• Asian-Australasian Journal of Animal Sciences
• /
• 제28권9호
• /
• pp.1217-1225
• /
• 2015

Chicken is a major food source for humans, hence it is important to understand the mechanisms involved in nutrient absorption in chicken. In the gastrointestinal tract (GIT), the microbiota plays a central role in enhancing nutrient absorption and strengthening the immune system, thereby affecting both growth and health of chicken. There is little information on the diversity and functions of chicken GIT microbiota, its impact on the host, and the interactions between the microbiota and host. Here, we review the recent metagenomic strategies to analyze the chicken GIT microbiota composition and its functions related to improving metabolism and health. We summarize methodology of metagenomics in order to obtain bacterial taxonomy and functional inferences of the GIT microbiota and suggest a set of indicator genes for monitoring and manipulating the microbiota to promote host health in future.

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권2호
• /
• pp.259-262
• /
• 2004

The ability of Modified Glucomannan (MG) to bind T-2 toxin (T-2) in the gastrointestinal tract has been tested in vivo by feeding 120 five-wk-old broiler chicken with the following six treatment diets, 1) Control diet; 2) Control+MG (0.1%); 3) Control+T-2 (500 ppb); 4) Control+T-2 (500 ppb)+MG (0.1%); 5) Control+T-2 (1,000 ppb) and 6) Control+T-2 (1,000 ppb)+MG (0.1%). Twenty birds were assigned to each treatment group, which had five experimental groups. Four birds of each experimental group were sacrificed at an interval of 30 min i.e. at 0, 30, 60, 90 and 120 min after feeding experimental diets. The whole gut contents of each bird were collected, dried and toxin concentration was determined. Percent T-2 recovered from the gut was significantly lower (p<0.05) in the groups fed MG at all the time intervals. The percent T-2 adsorbed by the MG at different T-2 levels (500 and 1,000 ppb) was 15.97 and 14.77, 22.53 and 22.67, 26.88 and 28.03, and 31.50 and 31.83 at 30, 60, 90 and 120 min, respectively.

• 한국가금학회지
• /
• 제33권1호
• /
• pp.81-95
• /
• 2006

닭의 대장은 해부학적, 생리학적으로 돼지의 대장이나 소의 men과 다르다. 닭의 대장은 소의 men이나 돼지의 대장에 비교하여 잘 발달되어 있지 않다. 그러나 닭의 대장속에 있는 미생물군은 rumen 속의 것과 비슷하다. 특히 닭의 맹장속에는 많은 미생물이 있으며 이 미생물군은 나이, 사료, 성성숙의 정도, 항생제 사용 유무 등에 따라서 다양하게 나타난다. 단백질은 장내의 미생물 형성에 중요한 영양소이다. 닭에서 소장의 길이는 전장 길이의 65%를 차지하며 닭의 맹장은 8.1 %그리고 직장과 공장은 4.6 %를 차지한다. 소장 내에 분포하는 미생물 군은 현재까지 약 10%가 구명된 상태로서 나머지 90%에 대한 정보는 전무하다. 최근의 연구에 따르면 에너지, 저급지방산 (VFA)과 그리고 전해물질이 대장에서 약간씩 흡수되는 것으로 알려져 있다. 닭의 소장은 각종 효소등이 분비되어 소화가 일어나는 중추적인 역할을 하는 것으로 알려져 있다. 앞으로도 많은 연구가 과당류 즉 sucrose thermal oligosaccharide caramel (STOP), fructooligosaccharides (FOS), mannanoligosaccharide (MOS), galactooligosaccharide (GOS) 그리고 isomaltooligosaccharides (IMO)등이 맹장과 대장내에서 어떻게 소화가 일어나는지에 관해서 집중되어야 한다. 과량의 섬유질 함량은 닭의 소화에 치명적일 수 있지만 적당량을 사료에 혼합하여 급여하면 소장의 길이와 함량을 증가시킬 수 있는 효과가 있다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권9호
• /
• pp.1324-1329
• /
• 2008

