• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.180-188
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• 2018

Objective: The aim of this study was to investigate the effect of single nucleotide polymorphisms (SNPs) of the melanogenesis associated transcription factor (MITF) and dopachrome tautomerase (DCT) genes on plumage coloration in Asian native duck breeds. MITF encodes a protein for microphthalmia-associated transcription factor, which regulates the development and function of melanocytes for pigmentation of skin, hair, and eyes. Among the tyrosinase-related family genes, DCT is a pigment cell-specific gene that plays important roles in the melanin synthesis pathway and the expression of skin, feather, and retina color. Methods: Five Asian duck varieties (black Korean native, white Korean native, commercial Peking, Nageswari, and Bangladeshi Deshi white ducks) were investigated to examine the polymorphisms associated with plumage colors. Among previously identified SNPs, three synonymous SNPs and one indel of MITF and nine SNPs in exon regions of DCT were genotyped. The allele frequencies for SNPs of the black and white plumage color populations were estimated and Fisher's exact test was conducted to assess the association between the allele frequencies of these two populations. Results: Two synonymous SNPs (c.114T>G and c.147T>C) and a 14-bp indel (GCTGCAAAC AGATG) in intron 7 of MITF were significantly associated with the black- and white-colored breeds (p<0.001). One non-synonymous SNP [c.938A>G (p.His313Arg)] in DCT, was highly significantly associated (p<0.001) and a synonymous SNP (c.753A>G) was significantly associated (p<0.05) with black and white color plumage in the studied duck populations. Conclusion: The results of this study provide a basis for further investigations of the associations between polymorphisms and plumage color phenotypes in Asian duck breeds.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.3
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• pp.423-431
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• 2020

This study was conducted to investigate in vivo and in vitro digestibility in juvenile Atlantic Bluefin tuna Thunnus thynnus. In vivo digestibility was compared between four experimental diets to determine the optimum dietary inclusion level of an enzyme-treated sardine fish meal (EFM) and sardine fish meal (FM). The experimental diets were as follows; EFM75 (75% EFM), EFM60 (60% EFM and 15% FM), FM75 (75% FM) and SL (frozen sand lance) as a raw fish feed. Feces of Bluefin tuna (90.3 g) were collected both by siphoning from a 700 L cage and by dissection in 69 ton concrete rearing tanks. For the siphoning method, protein digestibility was higher in the tuna fed SL diet than that of other groups. The lowest protein digestibility was observed in FM75. For the dissection method, protein digestibility was higher in tuna fed EFM75 diet than that of other groups. The lowest protein digestibility was observed in the EFM60 group. In vitro digestibility was compared in six protein sources to find an alternative source of EFM for the tuna feed. The highest in vitro digestibility was observed in EFM (92%) followed by low temperature FM (72%), meat meal (65%), feather meal (60%), sardine fish meal (57%) and poultry by-product meal (55%).

• Journal of Aquaculture
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• v.12 no.4
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• pp.293-301
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• 1999

This study was conducted to evaluate the possible utilization of 5 different animal protein sources in juvenile rainbow trout, Oncorhynchus mykiss. Meat and bone meal (MBM), feather meal (FM), squid liver powder (SLP), poultry by-product(PBP) and blood meal (BM) were chosen to be the candidate for the possible ingredients for the dietary fish meal replacer in rainbow trout feed. Six different diets were formulated of isonitrogenous and isocaloric basis of $48\textperthousand$ crude protein and 16.7 kJ/g diet: diet 1, $100\textperthousand$ white fish meal (WFM); diet w, $80\textperthousand$ WFM +20% MBM; diet 3, 80% WFM +20% FM; diet 4, 80% WFM+20% SLP; diet 5, 80% SFM+20% PBP; diet 6, 80% WFM +20% BM. As the dietary protein sources, each diet containing 34.7% of animal protein were supplied by WFM with and without MBM, FM, SLP, PBP or BM and approximately 64.2% of plant protein. After one week of conditioning period, fish averaging 2g were divided into six groups and fed one of the experimental diets for 8 weeks. After eight weeks of feeding trials, there were no significant differences in weight gain and feed conversion ratio among groups of fish fed diet 1, 3, 4, 5 and 6(P>0.05). However, weight gain of fish fed diet 2 were significantly lower than those of fish fed diet 1, 3, 4, 5 and 6(P<0.05). These results indicated that FM, SLP, PBP and BM can be used as a dietary fish meal replacer up to 20% in juvenile rainbow trout.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.10
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• pp.1504-1510
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• 2013

