宁夏利通区产奶期奶牛锰、锌、硒盈缺状况调查

对宁夏吴忠市利通区4个奶牛场和10户农户奶牛产奶期微量元素锰、锌、硒营养状况进行调查，分别测定了盛乳期、产奶中期、产奶后期奶牛血清硒，被毛锰、锌的含量和血清中谷胱甘肽过氧化物酶的活性。结果表明：产奶各期小户、大户和中户奶牛(1)被毛锰低于正常范围，示饲料中缺锰，小户奶牛缺乏较严重，均不能满足需要量。各期各户奶牛被毛锌含量变化范围较小，均在正常范围之内，混合饲料中的锌基本适宜，饲喂状况良好。各期日粮硒含量中户最适宜，硒代谢正常；其次为中户(2)与散户，均在正常范围之内；小户与大户奶牛血硒指标偏低，均在缺硒范围之内，示饲料中缺硒。     

宁夏利通区产奶期奶牛钙、磷盈缺状况调查

本项目对宁夏吴忠市利通区4个奶牛场和10户农户进行奶牛产奶期钙磷营养状况调查,分别测定了饲料钙磷含量,奶牛产奶期血清中钙、磷、羟脯氨酸、碱性磷酸酶、甲状旁腺素、降钙素含量。结果表明:散户血液钙、磷含量正常,但羟脯氨酸、碱性磷酸酶、甲状旁腺素明显升高,日粮钙、磷不足,处于钙、磷缺乏亚临床状态。小户血液钙、磷及相关生化指标基本正常,它们的含量分别为:碱性磷酸酶2.10±0.11-3.23±1.08mg/100ml、羟脯氨酸1.41±1.00-2.84±0.65μg/mL、甲状旁腺素104.24±68.25-58.91±30.51pmol/l、降钙素20.93±26.36-10.27±5.56pmol/l,各被调查户产奶牛血液的降钙素的水平处于正常范围之内,血液降钙素平均水平为9.4686±10.9042pmol/l,95％的置信区间为6.5208-12.4164pmol/l。     

畜禽微量元素代谢障碍疾病的调查和防治研究 Ⅰ.“摆腰病”羊主要生理生化指标的研究

选用20只“摆腰病”羊,分为补铜组和补硒组,治疗前和治愈后分别测定其主要生理生化指标,同时在病区和非病区选择21只健康羊作对照。结果表明,病羊血铜、毛铜、血清铜蓝蛋白含量、血液GSH-Px及血清碱性磷酸酶活性均明显降低,血氟含量升高,与非病区健康羊相比,差异极显著(P<0.01)。病羊的各项血液常规指标处于正常范围内。补铜能使这些生化指标恢复到正常水平,补硒的功效与补铜基本相同,但补硒并不能明显地增加病羊毛铜及激活血清铜蓝蛋白酶活性,相反,补硒能提高血钙,并能促进机体造血功能。本试验初步证明,缺铜是“摆腰病”羊的主要病因之一,补硒对病羊铜代谢的影响表现为协同作用。     

介绍一种奶牛群体高产饲养技术管理方法

一、问题的提出根据中华人民共和国专业标准《高产奶牛饲养管理规范》的规定,高产奶牛饲养分如下五个阶段:干乳期、围产期、泌乳盛期、泌乳中期和泌乳后期。而其泌乳盛期是产奶的最高阶段,也是最难饲养的阶段。奶牛在这个阶段饲养不好,不仅影响整个泌乳期的产奶量,而且会患各种代谢疾病、繁殖疾病,甚至死亡。饲养者最关心的问题是盛乳期奶牛的饲养技术,即如何满足其营养需要,使奶牛     

高产奶牛各阶段的饲养要点

根据奶牛产奶和生长发育各阶段的不同特点,可将奶牛的饲养分为7个不同时期:干乳期、围产期、泌乳盛期、泌乳中期、泌乳后期、犊牛饲养期、育成牛饲养期.要想满足奶牛营养需要,达到高产目标,各个时期的饲养也不尽相同.     

