【作者】 刘庆华；

【导师】 王根林； 梁学武；

【作者基本信息】 南京农业大学 ， 动物遗传育种与繁殖， 2009， 博士

【摘要】 本研究目的在于揭示娟荷杂交牛耐热性能及其机理,为培育我国的耐热品系奶牛积累基础。通过分析娟荷杂交牛和荷斯坦奶牛产奶性能,测定热应激对血液流变学、血清无机离子浓度、酶活性、一氧化氮合成酶(NOS)活力、一氧化氮(NO)浓度、丙二醛(MDA)含量、总超氧化物歧化酶(T-SOD)活力、总抗氧化能力(T-AOC)的变化情况,分析不同群体奶牛在不同环境温度下免疫功能指标的变化,探讨高温环境对奶牛免疫功能的影响规律,同时对血液HSP70的表达、HSP基因多态性与荷斯坦和娟-荷杂交牛耐热性能的相关性进行了分析。结果表明,与荷斯坦奶牛相比,娟荷杂交牛耐热性能较强,并初步探讨了其耐热应激的相关机理。1娟荷杂交牛培育及与荷斯坦奶牛性能比较选用第1胎次、产犊日期、产奶量相近的娟荷杂交一代牛、娟荷级进杂交二代牛和荷斯坦奶牛各10头,测定全期泌乳性能及热应激期的体温、皮温、呼吸率及产奶性能等指标。结果表明：在热应激期间牛舍内平均温度为31.10℃(20.13℃～39.40℃),温湿度指数THI平均为81.75条件下,娟荷杂交一代牛、娟荷级进杂交二代牛直肠温度、皮温、呼吸频率与荷斯坦牛比均差异显著(P<0.05),娟荷杂交一代牛、娟荷级进杂交二代牛之间差异不显著(P>0.05)。在同一营养水平下,娟荷杂交一代牛、娟荷级进杂交二代牛乳中乳脂率、乳蛋白率、乳总固体物都比荷斯坦高,其中乳脂率和乳蛋白率均差异极显著(P<0.01)。305 d泌乳量和4%标准奶量荷斯坦牛均高于娟荷杂交一代牛、娟荷级进杂交二代牛,但差异均不显著(P>0.05)。从单位体重产奶量及料奶比指标看,娟荷级进杂交二代牛与娟荷杂交一代牛、荷斯坦牛之间差异显著(P<0.05),娟荷杂交一代牛与荷斯坦牛之间差异不显著(P>0.05)。荷斯坦牛、娟荷杂交一代牛、娟荷级进杂交二代牛7、8月份产奶量月下降率分别为14.50%、12.31%；13.89%、3.19%；13.38%、11.08%。产奶量月下降率娟荷杂交一代牛、娟荷级进杂交二代牛比荷斯坦牛下降幅度明显降低,差异显著(P<0.05)。结果表明娟荷杂交牛具有较好耐热性及较高生产性能。2热应激对奶牛血液流变学与生化指标的影响60头健康娟荷杂交牛和荷斯坦奶牛分为3组,分别于冬季12月份(牛舍日平均气温为10.35℃,THI为47.24)和次年夏季7月份(牛舍日平均气温为31.07℃,THI为82.61)条件下,测定热应激对血液流变学及血清无机离子浓度和酶活性的影响。结果表明：除血沉外,全血比黏度、血浆比黏度、红细胞压积荷斯坦牛、娟荷杂交牛夏季都明显升高,与冬季之间差异均极显著(P<0.01),但在夏季或冬季荷斯坦牛与娟荷杂交牛之间差异不显著。血清K+浓度娟荷杂交牛冬季与夏季之间差异显著(P<0.05),荷斯坦牛冬季与夏季之间以及荷斯坦牛与娟荷杂交牛之间差异不显著。热应激极显著降低血清Na+浓度、血清Ca2+浓度(P<0.01),但夏季或冬季荷斯坦牛与娟荷杂交牛之间差异不显著。血清Cl-浓度不同品种及季节之间差异均不显著。热应激显著升高谷丙转氨酶、碱性磷酸酶活性(P<0.05),但夏季或冬季各品种之间差异不显著。谷草转氨酶冬季荷斯坦牛与娟荷杂交牛之间差异显著(P<0.05),其余季节和品种之间差异均不显著。结果显示,娟荷杂交牛和荷斯坦奶牛的全血比黏度、血浆比黏度、红细胞压积、血清Na+浓度、血清Ca2+浓度以及谷丙转氨酶、碱性磷酸酶活性之间的差异均不显著,谷草转氨酶冬季荷斯坦牛与娟荷杂交牛之间差异显著(P<0.05),这些指标不同季节之间差异显著。这些指标可以作为奶牛热应激程度的参考指标。奶牛血液生理与生化指标与季节或外界温度变化关系较大,娟荷杂交一代牛、娟荷级进杂交二代血液生理与生化指标变化差异不显著。3热应激对奶牛抗氧化特性的影响60头健康娟荷杂交牛和荷斯坦奶牛分为3组,分别在冬季和夏季测定热应激对血清中一氧化氮合成酶(NOS)活力、一氧化氮(NO)浓度、丙二醛(MDA)含量,总超氧化物歧化酶(T-SOD)活力,总抗氧化能力(T-AOC)的变化情况。结果表明：不论荷斯坦牛还是娟荷杂交牛夏季血清中一氧化氮合成酶(NOS)活力都显著低于冬季一氧化氮合成酶(NOS)活力(P<0.01)；而夏季娟荷杂交牛血清中一氧化氮合成酶(NOS)活力显著低于荷斯坦牛血清中一氧化氮合成酶(NOS)活力(P<0.01)；但是冬季娟荷杂交牛和荷斯坦牛血清中一氧化氮合成酶(NOS)活力则差异不显著(P>0.05)。荷斯坦牛血清中NO浓度冬季与夏季差异显著(P<0.05),而娟荷杂交牛血清中NO浓度冬季与夏季差异不显著(P>0.05)；夏季荷斯坦牛与娟荷杂交牛血清中NO浓度差异不显著(P>0.05),而冬季荷斯坦牛和娟荷杂交牛血清中NO浓度差异显著(P<0.05)。夏季娟荷杂交牛血清中MDA含量显著低于荷斯坦牛(P<0.05)；T-SOD活力显著高于荷斯坦牛(P<0.05)；T-AOC有升高的趋势但差异不显著。在冬季,娟荷杂交牛与荷斯坦牛相比血清中的MDA含量、T-SOD活力和T-AOC均无显著差异。无论娟荷杂交牛还是荷斯坦牛,夏季与冬季相比血清中MDA含量、T-SOD活力均差异极显著,荷斯坦牛血清中T-AOC差异显著,而娟荷杂交牛血清中T-AOC无显著性差异。由此表明,热应激对奶牛的抗氧化能力产生显著的影响；夏季娟荷杂交牛的抗氧化能力高于荷斯坦牛,更能适应热带和亚热带地区高温高湿的气候条件。这为奶牛热应激的诊断和选育耐热奶牛品种提供理论根据。4热应激对奶牛免疫功能的影响采用MTT法、ELASA、玫瑰花环试验法等方法,对不同群体奶牛在接受不同温度环境后免疫功能指标的变化,来探讨高温环境对奶牛免疫功能的影响规律。研究发现：(1)从不同的月份采样测定的IgM,IgG,IgA总量差异均不显著(P>0.05)。娟荷杂交牛各个时期三类免疫球蛋白水平比荷斯坦牛高,娟荷杂交牛夏季IgM含量与荷斯坦牛相比差异显著(P<0.05),IgG,IgA差异均不显著(P>0.05)。(2)荷斯坦牛、娟荷杂交牛体细胞数7月与3月、11月之间差异均显著(P<0.05),夏季奶牛体细胞数明显高于其他季节,与夏季乳房炎发生率高的生产现象相一致。但各个时期体细胞数荷斯坦牛与娟荷杂交牛之间差异不显著(P>0.05)。(3)11月份奶牛淋巴细胞刺激指数上升,显著高于7月份(P<0.05),亦高于3月份(P<0.05)。这表明不同季节或月份对奶牛淋巴细胞转化有一定的影响作用,但荷斯坦牛与娟荷杂交牛在不同时期淋巴细胞刺激指数差异均不显著(P>0.05)。无论是荷斯坦牛或娟荷杂交牛,7月的E-玫瑰花环形成率均低于3月与11月,差异均显著(P<0.05),夏季娟荷杂交牛的E-玫瑰花环形成率显著高于荷斯坦牛(P<0.05)。夏季娟荷杂交牛的E-玫瑰花环形成率、IgM含量均高于荷斯坦牛,说明娟荷杂交牛在夏季的机体免疫功能较强,能较好地抵抗热应激的危害。5奶牛HSP基因表达、多态性与耐热性的关系分析研究HSP基因多态性与荷斯坦和娟-荷F1血清生化指标的相关性,为进一步加快奶牛耐热育种进程提供参考依据。采用PCR-SSCP技术对荷斯坦和娟荷杂交一代牛两个奶牛群体的热应激基因(HSPA8和HSPA3)进行了SNP分析,对部分基因型个体的PCR产物进行测序和序列比较,并分析了标记基因型与奶牛血清生化指标间的相关性。测序发现HSPA8座位存在T缺失突变以及C→G颠换和T→C转换突变；HSPA3座位发现C→A颠换突变。