Journal articles on the topic 'Progeny merit'
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1
Allaire, F. R., and H. L. Barr. "Sire Selection Using Cow Traits to Improve Quadratic Merit in Progeny." Journal of Dairy Science 73, no. 6 (June 1990): 1625–30. http://dx.doi.org/10.3168/jds.s0022-0302(90)78833-9.
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SMITH, C., and J. RUANE. "USE OF SIB TESTING AS A SUPPLEMENT TO PROGENY TESTING TO IMPROVE THE GENETIC MERIT OF COMMERCIAL SEMEN IN DAIRY CATTLE." Canadian Journal of Animal Science 67, no. 4 (December 1, 1987): 985–90. http://dx.doi.org/10.4141/cjas87-103.
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Groups of sibs, sisters to bulls being bred for progeny testing, can be produced by multiple ovulation and embryo transfer (MOET). Sib tests are complete at 3 yr of age, and progeny tests when bulls are about 5.5–6 yr of age. The merit of commercial semen could be increased by using the bulls with the highest estimated breeding values from both the sib test group and the progeny test group rather than only from the latter. With current selection rates (20%) among progeny-tested bulls for commercial use, current genetic trend (0.1 SD units per year) in bulls and with the equivalent of 3–7 full sisters per bull, the relative genetic superiority of semen from the combined groups could be from 1.10 to 1.20 times that from the progeny-tested group alone. Key words: Embryo transfer, sib testing, progeny testing, commercial semen
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Hieber, Jordan K., Rachel L. Endecott, Jane A. Boles, and Jennifer M. Thomson. "Identification of Genomic Regions for Carcass Quality Traits within the American Simmental Association Carcass Merit Program." Animals 11, no. 2 (February 10, 2021): 471. http://dx.doi.org/10.3390/ani11020471.
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USDA quality and yield grade are primary driving forces for carcass value in the United States. Carcass improvements can be achieved by making selection decisions based on the results of genetic evaluations in the form of expected progeny differences (EPD), real-time ultrasound imaging, and physical evaluation of candidate breeding animals. In an effort to advance their ability to accurately predict the breeding value of potential sires for carcass traits, the American Simmental Association launched the Carcass Merit Program as a means to collect progeny sire group carcass information. All records were extracted from the American Simmental Association database. Progeny data were organized by sire family and progeny performance phenotypes were constructed. Sire genotypes were filtered, and a multi-locus mixed linear model was used to perform an association analysis on the genotype data, while correcting for cryptic relatedness and pedigree structure. Three chromosomes were found to have genome-wide significance and this conservative approach identified putative QTL in those regions. Three hundred ninety-three novel regions were identified across all traits, as well as 290 novel positional candidate genes. Correlations between carcass characteristics and maternal traits were less unfavorable than those previously reported.
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Burggraaf, V. T., and D. B. Lineham. "Effect of easy calving beef sires on the birth weight and growth of dairy beef cattle." NZGA: Research and Practice Series 16 (January 1, 2016): 329–32. http://dx.doi.org/10.33584/rps.16.2016.3250.
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The impact of using high genetic merit beef bulls in a dairy beef supply chain was compared to using unrecorded beef bulls. Dairy cows were inseminated with Ezicalve Hereford semen (high genetic merit for calving ease and growth), followed by natural mating with Ezicalve and unrecorded Hereford bulls. The resulting 186 progeny were monitored from birth to 2 years old. Ezicalve sired calves required no calving assistance and averaged 4 kg lighter at birth than those from unrecorded sires (P
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Hayes, B., R. K. Shepherd, and S. Newman. "Look ahead mate selection schemes for multi-breed beef populations." Animal Science 74, no. 1 (February 2002): 13–23. http://dx.doi.org/10.1017/s1357729800052206.
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AbstractLook ahead mate selection (LAMS) schemes have been proposed to improve longer-term genetic merit when both selection and crossbreeding are important. We investigate the performance of a LAMS scheme which includes both predicted progeny merit and predicted grandprogeny merit in a mate selection index (MSI). Simulation of a multi-breed beef population, with additive breeding values, direct and maternal breed effects and direct and maternal heterosis was used to compare response from the LAMS scheme to mate selection on progeny merit only (PROG), selection on estimated breeding value (EBV) followed by random mating (RAND) and a structured crossbreeding scheme (CROSS). An additional strategy, LAMS + CO, was similar to LAMS but included a negative weighting on the coancestry of selected animals in the MSI to reduce inbreeding. LAMS gave up to 3% greater response in generation eight than PROG, 4·5% greater response than RAND, and 15% greater response than CROSS. Results from LAMS + CO were very similar to LAMS but inbreeding was 11% less from LAMS + CO at generation eight. The advantage of LAMS and LAMS + CO over PROG in later generations was hypothesized to be the result of positive assortative mating and greater use of maternal effects. Evidence to support the hypothesis of assortative mating was a positive significant correlation of EBVs of mates (sires and dams) in LAMS and LAMS + CO but not in PROG. Strategies PROG, LAMS and LAMS + CO all created closed populations of animals with optimum composite breed proportions.
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Sutherland, R. A. "A note on calculating the benefit from replacing one breed by another." Animal Science 41, no. 2 (October 1985): 265–67. http://dx.doi.org/10.1017/s0003356100027975.
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ABSTRACTFormulae are derived to calculate the genetic merit of a commercial population during replacement of one breed by another, based on the rates of genetic change in the old and new breeds, the initial difference between the breeds, the lag between the first use of replacement stock and the appearance of their genes in commercial progeny and the effect of replacement on the old breed improvement scheme. By comparing the merit of the population with and without replacement the value of a change in breed can be assessed. The method is illustrated with an example from pig breeding.
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Meland, O. "Procedures of sire selection, sampling and application of new technology." BSAP Occasional Publication 19 (1995): 9–12. http://dx.doi.org/10.1017/s0263967x00031748.
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AbstractThe objective of any well designed progeny test programme is to identify those individuals that have inherited the favourable genes from his parents. Bulls that enter a progeny test programme have been highly selected on a set of selection criteria. The criteria vary among organizations based upon their breeding philosophy and their prediction of the future economic value of various traits. The accuracy of choosing among this highly selected group is quite low. Increasing the accuracy of selection before progeny testing is the greatest potential application of genetic marker technology. Markers associated with traits of importance can greatly enhance traditional selection methods by increasing the prospect of an individual having the desired characteristics. Genetic marker-assisted selection can greatly increase the actual genetic merit of traits of economic importance
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Shi, Junsong, Baohua Tan, Lvhua Luo, Zicong Li, Linjun Hong, Jie Yang, Gengyuan Cai, Enqin Zheng, Zhenfang Wu, and Ting Gu. "Assessment of the Growth and Reproductive Performance of Cloned Pietrain Boars." Animals 10, no. 11 (November 6, 2020): 2053. http://dx.doi.org/10.3390/ani10112053.
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How to maximize the use of the genetic merits of the high-ranking boars (also called superior ones) is a considerable question in the pig breeding industry, considering the money and time spent on selection. Somatic cell nuclear transfer (SCNT) is one of the potential ways to answer the question, which can be applied to produce clones with genetic resources of superior boar for the production of commercial pigs. For practical application, it is essential to investigate whether the clones and their progeny keep behaving better than the “normal boars”, considering that in vitro culture and transfer manipulation would cause a series of harmful effects to the development of clones. In this study, 59,061 cloned embryos were transferred into 250 recipient sows to produce the clones of superior Pietrain boars. The growth performance of 12 clones and 36 non-clones and the semen quality of 19 clones and 28 non-clones were compared. The reproductive performance of 21 clones and 25 non-clones were also tested. Furthermore, we made a comparison in the growth performance between 466 progeny of the clones and 822 progeny of the non-clones. Our results showed that no significant difference in semen quality and reproductive performance was observed between the clones and the non-clones, although the clones grew slower and exhibited smaller body size than the non-clones. The F1 progeny of the clones showed a greater growth rate than the non-clones. Our results demonstrated through the large animal population showed that SCNT manipulation resulted in a low growth rate and small body size, but the clones could normally produce F1 progeny with excellent growth traits to bring more economic benefits. Therefore, SCNT could be effective in enlarging the merit genetics of the superior boars and increasing the economic benefits in pig reproduction and breeding.
