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Rosalia C M Simmen - One of the best experts on this subject based on the ideXlab platform.

  • Genetic Parameter estimates for serum insulin like growth factor i concentrations and body weight and weight gains in angus beef cattle divergently selected for serum insulin like growth factor i concentration
    Journal of Animal Science, 2006
    Co-Authors: M E Davis, Rosalia C M Simmen
    Abstract:

    Data for the current study were obtained from a divergent selection experiment in which the selection criterion was the average serum IGF-I concentrations of 3 postweaning blood samples collected from purebred Angus calves. Multiple-trait derivative-free REML procedures were used to obtain Genetic Parameter estimates for IGF-I concentrations and for BW and BW gains measured from birth to the conclusion of a 140-d postweaning performance test. Included in the analysis were 2,674 animals in the A⁻¹ matrix, 1,761 of which had valid records for IGF-I concentrations. Direct heritability estimates ± SE for IGF-I concentration at d 28, 42, and 56 of the postweaning period and for mean IGF-I concentrations were 0.44 ± 0.07, 0.51 ± 0.08, 0.42 ± 0.07, and 0.52 ± 0.08, respectively. Heritability estimates for maternal Genetic effects ranged from 0.10 ± 0.05 to 0.20 ± 0.06. The proportion of total phenotypic variance due to the maternal permanent environmental effect was essentially zero for all measures of IGF-I concentrations. Genetic correlations of IGF-I concentrations with weaning and post-weaning BW ranged from 0.07 ± 0.12 to 0.32 ± 0.11 and generally demonstrated an increasing trend during the postweaning period. Averaged across the various measures of IGF-I, the Genetic correlation of IGF-I with preweaning gain was 0.14, whereas the Genetic correlation with postweaning gain was 0.29. Genetic correlations between IGF-I and BW gain were positive during all time intervals, except between weaning and the beginning of the postweaning test and from d 84 to 112 of the postweaning period. Environmental and phenotypic correlations of IGF-I with BW and BW gains were generally positive, but small. These results indicate that postweaning serum IGF-I concentration is moderately to highly heritable and has small positive Genetic, environmental, and phenotypic correlations with BW other than birth weight and with pre- and postweaning gain. Therefore, if IGF-I proves to be a biological indicator of an economically important trait (e.g., efficiency of feed use for growth) in beef cattle, it should be possible to rapidly change IGF-I concentrations via selection without significantly altering live weight or rate of gain.

  • Genetic Parameter estimates for serum insulin like growth factor i concentration and performance traits in angus beef cattle
    Journal of Animal Science, 1997
    Co-Authors: M E Davis, Rosalia C M Simmen
    Abstract:

    Data for this study were obtained from an experiment involving divergent selection for blood serum IGF-I concentration in beef cattle. Multiple trait derivative-free REML procedures were used to obtain Genetic Parameter estimates for IGF-I concentration at d 28, 42, and 56 of the postweaning period and for mean IGF-I concentration, as well as for weights and gains. Included in the analysis were 1,563 animals in the A -1 matrix, 731 of which had valid records for mean IGF-I concentration. Direct heritabilities (h d 2 ) were .42 + .13, .53 + .15, .71 + .16, and .48 + .13 for IGF-I at d 28, 42, and 56 of the postweaning period and for mean IGF-I, respectively. Heritability of maternal Genetic effects (h m 2 ) ranged from .02 to .12, whereas the proportion of the total variance due to the maternal permanent environmental effect (c 2 ) was essentially zero for all measures of IGF-I. Genetic correlations of IGF-I with weaning and postweaning weights and with postweaning weight gain ranged from -.21 to -.54 and averaged -.38. The environmental correlation between IGF-I and performance traits varied from .10 to .35 and averaged .22. Phenotypic correlations of IGF-I concentrations with weaning weight and postweaning weights and gains ranged from -.01 to .12 and averaged .04. Estimates of h d 2 indicate that it should be possible to change IGF-I concentration in beef cattle via selection. Negative Genetic correlations imply that, if the goal is to make Genetic improvement in weaning weights, postweaning weights and(or) postweaning gain in beef cattle, selection should be for decreased postweaning serum IGF-I concentration.

M E Davis - One of the best experts on this subject based on the ideXlab platform.

  • Genetic Parameter estimates for serum insulin like growth factor i concentrations and body weight and weight gains in angus beef cattle divergently selected for serum insulin like growth factor i concentration
    Journal of Animal Science, 2006
    Co-Authors: M E Davis, Rosalia C M Simmen
    Abstract:

    Data for the current study were obtained from a divergent selection experiment in which the selection criterion was the average serum IGF-I concentrations of 3 postweaning blood samples collected from purebred Angus calves. Multiple-trait derivative-free REML procedures were used to obtain Genetic Parameter estimates for IGF-I concentrations and for BW and BW gains measured from birth to the conclusion of a 140-d postweaning performance test. Included in the analysis were 2,674 animals in the A⁻¹ matrix, 1,761 of which had valid records for IGF-I concentrations. Direct heritability estimates ± SE for IGF-I concentration at d 28, 42, and 56 of the postweaning period and for mean IGF-I concentrations were 0.44 ± 0.07, 0.51 ± 0.08, 0.42 ± 0.07, and 0.52 ± 0.08, respectively. Heritability estimates for maternal Genetic effects ranged from 0.10 ± 0.05 to 0.20 ± 0.06. The proportion of total phenotypic variance due to the maternal permanent environmental effect was essentially zero for all measures of IGF-I concentrations. Genetic correlations of IGF-I concentrations with weaning and post-weaning BW ranged from 0.07 ± 0.12 to 0.32 ± 0.11 and generally demonstrated an increasing trend during the postweaning period. Averaged across the various measures of IGF-I, the Genetic correlation of IGF-I with preweaning gain was 0.14, whereas the Genetic correlation with postweaning gain was 0.29. Genetic correlations between IGF-I and BW gain were positive during all time intervals, except between weaning and the beginning of the postweaning test and from d 84 to 112 of the postweaning period. Environmental and phenotypic correlations of IGF-I with BW and BW gains were generally positive, but small. These results indicate that postweaning serum IGF-I concentration is moderately to highly heritable and has small positive Genetic, environmental, and phenotypic correlations with BW other than birth weight and with pre- and postweaning gain. Therefore, if IGF-I proves to be a biological indicator of an economically important trait (e.g., efficiency of feed use for growth) in beef cattle, it should be possible to rapidly change IGF-I concentrations via selection without significantly altering live weight or rate of gain.

  • Genetic Parameter estimates for serum insulin like growth factor i concentration and performance traits in angus beef cattle
    Journal of Animal Science, 1997
    Co-Authors: M E Davis, Rosalia C M Simmen
    Abstract:

    Data for this study were obtained from an experiment involving divergent selection for blood serum IGF-I concentration in beef cattle. Multiple trait derivative-free REML procedures were used to obtain Genetic Parameter estimates for IGF-I concentration at d 28, 42, and 56 of the postweaning period and for mean IGF-I concentration, as well as for weights and gains. Included in the analysis were 1,563 animals in the A -1 matrix, 731 of which had valid records for mean IGF-I concentration. Direct heritabilities (h d 2 ) were .42 + .13, .53 + .15, .71 + .16, and .48 + .13 for IGF-I at d 28, 42, and 56 of the postweaning period and for mean IGF-I, respectively. Heritability of maternal Genetic effects (h m 2 ) ranged from .02 to .12, whereas the proportion of the total variance due to the maternal permanent environmental effect (c 2 ) was essentially zero for all measures of IGF-I. Genetic correlations of IGF-I with weaning and postweaning weights and with postweaning weight gain ranged from -.21 to -.54 and averaged -.38. The environmental correlation between IGF-I and performance traits varied from .10 to .35 and averaged .22. Phenotypic correlations of IGF-I concentrations with weaning weight and postweaning weights and gains ranged from -.01 to .12 and averaged .04. Estimates of h d 2 indicate that it should be possible to change IGF-I concentration in beef cattle via selection. Negative Genetic correlations imply that, if the goal is to make Genetic improvement in weaning weights, postweaning weights and(or) postweaning gain in beef cattle, selection should be for decreased postweaning serum IGF-I concentration.

Didier Boichard - One of the best experts on this subject based on the ideXlab platform.

  • short communication Genetic Parameters for milk protein composition predicted using mid infrared spectroscopy in the french montbeliarde normande and holstein dairy cattle breeds
    Journal of Dairy Science, 2017
    Co-Authors: Marie Sanchez, M Ferrand, M Gele, D Pourchet, Guy Miranda, Patrice Martin, Mickael Brochard, Didier Boichard
    Abstract:

    ABSTRACT Genetic Parameters for the major milk proteins were estimated in the 3 main French dairy cattle breeds (i.e. Montbeliarde, Normande, and Holstein) as part of the PhenoFinlait program. The 6 major milk protein contents as well as the total protein content (PC) were estimated from mid-infrared spectrometry on 133,592 test-day milk samples from 20,434 cows in first lactation. Lactation means, expressed as a percentage of milk (protein contents) or of protein (protein fractions), were analyzed with an animal mixed model including fixed environmental effects (herd, year × month of calving, and spectrometer) and a random Genetic effect. Genetic Parameter estimates were very consistent across breeds. Heritability estimates (h 2 ) were generally higher for protein fractions than for protein contents. They were moderate to high for α S1 -casein, α S2 -casein, β-casein, κ-casein, and α-lactalbumin (0.25 2 2 g ) varied depending on how the percentage was expressed. The PC was strongly positively correlated with protein contents but almost Genetically independent from protein fractions. Protein fractions were generally in opposition, except between κ-casein and α-lactalbumin (0.39 g S2 -casein (0.36 g g estimates were positive, with highest values found between caseins (0.83 g g g

Nguyen Hong Nguyen - One of the best experts on this subject based on the ideXlab platform.