HSP基因的HSPA8位点表现多态性,两个群体显出AA、AB、BB三种基因型,BB基因型只存在于娟-荷F1群体中。HSPA3位点也表现多态,两个群体显出AA、AB、BB三种基因型,且主要都是AB基因型个体。该基因座处于Hardy—Weinberg平衡状态(P>0.05)。相关性分析表明,HSPA3和HSPA8位点多态性与血清中的T-SOD活力、MDA含量存在相关性。设计引物扩增HSPA1A基因的5’-侧翼区,通过PCR-SSCP技术分析启动子区的多态性,寻找SNPs位点,分析发现：扩增片段大小280bp,扩增产物具有基因多态性。供试的80头娟-荷F1和荷斯坦奶牛共发现4种基因型,分别为：AA型、BB型、AB型和AC型,卡方检验奶牛在该位点基因频率差异极显著(P<0.01),未达到Hardy-Weinberg平衡。AC型奶牛耐热性能高于其他基因型(AA,AB,BB)奶牛,差异显著(P<0.05)。建议作为抗热应激的奶牛选育分子遗传标记。在进样量相同的情况下,夏季荷斯坦牛血液淋巴细胞HSP70表达量最高,11月的次之,3月的血液淋巴细胞HSP70表达量最低。3月的荷斯坦牛血液淋巴细胞HSP70表达量和11月的HSP70表达差异显著(P<0.05),11月的和3月、7月的HSP70表达差异均极显著(P<0.01)。娟荷杂交一代牛血液淋巴细胞热应激蛋白HSP70表达量是荷斯坦奶牛的2.1倍,差异显著(P<0.05)。6热应激奶牛肝脾HSP70的表达特征及细胞凋亡观测为了探讨热应激对奶牛组织形态和机能的影响,对热应激奶公犊肝脏、脾脏进行了显微结构观察,分析了HSP70在肝、脾的表达特征,并进行了细胞凋亡的观察。结果表明：各组在常温状态下,其肝脾结构基本一致；娟荷杂交牛较荷斯坦牛脾脏组织内淋巴小结界限较大,红髓、白髓结构完整性较好,边缘被膜平整,淋巴小结内的淋巴细胞排列较致密,反映娟荷杂交牛较耐热的组织结构差异。在不同热应激刺激状态下,各组奶牛肝脾均有不同程度的损伤,而且肝脾细胞的超微结构变化随热应激后不同时间点而有所不同。热应激奶牛组织中HSP70含量随应激时间的延长呈现波动变化,与同期各组织细胞所呈现的病理损伤变化存在一定的相关,提示HSP70含量可作为判定组织应激损伤的标志之一。热应激对奶牛器官组织的影响是逐渐加重的过程,呈现部分淋巴细胞从凋亡到坏死的病理学变化过程。不同高温热应激均可造成肝脏、脾脏结构及其细胞的损伤,温度越高损伤越重。结论：热应激条件下,娟荷杂交牛直肠温度明显比荷斯坦牛低,每千克单位体重产奶高于荷斯坦牛,产奶量月下降率娟荷杂交牛比荷斯坦牛下降幅度明显降低。夏季娟荷杂交牛的抗氧化能力高于荷斯坦牛,娟荷杂交牛的E-玫瑰花环形成率、IgM含量均高于荷斯坦牛,娟荷杂交牛在夏季的机体免疫功能较强,能较好地抵抗热应激的危害。HSPA3和HSPA8位点多态性与血清中的T-SOD活力、MDA含量存在相关。HSPA1A位点与耐热性能存在多态性,与热应激反应有关,4种基因型的奶牛中AC型奶牛在高温季节耐热性能指标显著高于其它三种基因型奶牛。在相同热应激条件下,娟荷杂交一代牛热应激蛋白HSP70的表达显著高于荷斯坦奶牛热应激蛋白HSP70的表达。热应激对奶牛器官组织的影响是逐渐加重的过程,呈现部分淋巴细胞从凋亡到坏死的病理学变化过程。不同高温热应激均可造成肝脏、脾脏结构及其细胞的损伤,温度越高损伤越重。综合上述指标可得出,娟荷杂交牛比荷斯坦牛更能适应热带和亚热带地区高温高湿的气候条件。更多还原

【Abstract】 This study is aimed at heat tolerance and functioning mechanisms of Jersey×Holstein dairy cows for accumulating basis to breed high heat tolerance cows in China. In this paper, milk abilities was compared among Jersey×Holstein F1 and Jersey×(Jersey×Holstein) and Holstein cows, the effect of heat stress on hemorheology status and plasma inorganic ion concentrations and plasma enzyme levels in dairy cows were detected. The effects of heat stress on changes in nitric oxide synthase (NOS) activities, nitric oxide(NO) concentrations, MDA contents, T-SOD and T-AOC activities were evaluated. Changes of immunological function in different dairy populaions under different temperature condition were analysed, MTT chromatometry, ELASA, erythrocyte rosette test, western blot methods were useed to discuss the variation law of hot season affected immunological function of dairy cows. At the same time, the expressions of HSP70 in blood lymphocytes were studied. The polymorphisms of HSP gene and their correlation to biochemical indexes in serum of Holstein and Jersey×Holstein F1 dairy cows were investigated. The single-strand conformation polymorphism (PCR-SSCP) method was used to analyze for SNPs of the HSP gene. Expression profiles of HSP70 and cell apoptosis in liver and spleen of heat stress cows were analysed. The results indicated that Jersey xHolstein cows had higher heat tolerance than Holstein cows.1 Analysis on milk performance of Jersey×Holstein and Holstein dairy cows30 Jersey×Holstein F1 and Jerseyx(JerseyxHolstein) and Holstein cows in first parturition and same lactation stage were selected into 3 groups.The milk performance of first lactation and rectal temperature, skin temperature and breath rate of