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TEEPKER, GEORG, and DAVID S. KELLER. "SELECTION OF SIRES ORIGINATING FROM A NUCLEUS BREEDING UNIT FOR USE IN A COMMERCIAL DAIRY POPULATION." Canadian Journal of Animal Science 69, no. 3 (September 1, 1989): 595–604. http://dx.doi.org/10.4141/cjas89-071.
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Bulls that originate from breeding schemes with extensive use of multiple ovulation and embryo transfer (MOET) can be selected on pedigree information, the performance of their contemporary female full- and half-sibs or based on a progeny test. Combined selection across groups of bulls with different sources of information is shown to be superior to selection of progeny tested bulls alone. The magnitude of the superiority for a given selection rate is determined by the differences in genetic merit between the groups and ranges from 5 to 65%. Depending on the annual genetic progress the majority of the bulls are selected either on pedigree or progeny information. The proportion of sib-tested bulls ranges from 9 to 23%. When breeding activities are concentrated in nucleus herds, possible genotype by environment interactions between performance in the test herd and in the commercial population have to be considered. Genotype by environment interactions increase the proportion of progeny tested sires that will be selected. However, the proportion of progeny tested sires used is reduced by genotype by environment interactions among the groups of a heterogenous commercial production environment. Key words: Embryo transfer, sire selection, genotype-by-environment interactions
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Carvalheiro, Roberto, Sandra Aidar de Queiroz, and Brian Kinghorn. "Optimum contribution selection using differential evolution." Revista Brasileira de Zootecnia 39, no. 7 (July 2010): 1429–36. http://dx.doi.org/10.1590/s1516-35982010000700005.
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A program to determine optimum contribution selection using differential evolution was developed. The objective function to be optimized was composed by the expected merit of the future progeny and the coancestry among selected parents. Simulated and real datasets of populations with overlapping generations were used to validate and test the performance of the program. The program was computationally efficient and feasible for practical applications. The expected consequences of using the program, in contrast to empirical procedures to control inbreeding and/or to selection based exclusively on expected genetic merit, would be the improvement of the selection response and a more effective control of inbreeding.
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Woolliams, J. A., and C. Smith. "The value of indicator traits in the genetic improvement of dairy cattle." Animal Production 46, no. 3 (June 1988): 333–45. http://dx.doi.org/10.1017/s0003356100018948.
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ABSTRACTThe value of indicator traits (7), such as physiological or biochemical traits in the genetic improvement of dairy cattle for milk yield (M) was studied. First, some corrections were made to the base rates of genetic change possible by improvement systems based on progeny testing and on multiple ovulation and embryo transfer (MOET), and on combinations of these. Efficient field progeny-testing systems can be competitive with current adult MOET nucleus herd schemes but juvenile MOET nucleus herd schemes offer substantial increases in rates of response. With high co-heritability, selection for the T alone may allow greater rates of response than those currently considered feasible using progeny testing. However, faster rates are obtained with combined selection. When breeding values are accurately measured by pedigree and performance records on M, as in the progeny test, the extra rates of response with combined selection may be small. Where breeding values are less accurately assessed, as in juvenile MOET nucleus schemes, the extra rates of response can be appreciable. For T with co-heritability (hMrGhT) of 0·27 and the CV for M from 0·15 to 0·20, response rates of 2·0 to 2·7% of the mean per year possible by traditional methods could be increased to 2·2 to 2·9% in progeny testing schemes, 2·3 to 3·1% and to 4·3 to 5·7% for adult and juvenile MOET nucleus schemes respectively.A possible useful indicator trait is blood urea nitrogen (BUN) measured in young animals after a short fast. Results from four experiments with calves having high or low genetic merit for M were summarized. The pooled co-heritability estimate was —0·27 (s.e. 0·05). With this, or even a more modest effect, BUN would be a useful indicator trait in selection for milk production. Its use in practice in high and low selection lines or in a section of the industry, would allow assessment of the merit of the method.
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JOHNSON, ER. "Genetic improvement in beef cattle using a progeny testing system based on carcase merit." Australian Veterinary Journal 73, no. 6 (June 1996): 225–32. http://dx.doi.org/10.1111/j.1751-0813.1996.tb10040.x.
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Crews, D. H. "The relationship between beef sire carcass EPD and progeny phenotype." Canadian Journal of Animal Science 82, no. 4 (December 1, 2002): 503–6. http://dx.doi.org/10.4141/a02-037.
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Carcass data from purebred steer (n = 207) and heifer (n = 66) progeny of 15 Charolais sires with carcass expected progeny differences (EPD) were used to quantify the relationship between sire EPD and progeny phenotype for hot carcass weight, fat thickness, muscle area, marbling score, and percent lean yield. The model included six slaughter date × sex subclasses, the linear effect of age at harvest (434 ± 18 d), and the appropriate sire EPD for each trait of interest. Differences of the regression coefficients from their theoretical expectation of one were tested using general linear models procedures. Sire EPD was positively (P < 0.0001) associated with progeny performance for hot carcass weight, fat thickness, muscle area, marbling score, and percent lean yield. For all traits, the regression coefficients were not different (P > 0.27) from one. Regression coefficients were 1.16 ± 0.41 kg, 1.27 ± 0.27 mm, 1.23 ± 0.23 cm2, 1.26 ± 0.23 score, and 0.84 ± 0.19% for hot carcass weight, fat thickness, muscle area, marbling score, and percent lean yield, respectively. These results suggest that carcass EPD for hot carcass weight, fat thickness, muscle area, marbling score, and percent lean yield were related to progeny differences at or near theoretical expectations. Selection for carcass merit using appropriate EPD would be expected to be successful. Key words: Beef cattle, carcass, expected progeny difference
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Weik, Franziska, Rebecca E. Hickson, Stephen T. Morris, Dorian J. Garrick, and Jason A. Archer. "Genetic Parameters for Growth, Ultrasound and Carcass Traits in New Zealand Beef Cattle and Their Correlations with Maternal Performance." Animals 12, no. 1 (December 23, 2021): 25. http://dx.doi.org/10.3390/ani12010025.
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Research has shown that enhancing finishing performance in beef cows is feasible; however, any adverse impact of selection strategies for finishing performance on the performance of the maternal herd should be taken into account. The aim of this research was to examine the inheritance of growth, ultrasound and carcass traits in finishing beef cattle and to evaluate their correlations with maternal performance traits. Data were collected from a nationwide progeny test on commercial New Zealand hill country farms comprising a total of 4473 beef cows and their progeny. Most finishing traits were moderately to highly heritable (0.28–0.58) with the exception of meat or fat colour and ossification (0.00–0.12). Ultrasound scan traits had high genetic correlations with corresponding traits measured at slaughter (rg = 0.53–0.95) and may be used as a selection tool for improved genetic merit of the beef carcass. Fat content determined via ultrasound scanning in the live animal or at slaughter in finishing cattle is positively genetically correlated with rebreeding performance (rg = 0.22–0.39) in female herd replacements and negatively correlated with mature cow live weight (rg = −0.40 to −0.19). Low-magnitude associations were observed between the genetic merit for carcass fat traits with body condition in mature cows.
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Ribeiro, Virgínia Mara Pereira, Fernanda Albuquerque Merlo, Gabriela Canabrava Gouveia, Larissa Kretli Winkelstroter, Luíza Rodrigues Alves Abreu, Marcos Vinícius Gualberto Barbosa da Silva, João Cláudio do Carmo Panetto, Leandro de Carvalho Paiva, Marcello de Aguiar Rodrigues Cembranelli, and Fabio Luiz Buranelo Toral. "Genetic analysis of productive and reproductive traits in multiple-breed dairy cattle populations." Pesquisa Agropecuária Brasileira 52, no. 11 (November 2017): 1109–17. http://dx.doi.org/10.1590/s0100-204x2017001100017.
