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1.
为调查我国当前主流饲喂方式下奶牛静脉血内毒素浓度的范围及内毒素浓度与产奶量的相关性,本试验首先验证了应用鲎试剂法定量奶牛静脉血中内毒素浓度的可行性,在此基础上,分别检测了安徽牧场1(60头,饲粮精粗比45∶55)、江苏牧场(15头,按产奶量高低精粗比分别为20∶80、45∶55、50∶50)和安徽牧场2(14头,饲粮精粗比70∶30)共89头奶牛的尾静脉血中内毒素浓度,并进行了内毒素浓度与产奶量的相关性分析.结果表明:鲎试剂法可有效检测奶牛静脉血中内毒素浓度,3个牧场奶牛静脉血中内毒素浓度高低不等,在0~ 1.50 EU/mL范围内.奶牛静脉血中内毒素浓度与产奶量之间的相关性皆不显著(P>0.05),但安徽牧场2的相关系数(0.195 2)大于安徽牧场1(0.020 5)和江苏牧场(0.037 6).结果提示,鲎试剂法可用于定量检测奶牛血中内毒素浓度,在我国当前的饲喂方式下,奶牛血液中普遍含有内毒素,静脉血内毒素浓度与产奶量无显著相关性.  相似文献   

2.
本试验旨在研究饲粮粗蛋白质(CP)水平对中国荷斯坦奶牛产奶性能、氮利用及血液激素的影响。采用重复 4×4拉丁方设计,8头经产中国荷斯坦奶牛随机分为 4个处理。4个处理的饲粮 CP水平分别为 12.56%、13.96%、15.53%和 16.93%。试验分为 4个周期,每个周期18d。在 4d收集期内,全量收集粪、尿,每天测量产奶量、乳成分和干物质摄入量(DMI),并在收集期最后 1d采集血样。结果表明:4个饲粮处理的 DMI基本相同(P>0.05);饲粮 CP水平12.56%的产奶量和能量校正奶(ECM)明显低于饲粮 CP水平 13.96%至 16.93%(P<0.05),饲粮 CP水平 13.96%至 16.93%的产奶量和 ECM 基本相同,其中饲粮 CP水平 13.96%和16.93%的产奶量分别为28.18和28.72kg/d,ECM分别为32.64和32.04kg/d;乳成分中仅乳蛋白率随着饲粮 CP水平增加而提高(P<0.05);饲粮 CP水平 12.56%和 13.96%的乳氮效率明显高于饲粮 CP水平 15.53%和 16.93%(P<0.05或 P<0.01);随着饲粮 CP水平的提高,尿氮排出量不断增加,乳氮排出量也缓慢上涨,体内氮沉积显著增加(P<0.05或 P<0.01),只有饲粮 CP水平 16.93%的粪氮排出量明显增加(P<0.05);饲粮 CP水平 12.56%的血液瘦素浓度最高(P<0.05),催乳素(PRL)、生长激素(GH)、胰岛素样生长因子 1(IGF 1)、血糖、非酯化脂肪酸(NEFA)和 β-羟丁酸(BHBA)浓度较高;而饲粮 CP水平 16.93%的血浆尿素氮(PUN)浓度最高(P<0.01),胰岛素和 GH浓度较高,IGF 1浓度较低。由此可见,饲粮 CP水平13.96%适合中国荷斯坦奶牛产奶量28kg/d或 ECM32kg/d的泌乳性能、氮利用和内分泌调节。  相似文献   

3.
本试验旨在研究饲粮全棉籽比例对奶牛泌乳性能和乳脂脂肪酸组成的影响。试验采用 4×4拉丁方试验设计,选择 8头泌乳早期的经产中国荷斯坦奶牛(产奶量、胎次、产犊日期接近,健康无疾病),分为 4组,每组 2个重复,每个重复 1头牛。A组饲喂基础饲粮,B、C和 D组分别饲喂含 5%、10%、15%全棉籽的试验饲粮。每期试验 28d,其中预试期为 7d,正试期为21d。结果表明:随着饲粮全棉籽比例的增加,奶牛产奶量有提高趋势(P>0.05),校正乳产量极显著提高(P<0.01)。全棉籽极显著地提高了奶牛的乳脂率(P<0.01),对乳蛋白率、乳糖率和乳非脂固形物率无显著影响(P>0.05)。全棉籽极显著降低了饱和脂肪酸(SFA)的含量(P<0.01),不同程度地提高了乳中多不饱和脂肪酸(PUFA)和单不饱和脂肪酸(MUFA)的含量(P<0.05或 P<0.01);短链脂肪酸和中链脂肪酸含量都显著降低(P<0.05),长链脂肪酸含量有不同程度的提高(P<0.05或 P<0.01)。结果提示,饲粮中添加全棉籽可以提高奶牛产奶量,优化乳脂脂肪酸组成,改善乳脂品质,并以 10%为泌乳早期奶牛最佳饲粮全棉籽比例。  相似文献   

