Hak-Kyu Kim

Performance of Growing Period of Large-Type Korean Native Ducks

This work was carried out to investigate the performance of growing period of large-type Korean native ducks. A total of four hundred twenty female and male duck chicks generated from A and B strains of ducks. Groups were four crossbreds (3 replications/crossbred, 35 birds/ replication) as 2×2 factors (2 strains, A and B; 2 genders, female and male). On the body weight, male of B strains was the highest among 4 treatments after the age of 4 week (P<0.05). Body weight of B strain was higher than that of A strain at all period (P<0.05). Body weight of male was higher compared to that of female after the age of 4 week (P<0.05). On the body weight gain, male of B strain was the highest and female of A strain was the lowest among 4 treatments at 0 8, 0 12, 0 16 and 0 20 weeks (P<0.05). Body weight gain of male was higher than that of female after the age of 4 week (P<0.05). On the feed intake, male of B strain was the highest among 4 treatments from the age of 0 week and to the age of 4, 12, 16 and 20 week (P<0.05). Feed intake of male was higher than that of female at 0 12, 0 16 and 0 20 weeks (P<0.05). On the feed conversion ratio, male of B strain was the highest among other treatments 0 4 weeks and female of A strain was at 0 8 and 0 12 weeks (P<0.05). Feed intake of female was higher compared to that of female at 0 8 weeks and male was high at 0 20 weeks. These results provided the basic data on the record of growing phase of large-type Korean native ducks.

The study on production and performance of crossbred Korean native chickens (KNC).

Department of Agricultural Biotechnology, Seoul National University, Seoul, KoreaABSTRACT The current work was carried out to investigate the effect of crossbred Korean native chickens (KNC) on performance and carcass ratio. Seven hundred twenty 1-d-old chicks were divided into groups by strain (A, B, C and D) and sex (male and female). Strains were A) (KNC egg-meat type C strains×KNC meat type S strains)×KNC meat type H strains, B) (KNC egg-meat type C strains×KNC meat type H strains)×KNC meat type S strains, C) (KNC native R strains×KNC meat type S strains)×KNC meat type H strains and D) (KNC native L strains×KNC meat type H strains×Ross broiler. Experimental diets consisted of 3 phases such as starter(05 weeks; CP 20.0%, ME 3,050 kcal/kg), earlier (58 weeks; CP 18.0%, ME 3,100 kcal/kg) and finisher (812 weeks; CP 16.0%, ME 3,150 kcal/kg). Body weight (BW) and feed intake (FI) was measured every week and carcass ratio(CR) was calculated at 5 and 10 week after starting experiment. There was no difference in BW among strains until 5 weeks (P>0.05), however D strain resulted in a higher BW after 5 weeks (P<0.05). Body weight gain (BWG) and FI in D strain were also significant higher compared to the other strains for all periods. However, D strains showed the lowest (P<0.05) fee conversion ratio (FCR). The other strains except D showed a similar BW, BWG, FI and FCR among strains. In addition, there were no differences in carcass weight (CW) and carcass ratio (CR) among strains at 5 weeks, however D strain showed higher CW and CR at 10 weeks. These results suggested the basic data that needed to develope the new strains.(Key words : Korean native chickens, crossbred, performance, carcass ratio)

Effect of Crossbreeding of Korean Native Duck and Broiler Ducks on Performance and Carcass Yield

National Institute of Animal Science, RDAABSTRACT This work was carried out to improve the performance and the carcass yield of Korea native duck (KND) according to crossbreeding KND and broiler duck (BD). Two hundred forty out of crossbred ducks were divided into 4 strains and selected as 120 ducks separated by sex, respectively. Crossbred ducks were native ducks ()×native ducks (), native ducks ()×broiler ducks (), broiler ducks ()×native ducks (), and broiler ducks ()×broiler ducks() as A, B, C and D, respectively. Broiler duck diet was fed as experimental diet for 03 weeks (CP 22.0%, ME 2,900 kcal/kg) and 38 weeks (CP 18.0%, ME 3,000 kcal/kg). Body weight of male was high compared to female, and that of B and C was high compared to A and low compared to D at 3 and 8 week (P C>B>A on body weight gain (P<0.05). In case of feed intake, there was no difference between male and female, and B and C were high compared to A and low compared to D (P<0.05). Male feed requirement was high at 38 weeks, and there was significant difference between A and B, C and between B and D. Carcass yield of 4 strains was shown as 70.1%, 70.8%, 73.1% and 71.2%, respectively. Finally, Crossbreeding of KND and BD may improve the performance and the carcass yield of KND.(Key words : Korean native duck, broiler duck, crossbred duck)