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Abstract: The objective of this work was to determine whether the random regression model using linear splines (RRMLS) is suitable to estimate the genetic parameters for productive and reproductive traits of a multiple-breed dairy cattle population, as well as to investigate the effect of the genetic group of the progeny on the genetic merit of the sire. The multiple-trait model (MTM) and the RRMLS with one knot fitted for every genetic group were used to obtain the genetic parameters. Records of 1/2 Holstein + 1/2 Gyr (1/2HG), 5/8 Holstein + 3/8 Gyr (5/8HG), and 3/4 Holstein + 1/4 Gyr (3/4HG) crossbreed dams were considered. The RRMLS showed better fitting. The additive and residual variances estimated by the MTM and the RRMLS were similar. Heritability varied from 0.20 to 0.33 for age at first calving, from 0.09 to 0.22 for first lactation length, and from 0.15 to 0.35 for first lactation 305-day milk yield, according to the genetic composition of the dams. The RRMLS is suitable to estimate the genetic parameters for productive and reproductive traits of multiple-breed dairy cattle populations. The genetic merit of the sires is affected by the genetic group of the progeny by which they are evaluated.
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McGuirk, B. J., J. Smith, and R. Mrode. "The use of pedigree estimates of genetic merit to predict progeny performance of Holstein Friesian bulls tested in the UK." Proceedings of the British Society of Animal Science 1997 (1997): 26. http://dx.doi.org/10.1017/s1752756200594678.
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Over the past 10 years, dairy breeding in the United Kingdom has switched from British Friesian to the North American type Holstein. Many of the bulls entering progeny testing in the UK in that period were sourced from overseas bull mothers, especially from the US. The aim of this study was to compare current predictions of the genetic merit of those bulls, using pedigree information, with the performance of their UK daughters.
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Danusevičius, Darius, and D. Lindgren. "Progeny Testing Preceded by Phenotypic Pre-selection – Timing Considerations." Silvae Genetica 53, no. 1-6 (December 1, 2004): 20–26. http://dx.doi.org/10.1515/sg-2004-0004.
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Abstract Progeny-testing is a common element in tree breeding. It takes long time until trees reach the sexual maturity. That time could be used for field testing followed by progeny-test of the selected phenotypes (two-stage strategy), or the time until mating could be reduced by forcing early flowering (singlestage strategy). Benefit of phenotypic pre-selection followed by progeny testing in long-term breeding was assessed as a function of the age at the pre-selection by the aid of a deterministic tree breeding simulator. As a criterion of goodness of a breeding program, annual progress in group merit (GM/Y-refers to the rate of change in the average of genetic gain and gene diversity) at a total budget constraint was used. For simplicity, a long-term program with balanced selection was studied. Scenarios with different genetic parameters, cost and time components were evaluated and optimised for resource allocation. At the optimum age of mating for progeny test, two-stage Phenotype/ Progeny strategy generated higher GM/Y than singlestage Progeny strategy at the age of mating for progeny test equal to three years, except for a typical scenario with weak JM correlation, low heritability and long rotation time. High heritability, short rotation and strong J-M genetic correlation favoured phenotypic pre-selection. Optimum age for phenotypic pre-selection varied from 6 to 17 years and the percentage of GM/Y lost in comparison to the maximum due to delay of mating for the progeny test until age 15 and 25 years ranged from 0 to 14% and from 1 to 29%, respectively. In the case of low heritability, long rotation, low J-M correlation, high cost for cycling and low budget, early mating age would bring little benefit if compared to mating at the optimum age. We suggest that, in long-term breeding based on progeny testing, investment in phenotypic pre-selection is more beneficial than investment to achieve early flowering to initiate the progeny test early.
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Nault, J. R., J. F. Manville, and T. S. Sahota. "Spruce terpenes: expression and weevil resistance." Canadian Journal of Forest Research 29, no. 6 (June 1, 1999): 761–67. http://dx.doi.org/10.1139/x99-053.
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White spruce (Picea glauca (Moench) Voss) and Engelmann spruce (Picea engelmannii Parry) parent trees were selected that were rated as highly resistant or highly susceptible to white pine weevil (Pissodes strobi Peck) attack, based upon attack measurements on their open-pollinated progeny. For each parent, levels of terpenes or other volatiles in leaf and bark were highly correlated within ramets and highly variable within progeny. For the ramets, levels of individual terpenes could not be used to predict resistance class because of their large variability. A multivariate model developed using the terpenes showing the greatest differences between resistant classes was found to predict the resistance levels of the original ortets well, with 15 of 16 parent trees correctly predicted using either leaf or bark chemicals. These models failed to predict the resistance level of the open-pollinated progeny. Discriminant analysis was also attempted by dividing the ramet data into independent sets and using each set to predict the other. Again, prediction was no better than chance. We conclude that there is no merit in using terpenes as a selection tool to find resistant genotypes amongst white and Engelmann spruce populations.
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Nalaila, Sungael, Paul Stothard, Stephen Moore, Zhiquan Wang, and Changxi Li. "Whole genome fine mapping of quantitative trait loci for ultrasound and carcass merit traits in beef cattle." Canadian Journal of Animal Science 91, no. 1 (March 2011): 61–73. http://dx.doi.org/10.4141/cjas10007.
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Nalaila, S. M., Stothard, P., Moore, S. S., Wang, Z. and Li, C. 2011. Whole genome fine mapping of quantitative trait loci for ultrasound and carcass merit traits in beef cattle. Can. J. Anim. Sci. 91: 61–73. Quantitative trait loci (QTL) mapped to large chromosomal regions have limited utility as DNA markers for marker-assisted selection (MAS) and are less informative as a reference for the identification of the underlying causative quantitative trait nucleotides (QTN). The objective of this study was to conduct a whole genome fine mapping of QTL for ultrasound and carcass merit traits in beef cattle using a greater density of single nucleotide polymorphism (SNP) markers, and to identify SNP markers within the QTL regions that are associated with the traits. A total of 418 steers from 28 sires were used in this study with nine ultrasound and seven carcass merit traits that were collected as part of a feedlot trial conducted from 2003 to 2005 at the University of Alberta Kinsella ranch. Sires and their progeny were genotyped for a total of 4592 SNP markers distributed across all 29 bovine autosomes (BTA). Across-family analyses detected 12 QTL for five ultrasound traits on nine chromosomes and 18 QTL for six carcass merit traits on 10 chromosomes (P<0.05). Within-family analyses identified 78 significant QTL for nine ultrasound and seven carcass merit traits (P<0.01). The use of a denser panel of SNP markers allowed fine mapping of QTL to smaller chromosomal regions ranging from 0.6 to 11 cM compared with relatively larger QTL regions of 4 to 24 cM reported in previous studies. Furthermore, single SNP marker association analyses identified 22 SNPs that were significantly associated with three ultrasound and four carcass merit traits under 12 QTL regions (P<0.05). These identified SNP markers significantly associated with the traits under the fine mapped QTL regions provide genomic tools for potential application of MAS and a reference to assist with the identification of QTN causing variations in ultrasound and carcass merit traits in beef cattle.
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Willam, Alfons, Christa Egger-Danner, Johann Sölkner, and Erwin Gierzinger. "Optimization of progeny testing schemes when functional traits play an important role in the total merit index." Livestock Production Science 77, no. 2-3 (November 2002): 217–25. http://dx.doi.org/10.1016/s0301-6226(02)00041-6.
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Clarke, A. M., M. J. Drennan, M. McGee, D. A. Kenny, R. D. Evans, and D. P. Berry. "Intake, growth and carcass traits in male progeny of sires differing in genetic merit for beef production." Animal 3, no. 6 (2009): 791–801. http://dx.doi.org/10.1017/s1751731109004200.