4.
尿素糖蜜多营养舔砖补饲牦牛效果的研究   总被引:7,自引:0,他引:7  
分别在天祝县和碌曲县选用90头天祝白牦牛和60头甘南牦牛进行了冷季放牧牦牛尿素糖蜜多营养舔砖的补饲试验,尿素糖蜜多营养舔砖含尿素10%,糖蜜10%,采食量为0.5kg/(d·头)。经5个月补饲后,天祝白牦牛和甘南牦牛的活重损失分别减少80.3%和46.8%,产奶量分别提高20%和13.6%,怀孕率分别提高17.4和20.0个百分点,投入产出比分别达到1∶3.50和1∶2.11。处理组与对照组之间存在极显著差异(P<0.01),证明尿素糖蜜多营养舔砖是实施高寒牧区放牧牦牛冷季补饲的一条新的有效途径  相似文献   

5.
硫酸钠对奶牛增乳效果的研究   总被引:8,自引:0,他引:8  
为寻找价廉而且又能提高奶牛产奶量的饲料添加剂,我们选择硫酸钠作为研究对象进行了奶牛增乳效果对比试验。1材料与方法1.1试验牛的选择与分组从黑白花奶牛品种牛群中选择年龄、胎次、泌乳天数以及产奶量等相近的16头泌乳期牛,随机分成试验组和对照组。1.2基础日粮组成及营养成分基础日粮由精料和粗料两部分组成。精料配方(%):玉米33、麸皮13.5、蛋白粉3.1、葵籽饼13、石粉1.2、食盐0.3、牛浓缩料6239为2.0、磷酸氢钙0.7、牛矿物添加剂0.2、啤酒糟(折干)33.0。其营养水平为粗蛋白质18…  相似文献   

6.
奶牛泌乳盛期补饲碘的效果   总被引:1,自引:0,他引:1  
选用15头泌乳盛期荷斯坦牛,采用对比试验研究日粮中添加碘对奶牛产奶量的影响,结果是:补饲K115和25mg/头.日组的日平均奶量分别比对照组高3.49千克(P<0.05)和2.76千克(P<0.05)。两个试验组之间日平均奶量无显著差异(P>0.05)。三个组牛血清中T4和T3浓度无明显差异。  相似文献   

7.
奶牛日粮中添加奶牛增产剂的试验   总被引:1,自引:0,他引:1  
利用奶牛增产剂饲喂日产16 kg 的泌乳后期奶牛。结果表明:每天每头饲喂0.5 kg,可提高产奶量1.81 kg/d·头,净增幅度为12 %(P>0 .05) 。每头每天饲喂0.6 kg,可提高产奶量3.59 kg/d·头,净增奶幅度为25.6 % ,差异显著( P<0 .05) 。  相似文献   

8.
魏金琪  史金梅 《养猪》1994,(3):29-30
51头50千克以上的肥育猪,随机分为3组(每组17头),对照组只喂基础饲粮,2个试验组分别在基础饲粮中添加250ppm和500ppm乳猪香。结果表明,对50千克以上的肥育猪饲粮中添加乳猪香有效,250ppm为适宜剂量,与对照组相比日增重提高90克(P<0.01),千克增重少耗料0.51千克,千克增重饲料成本降低0.45元。  相似文献   

9.
对西宁市奶牛场97头荷斯坦奶牛不同初配月龄与头胎产奶量的关系进行了统计分析。结果表明,17.0~17.9月龄初配受孕的奶牛头胎产奶量最高,比16.9月龄以前初配受孕的高542.45kg(P<0.05),比18.0~18.9月龄初配受孕的高520.41kg(P<0.05),比19.0~19.9月龄初配受孕的高1042.01kg(P<0.01),比20.0月龄以上初配受孕的高201.29kg(P>0.05)。说明西宁地区的荷斯坦奶牛在17.0~17.9月龄初配较为理想。  相似文献   

10.
浅谈细菌内毒素检查法中的计算方法   总被引:3,自引:1,他引:2  
鉴于我国细菌内毒素检查的应用情况和兽药药品检测的实际情况,结合工作实践,对细菌内毒素检查法中的细菌内毒素限值(L)、最大有效稀释倍数(MVD)、最小有效浓度(MVC)、鲎试剂灵敏度复核(λc)及供试品干扰试验的判断(Es、Et)的计算方法进行了多次试验,Et在0.5Es~2.0Es(包括0.5Es和2.0Es)时,供试品在该浓度下不干扰试验。相反存在增强或抑制作用。  相似文献   

