• Asian-Australasian Journal of Animal Sciences
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• 제17권8호
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• pp.1039-1046
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• 2004

A model Indigenous Thai beef cattle breeding structure consisting of nucleus, multiplier and commercial units was used to evaluate the effect of changes in heritabilities of and genetic correlations between adaptation traits on genetic gain and profitability. A breeding objective that incorporated adaptation was considered. Two scenarios for improving both the production and the adaptation of animals where also compared in terms of their genetic and economic efficiency. A base scenario was modelled where selection is for production traits and adaptation is assumed to be under the forces of natural selection. The second scenario (+Adaptation) included all the information available for base scenario with the addition of indirect measures of adaptation. These measures included tick count (TICK), faecal egg count (FEC) and rectal temperature (RECT). Therefore, the main difference between these scenarios was seen in the records available for use as selection criteria and hence the level of investments. Additional genetic gain and profitability was generated through incorporating indirect measures of adaptation as criteria measured in the breeding program. Unsurprisingly, the results were sensitive to the changes in heritabilities and genetic correlations between adaptation traits. However, there were more changes in the genetic gain and profitability of the breeding program when the genetic correlations of adaptation and its indirect measures were varied than when the correlations between these measures were. The changes in the magnitudes of the genetic gain and profit per cow stresses the importance of using reliable estimates of these traits in any breeding program.

• Asian-Australasian Journal of Animal Sciences
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• 제21권4호
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• pp.478-483
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• 2008

Records of a Northeastern Thai indigenous cattle line population were used to estimate genetic parameters and annual trends for calf weights. The data set comprised records of 1,922 and 1,489 animals for birth and weaning weight, respectively born from 1993 to 2004. A bivariate analysis was carried out for variance and covariance components estimations using average information restricted maximum likelihood procedure. Average estimated breeding value and maternal breeding value of the animals born in 1993 were set to zero as a base group. Genetic trends of each trait were calculated by regressing average estimated breeding values and maternal breeding values on birth year of calves. Phenotypic trends for each trait were calculated by regressing the yearly adjusted weight on birth year of calves. The results revealed that the estimate of direct heritability, maternal heritability and maternal permanent environmental variance as a proportion of phenotypic variance for birth and weaning weight was 0.40, 0.14 and 0.04; 0.27, 0.05 and 0.23, respectively. Direct heritability was moderately heritable and genetic improvement through selection can be achieved. The estimate of phenotypic, direct genetic, maternal genetic and maternal permanent environmental correlation between birth and weaning weight was 0.48, 0.65, 0.98 and 0.73, respectively. The phenotypic trend, genetic trends of estimated breeding value and maternal breeding value for birth weight was 0.18, 0.04 and 0.01 kg/year, respectively. The phenotypic trend, genetic trends of estimated breeding value and maternal breeding value for weaning weight was -1.36, 0.32 and 0.03 kg/year, respectively. As maternal genetic effect was considerably less important than direct genetic effect, selection for improved weaning weight of this Northeastern Thai indigenous cattle line can place more emphasis on the direct genetic effect.

• Asian-Australasian Journal of Animal Sciences
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• 제15권5호
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• pp.627-632
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• 2002

Genetic parameters for dairy performance traits were estimated, breeding values for the traits of all breeding sires and cows were predicted and the genetic trends were estimated using the breeding values in the Central Cattle Breeding Station (CCBS). A total of 3,801 records for Bangladeshi Local, 756 records for Red Sindhi and 959 records for Sahiwal covering the period from 1961 to 1997 were used in this analysis. Traits considered were total milk production per lactation (TLP), lactation length (LL) and daily milk yield (DMY). The genetic parameters were estimated by the REML using MTDFREML program. The breeding values were predicted by a best linear unbiased prediction (BLUP). In all sets of data, the genetic trends for the dairy performance traits were computed as averages of breeding values for cows born in the particular year. The estimates of heritability for TLP (0.26 and 0.27) and DMY (0.28 and 0.27) were moderate in Bangladeshi local and Red Sindhi breed, respectively. Furthermore, the heritability estimate for LL (0.24) was moderate in Red Sindhi. The estimates of heritabilities for all traits were low in Sahiwal. The repeatability estimate was high for TLP, moderate for LL and moderate to high for DMY. All variances estimated in Bangladeshi Local were low, comparing the respective values estimated in both Red Sindhi and Sahiwal. On the other hand, additive genetic variances for the three traits were estimated very low in Sahiwal. The genetic trends for the three dairy production traits have not been positive except for the recent trend in Bangladeshi Local.

