• Journal of Microbiology and Biotechnology
• /
• v.17 no.12
• /
• pp.1996-2004
• /
• 2007

In this study, the optimization of culture medium using a Sterigmatomyces elviae mutant was investigated using statistical analysis to increase the cell mass and lactosucrose ($^4G-{\beta}$-D-galactosylsucrose) production. In basal medium, the cell mass and lactosucrose production were 4.12 g/l and 140.91 g/l, respectively. However, because of the low cell mass and lactosucrose production, optimization of culture medium was carried out to increase the cell mass and lactosucrose production. Culture media were optimized by the S. elviae mutant using analysis of variance (ANOVA) and response surface methodology (RSM). Central composite designs using RSM were utilized in this investigation. Quadratic models were obtained for cell mass and lactosucrose production. In the case of cell mass, optimal components of the medium were as follows: sucrose 1.13%, yeast extract 0.99%, bactopeptone 2.96%, and ammonium sulfate 0.40%. The predicted maximum value of cell mass was about 5.20 g/l and its experimental value was 5.08 g/l. In the case of lactosucrose production, optimal components of the medium were as follows: sucrose 0.96%, yeast extract 1.2%, bactopeptone 3.0%, and ammonium sulfate 0.48%. Then, the predicted maximum value of lactosucrose production was about 194.12 g/l and the corresponding experimental value was about 183.78 g/l. Therefore, by culturing using predicted conditions, the real cell mass and lactosucrose production increased to 23.3% and 30.42%, respectively.

• Journal of Wetlands Research
• /
• v.21 no.3
• /
• pp.215-223
• /
• 2019

In this study, we analyzed the water quality characteristics of major tributaries of Nakdong River through statistical analysis such as correlation analysis, principal component and factor analysis, and cluster analysis. Organic matter and nutrients are highly correlated, and are high in spring and autumn, and seasonal water quality management is required. Principal component and factor analysis showed that 82% of total variance could be explained by 4 principal components such as organic matter, nutrients, nature, and weather. BOD, COD, TOC, and TP items were analyzed as major influencing factors. As a result of the cluster analysis, the four clusters were classified according to seasonal organic matter and nutrient pollution. Kumho River watershed showed high pollution characteristics in all seasons. Therefore, effective management of water quality in tributary streams requires measures in consideration of spatio-temporal characteristics and multivariate statistical techniques may be useful in water quality management and policy formulation.

• Animal Bioscience
• /
• v.34 no.4
• /
• pp.516-524
• /
• 2021

Objective: The genetic evaluation of Santa Inês sheep was performed for resistance to gastrointestinal nematode infection (RGNI) and body size using different relationship matrices to assess the efficiency of including genomic information in the analyses. Methods: There were 1,637 animals in the pedigree and 500, 980, and 980 records of RGNI, thoracic depth (TD), and rump height (RH), respectively. The genomic data consisted of 42,748 SNPs and 388 samples genotyped with the OvineSNP50 BeadChip. The (co)variance components were estimated in single- and multi-trait analyses using the numerator relationship matrix (A) and the hybrid matrix H, which blends A with the genomic relationship matrix (G). The BLUP and single-step genomic BLUP methods were used. The accuracies of estimated breeding values and Spearman rank correlation were also used to assess the feasibility of incorporating genomic information in the analyses. Results: The heritability estimates ranged from 0.11±0.07, for TD (in single-trait analysis using the A matrix), to 0.38±0.08, for RH (using the H matrix in multi-trait analysis). The estimates of genetic correlation ranged from -0.65±0.31 to 0.59±0.19, using A, and from -0.42±0.30 to 0.57±0.16 using H. The gains in accuracy of estimated breeding values ranged from 2.22% to 75.00% with the inclusion of genomic information in the analyses. Conclusion: The inclusion of genomic information will benefit the direct selection for the traits in this study, especially RGNI and TD. More information is necessary to improve the understanding on the genetic relationship between resistance to nematode infection and body size in Santa Inês sheep. The genetic evaluation for the evaluated traits was more efficient when genomic information was included in the analyses.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.9
• /
• pp.1226-1234
• /
• 2015

The development of effective genetic evaluations and selection of sires requires accurate estimates of genetic parameters for all economically important traits in the breeding goal. The main objective of this study was to assess the relative performance of the traditional lactation average model (LAM) against the random regression test-day model (RRM) in the estimation of genetic parameters and prediction of breeding values for Holstein Friesian herds in Ethiopia. The data used consisted of 6,500 test-day (TD) records from 800 first-lactation Holstein Friesian cows that calved between 1997 and 2013. Co-variance components were estimated using the average information restricted maximum likelihood method under single trait animal model. The estimate of heritability for first-lactation milk yield was 0.30 from LAM whilst estimates from the RRM model ranged from 0.17 to 0.29 for the different stages of lactation. Genetic correlations between different TDs in first-lactation Holstein Friesian ranged from 0.37 to 0.99. The observed genetic correlation was less than unity between milk yields at different TDs, which indicated that the assumption of LAM may not be optimal for accurate evaluation of the genetic merit of animals. A close look at estimated breeding values from both models showed that RRM had higher standard deviation compared to LAM indicating that the TD model makes efficient utilization of TD information. Correlations of breeding values between models ranged from 0.90 to 0.96 for different group of sires and cows and marked re-rankings were observed in top sires and cows in moving from the traditional LAM to RRM evaluations.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.71-71
• /
• 2017