11.
Strain Y3343 isolated from a goat with septicemia and polyarthritis was studied. The strain was virulent and induced septicemia, polyarthritis and coagulopathy in two goats. Limulus amebocyte lysate active material was present in plasma, but not in higher titre in inoculated goats. Sonicated mycoplasma material induced a dramatic somatic cell response in the mammary gland of cows and goats and marked clotting of the cows' milk, but it did not clot limulus amebocyte lysate or kill chick embryos. Phenol-water extract clotted limulus amebocyte lysate and induced somatic cell response in cows but not in goats. The phenol-water extract did not kill chick embryos, was not pyrogenic in rabbits or goats, and did not induce generalized Shwartzman reaction or change the leukocyte kinetics in rabbits. It therfore appears that the virulence mechanisms of strain Y3343 can not be explained on the basis of factors with strong endotoxin activity.  相似文献   

12.
Left displaced abomasum (LDA) and abomasal volvulus (AV) occur most commonly in postparturient dairy cows. Our main hypothesis was that endotoxemia occurred more frequently in the peripheral blood of cows with LDA or AV than in healthy cows because increased luminal pressure in AV or LDA, or the presence of a hemorrhagic strangulating obstruction in AV, may have injured the abomasal mucosa, thereby facilitating translocation of luminal endotoxin into the circulation. Therefore, our main objective was to compare the prevalence and magnitude of endotoxemia in healthy postparturient cows with the prevalence and magnitude of endotoxemia in cows with AV and LDA. We examined 60 adult dairy cows in early lactation that were diagnosed with AV (n = 15) or LDA (n = 15) or were healthy on physical examination (control group, n = 30). Jugular venous blood was obtained from cows in all 3 groups, and right gastroepiploic venous blood was obtained during surgical correction of AV and LDA immediately after repositioning of the abomasum. Platelet-rich plasma endotoxin concentrations were measured with a chromogenic limulus amoebocyte lysate assay. Endotoxin was detected in jugular vein plasma in 50% (15/30) of control cows; however, the prevalence of endotoxemia was significantly lower (P < .05) in cows with AV (7%, 1/15) or LDA (20%, 3/15). Endotoxin was detected simultaneously in right gastroepiploic and jugular vein plasma in only 1 cow with LDA and 0 cows with AV. Contrary to our hypothesis, we conclude that endotoxemia is infrequently present in postparturient dairy cows with AV or LDA.  相似文献   

13.
According to the present study the limulus amebocyte lysate test (LAL) seems to be a convenient test to detect endotoxin in milk from udder quarters with and without inflammation. The correlation between endotoxin concentration and the results from the bacteriological investigation of 79 milk samples was good (Table I). Determination of endotoxin in 20 milk samples from cases of acute clinical mastitis with high cell count and a negative bacteriological culture showed that all but one had an endotoxin concentration of greater than 1.0 ng/ml milk (Table II). By using a micromethod of the LAL it is possible to detect cases of mastitis caused by gram-negative bacteria about one hour after the sample has reached the laboratory. In a preliminary field study milk from 13 cases of acute clinical mastitis were tested by a modified limulus amebocyte lysate (LAL) test ("cowshed test"). A 100% correlation to bacteriological findings was observed (Table IV). By using the LAL test to detect mastitis cases caused by gram-negative bacteria great economic advantages and less risk for resistance problems can be achieved by using proper antibiotics. This is the fact in Sweden where the frequency of acute clinical mastitis caused by streptococci (100% of strains sensitive for penicillin) and Staphylococcus aureus (about 90% of strains sensitive for penicillin) is high (70-80%) and about 20% are caused by gram-negative bacteria, mostly E. coli.  相似文献   