• 한국수산과학회지
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• 제53권4호
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• pp.544-550
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• 2020

This study was conducted to estimate the genetic improvements by selection criteria using the genetic parameters and breeding values for population of abalone Haliotis discus hannai. Genetic parameters and breeding values were estimated using all measurement data of growth traits (shell length, shell width and total weight) at 18 and 30 months old after artificial fertilization for 3,029 individuals produced in April 2014. Growth traits all exhibited moderate heritability (0.253-0.354). So it is considered that family selection will be more advantageous than individual selection. It was found that a higher genetic improvement could be expected when selecting the top 10% based on the breeding values of total weight rather than other traits. In particular, a higher genetic improvement could be expected when selecting the top 10% at 30 months old than 18 months old after artificial fertilization. This seems to be because the selection differential and heritability were higher at the 30 months old. Therefore, by estimating genetic parameters and breeding values of a population for production of the next generations by stage of growth, if they are used properly in selection and mating according to the improvement direction, it is considered that more breeding effects can be expected.

• Asian-Australasian Journal of Animal Sciences
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• 제9권4호
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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.

• 한국자원식물학회지
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• 제32권3호
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• pp.244-253
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• 2019

In crop breeding program, information about genetic dissimilarity on breeding resources is very important to corroborate genealogical relationships and to predict the most heterozygotic hybrid combinations and inbred breeding. This study aimed to evaluate the genetic variation in Kenyan sunflower breeding lines based on simple sequence repeat (SSR). A total of 83 alleles were detected at 32 SSR loci. The allele number per locus ranged from 2 to 7 with an average of 2.7 alleles per locus detected from the 24 sunflower accessions and the average value of polymorphic information contents (PIC) were 0.384. A cluster analysis based on the genetic similarity coefficients was conducted and the 24 sunflower breeding resources were classified into three groups. The principal coordinates (PCoA) revealed 34% and 13.38% respectively, and 47.38% of total variation. It was found that the genetic diversity within the Kenyan sunflower breeding resources was narrower than that in other sunflower germplasm resources, suggesting the importance and feasibility of introducing elite genotypes from different origins for selection of breeding lines with broader genetic base in Kenyan sunflower breeding program.

• Asian-Australasian Journal of Animal Sciences
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• 제19권12호
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• pp.1696-1701
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• 2006