This study was conducted to evaluate the potential of the transformed Lactobacillus reuteri Pg4 (T-Pg4) harboring the ${\beta}$-glucanase gene as a poultry probiotic. The probiotic properties of the T-Pg4 strain were evaluated in vitro by their adherence capability and acid and bile salt tolerance, and were evaluated in vivo by their survival and adhesion in the gastrointestinal tract (GIT) of specific-pathogen-free (SPF) chickens. The results showed that the T-Pg4 strain exhibited resistance to acidic conditions and contact with bile salt, and adhered efficiently to the crop and intestinal epithelial cells of chickens in vitro. The T-Pg4 strain also could survive and colonize the gastrointestinal epithelium of the experimental SPF chickens in vivo. In addition, radial enzyme diffusion was used to demonstrate that the Lactobacillus spp. randomly isolated from the GIT of the SPF chickens fed T-Pg4 possessed ${\beta}$-glucanase secretion capability. These findings have demonstrated that the transformed L. reuteri Pg4 survives transit through the stomach and intestine, and may secrete ${\beta}$-glucanase in the chicken GIT. Therefore, it is suggested that this organism could be used as a multifunctional poultry probiotic.

• Journal of Microbiology
• /
• 제43권3호
• /
• pp.251-256
• /
• 2005

In this study, we assessed the susceptibility of 12 Lactobacillus strains, all of which had been isolated from the gastrointestinal tracts of chicken, to three antibiotics (chloramphenicol, erythromycin and tetracycline) used commonly as selective markers in transformation studies of lactic acid bacteria. Among these strains, $17\%,\;58\%,\;and\;25\%$ were found to exhibit a high degree of resistance to $200\;{\mu}g/ml$ of tetracycline, erythromycin, and chloramphenicol, respectively. Seven of the 12 Lactobacillus strains exhibiting resistance to at least $50\;{\mu}g/ml$ of chloramphenicol or erythromycin, and five strains exhibiting resistance to at least $50\;{\mu}g/ml$ of tetracycline, were subsequently subjected to plasmid curing with chemical curing agents, such as novobiocin, acriflavin, SDS, and ethidium bromide. In no cases did the antibiotic resistance of these strains prove to be curable, with the exception of the erythromycin resistance exhibited by five Lactobacillus strains (L. acidophilus I16 and I26, L. fermentum I24 and C17, and L. brevis C10). Analysis of the plasmid profiles of these five cured derivatives revealed that all of the derivatives, except for L. acidophilus I16, possessed profiles similar to those of wild-type strains. The curing of L. acidophilus I16 was accompanied by the loss of 4.4 kb, 6.1 kb, and 11.5 kb plasmids.

• 한국가금학회지
• /
• 제22권2호
• /
• pp.105-115
• /
• 1995

The balance of microbial populations in the gastrointestinal (GI) tract of all warm-blooded animals is critical to the maintenance of health and resistance to disease. The composition of the populations can be altered by diet and environment, making the host animal susceptible to disease, and reducing growth rate and feed efficiency. Some feed additives including antimicrobial agents, prohiotics or yucca extract have been used to promote growth and feed utilization. There is evidence that part of growth-promoting effect of those feed additives results from the suppression of microbial urease activity or ammonia production in the GI contents of animals. Over 200 microbial species have been known to produce urease and the product of urea hydrolysis, ammonia, is toxic to animals. Carefully tested probiotics or other urease-suppressing agents can be a possible alternative to antimicrobial agents including antibiotics as growth promotants used for animals feeds.