  • effects of genotype by environment interaction on Genetic gain and Genetic Parameter estimates in red tilapia oreochromis spp
    Frontiers in Genetics, 2017
    Co-Authors: Nguyen Hong Nguyen, Azhar Hamzah, Ngo Phu Thoa
    Abstract:

    The extent to which Genetic gain achieved from selection programs under strictly controlled environments in the nucleus that can be expressed in commercial production systems is not well documented in aquaculture species. The main aim of this paper was to assess the effects of genotype by environment interaction on Genetic response and Genetic Parameters for four body traits (harvest weight, standard length, body depth, body width) and survival in Red tilapia (Oreochromis spp). The growth and survival data were recorded on 19,916 individual fish from a pedigreed population undergoing three generations of selection for increased harvest weight in earthen ponds from 2010 to 2012 at the Aquaculture Extension Center, Department of Fisheries, Jitra in Kedah, Malaysia. The pedigree comprised a total of 339 sires and 395 dams, tracing back to the base population in 2009. A multivariate animal model was used to measure Genetic response and estimate variance and covariance components. When the homologous body traits in freshwater pond and cage were treated as Genetically distinct traits, the Genetic correlations between the two environments were high (0.85 - 0.90) for harvest weight and square root of harvest weight but the estimates were of lower magnitudes for length, width and depth (0.63 – 0.79). The heritabilities estimated for the five traits studied differed between pond (0.02 to 0.22) and cage (0.07 to 0.68). The common full-sib effects were large, ranging from 0.23 to 0.59 in pond and 0.11 to 0.31 in cage across all traits. The direct and correlated responses for four body traits were generally greater in pond than in cage environments (0.011 – 1.561 vs. -0.033 – 0.567 Genetic standard deviation units, respectively). Selection for increased harvest body weight resulted in positive Genetic changes in survival rate in both pond and cage culture. In conclusion, the reduced selection response and the magnitude of the Genetic Parameter estimates in the production environment (i.e. cage) relative to those achieved in the nucleus (pond) were a result of the genotype by environment interaction and this effect should be taken into consideration in the future breeding program for Red tilapia.

  • quantitative Genetic Parameter estimates for body and carcass traits in a cultured stock of giant freshwater prawn macrobrachium rosenbergii selected for harvest weight in vietnam
    Aquaculture, 2013
    Co-Authors: Dinh Hung, Nguyen Hong Nguyen, Raul W Ponzoni, David A Hurwood, Peter B Mather
    Abstract:

    Abstract We estimated the heritability and correlations between body and carcass weight traits in a cultured stock of giant freshwater prawn (GFP) ( Macrobrachium rosenbergii) selected for harvest body weight in Vietnam. The data set consisted of 18,387 body and 1,730 carcass records, as well as full pedigree information collected over four generations. Variance and covariance components were estimated by restricted maximum likelihood fitting a multi-trait animal model. Across generations, estimates of heritability for body and carcass weight traits were moderate and ranged from 0.14 to 0.19 and 0.17 to 0.21, respectively. Body trait heritabilities estimated for females were significantly higher than for males whereas carcass weight trait heritabilities estimated for females and males were not significantly different ( P  > 0.05). Maternal effects for body traits accounted for 4 to 5% of the total variance and were greater in females than in males. Genetic correlations among body traits were generally high in the mixed sexes. Genetic correlations between body and carcass weight traits were also high. Although some issues remain regarding the best statistical model to be fitted to GFP data, our results suggest that selection for high harvest body weight based on breeding values estimated by fitting an animal model to the data can significantly improve mean body and carcass weight in GFP.

Marie Sanchez - One of the best experts on this subject based on the ideXlab platform.

  • short communication Genetic Parameters for milk protein composition predicted using mid infrared spectroscopy in the french montbeliarde normande and holstein dairy cattle breeds
    Journal of Dairy Science, 2017
    Co-Authors: Marie Sanchez, M Ferrand, M Gele, D Pourchet, Guy Miranda, Patrice Martin, Mickael Brochard, Didier Boichard
    Abstract:

    ABSTRACT Genetic Parameters for the major milk proteins were estimated in the 3 main French dairy cattle breeds (i.e. Montbeliarde, Normande, and Holstein) as part of the PhenoFinlait program. The 6 major milk protein contents as well as the total protein content (PC) were estimated from mid-infrared spectrometry on 133,592 test-day milk samples from 20,434 cows in first lactation. Lactation means, expressed as a percentage of milk (protein contents) or of protein (protein fractions), were analyzed with an animal mixed model including fixed environmental effects (herd, year × month of calving, and spectrometer) and a random Genetic effect. Genetic Parameter estimates were very consistent across breeds. Heritability estimates (h 2 ) were generally higher for protein fractions than for protein contents. They were moderate to high for α S1 -casein, α S2 -casein, β-casein, κ-casein, and α-lactalbumin (0.25 2 2 g ) varied depending on how the percentage was expressed. The PC was strongly positively correlated with protein contents but almost Genetically independent from protein fractions. Protein fractions were generally in opposition, except between κ-casein and α-lactalbumin (0.39 g S2 -casein (0.36 g g estimates were positive, with highest values found between caseins (0.83 g g g