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A nimal improvement in the tropics. Written by Wuttigrai Boonkum. The Arctic. HOT, HOTTER Temperatures have risen more in the Arctic than in the tropics. The Tropics. Studies trend about climate change. Nowadays, biologists worry primarily
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Animal improvement in the tropics Written by WuttigraiBoonkum
The Arctic HOT, HOTTER Temperatures have risen more in the Arctic than in the tropics. The Tropics
Studies trend about climate change Nowadays, biologists worry primarily about global warming’s effects on life in the Arctic
Hot temperature affecting creatures in the tropics “It’s taken a while for people to start applying the thinking of climate change to the tropics” says tropical ecologist Catherine Cardelús.
Arctic temperature increases could double those in the tropics 1.5OC 0.5OC metabolic changes in each region’s ectotherms would still be about equivalent. 1961 -------------------> 2010 Year
“You can’t assume that the temperature patterns tell you what the effects on biology will be”
Cow(head) Consume quantity(kg) Milk production(kg) Statistical for cow, milk and consume quantity Figure 1 Number of dairy cattle, milk production and consume quantity in Thailand Source:สำนักงานเศรษฐกิจการเกษตร (2550)
Why is heat stress important ? January 2003, NASA July 2003, NASA Red color is high heat area Yellow color is moderate heat area
respiration rumination sweating feed intake water intake panting Heat stress Heat stress on physiology Department of Animal Science, Faculty of Agriculture, Khon Kaen University
Why is heat stress important ? Heat stress low milk yield low feed intake die low fertility well-being
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
How heat stress occur ? Lower critical temp. Upper critical temp. Cold stress Thermoneutral zone 4-24 oC Heat stress humidity Heat production Ambient temperature
Heat stress in the world ในต่างประเทศ heatv stress สำคัญแค่ไหน บอกว่าทำไมประเทศไทยถึงสนใจอิทธิพลของ heat stress รูปโลก มีแผนที่ประเทศไทย ได้รับอิทธิพลจากลมมรสุม THI > 72 for production and around 68 for reproduction are considered to indicate heat stress in dairy cattle
x How to reduce the effects of heat stress ? Production traits adjustment of housing and facilities Feed and Feeding management Crossbreeding system B.indicus B.taurus
How to reduce the effects of heat stress ? Fertility traits avoiding breeding during hot conditions estrus synchronization timed artificial insemination
x Alternative method Production traits Fertility traits Genetic selection avoiding breeding during hot season estrus synchronization timed artificial insemination Housing and Shading management Feed and Feeding management Crossbreeding system Temporary/non sustainable B.indicus B.taurus Temporary/non sustainable
What traits are interest to study? Genetic selection Ravagnolo and Misztal, (2000) • Using regular monthly milk records • THI information at the collecting date • Using days open records How heat stress affect on genetic ?
Rectal temperature || milk temp. || physiological responses National genetic evaluation under hot-humid climates of Thailand Heat stress Department of Animal Science, Faculty of Agriculture, Khon Kaen University Milk production Temperature – humidity index; THI
ปัจจัยที่สัมพันธ์ต่อการเกิดความเครียดเนื่องจากร้อนในโคนมปัจจัยที่สัมพันธ์ต่อการเกิดความเครียดเนื่องจากร้อนในโคนม • 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
Expected benefits : Increase milk production level Improve genetic performance for heat tolerance National genetic evaluation under hot-humid climates of Thailand Department of Animal Science, Faculty of Agriculture, Khon Kaen University
Implications : Threshold point Best genetic performance for milk production under heat stress conditions National genetic evaluation under hot-humid climates of Thailand Estimated breeding value; EBV Department of Animal Science, Faculty of Agriculture, Khon Kaen University THI
Animal 1 Animal 2 Genetic effect Ent1 Ent2 No G x E interaction Animal 1 Animal 2 Genetic effect Genetic effect Animal 2 Animal 1 Ent1 Ent2 Ent1 Ent2 Scaling G x E interaction Reranking G x E interaction
Figure 2 Genetic lactation curve of top 5 sires separated by region in Thailand; all region (a), north (b), central (c), north east (d), east (e), and west (f).