The Experts below are selected from a list of 4104 Experts worldwide ranked by ideXlab platform

D P Evenson - One of the best experts on this subject based on the ideXlab platform.

  • Loss of Livestock Breeding efficiency due to uncompensable sperm nuclear defects.
    Reproduction, fertility, and development, 1999
    Co-Authors: D P Evenson
    Abstract:

    An important goal of modern analyses of semen is to elucidate the molecular traits of mammalian sperm chromatin structural abnormalities, defined here as 'uncompensable', that lead to abnormalities in fertility, pronuclear formation, early embryo quality and pregnancy outcome. Sperm with uncompensable nuclear abnormalities are able to fertilize oocytes both in vivo and in vitro; however, due to the uncompensable trait(s), the embryo development may be abnormal. Uncompensable nuclear traits can be experimentally induced in bull sperm by a mild thermal insult to the testis. Sperm nuclear morphology abnormalities seen in ejaculates 11-days post stress are likely related to molecular changes in chromatin observed 3-days post stress by the flow cytometric sperm chromatin structure assay (SCSA). The SCSA measures the susceptibility of sperm nuclear DNA to denaturation in situ. This susceptibility has been correlated with the presence of DNA strand breaks that may be derived in part by oxidative stress and possibly by a unique, abortive apoptotic mechanism. The extent of DNA denaturation is not significantly related to the level of disulfide bonding between the chromatin protamines. The use of human sperm with uncompensable nuclear traits for artificial reproductive techniques is also discussed. The goal of this research is to remove from semen doses those sperm with uncompensable nuclear traits and thereby increase male fertility potential.

  • loss of Livestock Breeding efficiency due to uncompensable sperm nuclear defects
    Reproduction Fertility and Development, 1999
    Co-Authors: D P Evenson
    Abstract:

    An important goal of modern analyses of semen is to elucidate the molecular traits of mammalian sperm chromatin structural abnormalities, defined here as ‘uncompensable’, that lead to abnormalities in fertility, pronuclear formation, early embryo quality and pregnancy outcome. Sperm with uncompensable nuclear abnormalities are able to fertilize oocytes both in vivo and in vitro; however, due to the uncompensable trait(s), the embryo development may be abnormal. Uncompensable nuclear traits can be experimentally induced in bull sperm by a mild thermal insult to the testis. Sperm nuclear morphology abnormalities seen in ejaculates 11-days post stress are likely related to molecular changes in chromatin observed 3-days post stress by the flow cytometric sperm chromatin structure assay (SCSA). The SCSA measures the susceptibility of sperm nuclear DNA to denaturation in situ. This susceptibility has been correlated with the presence of DNA strand breaks that may be derived in part by oxidative stress and possibly by a unique, abortive apoptotic mechanism. The extent of DNA denaturation is not significantly related to the level of disulfide bonding between the chromatin protamines. The use of human sperm with uncompensable nuclear traits for artificial reproductive techniques is also discussed. The goal of this research is to remove from semen doses those sperm with uncompensable nuclear traits and thereby increase male fertility potential. Extra key words: male fertility potential, sperm chromatin structure assay (SCSA).

J A M Van Arendonk - One of the best experts on this subject based on the ideXlab platform.

  • selaction software to predict selection response and rate of inBreeding in Livestock Breeding programs
    Journal of Heredity, 2002
    Co-Authors: M J M Rutten, Piter Bijma, John Woolliams, J A M Van Arendonk
    Abstract:

