Marker Assisted Selection-Applications and Evaluation for Commercial Poultry Breeding

Sodhi, Simrinder Singh,Jeong, Dong Kee,Sharma, Neelesh,Lee, Jun Heon,Kim, Jeong Hyun,Kim, Sung Hoon,Kim, Sung Woo,Oh, Sung Jong The Korean Society of Poultry Science 2013 韓國家禽學會誌 Vol.40 No.3

Poultry industry is abounding day by day as it engrosses less cost of investment per bird as compared to large animals. Poultry have the most copious genomic tool box amongst domestic animals for the detection of quantitative trait loci (QTL) and marker assisted selection (MAS). Use of multiple markers and least square techniques for mapping of QTL affecting quality and production traits in poultry is in vogue. Examples of genetic tests that are available to or used in industry programs are documented and classified into causative mutations (direct markers), linked markers in population-wide linkage disequilibrium (LD) with the QTL (LD markers), and linked markers in population wide equilibrium with the QTL (LE markers). Development of genome-wide SNP assays, role of 42 K, 60 K (Illumina) and 600 K (Affymetrix$^{(R)}$ Axim$^{(R)}$) SNP chip with next generation sequencing for identification of single nucleotide polymorphism (SNP) has been documented. Hybridization based, PCR based, DNA chip and sequencing based are the major segments of DNA markers which help in conducting of MAS in poultry. Economic index-marker assisted selection (EI-MAS) provides platform for simultaneous selection for production traits while giving due weightage to their marginal economic values by calculating predicted breeding value, using information on DNA markers which are normally associated with relevant QTL. Understanding of linkage equilibrium, linkage dis-equilibrium, relation between the markers and gene of interest are quite important for success of MAS. This kind of selection is the most useful tool in enhancing disease resistance by identifying candidate genes to improve the immune response. The application of marker assisted selection in selection procedures would help in improvement of economic traits in poultry.

Antimicrobials, Gut Microbiota and Immunity in Chickens

Lee, Kyung-Woo,Lillehoj, Hyun S. The Korean Society of Poultry Science 2011 韓國家禽學會誌 Vol.38 No.2

The use of antimicrobials will be soon removed due to an increase of occurrence of antibiotic-resistant bacteria or ionophore-resistant Eimeria species in poultry farms and consumers' preference on drug-free chicken meats or eggs. Although dietary antimicrobials contributed to the growth and health of the chickens, we do not fully understand their interrelationship among antimicrobials, gut microbiota, and host immunity in poultry. In this review, we explored the current understanding on the effects of antimicrobials on gut microbiota and immune systems of chickens. Based on the published literatures, it is clear that antibiotics and antibiotic ionophores, when used singly or in combination could influence gut microbiota. However, antimicrobial effect on gut microbiota varied depending on the samples (e.g., gut locations, digesta vs. mucosa) used and among the experiments. It was noted that the digesta vs. the mucosa is the preferred sample with the results of no change, increase, or decrease in gut microbiota community. In future, the mucosa-associated bacteria should be targeted as they are known to closely interact with the host immune system and pathogen control. Although limited, dietary antimicrobials are known to modulate humoral and cell-mediated immunities. Ironically, the evidence is increasing that dietary antimicrobials may play an important role in triggering enteric disease such as gangrenous dermatitis, a devastating disease in poultry industry. Future work should be done to unravel our understanding on the complex interaction of host-pathogen-microbiota-antimicrobials in poultry.

Protein Quality and Amino Acid Utilization in Chickens

Kim, Ji-Hyuk The Korean Society of Poultry Science 2015 韓國家禽學會誌 Vol.42 No.1

It is well known that dietary protein affects the growth performance and carcass composition of poultry. Over the last several decades, numerous studies have been carried out to investigate to optimize the level of dietary protein since the protein is an important and expensive constituent in poultry feed. It is generally accepted that dietary protein should represent a balance of amino acids supporting the requirements for growth and maintenance of birds. A protein with balanced essential amino acids that matches a bird's requirement and sufficient non-essential amino acid nitrogen to enable the synthesis of all of the non-essential amino acids, is referred to as an 'ideal protein'. Feeding of excess protein or amino acids may result in an amount of nitrogen emission. Most common method to reduce nitrogen emission is using diet formulation which has lower dietary crude protein level and higher concentration of amino acid supplements. However, there are conflicting reports whether low protein diets supplemented with synthetic amino acids can obtain the growth performance equal to high protein diets. Excessive nitrogen excretion caused by amino acid imbalance also may influence the environment of poultry house due to ammonia production from uric acid. These environmental conditions may increase the incidence of skin problem or respiratory diseases of chickens. Various strategies based on comprehensive understanding should be tested to optimize nitrogen utilization and reduce nitrogen emission while maintaining the performance in poultry production.