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Persaud, P., G. Simm, H. Parkinson, and W. G. Hill. "Relationship between sires transmitting ability and daughter performance in a high yielding dairy herd." Proceedings of the British Society of Animal Production (1972) 1990 (March 1990): 11. http://dx.doi.org/10.1017/s0308229600017955.
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In the UK feed accounts for 0.80 to 0.90 of the variable costs of dairy production. In recent years the imposition of milk quotas has served to emphasise the importance of efficient milk and milk solids production. In field progeny testing schemes, sires’ transmitting ability or breeding value can be predicted for milk production traits, but not for feed Intake or for efficiency of milk production. As breeders continue to select on production traits, using sires of high genetic merit for production, the important question then is, ‘what correlated response occurs in gross efficiency and in feed consumption?’.
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RATHOD, B. S., M. P. PATEL, A. B. CHAUDHARI, Y. M. GAMI, and H. H. PANCHASARA. "Conservation and improvement of Kankrej cattle (Bos indicus): Status vis-Ã -vis strategies." Indian Journal of Animal Sciences 90, no. 8 (January 6, 2021): 1130–35. http://dx.doi.org/10.56093/ijans.v90i8.109292.
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The present study was conducted at Livestock Research Station, to compare performance of Kankrej cattle at farm and field condition, and to suggest strategies for the overall improvement of this prestigious breed. The average lactation yield (lit.), standard lactation (lit.), fat percentage, age at first calving and calving interval in the farmers herd was 1669.96±12.24 (1523), 1751.23±12.94 (617), 4.13±0.03 (617), 1464.08±18.41 (260) and 549.93±8.61 (387), respectively during the initial phage of progeny testing program initiated by station and the performance of migratory herd was 2.64 litre (wet average). While, the average lactation yield (lit.), standard lactation (lit.), fat percentage, age at first calving and calving interval at station was 2682.27±126.71 (59), 2501.15±87.72 (59), 4.08±0.09 (49), 1218.42±35.27 (12) and 435.73±13.94 (36), respectively (Elite herd, Anonymous 2018). The lactation yield of daughters born under the progeny testing program was 2050.29±119.20 (104) litres. Looking to the performance gap between the herd maintained at station, field and pastoralist indicates wide scope for the genetic improvement in Kankrej breed by following strict breeding strategies which are discussed in this paper. Conclusively, intensive selective breeding with the use of artificial insemination technology at large scale and progeny testing with precise recording at small scale will solve the purpose in the non-migratory population while, supply of high genetic merit male calf or proven bull’s male calf to the Maldharis having migratory population.
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Marsh, S. P., and D. Pullar. "Production and carcase traits of progeny sired by Limousin bulls with high and below average beef values." Proceedings of the British Society of Animal Science 2002 (2002): 193. http://dx.doi.org/10.1017/s1752756200008498.
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Pedigree beef cattle breeders who record with the Signet Beefbreeder service have their records analysed by a Best Linear Unbiased Prediction (BLUP). BLUP uses the records (weights and measurements) that have been recorded, for the individual and related animals, to determine the likely performance of an individual’s progeny. The analysis calculates Estimated Breeding Values (EBVs) for several traits of economic value, which are the assessments of genetic merit of the animal. EBVs are calculated for 200 day weight, 400 day weight, fat depth, muscle depth and muscle score. An economic assessment, or index, is calculated using this data, called the Beef Value. The objective of this experiment was to compare the performance of dairy-bred beef calves sired by bulls with either a high (top 10% of breed) or below average (bottom 25%) Beef Value.
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Lee, A. J., A. J. McAllister, C. Y. Lin, and T. R. Batra. "A comparison of Canadian Holstein bulls with those in the National Cooperative Dairy Cattle Breeding Project." Canadian Journal of Animal Science 74, no. 2 (June 1, 1994): 217–21. http://dx.doi.org/10.4141/cjas94-030.
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Direct comparisons of industry Holsteins to project Holsteins and to crossbred C lines in the National Cooperative Dairy Cattle Breeding Project were made at Ottawa. The industry Holstein group was composed of the eight Holstein young bulls in AI units awaiting proof in 1984, which had the highest pedigree indexes for protein yield. They were mated to both Holstein and crossbred C line females at Ottawa. Project Holstein and C line bulls were mated to females of their respective lines. Matings within the crossbred C line resulted in greater calving ease and fewer retained placentae (P < 0.05) than matings of Holsteins to either Holstein or C line females. Crossbred C line cattle were smaller and produced less milk, fat and protein in the first 24 wk of first lactation than Holsteins. Project and industry Holstein progeny were equivalent in early first lactation, milk fat and protein yield, but progeny of industry bulls were larger at all ages. Selection for protein yield over 14 yr in a 300 milking cow population produced young bulls of comparable genetic merit for production traits to that of intensely pedigree selected industry bulls. Key words: Holstein, selection, crossbred, yield, heifer
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Brown, Austin R., Julie Finzel, Rosie Busch, Morgan Doran, John Harper, Dan Macon, Rebecca Ozeran, and Alison L. Van Eenennaam. "PSIII-2 Late-Breaking: Collaboration to Demonstrate the Potential Use and Value of Electronic Identification and DNA Testing in the Sheep Industry." Journal of Animal Science 100, Supplement_4 (October 22, 2022): 33–34. http://dx.doi.org/10.1093/jas/skac313.048.
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Abstract The dearth of individual performance records derived from an extensively driven production system coupled with the impracticality of utilizing reproductive technologies makes commercial genetic improvement challenging in small ruminants. We collaborated with five producers throughout California to assess how electronic ID (EID) and genetic testing could inform ram selection. Our objective was to determine how the data collected from these technologies could augment genetic improvement on commercial ranches. Familiarity and use of EID tags on ranches at the start of the research varied; thus, allowing for a qualitative reflection on the participant's perceptions of the usefulness of this technology. Ear notch samples were collected and EID ear tags were placed in 2,963 sheep; 305 rams, and 2,658 of their potential progeny. We partnered with Superior Farms (Dixon, CA) to genotype the animals using their Flock54 single nucleotide polymorphism panel which contains 956 markers for assigning parentage, and includes markers linked to quantitative trait loci and/or known single gene causative markers to aid in disease management. SNP data was used to assign paternity and determine sire prolificacy. A total of 524 carcass samples from ram lambs from two of the ranches were processed at Superior Farms' plant and assessed with a USDA-approved camera grading system (e+v, Oranienburg, Germany) that matches EID’s to carcass data. Progeny contemporary group deviations were calculated for hot carcass weight, yield grade, and ovine cutability calculation (OCC) which predicts the yield of edible product on the carcass. The average number of lambs per sire born at each ranch and the mean OCC of the progeny for each sire were compared using a one-way analysis of variance. There was a significant ranch effect on the average progeny number per ram (P < 0.05). The ranch with the lowest ram to ewe ratio (1:10) also has the lowest average progeny per ram and the ranch with the greatest ratio (1:50) has the most progeny per ram. There was a large range in the number of lambs per sire (0-135) within each ranch. There was a significant sire effect (P < 0.05) on average OCC within each progeny contemporary group, meaning some sires were producing offspring with significantly more marketable meat. The use of EIDs in combination with genetic testing, allowed for the collection of individual progeny performance data. This provided insight into sire performance and identified prolific sires that were also producing lambs with superior carcass merit. Producers could use this information to select for high-performing rams; however, there is an unavoidable delay between ram turnout and the collection of progeny carcass data. This limits the practical utility of these data and reinforces the value of having estimated breeding values available at ram purchase to select genetically superior rams.
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Bullock, K. D., F. A. Thrift, D. K. Aaron, and J. K. Bertrand. "Relationship between a bull's parental genetic merit difference and subsequent progeny trait variability in Angus, Gelbvieh, and Limousin cattle." Journal of Animal Science 78, no. 10 (2000): 2540. http://dx.doi.org/10.2527/2000.78102540x.