    Software was developed to predict selection responses and rates of inBreeding from Livestock Breeding programs. Variance components are needed as input for the program, which subsequently enables the user to evaluate various Breeding program designs. Consequently, Breeding program structures with discrete (e.g., fish or poultry Breeding) or overlapping generations (e.g., pig or cattle Breeding) can be evaluated for selection on multiple traits. For discrete generations, selection response of multistage selection schemes can be predicted as well. Rates of inBreeding can be predicted for Breeding programs with discrete generations and single-stage selection. With this software program, BLUP Breeding values (animal model) can be used as information sources. It also accounts for reduction of genetic variance due to selection (‘‘Bulmer effect’’), and for reduction of selection intensity due to finite population size and correlated index values of family members. Predefined information sources can be either switched on or off, according to the user’s needs. The number of traits is limited to a maximum of 20. Quantitative genetic research has resulted in a large amount of theory to predict selection response and rates of inBreeding of Livestock Breeding programs. Application of this theory in practical Livestock Breeding programs, however, is hampered by the lack of computer software that implements the available theory. Virtually all methods to predict responses of Breeding programs are based on selection index theory. After the basics of selection index theory were developed (Hazel 1943), further developments have aimed at, for example, the effect of selection on genetic (co)variances (Bulmer 1971), the effect of correlated index values on selection intensity (Meuwissen 1991), the effect of multistage selection (Tallis 1961; Young 1964), selection in overlapping generations (Meuwissen 1989), and prediction of selection response on BLUP Breeding values (Villanueva et al. 1993; Wray and Hill 1989). In addition, methods to predict rates of inBreeding in selection programs have recently been developed (Bijma et al. 2001; Bijma and Woolliams 2000; Woolliams and Bijma 2000). In this article, a computer program called SelAction is presented, which implements existing theory in order to provide a tool to predict selection response and rates of inBreeding in Livestock Breeding programs for a wide range of population structures and selection strategies. SelAction requires little computing time, allowing it to be used as an interactive optimization tool.

Dwi Nur Happy Hariyono - One of the best experts on this subject based on the ideXlab platform.

  • The Estimation of Breeding Value of Rams at Technical Implementation Unit Development Center for Livestock Breeding in Margawati Garut, West Java
    Proceeding of the 1st International Conference on Tropical Agriculture, 2017
    Co-Authors: Sumadi, Tety Hartatik, Dyah Maharani, Akhmad Fathoni, Ahmad Nurrudin, Dwi Nur Happy Hariyono
    Abstract:

    The objective of this study was to determine Breeding value (BV) of rams of Garut sheep at Technical Implementation Unit Development Center for Livestock Breeding Margawati, Garut, West Java. This research was conducted from April 2014 to October 2014. The materials which were used in this study were data record during the last 5 years (2009–2014) that consists of 55 rams and 579 lambs which have weaning weight data. Weaning weight data has previously been corrected based on the type of birth, sex, and weaning age of 100 days. The BV was estimated using the components of heritability and repeatability value which were previously analyzed. The heritability and repeatability values of this study were 0.45 ± 0.08 and 0.34 ± 0.09. Estimation of heritability for weaning weight was calculated using paternal half-sib correlation, and the repeatability was estimated using interclass correlations method. The Breeding value was estimated for the absolute value (NPabs) of rams based on weaning weight of the progenies. There were top 10 of dams with the highest BV. The result was sorted by the highest value to the lowest. The highest BV was 16.37 by the name antasena, and the lowest BV has been reported for wayang (15.45). The result of this study can be used as the basis recommendation for selecting rams in Technical Implementation Unit Development Center for Livestock Breeding in Margawati Garut, West Java.

  • Estimation of Breeding Value of Rams at Technical Implementation Unit Development Center for Livestock Breeding in Margawati Garut, West Java
    2016
    Co-Authors: Sumadi Sumadi, Tety Hartatik, Dyah Maharani, Akhmad Fathoni, Ahmad Nurrudin, Dwi Nur Happy Hariyono
    Abstract:

    This study was conducted to determine Breeding Value (BV) of rams of Garut sheep at Technical Implementation Unit Development Center for Livestock Breeding Margawati, Garut, West Java. This research was conducted on April until October 2014. The BV was estimated using the components of heritability and repeatability value which previously analyzed. A total of 55 rams and 609 lambs which having weaning weight were used in this study. Estimation of heritability for weaning weight was calculated using Paternal half-sib Correlation and the repeatability was estimated using correlation between class method. The Breeding value was estimated for the absolute value (NPabs) of rams based on weaning weight of the progenies. The highest BV was 16.37 by the nama Antasena and the lowest BV has been reported for Wayang (15.45)

Zhang Rui - One of the best experts on this subject based on the ideXlab platform.

  • Ecological Agriculture Technology in Urban Agriculture
    GREEN BUILDING TECHNOLOGIES AND MATERIALS, 2011
    Co-Authors: Lv Yanhang, Zhang Rui
    Abstract:

    Farming in city is the most significant practice of Urban Agriculture with important social and economic impact. It constructs a stable and sustainable eco-recycling system, utilizing daily waste for crops irrigation, Livestock Breeding and energy production. And these ecological technologies will be discussed about ecological characters, scientific principles and operation steps, to present the artificial agro-ecosystem efficiently in limited space.

