Department of Animal Science, University of California, Davis, CA USDA, Agricultural Research Service, Miles City, MT 59301

Transcription

1 What weighting should be given to BRD resistance in selection decisions? 1 Department of Animal Science, University of California, Davis, CA USDA, Agricultural Research Service, Miles City, MT Animal Genomics and Biotechnology Education

2 Overview Which traits are likely to benefit from genomics? What is the value of emerging molecular breeding values (MBV) for economically-relevant traits (ERT) for which no breed EPD exist? Bovine respiratory disease (BRD) The problem The potential Calculating relative economic value of BRD Industry structure implications

3 Potential benefits of genomics are greatest for economicallyimportant traits that Are difficult or expensive to measure Cannot be measured until late in life or after the animal is dead Are not currently selected for because they are not routinely measured Have low heritability Have undesired correlations with other economic traits Yep, looks like none of em were resistant Animal Genomics and Biotechnology Education

4 Genomics may increase the value of genetic gain ( G) appreciably if it enables: 1. Selection for economically-relevant traits (ERTs) that were previously omitted from breeding objectives due to lack of selection tools/criteria 2. The introduction of novel traits into the breeding objective, or 3. The development of high-value markets with new product specifications. Animal Genomics and Biotechnology Education

5 Determining the value of genomics Genomic information should not require any fundamental changes to the development of breeding objectives and selection index calculation Selection emphasis for new genomicallyenabled traits will need to be weighted by effect on profitability relative to other economically-important traits What is the relative economic value of these new traits in the breeding objective? Animal Genomics and Biotechnology Education

6 BRD: THE PROBLEM Year in and year out, diseases of the respiratory system are a major cause of illness and death in cattle from 6 weeks to two years of age. Sadly, this is as true today as it was 30 years ago despite development of new and improved vaccines, new broad spectrum antibiotics, and increased fundamental knowledge as to the cause of disease Montgomery, D Bovine Respiratory Disease & Diagnostic Veterinary Medicine. Proceedings, The Range Beef Cow Symposium XXI. December 1, 2 and , Casper, WY. Pages 1-6.

7 Bovine respiratory disease pathogens The etiologic agents associated with BRD include viruses bovine herpesvirus 1 bovine parainfluenza virus 3 bovine viral diarrhea virus 1 and 2 bovine respiratory syncytial virus bovine adenovirus A-D bovine coronavirus And bacteria Arcanobacterium pyogenes Manheimia haemolytica Pasteurella multocidaa Histophilus somni Mycoplasma spp.

8 Background and Rationale Bovine Respiratory Disease (BRD) has been extensively studied since the 1800s, and yet it remains prevalent More effective vaccines have not decreased the morbidity or mortality of BRD Mortality has increased as vaccine efficiency has increased 1.4% of all US feedlot cattle perish before reaching harvest weight Need to develop new approaches to tackle BRD Because of the high economic cost associated with BRD incidence, even these modest estimates (0.11) for heritability of BRD resistance should be considered for incorporation into beef cattle breeding programs * * Schneider, M.J., et al., Evaluation of fixed sources of variation and estimation of genetic parameters for incidence of bovine respiratory disease in preweaned calves and feedlot cattle. J. Anim Sci. 88: p

9 Disease resistance is a very attractive target trait The presence of genetic variation in resistance to disease, coupled with the increased consumer pressure against the use of drugs, is making genetic solutions to animal health problems increasingly attractive. The non-permanent effectiveness of chemical agent (due to development of resistance by the pathogen) further contributes to this interest. Newman, S. and Ponzoni, R.W Experience with economic weights. Proc. 5 th World Congress on Genetics Applied to Livestock Production. 18:

10 Other animal industries have successfully targeted selection for disease resistance In dairy cattle, selection programs have been developed to take advantage of genetic variability in mastitis resistance, despite the fact that the heritability of clinical mastitis is low and mastitis resistance has an adverse correlation with production traits Likewise chicken breeders have long used breeding to improve resistance to avian lymphoid leucosis complex and Marek s disease Stear, M. J., S. C. Bishop, B. A. Mallard, and H. Raadsma The sustainability, feasibility and desirability of breeding livestock for disease resistance. Res Vet Sci 71: 1-7

11 Objective To calculate the weighting (i.e. relative economic value) that should be given to selection for BRD resistance in a multi-trait selection index for Angus terminal sires.

