围产期奶牛高酮血症血液生化指标的监测

本试验选取30头年龄、胎次相近的健康围产期荷斯坦奶牛,根据分娩时间选取产前21 d、14 d、7 d、分娩当天和产后7 d、14 d、21 d共7个时间点,跟踪分析围产期奶牛部分血液生化指标变化规律。另选取171头年龄、胎次相近的围产期奶牛,根据测定的部分血液生化指标,筛选出高酮血症组(10头)与健康奶牛对照组(10头)进行统计学分析,找出与高酮血症相关性血液生化指标并进行ROC诊断评价,得出Cut-off point值。最后分析疾病危险因素,以OR值评价该指标对判定疾病的危险系数。结果表明,高酮血症组产前无发病,在产后14 d达最高发生率(10%),随后下降至4.8%,从时间来看,高酮血症的发生一般在分娩后1～3周,产后14 d最高;确定了高酮血症诊断的首选指标为BHBA、NEFA,辅助指标及cut-point值分别为DBIL(1.15 mmol/L)、AST(73.50 IU/L);危险因素分别为NEFA(OR=7.72),TG(OR=7.03),GGT(OR=6.71),LDH(OR=4.45),P(OR=6.23)。本试验为建立完整有效的奶牛群体监测体系对预防围产期奶牛生产性疾病具有现实意义。     

运动对围产期奶牛血液生化指标及免疫指标的影响

为了研究运动对围产期奶牛血液生化指标及免疫指标的影响。选取年龄、胎次和体况相近围产期健康高产奶牛30头,将奶牛随机分为2组,对照组(n=15)为非运动组;试验组(n=15)为运动组,分别采集-21,-7,0,7和30 d晨饲前静脉采血10 mL,分离血清检测生化指标、NEFA、BHBA和免疫指标,用SPSS 22.0的One-way ANOVA单因素方差分析。结果显示:运动组ALT在-7,0,7,30 d及AST在7,30 d和ALP在0,7,30 d显著(P<0.05)高于非运动组。运动组GLB、A/G和TP在-7,0,7和30 d和非运动相比差异极显著(P<0.01),GLB和TP显著高于非运动组。非运动组和运动组NEFA在分娩当天升高进而下降,非运动组NEFA趋势变化曲线高于运动组,分娩当天达到峰值且差异显著(P<0.05)。运动组与非运动相比Ca分娩当天和产后30 d组差异显著升高(P<0.05)。运动组分娩当天IgG、产后7 d TNF-α和产后30 d IgG和TNF-α显著(P<0.05)高于非运动组。综上表明,围产期奶牛分娩前适量的运动有助于维护围产期奶牛肝脏功能,提高GLB和TP的水平,维持产后Ca、IgG和TNF-α稳定,有利于维持机体免疫功能稳定。     

围产期奶牛几种血液生理生化指标监测

为了监测和诊断围产期奶牛常见营养代谢病,分别对产前15d、产前7d、产前1d、产后1d、产后7d、产后15d各10头共计60头围产期奶牛进行血液生理生化指标检测。结果显示,在整个围产期内奶牛血液中白细胞数、红细胞数、血红蛋白含量和红细胞压积差异不显著,不能作为围产期奶牛营养代谢病的监测依据。产前1d奶牛血清游离脂肪酸含量最低,为460.76±268.34μmol/L,与产前15d、产后7d、产后15d比较差异极显著(P<0.01)。产后7d奶牛血清葡萄糖含量最低,为2.12±0.35mmol/L,与其他时间测定值比较差异极显著(P<0.01)。产后1d奶牛血清中门冬氨酸氨基转移酶的含量最高,为15.33±3.24U/L,与产前15d、产前7d比较差异极显著(P<0.01)。产后15d奶牛血清中谷丙转氨酶活性和甘油三酯含量升高,分别为14.10±4.40U/L和0.90±0.14mmol/L,与产前不同时期比较差异极显著(P<0.01)。产后1d血清Ca含量降至最低值,为1.76±0.32mmol/L,血清羟脯氨酸含量和碱性磷酸酶活性升高,分别为25.50±7.90μmol/L和85.13±7.57IU/L,与产前不同时期比较差异极显著(P<0.01)。结果表明,利用血清游离脂肪酸、血清葡萄糖含量和血清门冬氨酸氨基转移酶活性,按公式计算Y值可作为诊断奶牛脂肪肝的依据。奶牛血清钙含量降低,血清羟脯氨酸含量和血清碱性磷酸酶活性升高可作为奶牛骨营养不良的诊断依据。尿酮体监测可作为奶牛酮病的诊断依据。     

