• Korean Journal of Poultry Science
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• v.43 no.1
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• pp.39-45
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• 2016

This study was carried out to evaluate performance and uniformity of White Korean native ducks collected from two areas in Korea. White ducklings were selected from all ducklings that were hatched from hatchery eggs of Korean native ducks. A total of two hundred forty white ducklings (1-d-old) were used in this work and were divided into 4 groups (4 replicates/group, 15 birds/replicate) with $2{\times}2$ factors (2 groups, J, H; genders, male and female). Weekly body weight of H groups was higher than that of J groups (P<0.05). Also, weekly body weight of male ducks was higher compared to that of female at 6~8 wk old (P<0.05). Uniformity of J groups was higher than that of H groups at the age of 1 wks old (P<0.05), and that of female duck was higher than that of male at the age of 6 wks old (P<0.05). Body weight gain of H group was higher than that of J group (P<0.05), and that of male duck was higher compared to that of female at 6~7 wks old (P<0.05). Feed intake of H group was higher compared to that of J group (P<0.05), but there was no significant difference between male and female on feed intake. On feed conversion ratio, J group was higher than H group at 4~5 wks, 7~8 wks and 0~8 wks old (P<0.05), and feed conversion ratio of male duck was higher than that of female at 1~2 wks, 5~6 wks and 6~7 wks old. Finally, these results was tended to show that performance of H groups was higher than that of J groups. Further researches need to carry out to commercial White Korean native ducks on performance and uniformity as well as meat quality and genetic characteristic.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.405-413
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• 2010

This study was carried out to determine the effect of dietary supplementation of quercetin and methoxylated quercetin extracted from onions on oxidation of chicken thigh during cold storage. For 35 days, 1-day-old 320 broiler chicks (Ross) were divided into 8 groups and supplemented the diet; basal diet only (T1), T1 with antibiotics (T2), vitamin E 20 IU (T3), vitamin E 200 IU (T4), quercetin 20 ppm (T5), quercetin 200 ppm (T6), methoxylated quercetin 20 ppm (T7), methoxylated quercetin 200 ppm (T8). After slaughtering the broilers, thigh meats were collected and analyzed the oxidation stability during storage at $4^{\circ}C$ for 7 days. Volatile basic nitrogen (VBN) was ranged from 10.98~15.37 mg% until day 3 and quercetin 20 ppm (T5) significantly reduced (p<0.05) the VBN value of thigh as much as antibiotics treatment group (T2). The supplementation of quercetin at a 200 ppm level significantly reduced 2-thiobarbituric acid reactive substances value when compared with the control. Supplementation of 20 ppm quercetin also affected fatty acid composition of chicken thigh and resulted in increase of C18:1w9 and decrease of C18:2w6 on day 3. In microbes of chicken thigh during storage, supplementation of 20 ppm quercetin significantly reduced total microbes compare to control on day 7 (p<0.05). There was no effect on the number of coliforms in thigh with quercetin diet. From these results, the dietary supplementation of 20 ppm of quercetin may have effects on enhancing oxidation stability.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.177-186
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• 2009

It is well-known that unregulated over-expression of foreign gene may have unwanted physiological or toxic effects in transgenic animals. To circumvent these problems, we constructed retrovirus vector designed to express the foreign gene under the control of the tetracycline-inducible promoter. However, gene expressions in the tetracycline-inducible expression system (Tet system) are not completely regulated but a little leaky due to the inherent defects in conventional Tet-based systems. A more tightly controllable regulatory system can be achieved when the advanced versions ($rtTA2^SM2$) of rtTA and a minimal promoter in responsive components (pTRE-tight) are used in combination therein. In this study, we tried to produce human thrombopoietin (hTPO) from various target cells and transgenic chickens using the retrovirus vector combined with Tet system. hTPO is the primary regulator of platelet production and has an important role in the survival and expansion of hematopoietic stem cells. In a preliminary experiment in vitro, higher hTPO expression and tighter expression control were observed in chicken embryonic fibroblast (CEF) cells. We also measured the biological activity of the hTPO using Mo7e cells whose proliferation is dependant on hTPO. The biological activity of the recombinant hTPO from CEF was higher than both its commercial counterpart and hTPO from other target cells. The recombinant retrovirus was injected beneath the blastoderm of non-incubated chicken embryos (stage X). Out of 138 injected eggs, 15 chicks hatched after 21 days of incubation. Among them, 8 hatched chicks were hTPO positive. When the Go transgenic chicken was fed doxycycline (0.5 mg per 1 gram of feed), a tetracycline derivative, hTPO concentration of the transgenic chicken blood was 200 ng/mL. Germline transmission of the transgene was confirmed in sperm of the Go transgenic roosters. These results are informative to establish transgenic chickens as bioreactors for the mass production of commercially valuable and biological active human cytokine proteins.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.373-382
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• 2010

