| Title |
Investigators | Department | Objectives | Approach Keywords | Progress Reports | Impact Statements | Publications | |
Project * COL00681 | |
| Title | National Beef Cattle Genetic Evaluation |
| Investigator(s) | Enns, RM; Garrick, DJ; Speidel, SE; Brigham, BW; |
| Department | Animal Science |
| Objectives | The objectives of this project are to 1.Identify economically relevant traits representing both costs and revenues of production from all sectors of the beef industry, 2.Develop new expected progeny differences (EPD) for the economically relevant traits identified 3 .Develop computational methods for national beef cattle genetic evaluation both for pure and multi-breed datasets, 4. Perform genetic evaluations for beef breed associations,5 .Support a list server for animal breeding professionals. |
| Approach | We have identified the economically relevant traits for the typical beef operation in the U .S. including the seedstock sector, the commercial cow/calf sector, and the feedlot/packer sector and continue to modify that list as needed. For instance, some cow/calf systems have additional economically relevant traits for adaptability, such as in the intermountain west where brisket disease is present. Based upon our list of ERT, the few that we have yet to finish are the days to finish EPD. As mentioned earlier we have identified two datasets that will help us complete the development of this EPD. The two datasets are different in that one has both a maternal breed and a terminal breed, individual feed intake, serial ultrasound data and animals sold based on ultrasound results. The other dataset has fewer ultrasound measures, but is much larger in size and contains more crossbred animals. By using both of these datasets, we will be able to examine heterosis effects and breed differences in rate of finishing. Our approach will be to evaluate various random regression models for days to a target weight, fat thickness, and quality grade. Included in this approach will be estimates of heritability for coefficients in higher order polynomial prediction equations, and evaluation of each order polynomial for its predictive ability. The random regression approach is different than typical approaches for genetic evaluation as random regression models develop prediction coefficients for each individual. These equations can then be used to identify time to any finish endpoint. In this scenario, weights are the predictor and days are the outcome whereas in typical evaluations, age is the predictor of weight, such as in average daily gain. This later method forces all producers to one endpoint, such as yearling weight. Our approach will produce EPD with much more flexibility, allowing producer to tailor selection decisions to their specific production and marketing systems.Once the appropriate random regression model is developed, we will perform a prototype genetic evaluation for one of our clients and submit that for their review. After approval we will make this methodology available to all clients of participating NBCEC institutions for release to their breeders. The previous will result in within-breed genetic evaluation and will be followed up with development of random regression techniques for multi-breed evaluation accounting for both animals registered in other breed organizations and for crossbreed animals. |
| Keywords | beef cattle, expected progeny differences, breeding value, genetic evaluation |
| Progress Reports | |
| 1998 | Problem. Expected progeny differences (EPD) have been the bellwether used by producers for predicting the genetic merit in seedstock beef cattle for the past fifteen years. However, currently only a limited number of traits have EPD widely available. Project Description. This project involves development and application of methods for producing EPD in new traits. Accomplishments. In 1998 several research projects were completed and several others were instituted. Specifically, methods for producing heifer pregnancy EPD in Limousin beef cattle and Salers Beef cattle were developed. Additionally, an EPD for stayability was produced for Limousin and Salers. Also, new national cattle evaluation programs were started for the US Brayford and Red Brangus beef breeds. New procedures were developed for carcass EPD for Red Angus, Salers and Limousin cattle. Age of dam by contemporary group interaction was studied in Salers. Additive genetic grouping was studied as a method for evaluating connection between beef breeds and as a method for exploring the relationship between ultrasound carcass measurements and actual carcass measurements. Production analyses were performed for 13 different beef breed organizations. |
| 1999 | 1999 was a productive year for the Colorado State University Center for Genetic Evaluation of Livestock. The Center is responsible for the production of expected progeny differences for twenty-one beef cattle breed associations, and companies in six different countries including the U.S., Brazil, Canada, Australia, New Zealand, and Venezuela. A major component of the EPD production service that CSU CGEL provides is its extensive research effort. The nine graduate students that worked in the Center in 1999 are critical to its success. These students, along with the faculty involved published numerous technical papers, and numerous popular articles on their research activities.The research activities of the center come from a cohesive theme. All research in the center is motivated by an idea called the principle of economically relevant traits. In brief, the principle says that genetic prediction is sensible only for traits directly associated with an economic return or cost. To that end, research projects in 1999 included the development of methods to predict the genetic merit for several economically relevant traits including mature cow maintenance energy feed consumption, pregnancy in heifers , pregnancy in cows, days to reach target slaughter endpoints, and methods for quantifying the effect on profit and risk of economically relevant traits. |