12 Scenario A 1000 cow-calf enterprise and retained ownership was assumed All progeny of terminal sires were harvested and so no economic value was associated with maternal traits Only phenotypes for weaning weight, feedlot average daily gain, feed intake, USDA yield grade, marbling score and BRD incidence (%) contributed to the breeding objective. The feedlot phase was divided into three periods. The first period (backgrounding) was terminated at a weight-constant end point of 850 lb. The second (growing) and third (finishing) periods were of 50 and 100 days duration, respectively.

13 Assumptions BRD occurred when calves were moved to the feedlot phase at weaning incidence rate of 10% the fixed cost of feedlot phase was unchanged a dead calf incurred no feed costs there was a 10% mortality from BRD there was a 13% reduction in ADG (1.3 lbs/d) for the first phase of feeding (weaning to 850 lbs) final yield grade was reduced by 0.1 the cost to diagnose and treat a BRD calf was $44

14 Prices, premiums and discounts used in developing the multi-trait selection index for Angus terminal sires. Weaned calf weight (lb) $/lb $/100lb < Prime High Choice Choice Select Standard > Yield Grade Carcass weight (lb) $/100 lb Yield Grade Base price Yield Grade < Quality/Yield Grade > Yield Grade

15 Results Trait (unit) Economic Value ($) Genetic SD Relative economic value (REV) Relative importance (relative to YG) BRD incidence (%) Weaning wt. (lb) Feed Intake (lb/d) Feedlot ADG (lb/d) Marbling score Yield Grade

16 Ninety percent of US cattle operations have fewer than 100 head, and most sell their cattle at auction prior to feedlot entry This relative economic value scenario was developed to maximize the profitability of a verticallyintegrated (retained ownership) production system In reality most producers financial returns are tied very closely to the number of calves, a function of reproduction, and less to feedlot performance and carcass traits, and even less to bovine respiratory disease incidence. To incentivize the inclusion of BRD resistance in selection decisions, a mechanism analogous to a calf preconditioning bonus would be needed to equitably share some of the value derived from reduced feedlot disease incidence and to compensate breeders and producers for reducing selection emphasis on other economically-relevant traits.

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20 Parnell, P.F Effective value chain partnerships are essential for rapid adoption of beef genetics technology. Association for the Advancement of Animal Breeding and Genetics

21 Ideally cattle would be genotyped once early in life and genotypes shared among production sectors to derive the maximum value from the fixed DNA collection and extraction costs Use Seedstock Nucleus Commercial Feedlot Processor DNA-assisted selection XXXX X XXXX XXXX Parentage XX X Recessive allele testing XX X Control of Inbreeding XX X Mate selection XX X DNA-assisted management Product differentiation Traceability X XX XX XX

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23 ? Integrated Program for Reducing Bovine Respiratory Disease in Beef and Dairy Cattle Jim Womack, PD Alan Dabney Scott Dindot Noah Cohen Chris Seabury Lawrence Falconer Lauren Skow Gary Snowder Holly Neibergs Shannon Neibergs Laurel Gershwin Terry Lehenbauer Cassandra Tucker Alison Van Eenennaam Mark Enns Jerry Taylor Funding for this project is provided by the National Institute of Food and Agriculture Mike MacNeil Curt Van Tassell Milt Thomas Robert Hagevoort Tim Ross OTHER COLLABORATORS Daniel Pomp (NC) Shiela McGuirk (WI) Adroaldo Zanella (Norway) Animal Bovine Biotechnology Respiratory and Disease Genomics Consortium Education

24 Our goal is to integrate research, education, and extension activities to develop cost-effective genomic and management approaches to reduce the incidence of BRD in beef and dairy cattle The objective of this multi-institutional project is to reduce the incidence of bovine respiratory disease by: Capitalizing on recent advances in genomics to enable novel genetic approaches to select for disease-resistant cattle Developing improved DNA-based tests for disease diagnosis Producing and delivering a variety of educational materials for beef and dairy cattle producers, and feedlot personnel on best management practices to reduce disease incidence Providing educational opportunities for undergraduate, graduate and veterinary students to generate a future human resource for the continued reduction in bovine respiratory disease incidence Animal Bovine Biotechnology Respiratory and Disease Genomics Consortium Education