• 대한수의학회지
• /
• 제52권4호
• /
• pp.223-230
• /
• 2012

The worldwide distribution and continuing genetic mutation of avian influenza virus (AIV) has been posed a great threat to human and animal health. A comparison of 3 isolates of AIV H9N2, A/chicken/Korea/KBNP-0028/00 (H9N2) (KBNP-0028), A/chicken/Korea/SNU8011/08 (H9N2) (SNU 8011) and an inactivated oil vaccine strain A/chicken/Korea/01310/01 (H9N2) (01310), was performed. The former 2 AIVs were isolated from field cases before and after the application of an inactivated H9N2 vaccine in 2007, respectively. The antigenic relationship, viral shedding, tissue tropism and genetic analysis were examined. The comparison of virus shedding from the cloaca and the oropharynx revealed that both isolates were more frequently isolated from the upper respiratory tract (90~100%) 1 day post inoculation (DPI) compared with isolation 5 DPI from gastrointestinal tracts (10~60%). Moreover, the isolate KBNP-0028 were recovered from all organs including bone marrow, brain and kidneys, indicating higher ability for broad tissue dissemination than that of SNU 8011. KBNP-0028 replicated earlier than other strains and with a higher titer than SNU 8011. In full-length nucleotide sequences of the NA gene and a partial sequence of the HA gene of SNU 8011, we found that there might be significant changes in tissue tropism, virus replication and genetic mutation in AIV H9N2 isolates.

• 대한수의학회지
• /
• 제52권4호
• /
• pp.213-221
• /
• 2012

A total of 18 Newcastle disease virus (NDV) isolates that were recovered from 1949 through 1997 were characterized and pathotyped. All viruses were highly virulent as determined by intracerebral pathogenicity indices ${\geq}1.81$ in day-old. These pathotypes are typical for viscerotropic velogenic NDV (VVNDV) pathotype viruses. Some differences were observed for the chicken red blood cell elution rate and thermostability of the hemagglutinin at $56^{\circ}C$. Three antigenic groups were identified by a hemagglutination-inhibition assay using NDV monoclonal antibodies. And the predominant gross lesions were as follows: discharge from the nasal cavity, tracheal mucus, petechial hemorrhage in the heart fat, kidney urates and hemorrhage with or without necrosis in the gastrointestinal tract. Severe hemorrhagic or necrotic lesions were also noted in the lymphoid organs and were localized primarily in the spleen and cecal tonsil. However, differences in the occurrence and frequency of the gross lesions were observed between the virus strains. Among them, NDV strains that induced neurological symptoms belonged only to genotype VI. This strain had spread throughout Korea during the late 1980s to the 1990s, which suggests that specific VVNDVs genotypes might result in neurological symptoms.

• 한국가금학회지
• /
• 제48권4호
• /
• pp.287-295
• /
• 2021

본 연구는 농장 단계에서의 절식 시간에 따른 육계의 중량 및 소화기관의 무게의 변화, 소낭 내 Salmonella, Campylobacter 오염, 혈액 매개변수, 계육 품질에 미치는 영향을 알아보기 위하여 수행하였다. 총 100 수의 육계(초기생체중, 1.906±0.06 kg)를 무작위로 5개의 처리구에 나누어 배치하였다. 절식 기간 동안 물은 공급했지만 사료는 공급하지 않았다. 절식 시간은 2, 3, 4, 5, 6시간으로 설정하였다. 생체중, 도축 전 체중, 도체중, 소화기관의 무게, 소낭 내 Salmonella 및 Campylobacter 수, 혈청 생화학적 조성, 백혈구, 적혈구, 혈소판 및 계육 품질을 분석하였다. 본 연구 결과 절식시간에 따른 도체중, 혈액 corticosterone, 가슴육 pH, 육색, 보수력에 유의적인 차이를 나타내지 않았다. 하지만, 6시간 절식한 육계의 소장 내 Salmonella 균 수가 유의적으로 낮았으며, 전단력은 유의적으로 가장 높았다. 6시간 동안 절식한 육계의 가슴육의 전단력은 증가하였으나 소비자의 관능적 특성에는 영향을 미치지 않았으며, Salmonella 균 오염도 감소하여 도계 시 오염도가 감소할 것으로 사료된다. 본 연구 결과는 농장단계에서의 절식시간 설정에 대한 참고 자료가 될 수 있을 것으로 사료되며, 향후 운송, 계류 시간도 함께 고려한 총 절식 시간에 대한 연구도 필요할 것으로 사료된다.