| 2000 | Problem. For selective breeding, Expected Progeny Differences (EPDs) have been the most important tool available to seedstock and commercial producers of beef cattle. However, currently there are a limited set of EPDs available, describing only a portion of the total influence breeding stock have on profit and risk. Project Description. This project develops the next generation of expect progeny differences (EPD). Emphasis is placed on developing EPD for economically relevant traits; traits that are directly associated with either a cost of production or a revenue stream. Current work is focused on female fertility traits, cost of feedlot finishing traits, and cow maintenance costs. Accomplishments. In 2000 we successfully developed and produced in prototype and production mode the first heifer pregnancy EPDs based on pregnancy observations. Additionally, we developed and produced the first EPDs for carcass traits based on both slaughter progeny data and ultrasound data from yearling seedstock. Also, we developed and tested a prototype mature cow maintenance EPD. In 2000 the project supported the sabbatical of Dr. Dorian Garrick, Al Ray endowed chair in animal breeding at Massey University, New Zealand. Dr. Garrick helped to develop the principle of economically relevant traits, a fundamental strategy for defining the value of traits and their genetic predictions. Dr. Garrick participated in a Beef Improvement Federation Symposium to introduce the topic to the U.S. industry. |
| 2001 | Problem. For selective breeding, Expected Progeny Differences (EPDs) are the most important tool available to seedstock and commercial producers of beef cattle. Historically EPDs have been available for only a portion of the traits that should be included in a sensible breeding objective. Project Description. The objective of this project is to develop a set of EPDs that relate directly to revenue and costs of beef production and can be included in national beef cattle genetic evaluation programs. A principle, called the principle of economically relevant traits (ERTs), was developed in order to have a sensible framework for identifying the appropriate traits. Current work includes cow maintenance feed requirements, fertility, and feedlot performance. Accomplishments. Work was begun on the methods for determining the value of alternative bulls available for selection based on their ERTs. Because this computation is relatively complex, we have designed a web based tool that will use a producers production data and the animal's predicted genetic merit to determine break even purchase price and risk. Work continues on the appropriate way to predict the time to alternative feedlot finish endpoints. |
| 2002 | Ultrasound records were incorporated into the North American Limousin Foundation (NALF) carcass evaluation in order to add accuracy to the carcass EPD. Ultrasound information is not economically relevant in and of itself, but is used to add accuracy to its correlated carcass counterpart; An international calving ease ERT was developed for the Red Angus Association of America (RAAA) in order to increase the accuracy of prediction for U.S. sires with relationship ties outside the U.S. International stayability and docility ERT were developed for NALF in order to increase the accuracy of prediction for U.S. sires with relationship ties outside the U.S.; Average net returns when a sire's progeny were fed to three alternative constant endpoints (weight, backfat or marbling) and then sold on a grid were calculated by simulation. Feeding costs as well as grid premiums and discounts were taken into account. The results indicated that interactions exist between sire genotype and feeding endpoint. Re-ranking occurred for sire net return at different endpoints. A manuscript is currently in preparation; Analysis of two data sets (NC State and CSU Rouse ranch) representing fed cattle with serial measurements on growth and feed intake and terminal carcass information proved the data was unsatisfactory in terms of the objective of determining the extent to which days on feed can account for variation in feed intake for cattle fed to weight, fat and marbling endpoints. Further research is reliant on obtaining access to new datasets with greater variation in days to finish than existed in the previous datasets; Development of the prediction error variance for mature cow maintenance energy is ongoing. Variability in the equations parameters has been identified and taken into account. Options for dealing with the non-linear relationship between mature size and metabolic liveweight are still being explored; Studies are being undertaken on the association between genetic relationships among animals and subsequent performance. In the first phase, the effects of inbreeding on fertility have been investigated. Future phases will consider the effects of inbreeding on carcass performance and on the use of marker information to modify the relationship matrix for use in evaluation. This is aimed at quantifying the extent to which additional information for predicting the merit of young bulls can be obtained by accounting for likeness among sibs, as determined by genetic markers. |