Native chickens hold a significant share of the market in China. In response to the huge demand from the market, the productivity of Chinese native chickens needs to be improved. Cross breeding is an effective method to increase productivity, although it might affect meat quality. In this study, two pure lines (SD02 and SD03) of Erlang mountainous chickens were hybridized with a yellow feather and faster growing line (SD01). The effect of hybridization on carcass and meat quality (physiochemical and textural traits) was measured in the $F_1$ population at d 91 of age. The hybrids exhibited higher body weight and dressed weight, and amount of semi-eviscerated, eviscerated, breast muscle and abdominal fat (p<0.05). Abdominal fat yield also increased (p<0.05) compared to the offspring of the two pure-lines. Meanwhile, there was no significant difference in meat quality traits except for the myofiber diameter and density and the shear force of the breast muscle. Overall, the offspring of cross-lines were similar to pure lines in meat color, pH value, inosinic acid, crude protein, crude fat, dry matter, moisture content and amino acid composition in the breast muscle. These results suggest that productivity can be improved via cross-breeding while maintaining meat quality of the Erlang mountainous chicken.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1372-1381
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• 2017

Objective: Our study provides information on phenotypes of local chickens and guinea fowl and their body measures as well as on major genes in local chickens in northern Ghana. Methods: Qualitative and morphometric traits were recorded on 788 local chickens and 394 guinea fowl in urban households in Tamale, Ghana. Results: The results showed considerable variation of color traits and numerous major genes in local chickens, while color variations and related genotypes in guinea fowl were limited. In local chickens, white was preferred for plumage, whereas dark colors were preferred for beak and shanks. More than half of the chickens carried at least one major gene, but the contributions of single gene carriers were low. All calculated allele frequencies were significantly lower than their expected Mendelian allele frequencies. We observed higher mean body weight and larger linear body measures in male as compared to female chickens. In female chickens, we detected a small effect of major genes on body weight and chest circumference. In addition, we found some association between feather type and plumage color. In guinea fowl, seven distinct plumage colors were observed, of which pearl grey pied and pearl grey were the most prevalent. Male pearl grey pied guinea fowl were inferior to pearl grey and white guinea fowl in terms of body weight, body length and chest circumference; their shank length was lower than that of pearl grey fowl. Conclusion: Considerable variation in qualitative traits of local chickens may be indicative of genetic diversity within local chicken populations, but major genes were rare. In contrast, phenotypic and genetic diversity in local guinea fowl is limited. Broader genetic diversity studies and evaluation of trait preferences of local poultry producers are required for the design of appropriate breeding programs.

• Korean Journal of Poultry Science
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• v.28 no.2
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• pp.135-142
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• 2001

