaccine has been considered in this country. We tried to develop inactivated vaccine with reassorted H9N3 AI virus which has different type of neuraminidase compare to those of field AI virus. Before reassorted vaccine was produced, we confirm the virus as master seed by limiting dilution, RT-PCR and sequencing method. Also, we evaluate the biological characteristics of the virus to find out the possibility of prevention against field infection of AI virus. Finally, we evaluate the safety and efficacy of the vaccine made of reassorted AI virus in the specific pathogen free (SPF) chickens. After limiting dilution, we choose RV7CE4 as a vaccine candidate and compare the gene sequence of this vaccine strain to those of AI05GA which is parents strain. Compared to amino acid sequences of specific gene of AI05GA and RV7CE4, exhibited a high degree of amino acid sequence homology. In the safety and efficacy test, there were no specific clinical signs or mortality. Reassorted H9N3 viruses were reisolated in cloaca swab on 5 days post inoculation. In the vaccine study, once or twice vaccination was performed and challenged with H9N2 field virus (01310). Vaccine has no adverse effect on birds and formed good immune capability which reduce viral shedding in the birds infected with 01310. Based on the above result, we developed reassorted H9N3 vaccine which will efficiently prevent the low pathogenic AIV (H9N2) infection in the poultry farms.

• Korean Journal of Veterinary Service
• /
• v.27 no.3
• /
• pp.281-288
• /
• 2004

As all other intensively farmed domestic species, most mortality in ostriches is closely to rearing conditions. While ostriches is also highly sensitive to stress, species-specific infectious disease play only a minor role. But investigation of ostrich's disease is not peformed almost in Korea. The study was performed to investigate the titers of antibody for Newcastle disease(ND), Infectious bronchitis(IB), Egg drop syndrome '76(EDS), Avian influenza(AI), salmonellosis, Mycoplasma gallisepticum infection(MG), Mycoplasma synoviae infection(MS), Infectious bursal disease(IBD), Brucellosis, Toxoplasmosis, Japanese encephalitis(JE), Porcine parvovirus infection, Encephalomyocarditis and Porcine reproductive respiratory syndrome (PRRS). The results obtained in the 62 ostrich sera slaughtered in Gyeongbuk province were summarized as follows: The average of antibody positive rates to ND, IB, EDS, AI(H9Nl), JE, Porcine parvovirus infection and Encephalomyocarditis by HI test were $75.8\%,\;100\%,\;0\%,\;0\%,\;51.6\%,\;50\%\;and\;56.5\%$ respectively. The antibody positive rates to salmonellosis, MG, MS by plate agglutination test were $12.9\%,\;25.8\%,\;and\;0\%$ respectively. Antibodies to disease agent such as IBD and AI by agar gel precipitation(AGP) test, Brucellosis by tube agglutination, toxoplasmosis by latex agglutination test and PRRS by IFA were all negative.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.4
• /
• pp.560-563
• /
• 2004

The study was undertaken to evaluate the effect of naked neck gene on mortality, cell mediated and humoral immune response in white plumage broiler population. The mortality of homozygous naked neck (Na/Na) broilers (11.71%) was comparatively lower than that of heterozygous naked neck (Na/na) (12.28%) and normally feathered (na/na) (13.59%) broilers. The humoral immune response was measured against (1% v/v) sheep red blood cells (SRBC) for total haemagglutinin (HA) antibody, 2-mercaptoethanol resistance (MER) or (IgG) antibody and 2-mercaptoethanol sensitive (MES) or (IgM) antibody titre on 7 days post-immunization. The titre was expressed as log2 of the highest dilution which shows complete haemagglutination. Total HA titers of Na/Na and Na/na (11.05$\pm$0.53 and 11.09$\pm$0.38) were comparatively higher than that of na/na (10.26$\pm$0.42). The MES antibody titre of Na/Na (8.50$\pm$0.53) and Na/na (7.63$\pm$0.45) broilers were significantly higher as compared to na/na (6.11$\pm$0.32) broilers. The MER titre of na/na genetic group (4.15$\pm$0.42) was significantly higher than Na/Na (2.55$\pm$0.37) and comparatively higher than Na/na (3.45$\pm$0.38) broilers. In vivo cell response to phytohaemagglutinin-P (PHA-P), measured as Foot Index (FI) in mm expressed significantly higher response in Na/na (0.473$\pm$0.05) and Na/Na (0.413$\pm$0.04) broilers as compared to na/na (0.304$\pm$0.03) broilers. The result of present study suggested that white plumage naked neck broilers had better immune response as compared to normally feathered broilers.