| 2003 | The number of Expected Progeny Differences (EPD) has increased from 5 to over 15 in the last 2 decades. The EPDs have become widely adopted by most breed associations and producer groups as a tool for making selection decisions that increase the rate of genetic improvement of beef cattle. Unfortunately, genetic progress does not necessarily lead to more profitable offspring and a more profitable beef production system as a whole. Much of this is a lack of methods for incorporating current EPD, most of which are for indicator traits, and the costs and incomes of production. Indicator traits, while important, are measured because they are related to traits that directly influence costs and incomes of production, the economically relevant traits. If EPD for economically relevant traits were readily available, producers could much more easily value selection decisions and the influence of those decisions on overall profitability, change in economically relevant traits should transfer directly to changes in profitability, given optimal management. For the cow/calf producer, feed requirements associated with maintaining the beef cow account for upwards of 70 percent of the costs of production for these producers. Historically, there has been no EPD that represents the costs of feed for the producing cow other than measurements on the indicator trait, mature weight. We used data from the Red Angus Association of America, one of the clients of the Colorado State University Center for Genetic Evaluation to develop a cow maintenance requirement EPD. This EPD is based on the weaning weight, body condition score at weaning, and mature weight observations on the individual. These observations are used to calculate milk production and mature metabolic weight genetic potentials which are, in turn, used in the calculations of the cow maintenance requirement EPD. The new EPD is expressed as Mcal of energy for maintenance required per month. The EPD ranged from minus 15 to plus 26 Mcal. A sire with a maintenance energy EPD of plus 20 will on average, produce offspring that require and additional 20 Mcal of energy for maintenance per month than offspring of a sire with an EPD of 0. These new EPD were reviewed by a technical committee made up of producers and scientists with subsequent approval to move from the prototype stage to production, making them available to all producers in the Red Angus breed. As this work was part of the National Beef Cattle Evaluation Consortium, this technology is available to participating breed associations and producer groups. |
| 2004 | Economically relevant traits are directly related to the cost or income resulting from the production of beef. Expected progeny differences (EPD) for these traits simplify animal selection by focusing genetic improvement and easing quantification of each traits effect on profitability. In the past, genetic evaluation procedures for stayability, one of the economically relevant traits, have been developed. The stayability EPD is a tool for selecting breeding stock that will produce offspring with longer, more productive life spans. This EPD has been adopted by several U.S. beef breed associations and their breeders. A prototype of this evaluation has also been delivered to an additional association and was subsequently accepted for regular implementation in the current year. The stayability EPD is calculated from data recorded on those cows that produce a calf at 2 years of age and are still in the herd at age 6. Developing methods for measuring correlated traits at earlier ages, as opposed to waiting 6 years for observations to be recorded, would increase accuracy of EPD for younger animals. Accuracy of EPD is a key factor influencing the rate of genetic improvement with increases in accuracy resulting in faster genetic improvement of animals through selection. To be useful, early indicators must be heritable and genetically related to stayability. We have completed evaluation of measurements at earlier ages with two industry datasets. These analyses estimated a heritability of .21 for stayability to 3 years of age and heritability of .26 for stayability to 4 years of age. Both indicate a significant genetic contribution in lifespan to these ages. The rank correlations between EPD for stayability to 3 years of age and EPD for stayability to 6 years of age was .63; while the rank correlations between EPD for stayability to 4 years of age and EPD for stayability to 6 years of age was .66. The rank correlations indicate a strong positive relationship between the underlying genetic mechanisms controlling stayablity to these ages. Work is ongoing to develop methodology to incorporate this information into national cattle evaluations to increase accuracy of EPD for stayability to 6 years of age. Further efforts to improve accuracy of stayability EPD, involved evaluating inbreeding effects on stayability. For every percentage point increase in inbreeding of the individual, stayability decreased .56 percent in preliminary results. By accounting for inbreeding, accuracy of evaluation of stayability would be increased further. |