亚临床酮病奶牛血液生化指标研究

为了阐明亚临床酮病对产后奶牛血液生化指标的影响,试验选择围产后期,胎次接近（1～3胎）的荷斯坦牛,根据血液β-羟丁酸（BHBA）浓度分为健康组（BHBA<1.2mmol/L）和亚临床酮病组（1.2≤BHBA<3.0 mmol/L）,每组各6头。对两组奶牛血液生化指标进行分析比较。结果显示,亚临床酮病组奶牛血液中葡萄糖（Glu）含量、甘油三酯（TG）含量以及血钾（K）浓度极显著低于健康组（P<0.01）;游离脂肪酸（NEFA）浓度、总胆固醇（TC）含量极显著高于健康组（P<0.01）;高密度脂蛋白胆固醇（HDLC）含量显著低于健康组（P<0.05）,而低密度脂蛋白胆固醇（LDLC）浓度显著高于健康组（P<0.05）;在奶牛肝功能指标中：亚临床酮病组谷丙转氨酶（ALT）活性极显著高于健康组;碱性磷酸酶（ALP）、谷氨酰转肽酶（GGT）、谷草转氨酶（AST）活性显著高于健康组;在奶牛抗氧化指标中：亚临床酮病奶牛超氧化物歧化酶（SOD）活性极显著低于健康组;丙二醛（MDA）含量显著高于健康组;谷胱甘肽过氧化物酶（GSH-Px）活性和总抗氧化能力（T-Aoc）...     

中草药添加剂对围产期奶牛血液生化指标及生产性能的影响

本研究旨在研究中草药添加剂对围产期奶牛血液生化指标及生产性能的影响。试验选择36头体况、预产期和胎次相近的荷斯坦奶牛,采用完全随机试验设计,分为3组,每组12头奶牛。3组奶牛在基础日粮中分别添加0、150和300 g/d的中草药添加剂,预饲期1周,正饲期6周。奶牛产后每周采集1次饲料样、血样和奶样,测定其干物质采食量、血液生化指标及乳成分等指标。结果表明,随着中草药添加剂饲喂量的增加,围产期奶牛产后产奶量表现出一定的升高趋势,产奶量分别增加5.1%和10.6%,但与对照组相比差异不显著（P>0.05）,围产期奶牛饲喂中草药添加剂对干物质采食量没有显著影响（P>0.05）。与对照组相比,随着中草药添加剂饲喂量的增加,乳中体细胞数显著降低（P<0.05）,分别下降62.7%和76.6%,但对乳中其他常规指标没有显著的影响（P>0.05）。与对照组相比,随着中草药添加剂饲喂量的增加,奶牛血清中非酯化脂肪酸（NEFA）含量显著降低（P<0.05）,降低水平分别为29.0%和35.1%,血清中其他常规指标没有显著变化（P>0.05）。综上所述,在本试验条件下,推荐围产期奶牛中草药添加剂添加量为300 g/d,可以显著降低乳中体细胞数和血中NEFA含量,改善奶牛健康状况,提高奶牛产后生产性能。     

应用血中生化指标检测围产期奶牛脂肪肝

测定了９头中国荷斯坦奶扣分娩前后血浆中葡萄糖，游离脂肪酸和天门冬氨酸氨基转移酶的含量，用以监测受试牛脂肪肝的发生转归。结果表明：在产后１５－２０ｄ内，脂肪肝患牛血糖平均值极显著低于正常牛；在产后２５ｄ内，血浆中ＦＦＡ平均值显著高于正常牛；在产后１０ｄ至２０ｄ间，血浆中ＡＳＴ平均值极显著高于正常牛。     

围产期奶牛低钙血症血液生化指标分析

低钙血症是一种围产期奶牛多发的代谢紊乱性疾病,不仅可降低奶牛的生产性能,还能诱导其他疾病的发生.选取陕西地区某集约化奶牛场90头围产期奶牛进行为期4周的血液生化指标监测,根据血钙的浓度将奶牛分为健康组、亚临床低钙血症组和临床低钙血症组并进行比较研究.结果显示,临床低钙血症奶牛产后1周体况丢失幅度较大;与亚临床低钙血症奶...     