• Korean Journal of Poultry Science
• /
• v.32 no.2
• /
• pp.113-123
• /
• 2005

Avian influenza (AI) virus (AIV) is distributed worldwide and it has been isolated from various species of wild and domestic birds. AI transfers with high speed and shows diverse pathogenicity syndroms. In Korea, several low Pathogenic AIV, H9N2, have been isolated from the commercial farms with severe decrease of egg production and mortality resulted in severe economic loss since 1996. Therefore, it has been requested to develop AI vaccines to prevent clinical signs and economic losses from the field infection of AIV. To develop a killed vaccine that efficiently prevents low pathogenic AIV (H9N2), evaluation on the pathogenicity and selection of an inactivator for H9N2 is taking place and is being tested safety and immunogenicity of vaccine produced. Based on the pathogenicity test and viral reisolation test, the ADL0401 isolate is the characteristic low pathogenic AIVs and has fairly similar biologic functions compared with MS96 which is the official low pathogenic AIV (H9N2) and one of the predominant AIV isolated from poultry farms in Korea. In antigenicity tests, the ADL0401 and MS96 virus have no significant antigenic difference. In inactivation tests, the ADL0401 isolates can be easily inactivated with $0.1\%$ Formalin at $37^{\circ}C$ within 1 hour with a little decrease of HA titer. The vaccine developed in the present report has no harmful effect on bird and forms good immune capability. Therefore, the isolates, ADL0401 can be used for a killed vaccine which can reduce the clinical signs and viral shedding in the birds infected with H9N2 low pathogenic AIVs.

• Advances in nano research
• /
• v.11 no.6
• /
• pp.649-655
• /
• 2021

Nanotechnology is widely considered a major technology of the twenty-first century. Nanoparticles (NPs) has been shown to pass through reproductively significant biological barriers such as the blood-testicle and placental barriers. Thus, the purpose of this study was to determine the effect of silver Nanoparticles (Ag-NPs) on sperm-egg interaction and spermatozoa quality parameters in quail spermatozoa. Semen was suspended in Ringer solution containing Ag-NPs levels at 5.5 × 106 sperm/ml (0, 0.01, 0.1, 1 and 10 ppm). The results indicated that when sperm were counted at 0.1 ppm, the number of holes formed on the inner perivitelline layer was significantly increased compared to the control. The 10 ppm group had a significant reduction in sperm viability. At 0.1 and 1 ppm, the membrane integrity was significantly decreased (P < 0.05). All treatments (except 0.01 ppm Ag-NPs) had a significant (P < 0.05) effect on the percentage of spermatozoa with an intact acrosome when compared to the control group. At 0.1, 1, and 10 ppm Ag-NPs, morphological defects in the acrosome were observed. As a result, Ag-NPs is likely capable of destroying the acrosome membrane. This research indicates that Ag-NPs may be cytotoxic to spermatozoa by impairing sperm functionality and increasing sperm mortality.

• Korean Journal of Poultry Science
• /
• v.44 no.2
• /
• pp.143-149
• /
• 2017

This study was carried out to collect basic data on the egg laying performance and disease occurrence on animal welfare-approved farms (AWAF) for laying hens with different housing types (windowless, open, and free-range house) and strains (Hy-line, Lohmann). Age at first egg laying was 151 d in the windowless house and 141 d in both the open and free-range houses, and the percentage peaks of each farm were 91.8%, 92.9%, and 86.3%. Average egg production according to housing types were 70.9%, 77.4%, and 65.6% at 18~38 wk old and 91.1%, 90.1%, and 76.2% at 32~36 wk. The average dirty and cracked egg ratio of the windowless, open, and free-range houses was 2.84%, 1.15%, and 0.23%, respectively. Mortality in the open house was lower than the other house types. Age of first egg laying for the Hy-line strain was 155 d and that for the Lohmann strain was 157 d, and the percentage peaks of the two strains were 92.9% (252 d) and 87.2% (237 d), respectively. Average egg production of the strains was 83.7% and 76.9%, respectively. The average dirty and cracked egg ratio of the Hy-Line and Lohmann strains was 3.85% and 2.97%, respectively. Mortality of the Hy-Line strain was lower than that of the Lohmann strain. There were significant differences (P<0.05) in the egg weight, HU, and egg yolk color of chickens raised in the open house compared with those of chickens raised in the other house types. In terms of antibody titer, that for Newcastle disease in open house chickens was lower than that of chickens raised in windowless and free-range houses. The antibody titer for low pathogenic avian influenza, avian infectious bronchitis, and avian pneumovirus was high at over 3.0 in all three farms. SG, Salmonella enteritidis, Salmonella pullorum, fowl adenovirus infection, and infectious laryngotrachitis were not detected in any of the three house types. The number of AWAF for laying hens has continuously increased in Korea, but there is currently little data on the housing types used on the AWAF for laying hens. Therefore, the results of the present study, in which analyzed the laying performance and disease occurrence on AWAF for laying hens, can use as basic data for the improvement of performance and prevention of disease on further AWFA for laying hens.