| 2005 | In the past, genetic evaluation of beef cattle often focused on traits for which data was easily collected. These traits were often indicator traits that were only indirectly related to profitability of beef production such as birth weight. Using a developed approach for identifying the economically relevant traits (ERT), or more precisely, the traits directly related to a cost or an income from the production of beef, EPD have begun to be calculated for ERT. Efforts have also begun to evaluate methodologies for increasing the accuracy of those EPD related to the economically relevant traits. Some of these ERT include stayability, heifer pregnancy, and docility. These EPD and all others currently produced are based on data from individual animals. Unfortunately, EPD for the ERT related to costs of production in the feedlot phase are lacking. Therefore it is difficult for producers to accurately select sires that will produce offspring with lower costs of production in this phase where the primary expense is the amount of feed consumed by the animals. The lack of EPD for this sector of the beef industry stems from the difficulty associated with measuring individual feed consumption when labor costs dictate that animals be fed in a group, or pen, setting. This restriction results in data on pen average performance but not on individual performance. A simulation was employed to develop methods to better utilize this pen average performance data to generate EPD for selection of sires whose progeny will have lower overall feed consumption and in turn lower feed costs in the feedlot. Results showed that better predictions of genetic merit were obtained when progeny were grouped in pens by sire. Reductions in the number of animals per pen also resulted in more accurate EPD. Regardless, the information currently generated in a pen setting can be used to calculate EPD when individual animal information is not available and that even though accuracy of the EPD is reduced, selection can be almost as effective as when individual observations are available. |
| 2006 | Continuing our approach for identifying the economically relevant traits (ERT), the traits that are directly related to a cost or an income from the production of beef, we have completed preliminary studies on developing EPD for days on feed in the feedlot. This ERT has a direct impact on profitability of beef production through a potential reduction in costs of production. Animals that more quickly reach appropriate harvest endpoints spend less time in the feedlot thereby reducing yardage and feed costs. Breed association field data including pedigree and performance data was used to estimate heritability for days on feed when the animals were fed to a constant back fat. A two-trait model was used that included weaning weight to account for any selective reporting and/or sequential culling and days to a constant back fat. Analysis indicated considerable genetic variation for this trait and yielded a heritability of .45, suggesting that development of EPD for this trait is feasible. In turn, selection on that EPD should yield a reduction in the number days animals are fed in the feedlot when those animals are fed to a target back fat endpoint. EPD for number of days to a constant backfat were then calculated using this heritability value. The range in these EPD were -33.5 to 69.9 days. Using this tool, producers should improve profitability in the feedlot through a reduction in costs while maintaining animal performance. Realizing that animals are often fed for target endpoints other than back fat, we are also evaluating days to a marbling score, or quality grade endpoint, and days to a weight endpoint. This approach is also being developed using additional sources of large quantities of field data. |
| Impact | |
| 1999 | Expected progeny differences (EPD) have been the bellwether used by producers for predicting the genetic merit in seedstock beef cattle for the past fifteen years. However, currently only a limited number of traits have EPD widely available. This project involves development and application of methods for producing EPD in new traits. |
| 2000 | In addition to the release in a production mode of the EPD previously described, we published several papers. Particularly important was the proceedings paper at the Beef Improvement Federation Annual Meeting on Economically Relevant Traits. This work has been reprinted in several national industry publications and is receiving substantial attention. |
| 2001 | Eliminating predictions of genetic merit for indicator traits and providing predictions of genetic merit for ERTs, only will improve a commercial producer's probability of making profitable selection decisions. This will result in more efficient beef production. To achieve this, a number of new analytical methods must be developed and adapted to properly account for the nature of threshold and time series data. |
| 2002 | This project involves the development and dissemination of technology for beef cattle genetic evaluation. The research continues to impact beef cattle production nationally and internationally through methods for incorporating advanced computational methods in beef improvement. |
| 2003 | This research has resulted in the first EPD that are simultaneously directly related to costs of production and easy for producers to value. We anticipate, and have already received many requests for information on this technology and its implementation. These EPD will help cow-calf producers both locally and nationally to select animals that will reduce their costs of production and thereby increase their profitability. |
| 2004 | Simulation of U.S. cow-calf production systems show that a herd-wide increase in stayability of 2 percent would increase profitability 79 dollars per bull. Given U.S. beef cow numbers of over 32 million, and an average of 1 bull per 30 cows, this 2 percent increase would produce nationally an increase in profitability of over 84 million dollars. Efforts to identify and calculate EPD for other economically relevant traits will further improve economic viability of U.S. beef production. |