John Woolliams - One of the best experts on this subject based on the ideXlab platform.

  • potential of promotion of alleles by genome editing to improve quantitative traits in Livestock Breeding programs
    Genetics Selection Evolution, 2015
    Co-Authors: Janez Jenko, Gregor Gorjanc, Bruce C A Whitelaw, John Woolliams, Matthew A Cleveland, Rajeev K Varshney, John M. Hickey
    Abstract:

    Genome editing (GE) is a method that enables specific nucleotides in the genome of an individual to be changed. To date, use of GE in Livestock has focussed on simple traits that are controlled by a few quantitative trait nucleotides (QTN) with large effects. The aim of this study was to evaluate the potential of GE to improve quantitative traits that are controlled by many QTN, referred to here as promotion of alleles by genome editing (PAGE). Multiple scenarios were simulated to test alternative PAGE strategies for a quantitative trait. They differed in (i) the number of edits per sire (0 to 100), (ii) the number of edits per generation (0 to 500), and (iii) the extent of use of PAGE (i.e. editing all sires or only a proportion of them). The base line scenario involved selecting individuals on true Breeding values (i.e., genomic selection only (GS only)-genomic selection with perfect accuracy) for several generations. Alternative scenarios complemented this base line scenario with PAGE (GS + PAGE). The effect of different PAGE strategies was quantified by comparing response to selection, changes in allele frequencies, the number of distinct QTN edited, the sum of absolute effects of the edited QTN per generation, and inBreeding. Response to selection after 20 generations was between 1.08 and 4.12 times higher with GS + PAGE than with GS only. Increases in response to selection were larger with more edits per sire and more sires edited. When the total resources for PAGE were limited, editing a few sires for many QTN resulted in greater response to selection and inBreeding compared to editing many sires for a few QTN. Between the scenarios GS only and GS + PAGE, there was little difference in the average change in QTN allele frequencies, but there was a major difference for the QTN with the largest effects. The sum of the effects of the edited QTN decreased across generations. This study showed that PAGE has great potential for application in Livestock Breeding programs, but inBreeding needs to be managed.

  • selaction software to predict selection response and rate of inBreeding in Livestock Breeding programs
    Journal of Heredity, 2002
    Co-Authors: M J M Rutten, Piter Bijma, John Woolliams, J A M Van Arendonk
    Abstract:

    Software was developed to predict selection responses and rates of inBreeding from Livestock Breeding programs. Variance components are needed as input for the program, which subsequently enables the user to evaluate various Breeding program designs. Consequently, Breeding program structures with discrete (e.g., fish or poultry Breeding) or overlapping generations (e.g., pig or cattle Breeding) can be evaluated for selection on multiple traits. For discrete generations, selection response of multistage selection schemes can be predicted as well. Rates of inBreeding can be predicted for Breeding programs with discrete generations and single-stage selection. With this software program, BLUP Breeding values (animal model) can be used as information sources. It also accounts for reduction of genetic variance due to selection (‘‘Bulmer effect’’), and for reduction of selection intensity due to finite population size and correlated index values of family members. Predefined information sources can be either switched on or off, according to the user’s needs. The number of traits is limited to a maximum of 20. Quantitative genetic research has resulted in a large amount of theory to predict selection response and rates of inBreeding of Livestock Breeding programs. Application of this theory in practical Livestock Breeding programs, however, is hampered by the lack of computer software that implements the available theory. Virtually all methods to predict responses of Breeding programs are based on selection index theory. After the basics of selection index theory were developed (Hazel 1943), further developments have aimed at, for example, the effect of selection on genetic (co)variances (Bulmer 1971), the effect of correlated index values on selection intensity (Meuwissen 1991), the effect of multistage selection (Tallis 1961; Young 1964), selection in overlapping generations (Meuwissen 1989), and prediction of selection response on BLUP Breeding values (Villanueva et al. 1993; Wray and Hill 1989). In addition, methods to predict rates of inBreeding in selection programs have recently been developed (Bijma et al. 2001; Bijma and Woolliams 2000; Woolliams and Bijma 2000). In this article, a computer program called SelAction is presented, which implements existing theory in order to provide a tool to predict selection response and rates of inBreeding in Livestock Breeding programs for a wide range of population structures and selection strategies. SelAction requires little computing time, allowing it to be used as an interactive optimization tool.