A novel sterategy has been established to determine the origin of the Primordial Germ Cells (PGCs) in avian embryos directly and the developmental fate of the PGCs for the application to Poultry biotechnology. Cells were removed from 1) the centre of area pellucida, 2) the outer of area pellucida and 3) the area opaca of the stage X blastoderm (Eyal-Giladi & Kochav, 1976). When the cells were removed from the centre of area pellucida, the mean number of circulating PGCs in blood was significantly decreased in the embryo at stage 15 (Hamburger & Hamilton, 1951) as compared to intact embryos. When the cells were replenished with donor cells, no reduction in the PGCs number was observed. The removal of cells at the outer of area pellucida or at the area opaca had no effect on the number of PGCs. In case, another set of the manipulated embryos were cultured ex vivo to the hatching and reared to the sexual maturity, the absence of germ cells and degeneration of seminiferous tubules was observed in resulting chickens derived from the blastoderm in which the cells were removed from the centre of the area pellucida. It was concluded that the avian Primordial Germ cells are originated at the center of area pellucida. Developmental ability of the cells to differentiate into somatic cells and germ cells in chimeras were analyzed. Somatic chimerism was detected as black feather attributed from donor cells. Molecular identification by use of female - specific DNA was performed. It was confirmed that the donor cells could be differentiated into chimeric body and erythrocytes. Donor cells retained the ability to differentiate into germline in chimeric gonads. More than 70% of the generated chimeras transmitted donor derived gametes to their offspring indicating that the cells at the center of area pellucida had the high ability to differentiate into germ cells. A molecular technique to identify germline chimerism has been developed by use of gene scan analysis. Strain specific DNA fragments were amplified by the method. It would be greatly contributed for the detection of germline chimerism. Mixed- sex chimeras which contained both male and female cells were produced to investigate the developmental fate of male and female cells in ovary and testes. The sex combinations of donor and recipient of the resulting chimeras were following 4 pairs; (1) chimeras (ZZ/ZZ) produced by a male donor (ZZ) and a male recipient (ZZ), (2) chimeras (ZW/ZW) produced by a female donor (ZW) and a female recipient (ZW), (3) chimeras (ZZ/ZW) Produce by a male donor (ZZ) and a female recipient (ZW), (4) chimeras (ZW/ZZ) produced by a female donor (ZW) and a male recipient (ZZ). It was found that genetically male avian germ cells could differentiate into functional ova and that genetically female germ cells can differentiate into functional spermatozoa in the gonad of the mixed- sex chimeras. An ability for introduction of exogenous DNA into the PGCs from stage X blastoderms were analyzed. Two reporter genes, SV-$\beta$gal and RSV-GFP, were introduced into the PGCs. Expression of bacterial/gal was improved by complexing DNA with liposome detectedcc in 75% of embryos at 3 days embryos. At the embryos incubated for 1 day, expression of the GFP was observed all the embryos. At day 3 of incubation, GFP was detected in about 70% of the manipulated embryos. In case of GFP, expression of the transgene was detected in 30 %e of the manipulated embryos. These results suggested that the cells is one of the most promising vectors for transgenesis. The established strategy should be very powerfull for application to poultry biotechnology.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.71-73
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• 2001

In this study, we could improve transmission efficiency of germline chimeras by transfer of gonadal PGCs (gPGCs) cultured in vitro. Of hatched recipient chicks, 301 chickens (141 males and 160 females) were brought up to sexual maturity and these WLs (KOC) were mated with KOCs for testcross, resulting in 27 germline chimeras (15 males and 12 females) identified by black feather color of their progenies. The production efficiency of germline chimera production of experimental groups was observed (P=0.6831). The average transmission efficiency of proven germline chimeras was 0.6 ∼56.5% (15.0% on average). The transmission efficiency of experimental group which were transferred 10-days cultured gPGCs without Ficoll treatment was highest (49.7%) and that of experimental stock which transferred non-cultured gPGCs with Ficoll treatment was lowest (0.6%). The duration of in vitro culture before transferring was significantly important for the high efficiency of germline transmission. Transferring 10-days cultured gPGCs made the transmission efficiency higher rather than transferring non-cultured and 5-days cultured gPGCs, 50 times and 10 times, respectively (p<0.0001). However, Ficoll treatment for increasing the population ratio of gPGCs negatively affected the transmission efficiency and the effects of sexuality and the reciprocal interaction between treatments showed no significant differences. These findings demonstrated that the crucial factors for improving the germline transmission were the duration of in vitro culture prior to transfer. Thus, we developed the complete system for production of germline chimera using cultured gPGCs with highly improved efficiency and this system would be useful for genetic manipulation and obtaining the transgenic aves.