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Haley, C. S., Y. Gu, and R. Thompson. "Genetic estimates for growth and carcass traits of pigs from closed herds on restricted feeding." Proceedings of the British Society of Animal Production (1972) 1989 (March 1989): 15. http://dx.doi.org/10.1017/s0308229600010163.
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The major components of economic performance in pigs - growth rate, feed conversion ratio and carcass merit - have been the targets of selection for a number of years in the closed herds of breeding companies. Over the past 20 years substantial progress has been made for these traits. Declining fatness in closed herds may lead to a decline in the genetic variation for growth and carcass traits, and thus reduced opportunities for selection. This could arise either as genetic variation is exhausted in closed lines, or as physiological selection limits are approached. In this study genetic variation in closed lines with a history of selection for growth and carcass traits was investigated.The data were collected from two closed lines between 1979 and 1985 by the Cotswold Pig Development Company Ltd. The two lines were housed on a single farm in the same environment and had a history of selection based upon an index of growth rate and fat depths. There were 167 sires with 4722 male and 5386 female progeny in line A, a synthetic breed based largely upon the Landrace breed, and 164 sires with 4160 male and 3887 female progeny in line B, derived from the Large White breed.
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Nanda, Rishi, Anjali k, Senthamilan S, Gurudutt Doneriya, Meeti Punetha, G. Singh, and V. S. Chouhan. "Ovum Pick-up in Ruminants." Animal Reproduction Update 1, no. 1 (2021): 46–50. http://dx.doi.org/10.48165/aru.2021.1206.
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Ovum Pick-up (OPU) associated with IVF has become advancement in ruminant reproduction. Transvaginal OPU guided by ultrasound is a non- invasive technique for cumulating oocytes from Graafian and antral follicles from live donor animals especially from cattle. Laparoscopic OPU in combination with in vitro embryo production increases the possibility of obtaining viable offspring in small ruminants. OPU does not impede with the usual reproduction and production performance of the donor animals and can be apply in various physiological states and circumstances of animals like different ages and reproductive disorders. The persistent collection of oocytes through OPU techniques concedes us to acquire the highest possible progeny of animals with merit genetic value, genetic improvement and advancement in animal selection. Here, we are presenting an overview of OPU from ruminants with factors affecting their outcome.
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Coleman, Lucy, Penny Back, Hugh Blair, Nicolas López-Villalobos, and Rebecca Hickson. "Sire Effects on Birth Weight, Gestation Length, and Pre-Weaning Growth of Beef-Cross-Dairy Calves: A Case Study in New Zealand." Dairy 2, no. 3 (July 23, 2021): 385–95. http://dx.doi.org/10.3390/dairy2030030.
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Production of beef-cross-dairy calves from dairy cows increases the value of non-replacement calves born to the dairy herd. The use of beef-breed sires may impact on calf birth weight, gestation length and pre-weaning growth rate of calves, which in turn influences the profitability of the dairy farm. The aim of this case study was to compare the birth weight, gestation length, and pre-weaning growth of progeny born to mixed-aged dairy cows on a single farm which were artificially bred to a selection of Angus and Hereford bulls, typical of those used over dairy herds in New Zealand. The birth weight, gestation length and pre-weaning growth of 980 calves sired by 65 sires were compared. Mean progeny birth weight (range 33.3–41.4 kg), gestation length (range 276.1–288.6 days), age at weaning (range 70.3–88.3 days) and pre-weaning ADG (range 0.63–0.76 kg/d) differed among sires (p < 0.001). There was a negative genetic correlation (−0.31) and positive phenotypic correlation (0.36) between gestation length and birth weight. Age at weaning was negatively correlated with birth weight (genetic: −0.56, phenotypic: −0.57). Bulls used in this study, and other bulls with similar genetic merit for birth weight and gestation length would be suitable for mating mixed-aged dairy cows in New Zealand.
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Pryce, J. E., G. Simm, R. F. Veerkamp, and J. D. Oldham. "Genotype by nutrition interactions from Langhill dairy cows in three lactations." Proceedings of the British Society of Animal Science 1999 (1999): 200. http://dx.doi.org/10.1017/s1752756200003550.
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The economic pressures on the dairy industry may force more farmers to consider reducing the amount of concentrates fed to cows in order to keep costs down. We have been testing whether the long-term performance of daughters of sires progeny tested in high concentrate systems maintain their advantage over cows of average genetic merit when managed in a lower input feeding system. This paper extends the scope of our initial report (Chalmers et al., 1997) and includes data on reproductive performance.Data were from Holstein-Friesian cows managed at the Langhill Dairy Cattle Research Centre. Sires of the Selection (S) line are among the highest available in the UK for predicted transmitting abilities of weight of fat plus protein (PTA F+P). Sires of Control (C) line cows are about UK average for PTA F+P.
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Swanson, G. J. T., H. Joanne Bellamy, and G. Oliver. "A Comparison of Methods to Convert Foreign Progeny Test Evaluations to Approximate United Kingdom Improved Contemporary Comparison Equivalents (Friesian/Holstein)." Proceedings of the British Society of Animal Production (1972) 1988 (March 1988): 112. http://dx.doi.org/10.1017/s0308229600017505.
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A major problem facing breeders interested in using bulls from other populations is that the foreign bull evaluations cannot be directly compared with the evaluations produced in the United Kingdom (UK). This is due to differences in the units of measurement, the base against which all bulls are compared and the method used to express the merit of the bulls. In order that selection is possible on an equal basis, it is necessary to be able to convert bull evaluations from the scale used in the country of export to that used in the importing country.The general formula used to convert evaluations is of the form Y = a + bX where Y is the converted evaluation, X is the evaluation in the exporting country, a is the difference between the bases used for bull evaluations and b is the factor to take account of the differences in scale.
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Rosales Nieto, C. A., M. B. Ferguson, C. A. Macleay, J. R. Briegel, D. A. Wood, G. B. Martin, R. Bencini, and A. N. Thompson. "Milk production and composition, and progeny performance in young ewes with high merit for rapid growth and muscle and fat accumulation." Animal 12, no. 11 (2018): 2292–99. http://dx.doi.org/10.1017/s1751731118000307.
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Lewis, R. M., G. Simm, W. S. Dingwall, and S. V. Murphy. "Selection for lean growth in terminal sire sheep to produce leaner crossbred progeny." Animal Science 63, no. 1 (August 1996): 133–42. http://dx.doi.org/10.1017/s1357729800028368.
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AbstractA progeny test was designed to test whether genetic superiority for lean growth in terminal sires is expressed in their crossbred progeny when reared in a different environment. In each of 1986, 1987 and 1988, 22 Suffolk rams were chosen at the conclusion of an indoor, intensive performance testing regime on an index score that rated their propensity for lean growth, while constraining fat growth, at 150 days of age. Half of these rams had high index scores and half had low index scores. In each year, around 400 crossbred ewes were mated and the resulting lambs were finished on grass to one of three target live weights (35·5, 41·5, and 47·0 kg). Shoulder joints were dissected on 1505 lambs whilst half carcasses were dissected on 372 lambs. Double sampling techniques were then used to combine the data from the shoulder and half carcass more precisely to predict the lean, fat and bone weight and content in the carcass.With each increment in target live weight, the carcasses were heavier and had proportionally more fat. The progeny of high index rams consistently had 144 (s.e.d. 32) g more lean, 66 (s.e.d. 12) g more bone, and 186 (s.e.d. 32) g less fat in a 19·7 (s.e. 0·5) kg carcass than progeny of low index rams, from the double sampling procedure. This improved composition reflected a correlated response to ram selection on the index. One standard deviation increase in ram index score corresponded to 51 g more lean and 64 g less fat in the 20 kg carcass of their crossbred offspring. These results show that the use of rams with high lean index scores in a crossbreeding system will produce lambs with leaner carcasses. Visual appraisals of fat and conformation both increased as the weight and, consequently, the fatness of the carcass increased. Offspring of high index rams were consistently scored as less fat than offspring of low index rams. But, at the lighter weights (35·5 and 41·5 kg), they were also scored lower in conformation — in effect, a penalty for their higher genetic merit for lean growth.