14.
本试验采用动静脉血插管技术,以泌乳中期荷斯坦奶牛为研究对象,研究玉米秸秆饲粮条件下阴外动脉灌注氨基酸(AA)混合物对奶牛产奶性能、尾动脉血和乳静脉血中短链脂肪酸(SCFA)浓度及其比例以及乳腺内SCFA摄取规律的影响。采用2×2交叉试验设计,将体况良好、体重相近、日乳产量为(20.17±1.28)kg的8头经产(2~3胎)荷斯坦奶牛随机分为采食不同饲粮的2组[苜蓿组(MF组)和玉米秸秆组(CS组)],每组4头。2组奶牛饲喂的饲粮精粗比均为45∶55,精饲料组成相同,粗饲料组成不同,MF组粗饲料由苜蓿干草、玉米青贮和羊草组成,CS组以单一的玉米秸秆全部替代MF组饲粮中的粗饲料。试验分为2个阶段,每个阶段20 d,均分为饲粮适应期(预试期)14 d,载体灌注期3 d,正式灌注期3 d。在第1阶段,在载体灌注期,MF组奶牛接受载体灌注(阳性对照组1),CS组奶牛也接受载体灌注(对照组);在正式灌注期,MF组奶牛继续接受载体灌注(阳性对照组2),CS组奶牛接受AA混合物灌注;在第2阶段,将2组动物互换后处理方法同第1阶段。每个正式灌注期的最后2 d采集乳样和血样。结果显示:CS组奶牛阴外动脉灌注AA混合物可显著提高乳蛋白率(P0.05),对乳产量、4%乳脂校正乳(FCM)产量、乳脂率、乳脂产量、乳蛋白产量有一定促进效果,但部分指标仍然显著低于MF组(P0.05)。CS组奶牛阴外动脉灌注AA混合物可趋于显著地提高乳静脉血中乙酸的浓度(P=0.09),显著降低乳腺内乙酸的动静脉差(P0.05),缩小CS组与MF组奶牛在乳腺对乙酸的摄取量和摄取效率方面存在的差距。CS组奶牛阴外动脉灌注AA混合物对提高尾动脉血中乙酸/丙酸、(乙酸+丁酸)/丙酸有一定的促进效果(P0.05)。由此得出,以玉米秸秆为粗饲料的奶牛阴外动脉灌注AA混合物可显著提高乳蛋白率,增加乳静脉血中的乙酸浓度,同时缩小与以苜蓿干草、玉米青贮和羊草为粗饲料的奶牛在乳腺对乙酸的摄取量和摄取效率方面存在的差距。  相似文献   

15.
The aim of the present study was to compare endotoxin activities detected in raw milk samples obtained from cattle by a commercially available portable test system (PTS) and traditional microplate limulus amebocyte lysate (LAL)-based assay, which determined activities using a kinetic turbidimetric (KT) assay. Raw milk samples were obtained from 53 and 12 dairy cattle without and with clinical mastitis, respectively. Comparison between the KT and PTS was performed by the Friedman test. The Pearson product moment correlation coefficients were calculated to evaluate associations between any two continuous variables. Linear regression model analysis was also performed to obtain the equation describing the relationship between PTS and KT assay. The endotoxin activities detected in 200- or 400-fold diluted milk samples were similar between PTS and KT assay, whereas a significant difference was observed in 100-fold diluted milk (P<0.001). The results obtained from 200- (r2=0.778, P<0.001) and 400-fold diluted milk samples (r2=0.945, P<0.001) using PTS correlated with those using KT assay. The median milk endotoxin activities in Gram-positive and Gram-negative clinical mastitis cows were 0.655 and 11,523.5 EU/ml, respectively. The results of the present study suggest that PTS as a simple and easy test to assess endotoxin activity in raw milk is efficient, simple and reproducible.  相似文献   

16.
为了研究粗饲料组合对热应激奶牛氮素利用的影响,试验选取20头胎次和泌乳天数相似的健康荷斯坦奶牛,随机分成2组,每组10头,分别饲喂2种粗饲料组合饲粮:玉米青贮+苜蓿(0.92∶1.00,AF组)和玉米秸秆(CS组)。2组饲粮精料相同,精粗比均为63.7∶36.3。预试期1周,正试期8周。结果表明:1)与CS组相比,AF组奶牛产奶量及能量校正乳、4%脂肪校正乳、乳蛋白和乳糖产量显著或极显著升高(P0.01或P0.05)。2)奶牛对AF组饲粮粗蛋白质表观消化率极显著高于CS组(P0.01)。3)与CS组相比,AF组瘤胃微生物蛋白产量显著升高(P0.05),而尿液和血液尿素氮浓度极显著降低(P0.01)。4)与CS组相比,AF组氮摄入量和乳中氮产量极显著升高(P0.01),但氮转化效率显著降低(P0.05)。结果提示,与玉米秸秆相比,玉米青贮+苜蓿的组合能提高饲粮粗蛋白质水平,增加热应激奶牛粗蛋白质表观消化率,促进瘤胃微生物蛋白和乳蛋白的合成,但氮的转化效率有待提高。  相似文献   