• Korean Journal of Poultry Science
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• v.9 no.1
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• pp.1-16
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• 1982

Excessive fat deposition, particularly in the abdominal region, has become a problem in broiler production. When the caloric intake exceeds the body demands for energy, excess food is stored as fat in broilers. Researchers have shown that fat deposition varies with breed, strain, sex age, nutrition, exercise, ambient temperature and rearing systems. These factors affect fat deposition through their effects on the size or the number of adipose cells or a combination of both. In some measurements on live birds to predict body fat, the wet weight and percentage fat of skin in pectoral feather tract are significantly correlated with percentage abdominal fat. But these correlation coefficients are not so high. Therefore, correlation coefficients indicate that these measurements on live birds ate not useful for estimating body fat weight and percentage. Most reports show that an increase in the proportion of carcass fat, when measured at a given age, is correlated with selection for increased body weight. On the other hand some research results show that selection for body$.$weight gain dose not lead to an alteration in the proportion carcass fat when measured at a given body weight. Besides, selection for improved food conversion efficiency alone resulted in a decrease in carcass fat and an increase in protein and water when measured at either a given age or body weight, Thus eventhough it is uncertain whether carcass fat is increasing as a result of body-weight selection in broilers: however it is clear that selection for improved food conversion efficiency, either alone or in combination with growth rate, should result in leaner carcasses than selection for growth rate alone.

• Korean Journal of Poultry Science
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• v.20 no.4
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• pp.209-216
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• 1993

This study was conducted to classify Korean native chicken(KNC) and imported chicken by phenotypic performances and DNA fingerprinting. Two lines, KNC and White Leghorn(WL) , of chicken were maintained in the laboratory of Yeungnam University. Economic traits (body weight, sexual maturity, hen-day egg production, egg weight) and phenotypic characteristics (body-type, head, feather, shank) were checked. The DNA fingerprinting was analyzed for both breeds. The growth rate of the KNC was similar to WLS and sexual maturity of the KNC came later than WL. Hen-day egg production of the KNC was also slightly lower than the WL. The egg weight was about 10g lighter than WL. There was no difference in body weight of female KNC compared to the WL after 28 weeks. The study confirms difference between KNC and WL in DNA fingerprinting as well as its outlook. Thus, we suggest that these should be tested in nationwide districts about chickens known as the KNC using DNA fingerprinting. Then, the confirmed KNC populations should be maintained and used for the genetic improvement. Finally, only confirmed KNC should be in market which induce consumer to seek the KNC by its favorite.

• Korean Journal of Poultry Science
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• v.46 no.1
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• pp.39-46
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• 2019

This study was conducted to investigate the effect of dietary bee venom on serum characteristics, antioxidant activity, and hepatic fatty acid composition in broiler chickens. A group of 875 one-day-old feather-sexed male broiler chicks were randomly allocated to five treatments with seven replicates (25 birds/replicate) for three weeks. A corn-soybean meal-based diet was used as the basal diet. Five dietary treatments were compared: 1) basal diet, 2) basal diet containing $10{\mu}g/kg$ of bee venom powder, 3) basal diet containing $50{\mu}g/kg$ of bee venom powder, 4) basal diet containing $100{\mu}g/kg$ of bee venom powder, and 5) basal diet containing $500{\mu}g/kg$ of bee venom powder. At 21 days, one bird per pen was slaughtered by asphyxiation in $CO_2$ gas, and blood was collected to measure serum characteristics and antioxidant activity. In addition, the liver was excised to measure the concentration of malondialdehyde and determine fatty acid composition. Increasing dietary bee venom in the diet failed to affect most serum parameters except for triglyceride and non-esterified fatty acids. Dietary bee venom inclusion quadratically increased the concentration of stearic acid (P<0.05), but decreased palmitoleic acid, oleic acid, linoleic acid, mono-unsaturated fatty acids, and poly-unsaturated fatty acids. Finally, dietary bee venom tended to lower hepatic malondialdehyde contents quadratically (P=0.054). In conclusion, our study revealed that dietary bee venom improved antioxidant capacity and affected fatty acid metabolism in broiler chickens.