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Kutlu, Hasan Rüştü, and Uğur Serbester. "Ruminant Beslemede Son Gelişmeler." Turkish Journal of Agriculture - Food Science and Technology 2, no. 1 (January 11, 2014): 18. http://dx.doi.org/10.24925/turjaf.v2i1.18-37.37.
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One of the most industrialized animal production branches of ruminant production successfully requires a blending of theoretical knowledge of nutritional principles with practical stockmanship, maintaining health and dealing with numbers. It is well known that high yielding, dairy cows, require balanced diet with adequate nutrients for yielding. This is not provided with only a few feedstuffs. Milk production in dairy cows is related to the improvements in genetic merit of farm animals and also developments in feed science, feed technology and animal nutrition. In particular, feeds and feed technology studies associated with sustainability, economical perspectives and product quality in the last decade have been in advance. In the present work, recent advances in feed sources and feed technology, minerals (macro and trace minerals ), vitamins and amino acids, feed additives (antibiotics alternative growth stimulants, rumen modulator, organic acids, antioxidants, enzymes, plant extracts), nutrition-products (meat-milk-progeny) quality and functional food production (milk, meat) nutrition-reproduction, nutrition-animal health, nutrition-environmental temperature, nutrition-global warming were evaluated.
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Conington, J., G. Simm, S. Bishop, and A. Waterhouse. "Environmental and genetic influences on hill lamb performance." Proceedings of the British Society of Animal Production (1972) 1993 (March 1993): 36. http://dx.doi.org/10.1017/s0308229600023655.
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Fat reserves are often perceived as essential to the hill ewe, so that they may be mobilised in adverse conditions to meet energy deficits. However, deer and some primitive breeds of sheep are remarkably lean animals which survive and thrive/reproduce in such conditions. The consequence of using genetically lean sheep in hill environments to meet the ultimate goal of reducing carcass fat is largely unknown. It is possible that the ewes' maternal ability, performance and welfare are in some way compromised. An SAC/IAPGR Hill Sheep Project was instigated: (1) to investigate if selection for differing fat levels under intensive concentrate feeding has any effect on progeny reared in extensive situations; (2) to determine the relationships between growth, carcass, reproduction, wool and survival traits, and to investigate which traits would be useful in an index of overall merit; and (3) to investigate if selection for improved carcass and growth characteristics affect maternal performance and survivability.
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McGuirk, B. J. "Effects of weaner nutrition on sire and flock rankings: a re-analysis of historical data." Animal Production Science 49, no. 12 (2009): 1100. http://dx.doi.org/10.1071/an09032.
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Early work in the 1950s on the wool growth response of sheep from diverse genotypes for wool production in response to varying planes of nutrition at pasture did not show the significant genotype × environment interactions exhibited in later pen studies with the same or very similar genotypes. However, this early study used a log-transformation on all traits to adjust nutritional effects for scale. Re-analysis of the original (i.e. untransformed) data shows that superior genetic merit for clean fleece weight, different sire progeny groups or selection flocks is more apparent when hogget ewes are fed a high plane of nutrition at pasture. However, only in the case of flocks was the interaction statistically significant, and this interaction was insignificant when data were either log-transformed, or when an appropriate test that accounts for scale-type effects was applied. When left untransformed, the data are, thus, in agreement with the subsequent pen studies that examined data on untransformed clean wool production.
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Shahjahan, Md, Asma Khatun, Sumya Khatun, Md Mahbubul Hoque, Sohrab Hossain, Quazi M. Emdadul Huque, Tabith M. Awal, and Abdul Awal Mintoo. "Study on growth traits at weaning and yearling stages of indigenous and F1 crossbred buffalo in Bangladesh." Asian Journal of Medical and Biological Research 3, no. 4 (January 30, 2018): 499–503. http://dx.doi.org/10.3329/ajmbr.v3i4.35341.
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This study was planned to clarify the variation of body weight and average daily gain traits in both indigenous and F1 crossbreed (Local×Mediterranean) buffalo at weaning (sixth month) and yearling stages (twelfth month). Data were collected from 33 indigenous and 35 F1 crossbred buffalo progeny during the period of 2011 to 2014 with intensive management system at Research and Development farm of Lal Teer Livestock Limited in Bangladesh. The gathered data were analyzed using general linear model (GLM) and independent sample t test. The effect of parity, sex, season and breeding year on body weight and average daily gain were observed where significant values found in breeding period (p <0.01) of crossbred buffalo for body weight. It might be the reason of crossbreeding to indigenous buffalo cows using imported semen with better genetic merit. The parity (p <0.05), season (p <0.05) and breeding period (p <0.01) were also significant for average daily gain measurement which suggesting environmental adaptability beside additive genetic effects. Body weights were measured at weaning and yearling stages for both local (113 to 195 kg) and F1 crossbred (144 to 220 kg) buffalo progeny to screen the elite offspring for the Genetic Farm and Bull station. Similarly, average daily gain observed 469 to 457 g and 600 to 506 g at the previously mentioned two stages for both local and F1 buffalos, respectively. It was observed that studied traits were comparatively better in F1 buffalo progeny than indigenous. The comparison of average daily weight gains between indigenous and F1 buffalos at weaning and yearling periods showed significant differences for body weight (p <0.001) and average daily gain (p <0.05), respectively. It is concluded that genetic gain might be possible in local buffalo population by grading up process which could switch the traditional buffalo rearing to commercial level as well as meeting the nutritional demand of country people.Asian J. Med. Biol. Res. December 2017, 3(4): 499-503
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Clarke, A. M., M. J. Drennan, M. McGee, D. A. Kenny, R. D. Evans, and D. P. Berry. "Live animal measurements, carcass composition and plasma hormone and metabolite concentrations in male progeny of sires differing in genetic merit for beef production." Animal 3, no. 7 (2009): 933–45. http://dx.doi.org/10.1017/s1751731109004327.
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Skrzyszowska, Maria, and Marcin Samiec. "Generating Cloned Goats by Somatic Cell Nuclear Transfer—Molecular Determinants and Application to Transgenics and Biomedicine." International Journal of Molecular Sciences 22, no. 14 (July 13, 2021): 7490. http://dx.doi.org/10.3390/ijms22147490.
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The domestic goat (Capra aegagrus hircus), a mammalian species with high genetic merit for production of milk and meat, can be a tremendously valuable tool for transgenic research. This research is focused on the production and multiplication of genetically engineered or genome-edited cloned specimens by applying somatic cell nuclear transfer (SCNT), which is a dynamically developing assisted reproductive technology (ART). The efficiency of generating the SCNT-derived embryos, conceptuses, and progeny in goats was found to be determined by a variety of factors controlling the biological, molecular, and epigenetic events. On the one hand, the pivotal objective of our paper was to demonstrate the progress and the state-of-the-art achievements related to the innovative and highly efficient solutions used for the creation of transgenic cloned does and bucks. On the other hand, this review seeks to highlight not only current goals and obstacles but also future challenges to be faced by the approaches applied to propagate genetically modified SCNT-derived goats for the purposes of pharmacology, biomedicine, nutritional biotechnology, the agri-food industry, and modern livestock breeding.
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Shackell, Nancy L., and Roger W. Doyle. "Scale Morphology as an Index of Developmental Stability and Stress Resistance of Tilapia (Oreochromis niloticus)." Canadian Journal of Fisheries and Aquatic Sciences 48, no. 9 (September 1, 1991): 1662–69. http://dx.doi.org/10.1139/f91-197.