25 BRD Coordinated Agricultural Project

26 BRDC Industry and Scientific Advisory Board Mike Engler, PhD, Heather Burrow, PhD, CEO President, CEO Cactus Feeders Cooperative Research Centre for Immediate-Past Chairman, Beef Genomics in Australia Texas Cattle Feeders Association Tom Field, PhD Director of Producer Education National Cattlemen s Beef Association Michel Georges, DVM, PhD Professor Unit of Animal Genomics University of Liège, Belgium Walter Guterbock, DVM, MS Manager, Columbia River Dairy, OR Pamela Hullinger, DVM Clinical Professor Department of Medicine and Epidemiology UC Davis, CA Harris Lewin, PhD Vice Chancellor for Research UC Davis, CA Dan Grooms, DVM, PhD Extension Veterinarian Michigan State University, MI Bovine Respiratory Disease Consortium

27 RESEARCH HYPOTHESIS: Genetic selection for resistance to BRD coupled with improved animal health management can provide a significant, sustainable, and profitable reduction in the prevalence of BRD. Holly Neibergs, Washington State University, Research Coordinator The research component of this proposal will identify genetic loci and genomic rearrangements associated with BRD, and use these data to develop DNAbased BRD diagnostic tests and selection tools to identify BRD-resistant animals. Incorporating BRD into genetic evaluations and selection decisions offers a sustainable approach to reduce disease incidence. Selection for resistant animals will ultimately result in improved welfare, reduced antibiotic use and handling costs, superior production efficiency, and improved profitability. Reverse Site Visit 11/30/2010 Bovine Respiratory Disease Consortium

28 EDUCATION HYPOTHESIS: Didactic and experiential learning approaches describing the complex issues associated with BRD in the cattle industry will be most effective in preparing students to make the management decisions needed to reduce BRD impact. Milt Thomas, New Mexico State University, Education Coordinator The education component will develop undergraduate courses, and offer educational and research internships to cultivate a future human resource for continued reduction in BRD prevalence. 4-H youth will be exposed to approaches to minimize BRD though participation in educational games and instruction. Bovine Respiratory Disease Consortium

29 EXTENSION HYPOTHESIS: An integrated multidisciplinary approach to reducing BRD will be more successful than approaches which address only one aspect of the disease or a single sector of the cattle industry. Alison Van Eenennaam, University of California - Davis, Extension Coordinator The extension component will employ Advisory panel guidance to develop a sustained effort to disseminate, demonstrate, evaluate and document the impact of a range of educational outreach materials and best management practices for beef and dairy cattle producers, and feedlot personnel. All educational and outreach materials will be integrated into extension to ensure their continued accessibility. Bovine Respiratory Disease Consortium

30 CONCLUSIONS Genomic may enable selection for novel traits Need to derive relative economic value of these traits USDA National Institute of Food and Agriculture has recently funded two large 5-year, multi-institution grants on genomic approaches to feed efficiency and BRD Both projects employ high-density genotyping of large numbers of animals Both traits are valuable especially to the feedlot sector Will beef industry need to evolve a more verticallyintegrated structure to drive investment in using genomics to make genetic improvement in feedlot traits?

31 Parting thought. Breeds/groups that can organize themselves to take advantage of the rapidly-declining cost of genotyping and capture the cumulative supply chain value derived from using genomic information for multiple purposes (selection, parentage, genetic defects, marker-assisted management, product differentiation, traceability) will be ideally positioned to fully realize the nascent potential of genomic information.

32 The Integrated Program for Reducing Bovine Respiratory Disease Complex (BRDC) in Beef and Dairy Cattle Coordinated Agricultural Project is supported by Agriculture and Food Research Initiative Competitive Grant no and the DNA value determination project was supported by National Research Initiative competitive grant no ( Integrating DNA information into beef cattle production systems ) from the USDA National Institute of Food and Agriculture.