• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.203-212
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• 2023

This study conducted a diallel-crossbreeding test using four Korean native chicken parent stock lines (YC, YD, CK, and CF) to develop a native commercial layer with high egg-laying performance. A total of 312 chickens in six combinations were examined for various traits, including livability, body weight, age at first egg-laying, hen-day, and hen-housed egg production, egg weight, and egg quality, from hatching to 60 weeks of age. The results showed that the average survival rate was 77.1±18.8% with the YDYC combination having the highest survival rate along with excellent specific combining ability. The YDYC combination exhibited significantly higher body weight compared to the other combinations (P<0.01). The average age at first egg-laying was 121.3±2.5 days, with no significant difference between the combinations. The average hen-day egg production was 74.0±6.4%, and the hen-housed egg production was 181.4±33.8 eggs with the YDCF and YCCK combinations demonstrating the highest laying performance, while the YDYC and CKCF combinations had the lowest (P<0.05). Laying performance was more influenced by specific combining ability than general combining ability. The eggs from the YDYC combination were significantly lighter and had the darkest shell color (P<0.01), whereas the YDCF combination exhibited the thickest eggshells. There was no difference in internal egg quality among combinations, except the YDCF combination had the darkest yolk color. Overall, we concluded that the YCCK combination, characterized by high laying performance and livability, and the YDCF combination with high laying performance and good egg quality are the most desirable combinations for Korean native commercial layers.

• Korean Journal of Poultry Science
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• v.48 no.3
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• pp.101-110
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• 2021

In this study, we performed a cross-combination test using offspring from two paternal and five maternal parent stock lines to produce a new synthetic breed of Korean native commercial chickens. The survival rate, body weight, feed intake, and feed efficiency were measured for 10 crosses, with 837 Hanhyup-3 chickens used as a control. Most chickens had brown-based feathers, and there was little difference in color phenotypes among combinations. The average survival rate of the combinations was 94.9%, which was significantly different from that of Hanhyup-3 at 75.3% (P<0.01). There was significant differences in body weight among the combinations at all weeks of age (P<0.01). At 10 weeks of age, the FHHY combination was the heaviest with 2,300 g, while the weight of Hanhyup-3 was 1,922 g. In addition, the weight difference between the male and female chickens was 458 g. As a result of regression analysis, the duration needed to reach 1.9 kg was about 61 days for the FHFY, FHHY, and HFFY combinations, and 70 days for Hanhyup-3, exhibiting a 9-day difference. The average feed conversion ratio of the combinations until 10 weeks was 2.42, which was significantly different from that of Hanhyup-3 at 2.97 (P<0.01). In conclusion, FHHY, FHFY, and HFFY were determined to be the best new breed combinations based on production capacity. When these combinations are used as new commercial breeds, they are expected to increase the average weight by 18% and improve feed efficiency by 19%, as compared to the existing Hanhyup-3 breed.

• FLOWER RESEARCH JOURNAL
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• v.19 no.4
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• pp.225-230
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• 2011

This research was performed for making data-base of cross-breeding between Cymbidium goeringii cultivars. Morphological characteristics were investigated and then genetic relationship was analyzed. Collected 20 Cymbidium goeringii cultivars were clustered into 2 groups. Seven cultivars were clustered into group I, and thirteen cultivars were clustered into group II. Group I doesn't have leaf pattern. Group have leaf pattern. The genetic relationship among collected 20 Cymbidium goeringii cultivars was anaylzed using RAPD with ten 10-mers random primer. Eighty-nine bands were generated by RAPD. Among the rest, three bands were monomorphic and eight-six bands were polymorphic. Overall similarity degree ranged from 0.521 to 0.862. The result of RAPD analysis was clustered into 2 groups, too. Sixteen cultivars were clustered into GroupX, and four cultivars were clustered into GroupY. Result of classification with morphological characteristics and RAPD showed different pattern, but 4 cultivars of GroupY by RAPD analysis were included in groupby morphological characteristics. Crossbreeding combination among low related coltivars in RAPD analysis may get more efficient result.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.794-799
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• 2003

A study was conducted on 2102 records of 808 crossbred cows of various genetic groups maintained under 'All India Coordinated Research Project on Cattle' at C C S Haryana Agricultural University, Hisar, over 25 years period (1968-1993) with an objective to assess and compare the amount of percent improvement and heterotic effect for different performance traits in various genetic groups produced under this programme. Survivability sharply and significantly declined from 1/2 to $3/4^th$ bred and further from $3/4^th$ to inter-se bred. This may be due to periodic and management differences in addition to the higher level of exotic inheritance and decreased heterotic effect over the filial generations. Jersey and Holstein Friesian crosses among 1/2 breds and their 50% inheritance among $3/4^th$ and inter-se breds had highest improvement and heterosis in reproduction and production traits respectively. Among inter se bred genetic groups, BFH (I) had no recombination loss in SP and CI, while FJH (I), JFH (I) and FBH (I) had on recombination loss in AFC, LY, LL and PE. The crossbreeding of zebu cows with exotic breeds brings about spectacular improvement in comparison to the performance of zebu breed, while conventional selection over several generation would lead to only modest improvement. In addition to additive effect, there was sufficient heterosis in Jersey crosses for reproduction and Holstein Friesian crosses for production performance. Three breed crosses with exotic inheritance between 50 and 75 percent incorporating genes (25 to 50%) from both of these breeds is the best combination for stabilization.