Stable stand establishment is pre-requisite in direct rice seeding system for obtaining optimal yield of rice crop in rain-fed and waterlogged areas. Anaerobic condition on waterlogged soil causes low germination which significantly reduces crop yield. Due to low availability of tolerant genetic material for anaerobic germination, there is urgent need to evaluate rice germplasm for better germinability under anaerobic conditions. Seeds of the 185 rice accessions were evaluated for germination vigor and coleoptile length under anaerobic conditions. The variation among germplasm was tested for significance using analysis of variance and various multivariate components. Significant level of variation was observed among all accessions for germination vigor and coleoptiles length. Although highest mean values for coleoptiles length (2.1cm) and germination rate (60%) were observed in japonica accessions but maximum coleoptile length (4.68cm) and germination rate (96%) was found in indica genotype CO18. A highly significant and positive correlation was also observed between germination vigor and coleoptiles length, which signify the importance of elongated coleoptile under anaerobic conditions. The PCA analysis illustrated that 97.24% variation was accounted by PC1 while PC2 and PC3 explained 2.54% and 0.24% variation for germination vigor and coleoptile length. PCA scattered plot divided the accessions in four various groups. All AG tolerant accessions were included in group I. Likewise in the case of cluster analysis, two major clades (I and II) were formed. All accessions showing >40% germination rate were included in clade I, whereas all other accessions with <40% germination rate were grouped in clade II. Further more highly tolerant accessions (>80% germination) were grouped in sub-cluster IA.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.9
• /
• pp.1387-1399
• /
• 2020

Objective: The objective of this study was to estimate the genetic parameters and trends for milk, fat, and protein yields in the first three lactations of Thai dairy cattle using a 3-trait,-3-lactation random regression test-day model. Methods: Data included 168,996, 63,388, and 27,145 test-day records from the first, second, and third lactations, respectively. Records were from 19,068 cows calving from 1993 to 2013 in 124 herds. (Co) variance components were estimated by Bayesian methods. Gibbs sampling was used to obtain posterior distributions. The model included herd-year-month of testing, breed group-season of calving-month in tested milk group, linear and quadratic age at calving as fixed effects, and random regression coefficients for additive genetic and permanent environmental effects, which were defined as modified constant, linear, quadratic, cubic and quartic Legendre coefficients. Results: Average daily heritabilities ranged from 0.36 to 0.48 for milk, 0.33 to 0.44 for fat and 0.37 to 0.48 for protein yields; they were higher in the third lactation for all traits. Heritabilities of test-day milk and protein yields for selected days in milk were higher in the middle than at the beginning or end of lactation, whereas those for test-day fat yields were high at the beginning and end of lactation. Genetics correlations (305-d yield) among production yields within lactations (0.44 to 0.69) were higher than those across lactations (0.36 to 0.68). The largest genetic correlation was observed between the first and second lactation. The genetic trends of 305-d milk, fat and protein yields were 230 to 250, 25 to 29, and 30 to 35 kg per year, respectively. Conclusion: A random regression model seems to be a flexible and reliable procedure for the genetic evaluation of production yields. It can be used to perform breeding value estimation for national genetic evaluation in the Thai dairy cattle population.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.8
• /
• pp.981-986
• /
• 2010

Genetic parameters of growth traits were estimated in the German Angora rabbit reared in the sub-temperate region of India. Estimates of (co)variance components were obtained for body weights at weaning (42 days) and post-weaning at 84, 126 and 168 days. A total of 8,324 animal records were used for the analysis of these traits. The data were analyzed by restricted maximum likelihood (REML) fitting six animal models with various combinations of direct and maternal effects. A log likelihood ratio test was used to select the most appropriate univariate model for each trait. Direct heritability estimates were observed to be moderate for the traits under study. Heritability estimates for weaning (42 d), 84, 126 and 168 d weights obtained from the best models were $0.25{\pm}0.05$, $0.17{\pm}0.05$, $0.21{\pm}0.06$ and $0.12{\pm}0.05$. Maternal effects had higher importance at weaning, and declined with the advancement of age. Significant maternal permanent environmental effect on weaning and post-weaning weights was a carryover effect of maternal influences during pre-weaning age. The estimated repeatabilities of doe effects on body weights were 0.37, 0.22, 0.18 and 0.28 at weaning, 84, 126 and 168 d body weight, respectively. Results indicated that modest rate of genetic progress is possible for body weight traits of Angora rabbit through selection. Similarly, these growth traits could be included in selection criteria along with wool traits for early selection of the animals.