dairy cows were recorded. The results were shown as follows:In heat stress period, the average temperature was 31.10℃, the average THI was 81.75, rectal temperature, skin temperature and breath rate of Jersey×Holstein F1 and Jerseyx(Jersey×Holstein) in hot season had significantly differences (P<0.05) than Holstein cows, but there were no significantly differences (P >0.05) between Jersey×Holstein F1 and Jersey×(Jersey×Holstein). At the same nutritional level, milk fat percentage and milk protein percentage of Jerseyx(JerseyxHolstein) and JerseyxHolstein F1 had significantly differences (P<0.01)than Holstein cows.305 d milk yield and 4% standard milk yield of Holstein cows higher than those of Jersey×(JerseyxHolstein) and JerseyxHolstein F1, but there were no significant difference(P>0.05). Milk yield/kg body weight and feed efficiency of Jerseyx(JerseyxHolstein) had significantly differences(P<0.05)among JerseyxHolstein Fi and Holstein cows, but there were no significant difference(P> 0.05) between JerseyxHolstein F1 and Holstein cows. The milk decline rate per month from July to August of Holstein cows, JerseyxHolstein F1 and Jersey×(Jersey×Holstein) were 14.50%, 2.31%; 13.89%,3.19%; 13.38%,11.08%, respectively, there were significantly differences (P<0.05) among JerseyxHolstein F1, Jersey×(JerseyxHolstein) and Holstein cows. The results indicated that Jersey×Holstein had higher heat tolerance and better milk performance.2 Effect of heat stress on hemorheology status and biochemistry parameters in dairy cowsThe effects of heat stress on changes in hemorheology and plasma inorganic ion concentration and plasma enzyme levels were evaluated in two groups of 60 healthy Holstein and Jersey×Holstein F1 and Jersey×(Jersey×Holstein) dairy cows. These animals were subjected to a cool environment when the mean temperature-humidity index (THI) was 47.24 and temperature was 10.35℃during the month of December. This experiment was repeated during the hotter month of July of the following year, when the mean THI was 82.61 and temperature was 31.07℃. The results were showed as follows:Heat stress had no effect on ESR in Holstein and Jersey×Holstein cows but whole blood and plasma viscosity and PCV were elevated in hot season and had significantly differences compared with those in cold season (P<0.01), while there were no significantly differences between Holstein and Jersey×Holstein cows in hot or cold season. In addition, the content of plasma potassium of Jersey×Holstein cows was significantly different between hot and cold season (P<0.05), while there were no significantly differences between Holstein and Jersey×Holstein cows in hot or cold season. Heat stress decreased plasma natrium and calcium content (P<0.01), while there were no significantly differences between Holstein and Jersey×Holstein cows in hot or cold season. The content of plasma chloride was not significantly different between two breeds and two season. The content of ALT and ALP were elevated (P<0.05) with heat stress in Holstein and Jersey cows. The AST content was significantly different between Holstein and Jersey×Holstein cows in cold season (P< 0.05). These results indicated that