| 2005 | In 2004, over 32 million animals were harvested in the U.S. and on January 1, 2005 over 13 million cattle were on feed. The production and use of EPD for feed consumption could result in reduced costs of production for these cattle on feed and in turn improved profitability for the producers owning those cattle. If the average animal gains a total of 500 pounds in the feedlot and that gain costs 45 cents per pound, a 10 percent decrease in feed costs would result in a savings of over 20 dollars per head on feed resulting in a more efficient and profitable feedlot industry. For just those animals on feed January 1, this would potentially result in a total savings of 260 million dollars. Given the nature of genetic change, this progress could be maintained in perpetuity. |
| 2006 | Over 33 million animals were harvested in the U.S. in 2006. A reduction in time spent in the feedlot or in development could reduce production costs and in turn, improve profitability. For instance, assume 80% of the animals harvested were steers and heifers raised specifically for harvest who reached the same target endpoint and that yardage costs are typically $ .20/head/day. A reduction of 5 days in the feedlot, would result in approximately a $27 million dollar reduction in costs of production. Realizing that the spread in EPD for this data set encompassed over 100 days between the lowest and highest EPD, there is a large potential benefit to continued development and application of this technology. |
| Publications | |
| 1998 |
Al-Hur, F.S., Bourdon, R.M., Golden, B.L., Ellis, R.P., and Snowder, G.D. 1998. Factors affecting immunoglobulin G concentration and total solids percentage in ewe colostrum. J. Anim . Sci. 76(Suppl. 1)/J. Dairy Sci. 81(Suppl. 1):67(Abstr.) Choy, Y. H. 1998. Estimating parameters for mature weight. Ph.D. Dissertation. Colorado State University, Fort Collins Comstock, C.R., Golden, B.L., and Andersen, K.J. 1998. Implementation of an algorithm to estimate genotypic probabilities of protoporphyria in Limousin cattle. J. Anim. Sci. 76(Suppl. 1)/J. Dairy Sci. 81(Suppl. 1:55(Abstr.) Eler, J. P., Ferraz, J.B.S., Golden, B.L., and Silva, P.R. 1998. Effect of sire x herd interaction in estimation of (co)variance components in Nelore cattle. Proc. 6th World Cong. Genet. Appl. Livest. Prod. 26:165 Evans, J. L. Golden, B.L., Bourdon, R.M., and Long, K.L. 1998. Additive genetic relationships between heifer pregnancy and scrotal circumference in Hereford cattle. CSU Beef Program Report . p 219 Evans, J. L., Golden, B.L., and Comstock, C.R. 1998. Report II to the American Salers Association: results of analyses for carcass trait parameter estimation. Colorado State University, Fort Collins (Mimeo) Evans, J. L., Golden, B.L., Mallinckrodt, C.H., and Long, K.L. 1998. Approximate and empirical confidence intervals for heritability from Method R estimates. J. Anim. Sci. 76(Suppl. 1)/J. Dairy Sci. 81(Suppl. 1):57(Abstr.) Evans, J. L., Hyde, L.R., Kuehn, L.R., Comstock, C.R., and Golden, B.L. 1998. Report I to the American Salers Association: results of analyses for docility EPD, weaning age of dam by contemporary group interaction, and parameter reestimation. Colorado State University, Fort Collins (Mimeo) Golden, B. L. 1998. The world wide web: HTML, CGI, and JAVA applications in animal breeding. Proc. 6th World Cong. Genet. Appl. Livest. Prod. 27:409 Hyde, L. R. 1998. An international genetic evaluation of Charolais cattle. M. S. Thesis. Colorado State University, Fort Collins Hyde, L.R., Bourdon, R.M., Golden, B.L., and Comstock, C.R. 1998. Genotype by environment interactions for growth and milk traits in an international population of Charolais cattle. J. Anim. Sci. 76(Suppl. 1)/J. Dairy Sci. 81(Suppl. 1):60(Abstr.) Hyde, L.R., Comstock, C.R., and Golden, B.L. 1998. American Salers Association weaning weight adjustment factors for sex of calf and age of dam. Colorado State University, Fort Collins (Mimeo) Kuehn, L. A. and Golden, B.L. 1998. Keeping the herdbook straight: why is it important? Braunvieh World. May. p 16 Kuehn, L. A., Golden, B.L., Comstock, C.R., Hyde, L.R., and Andersen, K.J. 1998. Docility EPD for Limousin cattle. CSU Beef Program Report. p 73 Kuehn, L.A., Golden, B.L., Comstock, C.R., and Andersen, J. 1998. Docility EPD for Limousin cattle. J. Anim. Sci. 76(Suppl. 1)/J. Dairy Sci. 81(Suppl. ):85(Abstr.) Kuehn, L.A., Golden, B.L., Comstock, C.R., and Andersen, K.J. 1998. Docility EPD for Limousin cattle. Proc. West. Sec. Amer. Soc. of Anim. Sci. 49:69 Mallinckrodt, C.H., Golden, B.L., and Reverter, A. 1998. Confidence intervals for genetic parameters from Method R estimates. J. Anim. Sci. 76(Suppl. 1)/J. Dairy Sci. 81(Suppl. 1):70(Abstr.) |
| 1999 |
Bourdon, R.M. and Golden, B.L. 1999. Beef cattle breeding in the new millenium. American Red Angus, vol. XXXV no. 2, p. Evans, J. L., Kuehn, L.A., Hyde, L.R., Comstock, C.R., Golden, B.L., and Doubet, S. 1999. Docility EPD for Salers cattle. J. Anim. Sci. 77(Suppl. 1):100 (Abstr.) Evans, J.L., Golden, B.L., Bourdon, R.M., and Long, K.L. 1999. Additive genetic relationships between heifer pregnancy and scrotal circumference in Hereford cattle. J. Anim. Sci. 77:2621 Evans, J.L., Kuehn, L.A., Hyde, L.R., Comstock, C.R., Golden, B.L., and Doubet, S. 1999. Docility EPD for Salers cattle. Proc. Western Section Am. Soc. Anim. Sci. 50:59-63 Golden, B.L. and Bourdon, R.M. 1999. New EPDs: a rational vision for the future. Proc. 31st Annual Res. Symposium and Annual Mtg., June 6-8, Roanoke, VA, p. Golden, B.L. and Bourdon, R.M. 1999. The sire summary of the future. Rev. Bras. Reprod. Anim,. vol. 23, no. 2, p. 78 Golden, B.L., and Bourdon, R.M. 1999. EPDs Explained And The Principle of Economically Relevant Traits versus Indicators. Proc. U. S. Grains Foundation, EPD Project Golden, B.L., and Bourdon, R.M. 1999. New EPV's: A Rational Vision for the Future. Proc. Of a Beef Genetics Workshop. Massy University, New Zealand. New Zealand Beef Council Publication Hyde, L.R., Golden, B.L., Comstock, C.R., Kuehn, L.A. and Doubet, S. 1999. Age of dam by contemporary group interaction for weaning weight in Salers cattle. Proc. Western Section Am. Soc. Anim. Sci. 50:51-54 Hyde, L.R., Golden, B.L., Comstock, C.R., Kuehn, L.A., and Doubet, S. 1999. Age of dam by contemporary group interaction for weaning weight in Salers cattle. J. Anim. Sci. 77(Suppl. 