Study Of Heat Tolerance Traits Genetic Markers In Chinese Holstein Using RAPD

The Heat Stress in Dairy Cattle means the Dairy Cattle's body is subjected toexceed the body temperature regulates the heat incitement of ability, function in hangone adrenal glands skin quality system of body so that make the non- particularitydefense that the machine body cause respond and the particularity obstacle at inside ofwhole body adaption.When the air temperature is in the 5.0℃-24℃, the dairy cattleis placed in the best physiology appearance, When the air temperature rise, formaintaining the normal body temperature, the dairy cattle will lower to eat thequantity, producing the amount of milk to descend 10-25%, the butter rate and milkperotein rates descend, the immunity function descend, maintain to need to be rise,and cause produce the milk efficiency to descend.In this article,using half-sib correlation in bull method estimate heritability ofmilk yield, heritability of milk yield of heat tolerance and heritability of Potassiumcontent in Erythrocyies. the effects of concentration of Mg²⁺, dNTPs, random primers,template DNA,TaqDNA polymerase and anneal temperature on RAPD were analyzedwith Holstein cattle. An optimalized RAPD system with total volume 20μL includingMg²⁺ at 2.5 mmol/L, TaqDNA polymerase at 1 U, random primers at 2μmol/L,dNTP at 400μmol/L, template DNA at 100ng.The reaction program with 2 minutesat 94℃,which is followed by 40 cycles,each with 1 minutes at 94℃,1 minutes at 36℃,1 minutes at 72℃,and a final extension at 72℃for 5 minutes. In this experiment,with 10 high yield Holstein Cattle as materials, we was optimized RAPD reactionsystem. And 64 primers with better effect were selected in 154 random primers.Considered the detected result of potassium content in erythrocyte and productionperformance, three molecular markers relative to heat-tolerance in Holstein Cattlewere selected. We expect the research that helps to establish high-yield and high heattolerance dairy cattle breed.