whole blood and plasma viscosity and PCV, plasma natrium, calcium, and ALT and ALP had close relation with heat-stress, those indexes were independent of dairy breed.3 Effect of heat stress on anti-oxidative capability in Holstein and Jersey dairy cowsThe effects of heat stress on changes in the nitric oxide synthase (NOS), nitric oxide(NO), MDA contents, T-SOD and T-AOC activities were evaluated in three groups of 60 healthy Holstein and Jersey X Holstein dairy cows. These animals were subjected to a cool environment during the month of December and hotter month of July of the following year. The results were showed as follows:the levels of nitric oxide synthase (NOS) in blood serum in summer were significantly lower than those in winter both in Holstein and Jersey×Holstein cows (P<0.01). In summer, levels of nitric oxide synthase (NOS) of Jersey cow were significantly lower than those of Holstein (P<0.01). But in winter, the levels of nitric oxide synthase (NOS) in blood serum were no significant difference between Holstein and Jersey×Holstein cow (P>0.05). The levels of nitric oxide(NO) in blood serum in summer were significantly lower than those in winter in Holstein cow(P<0.05). But in Jersey×Holstein cow, the levels of nitric oxide (NO) in blood serum were no significant difference between summer and winter(P>0.05). In winter, the levels of nitric oxide (NO) in blood serum were significant difference between Holstein and Jersey×Holstein cow (P<0.05),but in summer there is no significant difference. In summer, compared with Holstein, the MDA contents of Jersey×Holstein evidently decreased (P< 0.05) and T-SOD activities of Jersey significantly increased (P<0.05), the T-AOC of Jersey×Holstein no significantly increased. however, in winter, there were no significant differences on the MDA contents and the T-SOD、T-AOC activities between Jersey×Holstein and Holstein cow. the MDA contents decreased (P<0.01) and the T-SOD activities increased (P<0.01) of both Jersey×Holstein and Holstein cow; the T-AOC activities of Holstein serum increased evidently (P<0.05) between hot and cold season. The experiment results indicated that heat stress would do harm to dairy cattle significantly; during heat stress the anti-oxidation capability of Jersey×Holstein was higher than Holstein, Jersey×Holstein was more suitable to live in the tropic and semi-tropica area than Holstein. It provided a scientific theory for the diagnosis of heat stress and selecting heat-resistant dairy cattle.4 Effect of heat stress on immunological function in dairy cowsChanges of immunological function under different temperature condition with MTT chromatometry, ELASA, erythrocyte rosette test were tested to discuss the variation law of hot season affected immunological function of dairy cows. The results indicated that:(1) the concentrations of immunoglobulin (IgG, IgA and IgM) in the serum of Jersey×Holstein cows were higher than Holstein cows, but there were not significantly different (P>0.05) in different months. In summer, the concentrations of IgM in the serum of Jersey×Holstein cows were significantly higher than Holstein cows (P<0.05). (2) In July, the somatic cell count (SCC) of different dairy cows were significant differences (P<0.05) than that of in March and November, but there were not significantly different (P>0.05) between Holstein and Jersey×Holstein cows in whole year. (3) In November, stimulated index of lymphocyts higher than that of in March and July (P<0.05), but there were not significantly different (P>0.05) between Holstein and Jersey×Holstein cows in different periods. In July, the erythrocyte rosette rate of different dairy cows were significant differences (P <0.05) than that of in March and November, the erythrocyte rosette rate of Jersey×Holstein cows were higher than that of Holstein cows. The results indicated that Jersey×Holstein had higher immunological function and could resist the harmfulness of heat stress.5 Studies on the relation between Polymorphism of HSP Gene and expression of heat stress protein 70 and heat tolerance in Dairy CowThe polymorphisms of HSP gene and their correlation to biochemical index in serum of Holstein and Jersey×Holstein F1 dairy cattle were investigated for the purpose of providing molecular maker information to facilitate the breeding efficiency. The heat tolerant traits were studied in Holstein and Jersey×Holstein F1 dairy cows. SNPs of HSP gene were analyzed by PCR-SSCP. And gene and genotype frequencies were calculated for the polymorphic loci in HSP gene. At the same time, the expression of HSP70 in blood lymphocytes were studied. Effects of genotypes in different locus on heat tolerant traits were estimated.The results indicated that T deletion mutations (C→G、T→C) in HSPA8 and (C→A) in HSPA3-exonl were detected. Results showed that the PCR products demonstrated polymorphisms, and showed three kinds of genotype AA/AB/BB in two populations, genotype BB only exist in Jersey×Holstein F1 population at locus HSPA8, however there were three kinds of genotypes AA/AB/BB and mainly was genotype BB in two populations at locus HSPA3. This polymorphic locus of HSP gene was at Hardy—Weinberg equilibrium (P>0.05). Correlation analysis showed that there was no relationship between the polymorphisms of HSPA3 and HSPA8 and T-AOC; However there were positive relationships between polymorphisms of HSPA3 and HSPA8 and MDA content and T-SOD activity.The single-strand conformation polymorphism (PCR-SSCP) method was used to analyze for polymorphism at the 5’-flanking region of the HSPA1A gene. The PCR-SSCP products of primer showed polymorphisms and could be divided into four genotypes:AA, AB, AC, CC among 80 Jersey×Holstein F1 and Holstein cows. The AC genotypic cows showed higher heat tolerance level than those of AA, AB, and BB genotype. These mutation sites can be used as molecular genetic markers to assist selection for anti-heat stress cows.In July, the expression of HSP70 in Holstein dairy cows were the highest, the next was in November, the expression of HSP70 in Holstein dairy cows in March were the lowest. the expression of HSP70 in Holstein dairy cows were significantly different (P<0.05) between March and November, there were significantly different (P<0.01) among July, November and March, the expression of HSP70 in Jersey×Holstein F1 was 2.1 times higher