This study was carried out to investigate the effect of reverse osmosis (RO)-treated deep sea water (DSW) supplementation on the quality characteristics of chicken breast meat. For 28 days, one-day-old broiler chicks (Ross 308) were divided into two groups and supplemented with either water (control) or RO-treated DSW (diluted with deionized water at 1:20 [RO-treated DSW:deionized water] ratio). The control group was fed on a basal diet containing 0.21% salt. Five birds were slaughtered on each group and breast meat from carcasses was stored at $4^{\circ}C$ for 9 days. The proximate composition, fatty acid composition, cholesterol content, mineral content, pH value, water-holding capacity and Warner-Bratzler shear force value were not affected by RO-treated DSW supplementation. At 6 day of storage, lipid oxidation (2-thiobarbituric acid reactive substances) was significantly higher in RO-treated DSW group than in the control (P<0.05). With regard to meat color, CIE $L^*$ value was significantly lower in RO-treated DSW group than in the control after 6 day of storage (P<0.05), whereas CIE $a^*$ and $b^*$ values were not significantly different between two groups during storage. Consequently, RO-treated DSW supplementation led to a darker color and reduced the lipid oxidation stability in chicken meat during storage. Therefore, these results may indicate that RO-treated DSW can not be used as drinking water of chickens because it negatively affects the quality of chicken meat.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.149-155
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• 2009

The present study was conducted to compare the carcass yields and meat characteristics of three types of commercial male chicks White mini broilers, Ross broilers and Hy-Line brown chicks under the identical feeding condition. One-hundred 1-d chicks of each type were randomly placed into four pens per group (25 chicks per pen) and fed corn-soybean meal based commercial diets for 35d, 18d or 49d, respectively. At the end of the feeding trial, the birds were sacrificed and subjected to carcass measurements. The dressing percentages of White mini broilers and Ross broilers were significantly higher (P<0.05) than that of Hy-Line brown cockerels. The rate of breast meat of Hy-Line brown cockerels was significantly lower (P<0.05) than those of White mini broilers and Ross broilers. However, Hy-Line brown cockerels showed higher (P<0.05) leg meats than the others. There were no significant differences in serum total cholesterol and the activities of glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase among the groups. The breast meats of White mini broilers presented highest lightness value. The yellowness of breast and redness of leg meats of White mini broilers and Ross broilers were significantly higher (P<0.05) than those of Hy-Line brown cockerels. There were no significant differences in the SOD-like activity and change of pH in edible meats among the groups. The meat color in White mini broilers was significantly higher than that of Hy-Line brown cockerels. No significant differences were observed in term of flavor, tenderness and overall acceptability. In conclusion, the physico-chemical properties and sensory characteristics of edible meats were not greatly affected by genotype if they were similar body weights and kept under the identical feeding condition. But the Hy-Line brown cockerels were less desirable as a meat-type strain due to lower carcass yields and inferior growth and feed conversion ratio.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.415-421
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• 2010

This work was carried out to investigate chemical composition and meat quality of crossbred Korean native chickens (KNC). Ninety 1-d male chicks were used in this work and were divided into 4 groups as A: (KNC egg-meat type C strains $\times$ KNC meat type S strains) (female) $\times$ KNC meat type H strains (male), B: (KNC egg-meat type C strains $\times$ KNC meat type H strains) (female) $\times$ KNC meat type S strains (male), C: (KNC native R strains $\times$ KNC meat type S strains) (female) $\times$ KNC meat type H strains (male), D: (KNC native L strains $\times$ KNC meat type H strains) (female) $\times$ Ross broiler (male) strains. They were fed the broiler diets for 12 weeks at the flat house and twenty seven chickens were slaughtered at week 5 and 10. Chicken thigh and breast were weighed and physicochemical compositions and sensory characteristics were investigated. Physical compositions of meats have no difference among strains at 5 week, and B strains differed from other strains at 10 week (P<0.05). The pH, moisture, and collagen content of meat from B strains were lower than other strains at 5 week. Ash and collagen of A strains were the lowest at 10 week (P<0.05), but others have no difference among strains. In sensory test, juiciness of D strains was the highest at 5 week, and tenderness of B strains was the lowest at 10 week (P<0.05). In conclusion, the crossbreeding of KNC did not affect physical traits but affected chemical composition of the chicken meat slaughtered at 5 week.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.167-181
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• 1991