A random regression model was applied for the first time for the analysis of test day records and to study the genetic persistency of first lactation milk yield of Indian Murrah buffaloes. Wilmink's Function was chosen to describe the shape of lactation curves. Heritabilities of test day milk yield varied from 0.33 to 0.58 in different test days. The highest heritability was found in the initial test day ($5^{th}$ day) milk yield. Genetic correlations among test day milk yields were higher in the initial test day milk yield and decreased when the test day interval was increased. The magnitude of genetic correlations between test day and 305 day milk yield varied from 0.25 to 0.99. The genetic persistencies of first lactation milk yield were estimated based on daily breeding values using two methods. $P_1$ is the genetic persistency estimated as a summation of the deviation of estimated daily breeding value on days to attain peak yield from each day after days to attain peak yield to different lactation days. $P_2$ is the genetic persistency estimated as the additional genetic yield (gained or lost) from days to attain peak yield to estimated breeding value on different lactation days relative to an average buffalo having the same yield on days to attain peak yield. The mean genetic persistency on 90, 120, 180, 240, 278 and 305 days in milk was estimated as -4.23, -21.67, -101.67, -229.57, -330.06 and -388.64, respectively by $P_1$, whereas by $P_2$ on same days in milk were estimated as -3.96 (-0.32 kg), -23.94 (-0.87 kg), -112.81 (-1.96 kg), -245.83 (-2.81 kg), -350.04 (-3.28 kg) and -407.58 (-3.40 kg) respectively. Higher magnitude of rank correlations indicated that the ranking of buffaloes based on their genetic persistency in both methods were similar for evaluation of genetic persistency of buffaloes. Based on the estimated range of genetic persistency three types of genetic persistency were identified. Genetic correlations among genetic persistency in different days in milk and between genetic persistencies on the same day in milk were very high. The genetic correlations between genetic persistency for different days in milk and estimated breeding value for 305 DIM was increased from 90 DIM to 180 DIM, and highest around 240 DIM which indicates a minimum of 240 days as an optimum first lactation length might be required for genetic evaluation of Indian Murrah buffaloes.

• Asian-Australasian Journal of Animal Sciences
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• 제17권1호
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• pp.13-17
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• 2004

The aim of this study was to investigate genetic development and genotype${\times}$environment interactions (GEI) in postweaning body weight of fattening bulls at the end of test period (WT-T) under various beef fattening environments. Data on a total of 24,247 fattening bulls obtained from the industrial farm, breeding farms and testing stations were used. Heritability estimates for WT-T in all environments were nearly similar. Significant genetic developments of sire, dam and progenies for WT-T were observed in all environments. However, many differences in annual genetic developments between the environments were significant. The genetic correlations for WT-T between industrial farm and breeding farms, industrial farm and testing stations and breeding farms and testing stations were respectively 0.004, 0.004 and 0.013. These low estimates of genetic correlations and significant differences in genetic developments among environments clearly show the existence of GEI for WT-T among various fattening environments. Results of this study indicate the need for environment-specific genetic evaluation and selection of beef bulls for commercial beef production.

• Journal of Plant Biotechnology
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• 제4권3호
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• pp.91-94
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• 2002

An efficient molecular breeding technique for coffee plants was developed. In order to produce transgenic coffee plants, we established a model transformation procedure via Agrobacterium method. We isolated a gene encoding a protein possessing 7-methylxanthine methyltransferase (theobromine synthase) activity, and it was designated as Coffea arabica 7-methylxanthine methyl transferase; CaMXMT. Using this clone, we produced transgenic coffee plants, in which the expression of CaMXMT is suppressed by double-stranded RNA interference (RNAi) andlor anti-sense methods. The expression pattern of CaMXMT was analyzed by reverse transcription-PCR method and we found that, in the transformed cell lines, the level of transcripts were obviously suppressed by RNAi. The endogenous level of caffeine in the transformed cells was dramatically reduced in comparison with non-transformed cells.

• Asian-Australasian Journal of Animal Sciences
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• 제16권7호
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• pp.939-945
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• 2003

Seventeen Chinese indigenous pig breeds and three introduced pig breeds had been carried out by means of vertical polyacrylamide gel electrophoresis (PAGE). According to the results, eight serum protein loci were highly polymorphic except Pi-2 and Cp. The polymorphism information content (PIC) of Hpx was the highest (0.5268), while that of Cp was the lowest (0.0257). The population genetic variation index showed that about 84% genetic variation existed in the population, and the rest of 16% distributed between the populations. The genetic variation of Yimeng black pig and Duroc were the highest and the lowest, respectively. The genetic variation of Chinese indigenous pig breeds was much more than that of exotic groups. Genetic distance results showed that Chinese indigenous pig breeds were classified into four groups with the three introduced pig breeds clustered into another group. The results also supported the geographic distribution of Chinese indigenous pig breeds in certain extent.