than that of Holstein dairy cows, it was significantly different (P<0.05) between two populations.6 Expression Profiles of HSP70 and cell apoptosis in liver and spleen of heat stress cowsTo investigate the effects of heat stress on histomorphology and function of cows, the histology of liver and spleen of initial stage of weaning calf in experimental heat stress were observed and the expression profiles of HSP70 in liver and spleen were analysed, the apoptotic cells were assayed. The result showed that the construction of liver and spleen in every group revealed no difference at normal temperature condition. Compared with Holstein cows, Jersey×Holstein cows had the larger bounds of microfold, the better structural and functional of red-eared slide and white-eared slide, the more compact lymphocyte arrangement of microfold in spleen, which reflected the difference in tissue construction and caused the difference in heat resistance. The different heat stress could damage liver and spleen at different degrees in all the groups, and the ultrastructure changed with the heat stress times going. The contents of HSP70 showed a curve change with the heat stress times prolonging, and had a certainty relation with histiocyte damages, which inferred that the contents of HSP70 could be as one of indicator to determinate histiocyte damages. The damages degree of organs and tissues in heat stress cows were gradually aggravated, part of lymphocyte were showed from apoptosis to putrescence as the hyperthermia stress increase, the damages of structures and cells in liver and spleen aggravated.Conclusion:In heat stress period, rectal temperature of Jersey×Holstein cows lower than that of Holstein cows, milk yield/kg body weight of JerseyxHolstein cow higher than that of Holstein cows. The milk decline rate per month of JerseyxHolstein cows significantly lower than that of Holstein cows. During heat stress the anti-oxidation capability of Jersey×Holstein was higher than Holstein, the erythrocyte rosette rate and the content of IgM of Jersey×Holstein cows were higher than that of Holstein cows. Correlation analysis showed that there were positive relationships between polymorphisms of HSPA3 and HSPA8 and MDA content and T-SOD activity. There were positive relationships between polymorphisms of HSPA1A and heat tolerance level, the AC genotypic cows showed higher heat tolerance level than those of AA, AB, and BB genotype. The expression of HSP70 in Jersey X Holstein cows was significantly higher than that of Holstein dairy cows.The results indicated that JerseyxHolstein had higher heat tolerance than Holstein cows, reflected in the differences in blood biochemical parameters, anti-oxidative capability and immunological function.The analysis of SNPs indicated that molecular marker for selection of anti-stress dairy cows. The damages degree of organs and tissues in heat stress cows were gradually aggravated, part of lymphocyte were showed from apoptosis to putrescence as the hyperthermia stress increase, the damages of structures and cells in liver and spleen aggravated. Jersey×Holstein was more suitable to live in the tropic and semi-tropica area than Holstein.更多还原