In order to study the effects of dietary yeast (Saccharomyces cerevisiae) products on the performance of broiler chickens, tow feeding trial using Arbor Acres strain were conducted. In experiment 1, 200 hatched male broiler chickens were divided into groups of 10 birds each and four groups were given each of the five dietary treatments : control, 0.25% yeast culture supplemented (YC-0.25%), 2.5% yeast culture supplemented(YC-2.5%), 0.05% live yeast supplemented(LY-0.05%) and 0.1% live yeast supplemented(LY-0.1%) . In experiment 2, 240 hatched broiler chickens(120 birds in each sex) were assigned to 2$\times$3(sex$\times$feed) factorial design Dietary treatments were control, 0.1% live yeast supplementation in finisher diet(LY-Finisher) , and 0.1% live yeast supplementation in whole period (LY-Whole). Results of experiment 1 showed that weight gain, feed intake and mortality were not significantly different among treatments. However, weight .gain of YC-0.25% and LY-0.1% tended to be greater than other treatments after 3wks of age Feed efficiency of LY-0.05% was poorer than those of control, YC-0.25% and LY-0.1% . Although nutrients availabilities were not significantly different among treatments, availiabilities of Ca and P were greater in yeast products supplemented groups than in control group. The number of Lactobacillus spp., Streptococcus spp . and yeast in small intestine tended to be greater in supplemented groups while that of Coliforms bacteria tended to be greafter in control group. In experiment 2, there were significant effects of factors (feed and sex) and interaction on growth rate. LY-Whole groups showed best weight gain in male while LY-Finisher groups did best in female broiler chickens. Feed intake and mortality were significantly higher in male broiler chickens. Feed$\times$sex interaction had a significant effect on feed efficiency. LY-Whole groups showed best feed efficiency in male while LY-Finisher did best in female broiler chickens. Availabilities of dry matter, Ca and P were higher in male than in female broiler chickens. Availabilities of Ca and P were higher in live yeast supplemented groups than in control groups. Live yeast supplemented groups tended to have greater number of Lactobacillus spp . and yeast in the small intestine and Stre))tococcu spp. in the small intestine and cecum, and lesser number of Coliforms bacteria in the small intestine The pH of small intestinal contents tended to be higher in live yeast supplemented groups.

• Korean Journal of Poultry Science
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• v.19 no.1
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• pp.27-34
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• 1992

Seventy-five commercial male day-old broiler chicks were used to investigate the effects of Oxytetracycline(OTC) and Lonicera japonica Thunberg(LJT) to be active in anti-bacteria and anti-virus on the growth rate, carcass rate and various intestinal organs sizes in broiler at 3 wk of age. Five experimental diets were formulated to have similar protein and energy levels, with OTC 0.04％ as low-level antibiotics and OTC 0.34％ as high-level antibiotics and 0.5％, 1.0％, 3.0％ level of LJT. Birds were housed randomly in 15 battery cages. Birds were 3 replicates per treatment and 5 chicks per replicate. In the body gain, 0.5％ level of LJT addition grew significantly higher than the other birds. The feed intake and feed efficiency were not significantly between other birds. The addition levels in OTC and LJT did not any consistent effect on the carcass rate. However, the chest meat percentage vs carcass volume in LJT 0.5％ treatment and the leg meat percentage vs carcass volume in DTC 0.04％ addition level were significantly higher than those of birds fed other diets. The liver weight rate was significantly higher in OTC 0.04％ level. However, the 0％ and LJT levels did not exert any consistent effect on the weights of gizzard, heart, bursa of fabricius, head and spleen of broilers. The abdominal and gizzard surrounding fat content rate was higher in bird LJT 1.0％ level than birds fed other levels.

• Korean Journal of Poultry Science
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• v.39 no.1
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• pp.45-52
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• 2012

This study was carried out to investigate the growth performance and the carcass ratio of meat-type Korean Native Ducks. Four hundred twenty Korean Native Ducks' chicks were selected and divided into four treatments (7 replications/ treatment, 15 birds/replication) by strains (A and B) and gender(male and female) with $2{\times}2$ fractal factors. There was no significant difference between A and B on the body weight at 2, 4, 6, and 8 weeks old (P>0.05). However, body weight of female was higher at 2 weeks old than male while that of male was higher at the 8 weeks old (P<0.01). Daily feed intake of male was higher compared to female during 6~8 weeks (P<0.05). On weekly body weight gain, there was no significant difference between strains, but gained body weight of male was higher until 2 weeks old while that of female was higher during 6~8 weeks (P<0.01). On the live body weight and carcass weight by strains and genders, B strain was higher than A strains at the 8 weeks of age (P<0.01). Carcass yield was the highest at 8 weeks of age in both strains (P<0.05). These results may provided the basic data on growth performance and carcass ratio of meat-type Korean Native Ducks.

• Korean Journal of Poultry Science
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• v.39 no.1
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• pp.71-76
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• 2012

This study was carried out to investigate the performance of growing period of two-crossbred of Korean Native Chickens. A total of four hundred eighty female 2-crossbred chicks that restored strains and were aboriginal at National Institute of Animal Science. Treatments were four crossbreds (4 replications/crossbred, 30 birds/replication) as A) C strain ${\times}$ S strain, B) C strain ${\times}$ H strain, C) R strain ${\times}$ S strain, and D) L strain ${\times}$ H strain, respectively. Livability of C crossbred was the highest as over 90% and that of B crossbred was the lowest as 73~78% during growing period (P<0.05). Body weight of A crossbred was the highest at the 4 week and that of D strain was the lowest at the 4 and 8 week (P<0.05). Weekly body weight of B and C crossbreds were higher than A and D crossbreds (P<0.05). There was no significant difference among four crossbreds. Weekly feed intake of D crossbred was the highest among all crossbreds at 0~4 weeks (P<0.05). These results suggested the basic data on the record of growing phase of 2-crossbreed Korean Native Chickens.