Effect of Dietary Metabolizable Energy and Crude Protein Concentrations on Growth Performance and Carcass Characteristics of Korean Native Ducks

National Institute of Animal Science, RDAABSTRACT This study was undertaken to assess dietary CP and ME concentrations for optimum growth performance and carcass characteristics of Korean Native male ducks. In a 3×3 factorial arrangement, 1-d-old Korean Native male ducks were completely randomized design to experimental diets with 3,000, 2,900, and 2,800 kcal of ME/kg of diet; each contained 23, 22, and 21% CP, respectively, from 0 to 3 wk of age. From 4 to 8 wk of age, experimental diets had 3,100, 3,000, and 2,900 kcal of ME/kg of diet, and each contained 19, 18, and 17% CP, respectively. Each dietary treatment was replicated 4 times, and feed and water were provided ad libitum. Body weight, feed intake and uniformity were measured at 3 wk and 8 wk, and carcass characteristics were evaluated at 8 wk. As CP increased from 21 to 23 %, the body weight, BW gain and feed conversion ratios (FCR) linearly improved (P 0.05). Carcass ratios of birds fed 3,000 kcal of ME/kg diets from 3 to 8 wk of age were quadratically increased significantly (P 0.05). Also, breast meat color, pH, cooking loss and shear force were not diffe-rent (P>0.05). Thus, diets with 2,800 kcal of ME/kg and 23% CP or with 2,900 kcal of ME/kg and 17% CP at 0 to 3 wk and 4 to 8 wk, respectively, were used more efficiently. However, diets with 3,000 kcal of ME/kg at 4 to 8 wk in carcass rate was quadratically increased.(Key words : native duck, metabolizable energy, crude protein, performance, carcass traits)

Chemical Composition and Meat Quality of Crossbred Korean Native Chickens (KNC)

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 × KNC meat type S strains) ( ) × KNC meat type H strains ( ), B: (KNC egg-meat type C strains × KNC meat type H strains) ( ) × KNC meat type S strains ( ), C: (KNC native R strains × KNC meat type S strains) ( ) × KNC meat type H strains ( ), D: (KNC native L strains × KNC meat type H strains) ( ) × Ross broiler ( ) 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.

Hatching and growing performance of three-way crossbreds of Korean native chickens (KNC).

National Institute of Animal Science, RDAABSTRACT This work was conducted to evaluate the hatching and growing performance of Korean native chicken (KNC) 3 strains crossbred. A total of 360 female pullets were produced from CY×C (A), CL×C (B), CG×C (C) and CW×C (D) crossbred kept in National Institute of Animal Science, Korea. Hatchability of A, B, C and D were 69.8, 70.7, 75.5 and 77.4%, respectively. Livability were not significantly different by 20 weeks among 4 strains. Body weight B was high compared to other strains at 20 weeks. The feed conversion ratio of 4 strains was no significantly different among strains at 20 weeks. These results suggested the basic data that needed to develope the new strains.(Key words : crossbred, Korean native chicken, livability, body weight, feed conversion ratio)

Evaluation of Korean Native Ducks on Production Efficiency Factor, Carcass Yield, Partial Meat Ratio and Meat Quality with Weeks

This work was carried to evaluate production efficiency factor, carcass yield and meat quality with weeks of Large-type Korean native ducks. Korean native ducks (n = 90) from National Institute of Animal Science (RDA, Korea) were used in this work. Ninety ducks were divided into 6 groups (15 birds/group) and were fed with meat-type duck diets for 8 wk old. When ducks grew at specific wk (6, 7 and 8 weeks), 2 ducks per group were slaughtered at 6, 7 and 8 wk old. Production efficiency factor, carcass yield, partial meat and meat quality were researched in this work. There was no significant difference on livability with weeks, but body weight at 7 and 8 wk old was higher than that at 6 wk old (P 0.05) and yellowness at 8 wk old was higher com- pared to other weeks (P<0.05). Cooking loss was the highest at 6 wk old as 31.6%, but water holding capacity was the highest at 8 wk old (P<0.05). There was no significant difference on shear force among weeks. pH at 6 wk old was the lower than that of other weeks as 5.84. Moisture content significantly decreased with weeks (P<0.05) and fat content at 8 wk was the highest as 1.88% (P<0.05). Protein content significantly increased with weeks until 20.9% at the age of 8 wk (P<0.05). Ash content at 7 and 8 wk old was the higher than that at 6 wk old (P<0.05). There was no significant difference on juiciness, tenderness, and flavor with weeks. Finally, these results may provide that shipping time at 7 wk old preferred to that at 6 and 7 wk old, but further research was needed because of deficiency of data.

