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Animal Genetic Improvement in Tropical Area Asst.Prof.Dr. Wuttigrai Boonkum Department of Animal Science, Faculty of Agriculture Khon Kaen University
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Why is heat stress important ? The Tropics HOT, HOTTER Temperatures have risen more in the Arctic than in the tropics.
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Economic losses Economic impacts of heat wave on dairy industry about $1 Billion 2003 economic loss $897 to $1500 million in US 2006 California heat wave kills 16,500 dairy cows statewide >2,000 cattle died in Nebraska during June 2009 2002 to 2007, Summer was the seasons with the highest of dairy deaths (15,773) in Italy
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Conclusions Global Change / Heat Stress Temp. THI Moderate Heat Stress Severe Heat Stress
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How heat stress occur ? Cold stress Heat stress Thermoneutral zone Heat production Ambient temperature 4-24 o C Lower critical temp. Upper critical temp. humidity
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Heat stress effects THI > 72 for production and around 68 for reproduction are considered to indicate heat stress in dairy cattle
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How heat stress occur ? pantingsweatingrespirationfeed intakeruminationwater intake
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How to reduce the effects of heat stress ? adjustment of housing and facilities adjustment of housing and facilities Feed and Feeding management Feed and Feeding management Crossbreeding system x B.indicus B.taurus Production traits
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How to reduce the effects of heat stress ? avoiding breeding during hot conditions avoiding breeding during hot conditions estrus synchronization timed artificial insemination timed artificial insemination Fertility traits
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Alternative method Housing and Shading management Housing and Shading management Feed and Feeding management Feed and Feeding management Crossbreeding system x B.indicus B.taurus Temporary/non sustainable Production traits avoiding breeding during hot season avoiding breeding during hot season estrus synchronization timed artificial insemination timed artificial insemination Fertility traits Temporary/non sustainable Genetic selection
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What traits are interest to study? Using regular monthly milk records THI information at the collecting date Ravagnolo and Misztal, (2000) Using days open records Genetic selection How heat stress affect on genetic ?
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Heat stress in Thailand Stress all time
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Results: Determination of heat stress threshold
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Publication
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Results: LSM and HI for DO summer winter
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ปัจจัยที่สัมพันธ์ต่อการเกิด ความเครียดเนื่องจากร้อนในโคนม Length of exposure to heat stress Level of production Stage of lactation Cooling management Feed consumption Feed offered Breed cattle species Size of the animal
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National genetic evaluation under hot-humid climates of Thailand Department of Animal Science, Faculty of Agriculture, Khon Kaen University Implications : Estimated breeding value; EBV THI Threshold point Best genetic performance for milk production under heat stress conditions
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Ent1 Ent2 Genetic effect Animal 1 Animal 2 Ent1 Ent2 Genetic effect Animal 1 Animal 2 No G x E interaction Reranking G x E interaction Ent1 Ent2 Genetic effect Animal 1 Animal 2 Scaling G x E interaction
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Conclusions
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ค่า EBV ของพ่อพันธุ์โคนมของกรมปศุสัตว์ปี 2553
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Another approach Integration of DNA Marker Technology DNA Marker ที่สัมพันธ์กับลักษณะสำคัญ ของโคนมเขตร้อน Disease Resistance Fertility trait Milk Production ยีนต้านทาน โรคเต้านมอักเสบ DRB3 ยีนต้านทาน โรคไข้เห็บ QTL Marker Leptin gene Heat tolerance HSP70 gene QTL marker RM188
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Marker for Heat tolerance (HSP70) B B C C A A Heat tolerant
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Marker for Fertility (Leptin) 1 522 bp อัลลีล A 522 bp อัลลีล B 441 bp B B Short Days Open
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Marker for Tropical Dissease resistance (DRB3) 689 bp 345 bp B. bigeminaA. marginale B. bovis 446 bp Anaplasma marginale DRB*51 Babesia bovisDRV*3, DRB*13, DRB*15, DRB*46? Babesia bigeminaDRB*10, DRB*15, DRB*46 Tickborne fever Resistant
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Genomic Selection in Dairy Cattle
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Genomic selection P = G + E Genetic evaluation or Molecular genetics Need time and data complete Appropriated major gene only
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Reliability of breeding values 50% reliability is realistic
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Advantages of Genomic Selection Increased genetic improvement (30-40%) Higher genetic level of test sires Higher genetic level of Delta embryo’s Wider portfolio of commercial bulls & higher level More outcross; less inbreeding
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Disadvantages of Genomic Selection New method, not fully proven or tested Need to genotype a sufficiently large set of animals for accurate GEBV Across breed accuracy low Genotypes still costly (10,000 bath/head)
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ROI-ET FRIESIAN High milk production 15 kg/d Fertility Heat tolerance Tropical disease resistant Tick fever Mastitis Thermoregul ation Heat response Longevity GPX Functional trait Type triat Skin type Survival/Culling Pregnancy rate Conception rate Conclusions
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