Recent Progress in Development of Vaccines against Avian Coccidiosis

Lillehoj, Hyun S. The Korean Society of Poultry Science 1999 韓國家禽學會誌 Vol.26 No.3

Protozoa of the genus Eimeria are the etiologic agents of avian coccidiosis, the most economically important Parasitic disease for the poultry industry. Coccidia multiply in intestinal epithelial cells of a wide range of hosts, including livestock in addition to poultry. Chemotherapy is extensively used to control coccidiosis. However, development of drug resistance by Eimeria parasites, the intensive cost and labor involved in the identification of new anticoccidial compounds and public awareness of drug residues in foods warrant alternative methods to prevent coccidiocic in the fast growing poultry industry. For these reasons, there is a great interest in developing vaccines against avian coccidiosis. Live Eimeria vaccines confer protective immunity, however a significant disadvantage of using these types of vaccines is their pathogenicity. Live parasites with attenuated pathogenicity also usually produce immunity but may revert back to a pathogenic form and may be contaminated with other pathogenic organisms. Killed Eimeria vaccines are safer but, unlike live attenuated vaccines, are not able to generate cytotoxic T lymphocyte responses. Recombinant vaccines are biochemically purified proteins produced by genetic engineering that consist of particular epitopes or metabolites of Eimeria. Unlike live attenuated organisms, recombinant vaccines do not possess as much risk and generally are able to induce both humoral and cell mediated immunity. DNA vaccines consist of genes encoding immunogenic proteins of pathogens that are directly administered into the host in a manner that the gene is expressed and the resulting protein generates a protective immune response. Although all of these different types of vaccines have been applied to coccidiosis, this disease continues to cause substantial morbidity and mortality in the poultry industry. Future development of an effective vaccine against coccidiosis will depend on further investigation of protective immunity to Eimeria infection and identification of important immundgenic parasite molecules.

Epidemiological Studies of Avian Paramyxovirus Type 4 and 6 in Commercial Chicken Flocks in Korea

Lee, Hae Rim,Koo, Bon-Sang,Jeon, Eun-Ok,Han, Moo-Sung,Min, Kyung-Cheol,Lee, Seung Baek,Bae, Yeonji,Choi, Kang-Seuk,Shin, Jeong-Hwa,Mo, In-Pil The Korean Society of Poultry Science 2013 韓國家禽學會誌 Vol.40 No.4

Avian paramyxovirus (APMV) type 4 and 6 were isolated during an avian influenza (AI) surveillance program of wild birds. This study also conducted experimental infection of wild-bird-origin APMV type 4 and 6 in specific pathogen free (SPF) chickens to study pathogenicity and transmission within domestic flocks. In addition, serological prevalence data of APMV type 4 and 6 in domestic fowls was conducted with chicken sera collected from 2007 to 2009 in order to understand infection status. The results of the animal experiment showed that APMV type 4 and 6 had the ability to infect chickens with sero-conversion and to transmit the virus from infected birds to contacted birds, but showed low pathogenicity. Serological tests revealed that APMV type 4 was widespread in the poultry industry, especially in layer flocks, but the positive rate for APMV type 6 was very low. This study concluded that wild bird-origin APMV type 4 and 6 could infect the chickens by inter-species transmission and the seroprevalence of APMV type 4 was quite high in Korean poultry. However, since almost all the chicken flocks had a high level of antibody titer against APMV type 1, there was possibility of cross reaction between APMV type 1 and 4, which made the interpretations more complicated. In order to understand infection status in the natural environment, additional study is necessary regarding the seroprevalence of APMV type 4 and 6 in the wild bird population.

Molecular Characterization of an H5N3 Influenza Virus Isolated from Spot-Billed Duck

Lee, Jin Hwa,Kwon, Hyuk Moo,Sung, Haan Woo The Korean Society of Poultry Science 2013 韓國家禽學會誌 Vol.40 No.3