1):99 (Abstr.) Kuehn, L. A., Golden, B.L., Comstock, C.R., Hyde, L.R., and Doubet, S. 1999. Genetic parameter estimates for birth weight, weaning weight, and postweaning gain in Salers beef cattle. Proc. Western Section Am. Soc. Anim. Sci. 50:83-87 Kuehn, L.A., Golden, B.L., Comstock, C.RHyde, L.R., and Doubet, S. 1999. Genetic parameter estimates for birth weight, weaning weight, and postweaning gain in Salers beef cattle. J. Anim. Sci. 77(Suppl. 1):99 (Abstr.) Ruppert, R.J., Hyde, L.R., Comstock, C.R., Golden, B.L. and Andersen, K.J. 1999. Correlation of carcass ultrasound to sire EPD in Limousin cattle. Proc. Western Section Am. Soc. Anim. Sci . 50:91-92 Ruppert, R.J., Hyde, L.R., Comstock, C.R., Golden, B.L., and Andersen, K.J. 1999. Correlation of carcass ultrasound to sire EPD in Limousin cattle. J. Anim. Sci. 77(Suppl. 1):101 (Abstr.) Summers, M.D., Evans, J.L., Hyde, L.R., Comstock, C.R., Golden, B.L., and J. Andersen, K.J. 1999. Estimates of heritability for heifer pregnancy in Limousin cattle. J. Anim. Sci. 77(Suppl. 1):100 (Abstr.). Summers, M.D., Evans, J.L., Hyde, L.R., Comstock, C.R., Golden, and Andersen, K.J. 1999. Estimates of heritability for heifer pregnancy in Limousin cattle. Proc. Western Section Am. Soc. Anim. Sci. 50:80-82 |
| 2000 |
Charteris, P.L., Hoag, D.L., Golden, B.L. 2000. Sensitivity of economic values for beef tenderness to payment system. Proc. 53rd Reciprocal Meat Conference, p. 128. Charteris, P.L., Hoag, D.L., Koontz, S.K., Amer, P.R., Golden, B.L. 2000. Economic values for tenderness in beef cattle. Proc. Western Section, Am. Soc. An. Sci., 51: 96-99. Charteris, P.L., Hoag, D.L., Koontz, S.K., Amer, P.R., Golden, B.L. 2000. Economic values for tenderness in beef cattle. J. An. Sci. 78 (Suppl. 2): 101. Doyle, S. P., B. L. Golden, R. D. Green, and J. S. Brinks. 2000. Additive genetic parameter estimates for heifer pregnancy and subsequent reproduction in Angus females. J. An. Sci. 78:2091-2098. Golden, B. L., D. J. Garrick, S. Newman, and R. M. Enns. 2000. Economically Relevant Traits A Framework for the Next Generation of EPDs. Proc. Beef Improvement Federation. |
| 2001 |
Golden, B. L., 2001. Genetic prediction for time to finish endpoints in cattle. J.Anim.Sci.Vol .79,Suppl.1/J.Dairy Sci. Vol.84, Suppl.1/Poult. Sci.Vol.80, Suppl.1/54th Annu. Rec. Meat Conf. ,Vol.II. |
| 2002 |
Eler, J. P., Silva, II, J.A., Ferraz, B.S., Oliveria, H.N., Evans, J.L. and Golden, B.L. 2002. Genetic Evaluation of the Probability of Pregnancy in Nelore Heifers. J. Anim. Sci. 80:951-954 . |
| 2003 |
Bullock, K.D., Pollak,E.J., Bertrand,J.K., Garrick,D., Enns,M., Weaber,B., and Wilson, D.E. 2003. International beef cattle genetic evaluation in the United States and the role of the National Beef Cattle Evaluation Consortium. Proceedings of the 2003 Interbull meeting. Rome, Italy. Bulletin No. 31:156-157. Cleveland, M.A., R.M. Enns, W.J. Umberger, and B.L. Golden. 2003. Simulation of net return using days to finish estimated breeding values in beef production. J. Anim. Sci. 81:89. Supplement 1. Comstock, S. 2003. Heifer pregnancy genetic prediction and simulation modeling techniques. Ph .D. Dissertation. Colorado State University. Fort Collins. Enns, R.M., and Garrick, D.J. 2003. The Economic benefits and potential when using current and future EPD, Economically Relevant Traits. Proceedings, The Range Beef Cow Symposium XVIII. Scottsbluff. Pp. 46-53. Garrick, D.J. 2003. Construccion y uso de indices economicos para el mejoramiento de la rentabilidad del ganado de carne. XIII reunion internacional sobre produccion de carne y leche in climas calidos memorias,Pp 15-18. Garrick, D.J. 2003. Cross-breeding and composite breed formation. In: The Role of Composites in Livestock Production, Proceedings of the 2003 Animal Industries Workshop. ISBN 0-86476-155 pages 21-29. Garrick, D.J., and Enns, R.M. 2003. How best to achieve genetic Change. Proceedings of the Beef Improvement Federation 35th Annual Research Symposium and Annual Meeting. Pp 48-50. Jubileu, J. 2003. The use of random regression models to predict days to finish in beef cattle . M.S. Thesis. Colorado State University. Fort Collins. Jubileu,J., Maiwashe, N., Cleveland, M., Tseveenjav,B., Enns, R.M., and Garrick, D.J. 2003. Estimates of genetic parameters of carcass traits in limousin cattle. J. Anim. Sci. 81:318. Supplement 1. Lopez-Villalobos, N. and D.J. Garrick. 2003. Accounting for feed intake in dairy cattle evaluation. Proceedings of the Association for the Advancement of Animal Breeding & Genetics 15th Conference, 15:318-321. Shafer, W. 2003. The Colorado Beef Cattle Production Model: effects of simulation with realistic levels of variability and extreme within-herd diversity. Ph. D. Dissertation. Colorado State University. Fort Collins. Sherlock, R.G., N. Lopez-Villalobos and D.J. Garrick. 2003. Genetic parameters for wool traits in ultra-fine New Zealand Merinos. Proceedings of the Association for the Advancement of Animal Breeding & Genetics 15th Conference, 15:277-280. Speidel, S.E., Enns,R.M., Garrick, D.J., Welsh, C.S., and BGolden, B.L. 2003. Current approaches to performing large scale beef cattle genetic evaluations, Proc. West Sect. Am. Soc . An. Sci. Vol 54. 7 pages. Tseveenjav, B., Blackburn,H.D., and Enns, R.N. 2003. Heritability estimates for semen characteristics of inbred and non-inbred Hereford bulls. J. Anim. Sci. 81:318. Supplement 1. |