围产后期奶牛的血液生化指标特征

本试验旨在通过对围产后期奶牛进行血液生化指标检测,探讨奶牛血液生化指标的变化规律以及与疾病相关指标的发生特点,为围产后期奶牛产后保健提供理论依据。试验选择年龄、体况、胎次相近的二胎以上无疾病史的健康奶牛30头,于分娩当天(0d),产后1,2,3,7,14,21d清晨饲喂前尾静脉采血10mL,分离血清进行血液生化指标β-羟丁酸(BHBA)、游离脂肪酸(NEFA)、门冬氨酸氨基转移酶(AST)、葡萄糖(GLU)、血钙(Ca2+)、血磷(P3+)和血镁(Mg2+)的检测。结果显示:在试验期内30头试验奶牛脂肪肝的发病率为46.7%,酮病的发病率为40.0%,低血钙的发病率为33.3%;血液中NEFA的浓度在分娩当天最低为(0.33±0.17)mmol/L,与产后7,14,21d差异极显著(P0.01),血清中NEFA浓度从产后1d逐步升高。奶牛分娩当天血糖浓度最高为(6.40±1.55)mmol/L,与产后1,2,3,7,14和21天的血糖浓度差异极显著(P0.01),奶牛产后在7~21d时,血液中BHBA浓度逐步升高,其中第21dBHBA浓度最高为(0.84±0.68)mmol/L,与0,1,2和3dBHBA浓度差异极显著P0.01。分娩当天Ca2+浓度为(2.29±0.31)mmol/L,与其他各天差异极显著P0.01。产后0d起,血清中P3+浓度逐步升高,其中0d相对于3,7,14,21d差异极显著P0.01。血清中Mg2+浓度产后1d最低为(1.56±0.42)mmol/L,0d血清Mg2+浓度与产后1,2,3,7,14,21d血清Mg2+浓度差异极显著P0.01,产后1~21d血清Mg2+浓度逐步升高,并处于平稳趋势。结果表明,该牛场奶牛产后营养代谢性疾病发病率较高,应加强对围产期奶牛的饲养管理及保健,对于集约化高产奶牛场应制定合理的保健方案,通过饲料添加剂对分娩牛保健,来预防围产期常见营养代谢性疾病。     

Effect of melatonin on biochemical variables of the blood in dairy cows

In order to examine the effect of exogenous melatonin on selected biochemical variables of the blood in ruminants, dairy cows were given the pineal gland hormone in the dose of 0.1 mg/kg body weight. One and four hours after melatonin administration blood samples were collected from the cows in the control and the treated group in order to determine the levels of glucose, insulin, total cholesterol, triglycerides, free fatty acids, as well as the activities of alanine and aspartate aminotransferase. The pineal gland hormone caused a significant increase in the levels of total cholesterol and triglycerides, slight increases in glucose and insulin levels, and a significant decrease in the concentration of free fatty acids. Melatonin did not exert an effect on the activity of liver enzymes.     

Colostrum production by primiparous and multiparous Holstein dairy cows and its usefulness as an estimator of full lactation milk yield

This study determined colostrum production of lactating primiparous and multiparous Holstein dairy cows, as well as the predictability of full lactation milk yield based upon this colostrum production. Holstein cows that calved between December 18, 2006 and December 24, 2007 (n = 134) had their first two post-partum milkings weighed and assayed for density. Cows then entered normal production groups and were assessed for milk yield and milk components every 4 or 5 weeks for the duration of their lactation. Primiparous cows produced less colostrum (10.6 versus 13.6 kg; P = 0.02) and density adjusted (DA) colostrum (5.2 versus 8.5 kg; P < 0.01), but there were no differences in estimated 305 day mature equivalent (305ME) milk production (mean = 13,654 kg) or lactation lengths (mean = 301 days) between parities. Colostrum and DA colostrum were poor estimators of subsequent 305ME milk production within primiparous cows (r² = 0.20 and 0.01 respectively) and multiparous cows (r² = 0.18 and 0.12 respectively). Colostrum production of these high producing cows was somewhat lower than expected, highly variable among cows within parity, higher for multiparous versus primiparous cows, and was not a good estimator of subsequent 305ME milk production.     

