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1、NutritionalandManagementStrategiestoReduceHeatStressImpactsonDairyCows減少奶牛熱應(yīng)激的營養(yǎng)及管理措施BobCollierProfessorandDirectorUniversityofArizona佐治亞大學(xué)教授、農(nóng)學(xué)及生物學(xué)院院長Introduction介紹?Allanimalshaveazoneofthermoneutraltemperaturesconducivetonormalfunction所有動物都有一個適合最佳功能的熱中性溫度區(qū)?Theuppercriticaltem
2、peratureiswheretheeffectsofheatstressstarttoappear達到這個臨界溫度的上限就就開始出現(xiàn)熱應(yīng)激HeatStress熱應(yīng)激?Thepointatwhichadairycow(orotheranimal)cannotdissipateanadequatequantityofheattomaintainbodythermalbalanceornormalbodytemperature熱應(yīng)激即奶牛不能釋放足夠的熱量以維持身體熱平衡或正常的體溫EffectofSeasononMilkandProteinYieldi
3、nDairyCows季節(jié)對牛奶及乳蛋白產(chǎn)量的影響39.001.1538.001.1037.001.0536.0035.001.00Protein(kg/d)MilkYield(kg/d)34.00MilkYield0.9533.00Protein32.000.90JanFebMarAprMayJunJulAugSepOctNovDecAdaptedfromBarashetal.J.DairySci.84:2314EffectofMonthofCalvingonBirthweightofHolsteinCalves產(chǎn)犢季節(jié)對荷斯坦犢牛初生重的影響Sum
4、mertoWinterRatio夏季冬季比率Israel臨界溫度下限臨界溫度上限熱平衡區(qū)間冷應(yīng)激最佳生產(chǎn)健康冷應(yīng)激冷熱有效環(huán)境溫度低高Source:NRC,1981SummertoWinterRatio夏季冬季比率Arizona佐治亞?Winter冬季(Dec-Feb)30.1kg/day?Summer夏季(June-Aug)26.1kg/day?Summer/WinterRatio夏季冬季比率0.86–22DHIAHerds2006WhatWeDon’tKnow我們所不知道的是Wearegivingup4kg/cow/day每天損失4公斤/頭Ona
5、4000cowdairythatis352cwt/dor$4576at$13milkStrategiesForImprovingHeatToleranceinCattle改善奶牛熱耐受力的措施?HeritabilityEstimatesofEnvironmentalEffects環(huán)境影響的可遺傳性–Sizeofopportunity可能性?MINIMIZEHEATGAINANDMAXIMIZEHEATLOSS減少熱量獲取增大散熱–ManagementandHousing管理及牛舍–Genesregulatingskin&haircoat調(diào)節(jié)皮膚及皮毛
6、的基因–NutritionalStrategiestoMaximizeHeatLoss增加散熱的營養(yǎng)措施?HomeorheticControlSystem調(diào)控系統(tǒng)–GeneticMarkers遺傳標記物–NutritionalManagement營養(yǎng)管理?IMPROVECELLULARSTRESSRESPONSE改善細胞應(yīng)激反應(yīng)–GenesregulatingHeatShockresponse基因調(diào)控?zé)釕?yīng)激反應(yīng)–AcclimatoryControls適應(yīng)性控制ProductionandHeatOutput產(chǎn)熱及散熱?Since1950,heatpro
7、ductionpercowhasincreasedanaverageof30MJor28,000Btu/dayintheHolsteinbreed自從1950年荷斯坦奶牛的平均產(chǎn)熱量增加了30MJ/天?Thisrequiresreevaluatingtherelationshipbetweenambienttemperature,milkyieldandthermalstresslevelincattle這需要重新評估牛舍溫度、奶產(chǎn)量及奶牛的應(yīng)激水平TemperatureHumidityIndex(THI)溫度濕度指數(shù)?Includesbothtem
8、peratureandhumidityindeterminingthepointsatwhichheatst