| 2004 |
Cleveland, M.A. Enns, R.M., Garrick, D.J., and Blackburn, H.D. 2004. Examining the genetic diversity of Hereford cattle. Abstract. Journal of Animal Science 82:Suppl.1 pp 451. Enns, R.M., Speidel, S., and Brigham, B. 2004. GEARING UP FOR EPD. International Texas Longhorn Association Journal, Longhorn Drover. Pp. 10-11. Center for Genetic Evaluation of Livestock. Colorado State University Garrick, D.J. 2004. High-altitude disease - an example of genetic variation for adaptability. Proceedings of the NBCEC Adaptability Symposium held in Kansas City 29-30 October 2004. Garrick, D.J. and Enns, R.M. 2004 Selecting for economically relevant traits Proceedings of the Beef Seedstock Conference on Genetic Innovations for Breeding Programs held by the Iowa Beef Center in Ames Iowa, 2 December 2004. Maiwashe, A., Garrick, D.M., and Enns, R.M. 2004. Weighting of information when predicting breeding values using the standard or marker-based inverse of the numerator relationship matrix. Abstract. Journal of Animal Science 82:Suppl.1 pp 243. Maiwashe, Azwhihangwisi. 2004. Improving genetic predictions by accounting for mendelian sampling or inbreeding depression. Ph.D. Dissertation. Miller, K.E., Whittier, J.C., Peel, R.K., Enns, R.M., Bruemmer, J.E., and Umberger, W.J. 2004 Case Study: Comparison of breeding and marketing systems for Red Angus cattle using an integrated computer-based spreadsheet. The Professional Animal Scientist 20: 429-436. Olson, K.M., Garrick, D.J., and Enns, R.M. 2004. Predicting breeding values for feed intake from individual or pen-fed data. Abstract. Journal of Animal Science 82:Suppl.1 pp 452. Speidel, S.E., Garrick, D.J., and Enns, R.M. 2004. Genetic prediction for estimating mature cow maintenance energy requirements. Abstract. Journal of Animal Science 82:Suppl.1 pp 450. Thomas, M., Enns, M., Silver, G., Garcia, M., Shirley, K., Beauchemin, V., and Hallford, D. 2004. Growth hormone (GH) gene polymorphisms appear to differentially influence pituitary responsivenesss to growth hormone releasing hormone (GHRH) among Bos taurus and Bos indicus-derivative cattle. Plant and Anim. Genome XII, 229. Thomas, M.G., Enns, R.M., Silver, G.A., Garcia, M.D., Shirley, K.L., Beauchemin, V.R., and Hallford, D.M. 2004. Growth hormone gene polymorphisms differentially predict ADG and carcass traits in performance tested Angus and Brangus bulls selected for semi-arid climates. J. Anim. Sci. 82(Suppl. 1):379. |
| 2005 |
Beckman, D.W., Speidel, S.E., Brigham, B.W., Garrick, D.J., and Enns, R.M. 2005. Genetic parameter estimates for docility in Limousin cattle. Proc. West. Sect. An. Sci. 56: 109-111. Brigham, B.W., Enns, R.M., Garrick, D.J., and Speidel, S.E. 2005. Using additional phenotypic information in data poor analyses. Proc. West. Sect. An. Sci. 56:105-108. Cleveland, M.A., Blackburn, H.D., Enns, R.M., and Garrick. D.J. 2005. Changes in inbreeding of U.S. Herefords during the twentieth century. Journal of Animal Science, 83:992-1001. Enns, R.M., Garrick, D.J., and Brigham, B.W. 2005. Variability in economic value is dependent upon herd average stayability. Proc. West. Sect. An. Sci. 56:112-115. Evans, R.D., Grandin, T., DeJarnette, J.M., Deesing, M., and Garrick, D.J. 2005. Phenotypic relationships between hair whorl characteristics and spermatozoal attributes in Holstein bulls . Animal Reproduction Science 85:95-103. Garrick, D.J. 2005. Calculating the distribution of the correlation between estimated breeding values from different analyses. Abstract. Journal of Animal Science 83, Suppl. 1, 73-74. Garrick, D.J. 2005. High Altitude disease - an example of genetic variation for adaptability. Proceedings of the Beef Improvement Federations 37th Annual Research Symposium and Annual Meeting held 6-9 July 2005 in Billings, Montana. 37:122-123. Garrick, D.J. 2005. Using appropriate genetic evaluations to make better selection decisions. Abstract. Journal of Animal Science 83, Suppl. 1, 327. Garrick, D.J. and Snell. R.G. 2005. Emerging technologies for identifying superior dairy cows in New Zealand. New Zealand Veterinary Journal, 53(6):390-399. Olson, K.M., Garrick, D.J., and Enns, R.M. 2006. Predicting breeding values and accuracies from group in comparison to individual observations. Journal of Animal Science, 84:88-92. Shafer, W.R., R.M. Enns, R.M., B.B. Baker, B.B., L.W. Van Tassell, L.W., B.L. Golden, B.L., W .M. Snelling, W.M., C.H. Mallinckrodt, C.H., K.J. Anderson, K.J., C.R. Comstock, C.R., Brinks, J.S., Johnson, D.E., Hanson, J.D., and Bourdon, R.M. 2005. Bio-economic simulation of beef cattle production: The Colorado Beef Cattle Production Model. Technical Bulletin TB05-02. Colorado State University Agricultural Experiment Station. 162 pages. Shirley, K.L., Thomas, M.G., Hallford, D.M., Silver, G.A., Beauchemin, V.R., Steiner, R., and Enns, R.M. 2005. Prediction of reproductive traits in Brangus heifers using a SNP and the translated product of the IGF-I gene. Proc. West. Sect. An. Sci. 56: 75-78. Speidel, S.E., Enns, R.M., and Garrick, D.J. 2005. Weaning weight heritability estimates in different environments. Proc. West. Sect. An. Sci. 56: 83-86. Van Cise, A, Grandin, T., Garrick, D.J., and Enns, R. 2005. Inheritance of hair whorl characteristics in Holstein cattle. Abstract. Journal of Animal Science 83, Suppl. 1, 380 Walker, R.S., Enns, R.M., Geary, T.W., Mortimer, R.G., LaShell, B.A., and Zalesky, D.D. 2005. Evaluation of gonadotropin-Releasing hormone at fixed-time artificial insemination in beef heifers synchronized using a modified CO-Synch plus controlled internal device release protocol. Am. Reg. Prof. An. Sci. 21: 449-454. |