Phagocytic and bactericidal activity of blood and milk-resident neutrophils against Staphylococcus aureus in primiparous and multiparous cows during early lactation

To examine the effect of parity on polymorphonuclear neutrophils (PMN) function, phagocytic and bactericidal activity of the PMN isolated from blood and milk against Staphylococcus aureus was compared between groups of 6 primiparous and 6 multiparous healthy dairy cows during early lactation using bacteriological and PMN-pathogen interaction assays. Latex-stimulated luminol-amplified chemiluminescence (CL) and viability of these PMN were also investigated. The phagocytosis and killing of S. aureus by blood were remarkably higher than those of milk PMN. Similarly, the CL and viability in blood PMN were markedly higher than in milk PMN. Both in blood and in milk the phagocytosis of S. aureus by PMN in primiparous cows was substantially higher than in multiparous cows. The killing activity of blood PMN against S. aureus was 42.3+/-3.4% and 23.2+/-1.7% in primiparous and multiparous, respectively. Milk PMN killed only 20.7+/-2% S. aureus in primiparous and 10.2+/-1.3% in multiparous cows. Blood and milk PMN CL and milk PMN viability were significantly higher in primiparous cows. The pronounced reduction in phagocytic and bactericidal activity in blood and milk-resident PMN from multiparous cows, in part, resulted from the pronounced decrease of PMN viability and free radicals production capacity; this suggests that heifers' udders could be more protected against S. aureus, which remains to be tested in the field.     

Differences between primiparous and multiparous dairy cows in the inter-relationships between metabolic traits, milk yield and body condition score in the periparturient period

During the early postpartum period dairy cows mobilize fat and muscle to support lactation. This is associated with alterations in blood metabolite and hormone profiles which in turn influence milk yield and fertility. This study developed models to determine how metabolic traits, milk yield and body condition score were inter-related at different times in the periparturient period and to compare these relationships in primiparous (PP, n=188) and multiparous (MP, n=312) cows. Data from four previous studies which included information on blood metabolic parameters, parity, milk yield, body condition score and diet were collated into a single dataset. Coefficients of polynomial equations were calculated for each trait between -1 week pre-calving and week +7 postpartum using residual maximum likelihood modelling. The completed dataset was used in a multiple correlation model to determine how the best fit curves were related to each other over time. PP cows had higher concentrations of insulin-like growth factor-I and lower beta-hydroxybutyrate concentrations throughout, higher leptin concentrations pre-partum and both the peak in non-esterified fatty acids and the nadir in urea concentration occurred earlier after calving. These differences were associated with significantly lower milk production. Leptin concentrations fell at calving and were related to body condition score. Insulin was negatively correlated with yield in MP cows only. In MP cows the relationship between insulin-like growth factor-I and yield switched from negative to positive between weeks +4 and +7. Both beta-hydroxybutyrate and urea were positively related to yield in PP cows. In contrast, in MP cows beta-hydroxybutyrate was negatively correlated with yield and urea was strongly related to body condition score but not yield. These results suggest that there are differences in the control of tissue mobilization between PP and MP cows which may promote nutrient partitioning into growth as well as milk during the first lactation.     

暑热宁对热应激奶牛血液生化指标的影响

奶牛是一种耐寒不耐热的动物,环境温度超过26℃时,即可引起奶牛的热应激反应,导致奶牛食欲下降,产奶量明显下降、情期受胎率显著下降,乳房炎、胎衣不下等疾病发病率明显升高[1],目前用于奶牛抗热应激的饲料添加剂种类很多,主要有有机铬、活性酵母、矿物质缓冲盐、镇静剂、抗生素、维生素、脂肪酸钙等添加剂[2].     

过瘤胃蛋氨酸和肉桂醛对奶牛血液生化指标的影响

试验旨在研究过瘤胃蛋氨酸(rumen-protected methionine,RPMet)和肉桂醛(cinnamic al-dehyde,CA)不同添加组合对奶牛血液生化指标的影响。选取年龄、体重、胎次、产奶量、乳成分及泌乳期[(90±15)d]相近的荷斯坦奶牛40头,随机分为10组,每组4头。对照组(C)饲喂基础日粮,试验组补饲不同水平组合的RPMet和CA,其中RPMet设3个水平,添加量分别为20(L)、25(M)、30(H)g/(d·头);CA设3个水平,添加量分别为15(L)、18(M)、21(H)g/(d·头),共9个不同水平组合,分别为LL、ML、HL、LM、MM、HM、LH、MH、HH。预试期15 d,正试期60 d。结果表明:饲粮中补饲RPMet和CA可以提高血清中总蛋白、白蛋白和生长激素的含量,降低血清中血糖、尿素氮和胰岛素的含量。在本试验条件下,综合考虑血液生化指标,最佳添加量组合为过瘤胃蛋氨酸30 g/(d·头),肉桂醛15 g/(d·头)。