• Title/Summary/Keyword: Breed

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Relationships between Water Drinking and the Productivity in Chicken (음수가 닭의 생산성에 미치는 영향)

  • 이상진
    • Korean Journal of Poultry Science
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    • v.21 no.2
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    • pp.119-131
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    • 1994
  • The physiological functions of drinking water in chicken were reviewed. The effects of ambient temperature, humidity, wind velocity, egg productivity, feed form, nutrients density, and breed types on the water consumption of chicken were summarized and discussed. Some guidelines for management of drinking water in commercial poultry farms were also suggested.

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Genetic Diversity and Origin of Chinese Domestic Goats Revealed by Complete mtDNA D-loop Sequence Variation

  • Liu, R.Y.;Lei, C.Z.;Liu, S.H.;Yang, G.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.2
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    • pp.178-183
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    • 2007
  • China has numerous native domestic goat breeds, but so far there has been no extensive study on genetic diversity, population demographic history, and origin of Chinese goats. To determine the origin and genetic diversity of Chinese goats, we analyzed the complete mtDNA D-loop sequences of 183 goats from 13 breeds. The haplotype diversity value found in each breed ranged from 0.9333 to 1.0000. The nucleotide diversity value ranged from 0.006337 to 0.025194. Our results showed that there were four mtDNA lineages (A, B, C and D), in which lineage A was predominant, lineage B was moderate, and lineages C and D were at low frequencies. Lineages C and D were observed only in the Tibetan breed. The results revealed multiple maternal origins of Chinese domestic goats. There was weaker geographical structuring in the 13 Chinese goat populations, which suggested that there existed high gene flow among goat populations caused by the extensive transportation of goats in the course of history.

Estimation of Genetic Characteristic and Cumulative Power of Breed Discrimination Using Microsatellite Markers in Hanwoo (Microsatellite Marker를 사용한 한우 품종 식별력 및 유전적 특성 분석)

  • Oh, Jae-Don;Lee, Jin-Ah;Kong, Hong-Sik;Park, Keong-Do;Yoon, Du-Hak;Jeon, Gwang-Ju;Lee, Hak-Kyo
    • Journal of Embryo Transfer
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    • v.23 no.3
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    • pp.203-209
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    • 2008
  • To estimate the genetic characteristics and cumulative power of discrimination (CPD) existing among Hanwoo (Korean cattle) and exotic foreign population (Angus, Herford, Charolais, Holstein) we used a total of 414 genomic DNAs from five breeds population (Hanwoo, Angus, Hereford, Charolais, Holstein). Genetic characteristics indices including mean allele number among loci, unbiased heterozygosity ($h_i$) within locus and polymorphic information content (PIC) and unbiased average heterozygosity (H) among loci in four breeds were calculated using the generated allele frequencies by each marker. The mean allele numbers for all loci ranged between 5 and 7 while heterozygosity (H) ranged from 0.75 (HW) to 0.64 (HF) among loci and across breeds heterozygosity (H) was 0.69. The generated unbiased average heterozygosity among loci in each breed was integrated to the global formula of CPD resulting in 99.71 % within the populations. The genetic variation of HW (Hanwoo) showed highest estimates among the analyzed breeds.

EFFECT OF BREEDING LENGTH ON GENETIC IMPROVEMENT IN JAPANESE HOLSTEIN POPULATION

  • Terawaki, Y.;Shimizu, H.;Fukui, Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.4
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    • pp.363-370
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    • 1996
  • The effect of breeding length of sire on genetic progress was examined in the Holstein dairy cattle population in Japan. Genetic progress was extimated by gene flow method. Breeding length of sires directly influences the replacement rates of sires and the selection intensity of sires because there are a fixed number of progeny tested young bulls per year. As breeding length of sires increased, rate of gene flow decreased and average proportions of genes deriving from selected animals had lower asymptotic values. When breeding length was short, average proportions of genes required a longer period to converge to asymptotic values. Changes of Rcow-sire's(sire to breed recorded cows) and Ncow-sire's(sire to breed non recorded cows) breeding length influenced not only transmission of their genes but also that of genes derived from all other selected animals. Irrespective of whether the discount rate was assumed to be 0 or 6%, longer term (${\geq}$ 20 years) expected total genetic improvement was maximized by a sire breeding length of five years. For shorter term assessment(10 years), genetic improvement was maximized by a sire breeding length of three years. There was a linear increase in the contribution of the sire to bulls pathway to the total genetic improvement, with increase in the term of assessment.