• Animal Bioscience
• /
• v.34 no.9
• /
• pp.1451-1459
• /
• 2021

Objective: The objectives of the study were to evaluate reproductive performance and selection response through genetic trend of community-based breeding programs (CBBPs) of Bonga sheep. Methods: Reproduction traits data were collected between 2012 and 2018 from Bonga sheep CBBPs. Phenotypic performance was analyzed using the general linear model procedures of Statistical Analysis System. Genetic parameters were estimated by univariate animal model for age at first lambing (AFL) and repeatability models for lambing interval (LI), litter size (LS), and annual reproductive rate (ARR) traits using restricted maximum likelihood method of WOMBAT. For correlations bivariate animal model was used. Best model was chosen based on likelihood ratio test. The genetic trends were estimated by the weighted regression of the average breeding value of the animals on the year of birth/lambing. Results: The overall least squares mean±standard error of AFL, LI, LS, and ARR were 375±12.5, 284±9.9, 1.45±0.010, and 2.31±0.050, respectively. Direct heritability estimates for AFL, LI, LS, and ARR were 0.07±0.190, 0.06±0.120, 0.18±0.070, and 0.25±0.203, respectively. The low heritability for both AFL and LI showed that these traits respond little to selection programs but rather highly depend on animal management options. The annual genetic gains were -0.0281 days, -0.016 days, -0.0002 lambs and 0.0003 lambs for AFL, LI, LS, and ARR, respectively. Conclusion: Implications of the result to future improvement programs were improving management of animals, conservation of prolific flocks and out scaling the CBBP to get better results.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.52 no.4
• /
• pp.469-473
• /
• 2007

With the aim to analyze stability performance of six promising barley genotypes, eleven yield related characters were evaluated employing varied irrigation treatments under the tropical climate of Northern part in Bangladesh. Analysis of variance(ANOVA), phenotypic index, regression co-efficient(bi) and deviation from regression($s^2_d$) of the individual genotypes were estimated to evaluate the stable performance of the genotypes. A significant interaction was observed between the genotypes and irrigation period($G{\times}T$). Among all the genotypes, BSH-2 showed stable performance for plant height under different irrigation period, where $P>\bar{X},\;bi{\sim}1\;and\;s^2_d{\sim}0$. High phenotypic index, lower bi value and low deviations from regression were observed in case of spikelet number per spike and grain number per spike for genotype BSH-2 and plant height, spike length and harvest index per plant for BB-2 which suggest that those parameters were not usually affected by irrigation. On the other hand the genotype BSH-2 for tiller number and BB-1 for the fertile tiller number were not suitable for favorable moisture content, where $P<\bar{X},\;bi>1.0\;and\;low\;s^2_d$. Thus we suggest that genotype BSH-2 might have transmit high mean and increased phenotypic stability to the next progenies, which may consider as an ideal genotype for developing improved barely cultivars.

• Animal Bioscience
• /
• v.37 no.3
• /
• pp.419-427
• /
• 2024

Objective: The objective of this study was to obtain (co) variance components and genetic parameter estimates for post-weaning body measurements such as body length (BL), height at withers (HW), and chest girth (HG) recorded at six (SBL, SHW, and SHG), nine (NBL, NHW, and NHG) and twelve (YBL, YHW, and YHG) months of age along with yearling weight (YW) in Nellore sheep maintained at livestock research station, Palamaner, Andhra Pradesh, India and also the association among body measurements with YW was studied. Methods: Data on 2,076 Nellore sheep (descended from 75 sires and 522 dams) recorded between 2007 and 2016 (10 years) were utilized in the study. Lambing year, sex of lamb, season of lambing and parity of dam were included in the model as fixed effects and ewe weight was kept as a covariate. Analyses were conducted with six animal models with different combinations of direct and maternal genetic effects using restricted maximum likelihood procedure. Best model for each trait was determined based on Akaike's information criterion. Results: Moderate estimates of direct heritability were obtained for the studied traits viz., BL (0.02 to 0.24), HW (0.31 to 0.49), and CG (0.08 to 0.35) and their corresponding maternal heritability estimates were in the range of 0.00 to 0.07 (BL), 0.13 to 0.17 (HW), and 0.07 to 0.13 (CG), respectively. Positive direct genetic and phenotypic correlations among the traits and they ranged from 0.07 (YBL-YW) to 0.99 (SBL-SHG, SHG-YW, and NBL-YBL) and 0.01 (SBL-YBL) to 0.99 (NBL-NHG), respectively. Further, the genetic correlations among all the body measurements and YW were positive and ranged from 0.07 (YW and YBL) to 0.99 (YW and SHG). Conclusion: There was a strong association of chest girth at six months with YW. Further, it is indicated that moderate improvement of post-weaning body measurements in Nellore sheep would be possible through selection.