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Growth and the stabilities of growth and development were examined in inbred, outbred, and interstrain hybrid lines of tilapia (Oreochromus niloticus) under two diet regimes. Developmental stability was quantified as the inverse of the number of deformed scale circuli (calcified ridges). Growth stability was measured as the inverse of the individual variability of circulus spacing (circulus spacing is an indirect measure of growth rate). Each line was fed an alternating diet of low-protein rice bran and high-protein commercial pellet or a constant diet of commercial pellet. Diet regime had a significant effect on growth, developmental stability, and growth stability. Genetic composition of line had a significant effect only on developmental stability. Inbred lines had lower developmental stabilities than outbred lines. Hybrid progeny had higher developmental stability than the average of the parent strain values. Faster growing individuals had higher developmental and growth stabilities and lower growth stabilities (only within the commercial pellet regime). Composite indices of "merit" can be constructed by combining the variables, according to the correlations among variables and breeding objectives.
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Sather, A. P., and S. D. M. Jones. "The effect of genotype on feedlot performance, carcass composition, and lean meat quality from commercial pigs." Canadian Journal of Animal Science 76, no. 4 (December 1, 1996): 507–16. http://dx.doi.org/10.4141/cjas96-077.
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A total of 60 female and 54 castrated male progeny of commercial Landrace × Large White F1 sows, backcrossed to Landrace or Large White boars, were slaughtered at an average liveweight of 102 kg. Four same-sex pigs were penned together. Large White sires were homozygous normal (NN) but Landrace sires were heterozygous carriers (Nn), at the halothane locus. Progeny genotypes at the halothane locus were determined by a DNA probe. Barrows grew 136 g d−1 faster (P < 0.0001), reaching market weight 13 d sooner (P < 0.0001) but with 3.2 mm more average back-fat (P < 0.0001) than gilts. Both sexes had similar feed requirements (P = 0.1221). Landrace and Large White-sired pigs had similar growth rate (P = 0.6458) and feed requirements (P = 0.9354), but Large White-sired pigs had 1.33 mm less grade fat thickness (P = 0.0131) and 1.72 more muscle depth (P = 0.0218) than Landrace-sired pigs. Nn pigs required 7 d longer (P < 0.0001) and 22 kg (P = 0.0393) more total feed to reach market weight than NN pigs, but they had 2.6 mm greater muscle depth (P = 0.0008) and had 1% greater commercial lean yield (P = 0.0291). However, meat quality of Nn pigs was reduced when compared with NN pigs. For example, colour reflectance and drip loss were higher (P < 0.0001) and soluble protein was lower (P < 0.0001) among the Nn pigs which also had less intrasmuscular fat (P = 0.0184). The results emphasize that the increased value of the carcass from Nn pigs may be offset by reduced feedlot performance and reduced meat quality, and questions the merit of the use of halothane gene to improve production efficiency in the commercial market. Key words: Swine production, halothane gene, breed effect, Landrace, Large White
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Marshall, K., J. H. J. van der Werf, and J. Henshall. "Exploring major gene-marker phase-typing strategies in marker-assisted selection schemes." Animal Science 78, no. 2 (April 2004): 213–27. http://dx.doi.org/10.1017/s135772980005400x.
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AbstractMajor gene-marker phase is generally assumed to be family specific. This has the consequence in relation to marker-assisted selection (MAS) that phase information about each family may need to be collected through progeny testing, which could represent a substantial cost. This paper examines the effect of different policies in relation to major gene-marker phase-typing on response to MAS. The different policies considered varied in the criteria by which individuals were selected for phase-typing, the number of individuals phase-typed, and the frequency of establishing phase. Stochastic simulation of a closed breeding nucleus, with either high or low levels of inbreeding and undergoing selection for two traits, was utilized. Total response under MAS was lower than that under genotypic assisted selection (GAS) for all phase-typing policies. For example, additional gains of 70% under GAS, achieved in year 1 and in comparison with non-MAS, corresponded to additional gains of 43% and 15% under MAS for linkage distances of 1 cM and 20 cM, respectively. The different phase-typing policies examined in relation to MAS did not have any effect on total response, although there were small effects on major gene response. For breeding nuclei with either level of inbreeding, higher major gene response was achieved when phase-typed sires were selected on the basis of high ranking for genetic merit rather than connectivity to the other selection candidates. Further, increasing the number of males phase-typed within any year did not increase the rate of major gene response, although phase-typing in more years was favourable for the large linkage distance. An overall conclusion of this study is that additional gain could be achieved under MAS within a closed nucleus when progeny testing to determine major gene-marker phase was limited to from one to a few individuals.
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Bertrand, Joseph Keith. "Using actual and ultrasound carcass information in beef genetic evaluation programs." Revista Brasileira de Zootecnia 38, spe (July 2009): 58–63. http://dx.doi.org/10.1590/s1516-35982009001300007.
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Increased movement toward alliances and grid pricing in the U.S. has led to an increase interest in genetic values for carcass traits. The literature suggests that carcass genetic values are an effective tool to enhance selection for carcass traits, and that it is possible to select sires within a breed that can increase marbling score without adversely affecting external fat thickness or percent retail product relative to the breed mean. Ultrasound has been investigated as a cheaper means of collecting carcass information. The literature indicates that carcass traits measured via ultrasound on yearling seedstock will respond to selection. Although the literature is variable on the subject, there are reported genetic correlation (r g) estimates between live animal ultrasound and actual carcass attributes that are greater than .70 for all ultrasonically measured carcass traits. When r g between seedstock ultrasound and slaughter cattle carcass measures are > 0.70, similar or greater genetic progress in finished cattle carcass merit could be achieved by using ultrasound information entirely compared to using typical carcass progeny information; however, the maximum accuracy of prediction using ultrasound information in lieu of finished cattle carcass information would be r g. Therefore both actual and live animal, ultrasonically measured carcass traits should be included in genetic evaluation programs, which will allow for an increase in the accuracy of prediction of carcass genetic values on young seedstock animals due to the inclusion of ultrasound information, and will also allow for the possible production of high accuracy sires based on finished cattle progeny carcass information. Multi-breed models are being developed to allow for the prediction of genetic values for carcass traits in populations composed of animals of varying breed composition.
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Smith, C. "Cloning and genetic improvement of beef cattle." Animal Science 49, no. 1 (August 1989): 49–62. http://dx.doi.org/10.1017/s0003356100004244.
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ABSTRACTCloning of cattle from embryos has been achieved by nuclear transfer. Repeated cloning to produce large clones of genetically identical individuals for commercial use may soon become possible. The main advantage in breeding will come from identifying and using superior clones, selected to fit particular husbandry and marketing niches. Two types of cattle clones will be required, terminal clones chosen for economic merit in production traits, such as growth and carcass traits, and maternal clones chosen for reproduction and maternal traits, such as short calving interval, ease of calving, milking and mothering ability and small mature size. Clonal selection and use will provide several steps of improvement. An initial gain will come by recruiting clones from elite stocks and further responses by selecting the best clones for commercial use. This will reverse the normal improvement lag between breeding and commercial stocks. Heterosis will also be exploited by using crossline clones. For continuous genetic improvement, genetic variation will be maintained by breeding the next generation from a number of selected male and female clones and testing and selecting their progeny, the new set of clones, as before. For maximum improvement rates, both male and female clones will need to be tested. In the short term (5 to 10 years), benefits will come from testing a large number of clones by which gains in economic merit of proportionately 0·15 to 0·30 of the mean can be achieved. Further improvements will come by rebreeding the best clones and testing and selecting the new set of clones from which annual genetic response rates of proportionately 0·02 to 0·03 per year are possible. Cloning thus offers considerable advantages in the improvement of beef cattle.
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Shojaei Saadi, Habib A., Éric Fournier, Christian Vigneault, Patrick Blondin, Janice Bailey, and Claude Robert. "Genome-wide analysis of sperm DNA methylation from monozygotic twin bulls." Reproduction, Fertility and Development 29, no. 4 (2017): 838. http://dx.doi.org/10.1071/rd15384.