| 2006 |
Evans, R.D., D.J. Garrick, P. Dillon, D.P. Berry and V. Olori. 2006. Effects of calving age, breed fraction and month of calving on calving interval and survival across parities in Irish spring-calving dairy cows. Livestock Production Science 100:216-230. Ahola, J. K., R. M. Enns, and T. Holt. 2006. Examination of potential methods to predict pulmonary arterial pressure score in yearling beef cattle. J. Anim. Sci. 84: 1259-1264. Beckman, D. W., S. E. Speidel, B. W. Brigham, D. J. Garrick, and R. M. Enns. 2006. Genetic parameters for stayability and body condition score in beef females. Proc. West. Sect. Am Soc. An. Sci. 57: 93-95. Beckman, D.W., S.E. Speidel, B.W. Brigham, D.J. Garrick and R.M. Enns. 2006. Genetic parameters for stayability and body condition score in beef females. Abstract. Journal of Animal Science 84, Suppl.2, 144. Brigham, B. W., S. E. Speidel, D. W. Beckman, D. J. Garrick, W. Vanderwert, S. Willmon, and R. M. Enns. 2006. Parameter estimates and breeding values for days to a constant fat endpoint. Proc. West. Sect. Am Soc. An. Sci. 57: 79-81. Brigham, B.W., S.E. Speidel, D.W. Beckman, D.J. Garrick, S. Willmon, W. Vanderwert and R.M. Enns. 2006. Parameter estimates and breeding values for days to finish to a constant endpoint. Abstract. Journal of Animal Science 84, Suppl.2, 143. Bullock, K.D., D.R. Strohbehn, R.L. Weaber, E.J. Pollak, D.J. Garrick, J.K. Bertrand, D.W. Moser and J.M. Reecy. 2006. From research to application: a model for educating beef producers in animal breeding technologies. Proceedings of the Eighth World Congress on Genetics Applied to Livestock Production. 34_601-850 Burns, E. M., R. M. Enns, and D. J. Garrick. 2006. The effect of simulated censored data on estimates of heritability of longevity in the Thoroughbred racing industry. Genet. Mol. Res. 5(1): 7-15. Crews, D. H., Jr., R. M. Enns, J. M. Rumph, E. J. Pollak, and R. L. Quaas. 2006. Genetic correlations of component carcass traits with retail product percentage in Simmental cattle. Proc. West. Sect. Am Soc. An. Sci. 57: 75-78. Enns, R. M., D. J. Garrick, and B.W. Brigham. 2006. Economic values of heifer pregnancy and calving ease vary with average herd performance. Proceedings of the 8th World Congress on Genetics Applied to Livestock Production. Paper: 31-03. Belo Horizonte, Brazil. 4 pages (no page numbers on CD). Enns, R.M. 2006. The Role of economically relevant and indicator traits. In: Beef Sire Selection Manual. National Beef Cattle Evaluation Consortium. Eds: K.D. Bullock, coordinator. pp. 51-54. Enns, R.M., D.J. Garrick and B.W. Brigham. 2006. Economic values of heifer pregnancy and stayability vary with average herd performance. Proceedings of the Eighth World Congress on Genetics Applied to Livestock Production. 31_927-2053. Garrick, D.J. 2006. Development of genetic evaluations and decision support to improve feed efficiency. Proceedings of the Beef Improvement Federation's 38th Annual Research Symposium and Annual Meeting. 38:32-40. Garrick, D.J. 2006. Genetic improvement - assessing the ramifications of genetic change. Invited. Proceedings of the Eighth World Congress on Genetics Applied to Livestock Production. 3_466-1550. Garrick, D.J. 2006. The evaluation, interpretation and relevance of stayability in genetic improvement of beef cattle. Invited. Abstract. Journal of Animal Science 84, Suppl.2, 87. Lopez-Villalobos, N. and D.J. Garrick. 2006. Crossbreeding Systems for Dairy Production in New Zealand. Invited. Invited. Proceedings of the Eighth World Congress on Genetics Applied to Livestock Production. 32_1024-1774. Olson, K.M., D.J. Garrick, and R.M. Enns. 2006. Predicting breeding values and accuracies from group in comparison to individual observations. J. Anim. Sci. 84: 88-92. Shirley K.L., D.J. Garrick, T. Grandin, M. Deesing. 2006. Inheritance of facial hair whorl attributes in holstein cattle. Proceedings Western Section, American Society of Animal Science , 57:63-66. Shirley, K.L., D.J. Garrick, T.Grandin and M. Deesing. 2006. Inheritance of facial hair whorl attributes in Holstein cattle. Abstract. Journal of Animal Science 84, Suppl.2, 141-142. Speidel, S. E., R. M. Enns, and D. J. Garrick. 2006. Potential re-ranking of sires for weaning weight in above- and below-average environments. Proc. West. Sect. Am Soc. An. Sci. 57: 82-85. Speidel, S.E., R.M. Enns and D.J. Garrick. 2006. Insignificant re-ranking of sires for weaning weight in above- and below-average environments. Abstract. Journal of Animal Science 84, Suppl .2, 143. Thomas, M. G., G. A. Silver, R. M. Enns. 2006. Relationships of DNA polymorphisms in growth hormone (GH) to growth and carcass traits observed in a population of Brangus bulls with larger number of sires. Plant and Animal Genome XIV: 233 Tseveenjav, B., D.J. Garrick and Y. Zagsduren. 2006. Simulation model for cashmere production system to improve fiber quality in Mongolia. Proceedings of the Eighth World Congress on Genetics Applied to Livestock Production. 5_162-361. Welsh, C. S., D. J. Garrick, R. M. Enns, and G. B. Nicoll. 2006. Threshold model analysis of lamb survivability in Romney sheep. New Zealand J. of Ag. Res. 49:411-418. Williams, J. L., D. J. Garrick, R. M. Enns, and K. L. Shirley. 2006. Inheritance of hair slickness score and its correlation with growth. Proc. West. Sect. Am Soc. An. Sci. 57: 29-31. |