Strategies to maintain genetic diversity in rare breeds of livestock

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Strategies to maintain genetic diversity in rare breeds of livestock. Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13. Why is genetic diversity important?. Genetic diversity and inbreeding are inversely related - PowerPoint PPT Presentation

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<ul><li><p>Strategies to maintain genetic diversity in rare breeds of livestockMark Knauer, PhDNorth Carolina State University Swine Extension SpecialistALBC 11-8-13</p></li><li><p>Why is genetic diversity important?Genetic diversity and inbreeding are inversely relatedTherefore, we work to keep inbreeding at a minimumWhat is inbreeding?Mating together animals that are related by ancestry</p></li><li><p>Inbreeding is unfavorableImpaired reproductionAdapted from Bereskin et al. (1968)</p></li><li><p>Inbreeding is unfavorableImpaired survivalAdapted from Bereskin et al. (1968)</p></li><li><p>Inbreeding is unfavorableImpaired growth performance</p><p>Adapted from Bereskin et al. (1968)</p></li><li><p>Inbreeding is unfavorableLargest reproductive issueGetting females bred &amp; continuing the population</p></li><li><p>Inbreeding is unfavorableIncreased incidence of genetic defectshermaphrodites</p></li><li><p>Other genetic defects</p></li><li><p>Calculating inbreeding</p><p>Where t = generation and F = 1/2NeWhere Ne = the effective population sizeFt = 1 (1 - F)t</p></li><li><p>Maintaining genetic diversity </p><p>Reduce the rate of inbreeding Ft = 1 (1 - F)t</p></li><li><p>Avoid mating close relativesAvoid mating in order of importanceParents and offspringFull siblings - brothers and sisters siblings brothers and sisters</p></li><li><p>Increase your population size</p></li><li><p>Increase the number of herd sires usedImportant to use as many males as possibleUsing a couple or several males, instead of just 1, significantly reduces inbreedingfavorableunfavorable</p></li><li><p>Bring in outside genetics live animals</p></li><li><p>If boar is too smallCollect semen off of the sow in heatInseminate sow with collected semenUse a breeding crateIf boar is too bigTrain to mount an AI dummyUse a breeding crateWhat if your new boar is too large/too small for your females? </p></li><li><p>Train to mount an AI dummy</p></li><li><p>Use a breeding crate</p></li><li><p>Bring in outside genetics semen</p></li><li><p>Develop a grade up program heritage 3/4 heritage 7/8 heritage</p></li><li><p>Maintaining genetic diversity </p><p>Lengthen the generation interval Ft = 1 (1 - F)t</p></li><li><p>Generation interval</p><p>Where L = generation interval</p><p>L = Lm + Lf2________</p></li><li><p>Lengthen the generation intervalDo not keep offspring out of gilt littersKeep offspring out of old boars and old sows</p></li><li><p>Keep offspring out of older parentsRate of inbreeding is 3 times less in scenario 2 vs. 1.</p><p>Age of boar (yr)Age of sow (yr)Generation intervalScenario 1211.5Scenario 2544.5</p></li><li><p>Strategies to maintain genetic diversityAvoid mating close relativesIncrease your population sizeIncrease the number of males used for breedingBring in outside geneticsLive animal introductionsSemenDevelop a grade up programLengthen the generation interval</p></li><li><p>Thank you all for your hard work!Maintaining heritage breeds can be challengingImportant to maintain the genetic diversity associated with heritage breeds</p></li><li><p>Thank you for your timeMark Knauermtknauer@ncsu.edu</p></li><li><p>Strategies to reduce inbreedingSample outside geneticsAt least once every 3 yearsLengthen your generation intervalRetain old sowsAvoid matingBrothers and sisters brothers and sistersParents and siblings</p></li><li><p>Strategies to reduce inbreedingSample outside geneticsAt least once every 3 yearsLengthen your generation intervalRetain old sowsAvoid matingBrothers and sisters brothers and sistersParents and siblings</p></li><li><p>Strategies to reduce inbreedingSample outside geneticsAt least once every 3 yearsLengthen your generation intervalRetain old sowsAvoid matingBrothers and sisters brothers and sistersParents and siblings</p></li><li><p>Other benefits of using AIGenetic improvementOnly one best herdGenetic cost - may be less expensive to use AI than maintain a boarHow many sows do you have?Increase number of potential matingsHow many of you have had a boar that was too big or too small to breed a desired female?</p></li><li><p>Other benefits of using AIGenetic improvementOnly one best herdGenetic cost - may be less expensive to use AI than maintain a boarHow many sows do you have?Increase number of potential matingsHow many of you have had a boar that was too big or too small to breed a desired female?</p></li><li><p>Other benefits of using AIGenetic improvementOnly one best herdGenetic cost - may be less expensive to use AI than maintain a boarHow many sows do you have?Increase number of potential matingsHow many of you have had a boar that was too big or too small to breed a desired female?</p></li><li><p>SummaryMultiple potential benefits to adopting AIMaintain genetic diversity!Genetic improvementReduce genetic costIncrease boar usageYou are taking a positive step today towards the benefits of AI technology</p></li><li><p>Why should you use AI?1# reason genetic diversity</p><p>Inbreeding causes inbreeding depression which is characterized by reduced fitness</p></li><li><p>Why should you use AI?Inbreeding - the breeding or mating of related individuals within a closed group animalsWhen is the last time you introduced outside genetics into your herd?</p><p>*</p></li></ul>