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Monozygotic (MZ) twins are of great interest to elucidate the contributions of pre- and postnatal environmental factors on epigenetics in the expression of complex traits and diseases. Progeny testing recently revealed that MZ twin bulls do not necessarily lead to identical genetic merit estimates (i.e. breeding values). Therefore, to explain differences in offspring productivity of MZ twin bulls despite their identical genetic backgrounds, we hypothesised that paternal sperm epigenomes vary between MZ twin bulls. In the present study, semen characteristics and global sperm DNA methylome were profiled for four pairs of MZ twin bulls. Some MZ twin pairs had divergent semen quality (sperm morphology, motility and viability). Comparative genome-wide DNA methylome surveys were performed using methyl-sensitive enrichment and microarray identification. Between 2% and 10% of all probes (400 000) were differentially methylated between MZ twin pairs. In addition, there were 580 loci differentially methylated across all pairs of MZ twins. Furthermore, enrichment analysis indicated a significant enrichment for fertility associated quantitative trait loci (P = 0.033). In conclusion, differences in the sperm epigenome may contribute to incongruous diverging performances of daughters sired by bulls that are MZ twins.
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Lohuis, M. M., C. Smith, and J. C. M. Dekkers. "MOET results from a dispersed hybrid nucleus programme in dairy cattle." Animal Science 57, no. 03 (December 1993): 369–78. http://dx.doi.org/10.1017/s1357729800042697.
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AbstractA dispersed hybrid MOET nucleus project was implemented in the Canadian dairy industry. Embryo yield, pregnancy rate, and effects of management and selection practices are reported. Repeatability of viable embryo yield was 0.31. Average viable embryo yield was 6.85 (s.e. 5.35) embryos per collection, with average pregnancy rates of 0.58, 0.46 and 0.51 for grade 1 fresh, frozen, and split embryos, respectively. Of the donors selected, 80% produced enough embryos to form a family of at least 15 offspring. Based on observed results, expectations of family size and structure and generation intervals were calculated. Only 10% of completed families are expected to result in less than three milking daughters. Generation interval for sib-tested sires was 58 months of age under practical field conditions, which was shorter by a factor of 0.19 than a traditional progeny test but longer than original theoretical estimates by a factor of 0.32. Realized selection intensities for a total merit index were 2.22 for sires and 3.77 for dams of embryos. Accuracies of selection for sires and dams were 0.93 and 0.73 respectively. To improve the scheme, use of more fresh embryos, embryo splitting and less delay in transferring frozen embryos are recommended.
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ALLAN, B. B., G. M. WEISS, and H. T. FREDEEN. "THE SENSITIVTY OF A TWO-TRAIT SELECTION INDEX TO CHANGES IN ECONOMIC WEIGHTS AND GENETIC PARAMETER ESTIMATES." Canadian Journal of Animal Science 65, no. 1 (March 1, 1985): 21–29. http://dx.doi.org/10.4141/cjas85-003.
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Two-trait selection indexes comprising average daily gain (G) and adjusted average backfat depth (F) were constructed utilizing several permutations of economic and genetic parameters. In these permutations the ratio of economic weights employed (value per kg G: value per mm F) ranged from 5:1 to 75:1, the ratios of heritabilities (G:F) ranged from 0.625:1 to 1:1 and the genetic and phenotypic correlations ranged from zero to 0.25. The relative merits of these indexes were evaluated by comparing the expected genetic merit of progeny produced by the top 10% of the boars identified by each index as applied to a population of 590 boars station tested under the Canadian Record of Performance (ROP) system. Responses were estimated for each component trait (G,F), for feed conversion (FC) and the aggregate genetic response (G + F + FC) in standard deviation units. The net economic value of the aggregate genetic response was calculated as the sum of the values of the genetic responses for the individual traits weighted by their economic values. Variation in the economic and genetic parameters influenced the expected genetic response for the component traits but the aggregate response and its economic value varied little over the range of parameters employed. Indeed, an index constructed from estimates of the actual genetic, phenotypic and economic parameters gave net returns that were only $0.04 per hog greater than an index based on equal economic weights, equal heritabilities and zero correlations. This index, of course, is the simple phenotypic index which leads to the conclusion that results of selection based on a phenotypic index will be fully comparable to those of a highly sophisticated genotypic index. Key words: Selection index sensitivity to parameter variation, genotypic selection index, phenotypic selection index, effectiveness of index selection
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Boukouvala, M. C., N. G. Kavallieratos, C. G. Athanassiou, and L. P. Hadjiarapoglou. "Biological activity of two new pyrrole derivatives against stored-product species: influence of temperature and relative humidity." Bulletin of Entomological Research 106, no. 4 (April 18, 2016): 446–56. http://dx.doi.org/10.1017/s0007485315001108.
Full textAbstract:
AbstractMembers of the pyrrole group are likely to have interesting properties that merit additional investigation as insecticides at the post-harvest stages of agricultural commodities. In the present work, the insecticidal effect of two new pyrrole derivatives, ethyl 3-(benzylthio)-4,6-dioxo-5-phenyl-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrrole-carboxylate (3i) and isopropyl 3-(benzylthio)-4,6-dioxo-5-phenyl-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrrole-carboxylate (3k) were studied as stored-wheat protectants against two major stored-product insect species, the confused flour beetle, Tribolium confusum Jaquelin du Val adults and larvae and the Mediterranean flour moth, Ephestia kuehniella Zeller larvae at different doses (0.1, 1 and 10 ppm), exposure intervals (7, 14 and 21 days), temperatures (20, 25 and 30°C) and relative humidity (55 and 75%) levels. For T. confusum adults, in the case of the pyrrole derivative 3i, mortality was low and it did not exceed 32.2% in wheat treated with 10 ppm 3i at 30°C and 55% relative humidity. Progeny production was very low (<1 individual/vial) in all combinations of 55% relative humidity, including control. In the case of the pyrrole derivative 3k, mortality reached 67.8% at 30°C and 55% relative humidity in wheat treated with 10 ppm after 21 days of exposure. Progeny production was low in all tested combinations (≤0.7 individuals/vial) of 55% relative humidity, including control. For T. confusum larvae, in the case of the pyrrole derivative 3i, at the highest dose, mortality was 82.2% at 25°C and 55% relative humidity whereas in the case of 3k it reached 77.8% at the same combination. In contrast, mortality at 75% relative humidity remained very low and did not exceed 13.3%. For E. kuehniella larvae, the highest mortalities, 44.4 and 63.3%, were observed in 10 ppm at 25°C and 55% relative humidity for both pyrrole derivatives. The compounds tested here have a certain insecticidal effect, but this effect is moderated by the exposure, the target species, the temperature and the relative humidity.
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Weik, Franziska, Rebecca E. Hickson, Stephen T. Morris, Dorian J. Garrick, and Jason A. Archer. "Genetic Parameters for Maternal Performance Traits in Commercially Farmed New Zealand Beef Cattle." Animals 11, no. 9 (August 26, 2021): 2509. http://dx.doi.org/10.3390/ani11092509.
Full textAbstract:
Maternal performance is a major driver of profitability in cow-calf beef cattle enterprises. The aim of this research was to evaluate the inheritance of maternal performance traits and examine the intercorrelation among reproduction, live weight, hip height, body condition and maternal contribution to calf weaning weight in 15-month-old heifers, 2-year-old cows and mature cows in New Zealand beef herds. Data were collected on a total of 14,241 cows and their progeny on five commercial New Zealand hill country farms. Heritabilities were low for reproductive traits in heifers and mature cows (0–0.06) but were greater in 2-year-old cows (0.12–0.21). Body condition scores were lowly (0.15–0.26) and live weights (0.42–0.48) and hip heights (0.47–0.65) highly heritable in heifers, 2-year-old cows and mature cows. Results indicate that 2-year-old cows with higher genetic potential for rebreeding ability may have greater genetic merit for live weight, hip height and body condition as heifers (rg = 0.19–0.54) but are unlikely to be larger cows at maturity (rg = −0.27–−0.10). The maternal genetic effect on weaning weight had a heritability of 0.20 and was negatively genetically correlated with body condition score in lactating cows (rg = −0.55–−0.40) but positively genetically correlated with rebreeding performance (rg = 0.48).