Among the 16 hemagglutinin (HA) subtypes of avian influenza virus (AIV), only the H5 and H7 subtypes have caused highly pathogenic avian influenza (HPAI) in poultry. However, most H5 or H7 subtype viruses are categorized as low pathogenic avian influenza (LPAI). Some AIVs, including the H5 and H7 HPAI viruses, have shown the ability to infect humans directly. In this study, we describe the biological and molecular characterization of an H5N3 AIV (SBD/KR/KNU SYG06/06) isolated from spot-billed duck (Anas poecilorhyncha) in Korea. A phylogenetic analysis of the eight viral genes showed that the SBD/KR/KNU SYG06/06 isolate belongs to the Eurasian lineage and that the SBD/KR/KNU SYG06/06 isolate was clearly different from HPAI H5N1 strains, including human isolates and the Italian HPAI H5N2 strains. Additionally, no relationship was found between SBD/KR/KNU SYG06/06 and the Korean HPAI H5N1 isolates. The SBD/KR/ KNU SYG06/06 isolate had avian specific receptor binding site residues in the HA protein and the four C-terminal amino acids in the NS1 protein. The HA protein of the SBD/KR/KNU SYG06/06 isolate exhibited the typical LPAI motif at the cleavage site and this virus produced no cytopathic effects in MDCK cells without trypsin. Given these results, we suggest that the H5N3 AIV isolated from the spot-billed duck should be considered an LPAI virus and should have no pathogenic effect in humans.

Utilization of NPN by Poultry: A REVIEW

Chee, Kew-M. The Korean Society of Poultry Science 1982 韓國家禽學會誌 Vol.9 No.2

비단백태 질소화합물의 가금에서의 이용 가능성은 오래 전부터 많은 사람들의 관심의 대상이 되어 있었다. Urea나 Diammonium Citrate같은 NPN들이 부로일러에서 비필항 아미노산들의 공급을 목적으로 이용될 수 있다는 많은 증거들이 있다. 그 mechanism 은 이들에 의해 공급되는 ammonia가 $\alpha$-ketoglutaric acid에 결합되어 glutamic acid가 되어 체내에서 transamination 방법에 의해 비필수 아미노산들의 합성에 기여할 수 있다는 것이다. 산란에서도 마찬가지 방법으로 이용될 수 있으나 육계에선 보다는 이용 효율이 낮다고 한다. 비단백태 질소 화합물의 급여가 사료섭취량에 영향을 주고, 산란율을 저하시키며 란중을 적게하는 원인이 되나 albumin의 질을 높인다는 장점도 보고되고 있다. 이들 화합물이 가중에서 효율적으로 이용되기 위해서는 사료내 단백질 수준이 정상보다 낮아야 하며 철수 아미노산을 충분히 함유하고 있어야 한다 장차 단백질 자원의 부족 현상이 더욱 심각해질 것을 예상할 때 비단백태 질소 화합물의 가축에서의 이용성을 높이는 연구는 매우 중요하다.

Biochemical and Histopathological Study of Aflatoxicosis on Ross 308 Broiler Chicks

Ko, Myung-Soon,Ahn, Meejung,Shin, Dong-Jin,Son, Youngho The Korean Society of Poultry Science 2017 韓國家禽學會誌 Vol.44 No.4

Totally, one hundred and sixty 1-day-old Ross 308 broiler chicks were fed with a diet containing 0, 0.5, 1.0, and 2.0 mg of aflatoxin $B_1(AFB_1)/kg$ of feed for 21 days. Body weight was lower for the $AFB_1$-treated broilers than for the control group. At 14 and 21 DPF, the broilers fed with 2.0 mg of $AFB_1/kg$ of feed weighed significantly lower than those of the other groups (p<0.05). Relative liver weights increased significantly in a dose-dependent manner, and relative spleen weights were significantly high in the chicks fed with 2.0 mg of $AFB_1/kg$ of feed at 21 DPF (p<0.001). Biochemical analyses showed that total protein and albumin levels decreased significantly at 7 and 14 DPF for the chicks of the group fed with 2.0 of mg $AFB_1/kg$ of feed, compared with those fed with 0.5 and 1.0 mg of $AFB_1/kg$ of feed (p<0.05). AST and ALT levels increased significantly at 14 and 21 DPF (p<0.05), and the AST levels, particularly, increased dose-dependently (p<0.05). Histopathological analyses showed that the liver tissues of the $AFB_1$-treated chicks showed significant lesions, including hemorrhage, hepatocyte necrosis, inflammatory cell infiltration, and fatty degeneration. The severity of both hepatocyte necrosis and inflammatory cell infiltration appeared to increase dose- and time-dependently. Similarly, hepatic fibrosis increased dose-dependently (p<0.05). The results of this study could improve our understanding of parameters used for evaluating aflatoxicosis in poultry.