17.
A chromogenic Limulus amebocyte lysate assay was used to measure portal and peripheral venous endotoxin concentrations in ten medically managed dogs undergoing surgery for correction of a single extrahepatic portosystemic shunt. In all dogs, both peripheral and portal venous blood samples were obtained at the time of surgical manipulation of the anomalous vessel. In six dogs, peripheral venous samples were obtained an average of 8.0 months after surgery. Five physically normal dogs without biochemical or histologic evidence of liver disease served as controls. Data analysis failed to demonstrate significant differences in peripheral and portal venous endotoxin concentrations between the control and study groups. Postoperatively five of six dogs showed a measurable reduction in peripheral venous endotoxin concentration over intraoperatively obtained values, but the differences were not statistically significant (P = 0.06). Based on results of this study it was concluded that systemic endotoxemia was not present in dogs with a single extrahepatic portosystemic shunt that were medically stable prior to surgery.  相似文献   

18.
荷斯坦牛抗热应激候选基因S441的检测   总被引:1,自引:0,他引:1  
本试验以S441为奶牛假定抗热应激候选基因。在核心母牛场湖南省奶牛原种场测定不同世代的种母牛213头,在核心公牛场湖南省种公牛站,以及北京、上海、南京、安徽等地测定种公牛46头,共检测出具有S441基因的母牛27头,检出率为12.7%(27/213),公牛15头,检出率为32.6%(15/46)。在湖南省奶牛原种场,有、无抗热应激候选基因的母牛在热应激期间的产奶量分别为1736.75kg和1528.63kg,产奶量下降率分别为3.51%和22.56%,产奶量差异不显著(P〉0.05),但产奶量下降率差异显著(P〈0.05),基本肯定该基因为抗热应激候选基因。  相似文献   

19.
本试验旨在探究围产期奶牛血钙浓度影响因素及其与生产性能的关系。于2018年7月20日—8月15日对北京地区36头围产期健康荷斯坦牛的血钙浓度进行测定,收集该牛场奶牛生产性能测定(DHI)报告,利用固定效应模型分析不同胎次、体况评分(BCS)、健康状况及血钙浓度变异度对血钙浓度的影响。结果表明:血钙浓度与产后天数存在显著的正向相关关系;经产牛的血钙浓度(1.40 mmol/L)极显著高于初产牛(1.31 mmol/L);不同BCS分组奶牛血钙浓度差异不显著;健康组的血钙浓度(1.41 mmol/L)显著高于患病组(1.30 mmol/L);血钙浓度变异度的大小影响奶牛的产奶量,初产奶牛低变异度组的产奶量(16.70 kg/d)显著高于中变异度组(9.75 kg/d)和高变异度组(5.63 kg/d)。本研究进一步揭示了围产期荷斯坦牛血钙浓度的变化规律以及其影响因素,为预防奶牛产后低血钙症的发生以及制定提高奶牛生产性能的饲养管理策略提供参考。  相似文献   

20.
产奶量差是奶牛个体同一胎次前后2个泌乳月产奶量的差值,可准确反映产奶量变化情况。为探究影响荷斯坦牛产奶量差的因素,本研究收集整理了江苏省某大型奶牛场2015-2018年55 193头次荷斯坦牛生产性能测定记录,并利用最小二乘法分析胎次、测定年度、产犊季节、泌乳月4个因素对荷斯坦牛产奶量差的影响。结果显示:胎次、测定年度、产犊季节、泌乳月及其交互作用对产奶量和产奶量差均有极显著影响(P<0.01)。其中,不同胎次、测定年度和产犊季节的荷斯坦牛总产奶量在第2个泌乳月增加最快,产奶量差为8.79kg;头胎第6泌乳月、二胎第7泌乳月和三胎及以上第6泌乳月产奶量下降最大,产奶量差分别为-2.86kg、-4.59kg和-6.13kg;2015-2018年4个测定年度中,第10、第6、第7、第6泌乳月产奶量降低最大,产奶量差分别为-2.26kg、-4.98kg、-4.44kg和-3.56kg;春季产犊的荷斯坦牛第4泌乳月、夏季产犊的荷斯坦牛第12泌乳月、秋季产犊的荷斯坦牛第9泌乳月、冬季产犊的荷斯坦牛第6或第7泌乳月产奶量下降最大,产奶量差分别是-4.34kg、-4.71kg、-5.36kg和-5.40kg。此外,产奶量差与泌乳持续力呈极显著正相关(P<0.01),与产犊间隔呈显著正相关(P<0.05),与泌乳天数、高峰奶、乳脂率、蛋白率、305d产奶量呈极显著负相关(P<0.01)。因此,产奶量差作为衡量奶牛产奶量变化的指标之一,可为牧场进行科学饲养管理提供参考。  相似文献   

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