The Study on Productivity of Commercial Korea Chickens for Crossbred Korean Native Chickens

This study was conducted to evaluate the productivity of Korean native chicken (KNC) 2 strains crossbred. The number of chicks analyzed in this study was 300. Crossbreds used in this studywere A) KNC R strains × KNC meat type S strains, B) KNC egg-meat D strains × KNC meat type H strains, C) KNC egg-meat D strains × KNC meat type S strains, D) KNC egg-meat C strains × KNC native Y strains, and E) KNC native Y strains × KNC meat type H strains. The crossbreds C had the highest performance on body weight gains at 7~10 weeks but crossbreds D showed the lowest (p<0.05). The feed conversion ratio of crossbreds D was the highest value at every weeks (p<0.05). But the carcass weight and carcass ratio of crossbreds D was the lowest value at every weeks (p<0.05). For the percentage of cutted meat, the ranges of mean were 30.60~33.75% in breast, 21.48~24.72% in leg, 11.95~14.33% in wing, 21.91~25.83% in back and of 7.38~8.72% in neck. The percentage of cutted meat for leg was the highest value at every weeks (p<0.05). These results suggested that

Changes of Fatty Acids and Amino Acids Contents of Korean Native Commercial Ducks Meats with Different Raising Periods

Poultry Science Division, National Institute of Animal Science, RDA, Seonghwan 330-801, KoreaABSTRACT This work was carried to evaluate effect of different raising periods on fatty acids and amino acids properties of Korean native commercial ducks. Korean native ducks (n = 90) from National Institute of Animal Science (RDA, Korea) were divided into 6 groups (15 birds/group) and were fed with meat-type duck diets for 8 wk old. When ducks grew at specific wk (6, 7 and 8 weeks), 2 ducks per group were slaughtered at 6, 7 and 8 wk old. Myristic acid (C14:0) and palmitic acid (C16:0) of saturated fatty acid (SFA) were the highest and arachidonic acid of unsaturated fatty acid (USFA) was the lowest at the age of 6 weeks old (P 0.05). Every non-essential amino acids were the highest at the age of 8 weeks among treatments (P<0.05). In conclusion, fatty acid contents and amino acid contents increased until the age of 8 weeks old, but further research was needed because of deficiency of data to suggest the correct shipping time.(Key words : Korean native ducks, large-type, fatty acid, amino acid)

Performance of Growing Period of Two-way Crossbreed Parent Stock for Producing of Laying-Type Korean Native Commercial Chickens

Poultry Science Division, National Institute of Animal Science, RDA, Seonghwan 330-801, KoreaABSTRACT This study was carried out to investigate the performance of laying period of two-crossbred of Korean native chickens for producing laying hens. A total of four hundred eighty female 2-crossbred chicks that restored strains and were aboriginal at National Institute of Animal Science. There were four crossbreds (4 replications/crossbred, 30 birds/ replication) as A) C strain×Y strain, B) C strain×L strain, C) C strain×G strain, and D) C strain×W strain, respectively. There were no significant difference on age at first egg among crossbreds (P>0.05). Egg weight and body weight of B crossbred at first egg was higher than other crossbreds (P 0.05). Hen-day egg production decreased after at the age of 38 weeks. Weekly egg production of A and B crossbreds was higher compared to C and D crossbreds at the age of 6872 weeks (P<0.05). These results suggested the basic data on the record of laying period of 2-crossbreed Korean Native Chickens for producing laying hens. (Key words : Korean native chickens, 2-crossbred, laying period, body weight, feed consumption ratio, egg weight, egg production)