Development of complete Culture System for Quail Embryos and Its Application for Embryo Manipulation

Ono, T. The Korean Society of Poultry Science 2001 韓國家禽學會誌 Vol.28 No.2

Gene and cell transfer technique will serve as a powerful tool for the genetic improvement of the poultry and to yield useful products. For avian transgenesis, Japanese quail may serve as an excellent animal model because of its small body size and fast growth rate. Recent progress was described on the manipulation of quail embryos such as the introduction of foreign genes and cells, and the subsequent culturing of the manipulated embryos yielding hatchlings. Intraspecific donor-derived offspring have been available in quail, however, further investigation will be required to obtain interspecific offspring with the aim of rescuing endangered species. Trans genesis will also be useful for improving the profitability and quality of poultry stocks and for developing stocks with novel uses. Considerable progress should soon be made toward the production of transgenic poultry. The key feature of the procedure described here is that embryos are initially taken out from the shell for ease of manipulation and then placed back in culture in addition to various operations midway during culture.

EU FP6 Welfare Quality^® Poultry Assessment Systems

Butterworth, A. The Korean Society of Poultry Science 2009 韓國家禽學會誌 Vol.36 No.3

동물복지는 유럽의 소비자들과 시민들에게 상당히 중요하다는 것이 최근의 여론조사에서 확인되었다. 동물복지는 개별동물의 특성이라는 것 때문에 연구자들 뿐만 아니라 다른 사람들도 동물에 근거한 평가기준 (동물에서 측정된 척도, 예를 들면, 동물의 건강과 행동)이 동물복지의 타당한 표식이 될 수 있다고 오래 동안 제안해왔다. 그러므로 복지의 평가기준은 필수적으로 동물을 사용한 평가 척도에 바탕을 둘 수 있으며, 반면에 자원을 근거로 한 평가 기준은 위해요소들을 평가할 수 있는 능력을 제공한다. 이 계획의 첫 번째 목표는 복지를 감시하는 체계를 개발하여 복지의 척도를 접근 가능하고 이해할 수 있는 정보로의 표준화된 변환을 통하여 복지의 상태를 평가할 수 있게 하는 것이다. 한편 얻어진 정보는 동물시설 관리자들에게 제공되어 동물복지의 상태에 대하여 알게 하며, 또 다른 한편으로는 소비자와 소매상에게 동물 관련 제품의 복지 상태에 대한 정보를 제공한다. 두 번째 목표는, 유해한 행동적 및 생리적인 사태의 발생을 최소화하고, 인간과 동물간의 관계를 향상시키며, 그리고 동물에게 안전하고 흥미로운 환경을 제공함으로써, 동물의 복지를 향상시키는 것이다. 포함되어야 할 복지에 대한 다른 측정 가능한 양상들은 복지의 표준들로 변환된다. 이들은, 동물복지과학으로 이해되는 것처럼, 동물에게 의미 있는 것을 반영한다. 일단 동물시설에 대한 모든 평가척도들이 측정되면, 그 시설물의 동물복지에 대한 전반적인 평가를 수행하기 위한 상향식 접근이 있게 된다. 먼저 수집된 자료 (즉, 그 동물 시설에 대한 다른 척도로 얻어진 수치) 는 합쳐져서 표준 점수가 계산된다. 그리고 나서 표준점수는 합쳐져서 원칙 점수가 계산되며, 마지막으로, 얻어진 원칙 점수에 따라서 그 동물 시설에 대한 복지의 범주가 정해진다. Animal welfare is of considerable importance to European consumers and citizens, this being most recently confirmed in EU barometer studies. Researchers and others have long proposed that animal-based measures (measures taken on animals, e.g. their health and behaviour) can provide a valid indicator of animal welfare; since welfare is a characteristic of the individual animal. Therefore, a welfare assessment can be essentially based on animal-based measures, but with use of resource measures to provide the capacity to assess 'risk factors'. The first goal of this project was to develop a welfare monitoring system that enables assessment of welfare status through standardised conversion of welfare measures into accessible and understandable information. The acquired information on one hand provides feedback to animal unit managers about the welfare status of their animals, and on the other, information on the welfare status of animal-related products for consumers and retailers. The second goal of Welfare $Quality^{(R)}$ was to improve animal welfare by minimising the occurrence of harmful behavioural and physiological states, improving human-animal relationships, and providing animals with safe and stimulating environments. The different measurable aspects of welfare to be covered are turned into welfare criteria. The criteria reflect what is meaningful to animals as understood by animal welfare science. Once all the measures have been performed on an animal unit, a bottom-up approach is followed to produce an overall assessment of animal welfare on that particular unit: first the data collected (i.e. values obtained for the different measures on the animal unit) are combined to calculate criterion-scores; then criterion-scores are combined to calculate principle-scores; and finally the animal unit is assigned to a welfare category according to the principle-scores it obtained.