高产奶牛各阶段饲养要点

<正>根据奶牛产奶和生长发育各阶段的不同特点,可将奶牛的饲养分为7个不同时期:干乳期、围产期、泌乳盛期、泌乳中期、泌乳后期、犊牛饲养     

奶牛产奶期饲养管理技术

1 产奶期的确定和划分 1．1一般规定：从产犊7天到奶牛停奶为奶牛的一个产奶期。1．2从奶牛泌乳的生理规律上，可把奶牛的产奶期分为升乳期，中期和后期。 2产奶牛的饲养管理目的 2．1要有较大的干物质采食量（DMI）：DMI为体重的3～3．5％，一般要达到21．5～23．5千克／天。     

液态发酵饲料对奶牛产奶性能、血清抗氧化能力及血液生化指标的影响

本试验旨在研究液态发酵饲料对奶牛产奶性能、血清抗氧化性能和血液生化指标的影响。选取40头健康的荷斯坦牛进行配对,随机分为对照组和试验组,每组20头,每组5个重复,每个重复4头奶牛,在相同的条件下饲养。对照组饲喂牛场全混合日粮;试验组在每吨TMR中添加5kg液态发酵饲料,预试期7d,正试期60d。结果发现:液态发酵饲料对奶牛产奶量、乳品质无显著影响(P0.05),但可显著提高奶牛血清总抗氧化能力及葡萄糖含量(P0.05),对超氧化物歧化酶活性、谷胱甘肽过氧化物酶活性及丙二醛、总蛋白和乳酸脱氢酶含量无显著影响(P0.05)。说明在日粮中添加液态发酵饲料对奶牛产奶性能无显著影响,但可在一定程度上提高奶牛血清抗氧化能力,改善奶牛血液营养物质代谢。     

产奶牛的饲养管理要点

<正>产奶牛在围产期、产奶早期、产奶中期、产奶后期和干乳期等几个阶段,应根据牛的生理状况、产奶量、体况膘情等因素,结合饲料供应状况,采取相应的饲养管理方法。1围产期围产期一般指奶牛产前15天到产后15天这一段     

产奶牛的饲养管理要点

产奶牛在围产期、产奶早期、产奶中期、产奶后期和干乳期等几个阶段,应根据牛的生理状况、产奶量、体况膘情等因素,结合饲料供应状况,采取相应的饲养管理方法。1 围产期 围产期一般指奶牛产前15天到产后15天这一段时间。在产前应做到以下几点。     

补铜对奶牛血浆铜含量和铜蓝蛋白活性及其相关性的影响

本试验选取了大庆地区某奶牛群11头泌乳奶牛，检测补铜前后奶牛血浆铜含量和铜蓝蛋白(CP)活性的变化，同时分析了两者相关性。结果表明：补铜前血浆铜在10.93 μmol/L以下者占被检牛数的54.55%（6/11），其血浆CP活性降低，两者呈现中度相关性（R2=0.53）；补铜后血浆铜含量与CP活性均极显著增高（P<0.01），血浆铜含量达到正常范围，两者呈现低相关性（R2=0.12）。〖JP〗结论：该奶牛场泌乳奶牛群中存在低铜血症病牛，血浆铜蓝蛋白可以作为奶牛低铜血症的一项检测指标。     

Lactoferrin concentrations in milk from normal and subclinical mastitic cows

The concentrations of lactoferrin (Lf) in quarter milk from normal lactating cows and subclinical mastitic cows were measured to determine whether the Lf concentration in milk is influenced by the age of the cow, the stage of lactation, number of milk somatic cells and the presence of pathogens. Lf concentrations in 111 quarter milk samples from 28 normal lactating cows and 270 quarter milk samples from 198 subclinical mastitic cows were measured by means of a single radial immunodiffusion test. Lf concentrations (means +/- standard deviations; logarithmic form) in normal cows and subclinical mastitic cows were 2.23 +/- 0.39 and 2.70 +/- 0.39, respectively. The mean milk Lf concentration (log) in subclinical mastitic cows was significantly (p<0.01) higher than that in normal cows. The mean milk Lf concentration (log) in normal lactating cows aged 5 years was lower than those in normal lactating cows aged 2 years (p<0.01) and 3 years (p<0.05). The results showed that the milk Lf concentration (log) is associated with age of the dairy cow (one-way analysis of variance test, p<0.01). The mean milk Lf concentration (log) in the latter lactational period tended to be higher than those in the peak and middle periods. Milk Lf concentrations (log) tended to be proportional to the level of the somatic cell count (SCC) score. Mean milk Lf concentrations (log) in subclinical mastitic cows infected with Staphylococcus aureus and with other streptococci species were significantly (p<0.01) higher than those in cows infected with coagulase-negative staphylococci and with Corynebacterium bovis.     

乳房炎病奶牛血清抗氧化物酶活性

将14头奶牛分为健康对照组和乳房炎组,分别在泌乳的不同时期采血液,分离血清,测定血清中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—Px）、过氧化氢酶（cAT）活性。结果显示,患病奶牛血清中SOD、GSH—Px、CAT活性显著低于对照组（P〈0．01或P〈0．05）。结果表明,患病奶牛血清中抗氧化物酶活性的降低导致自由基大量蓄积可能是乳房炎发病机理之一。     

铜对奶牛免疫能力的影响

[目的]检测实验奶牛血清中的微量元素铜的水平及相关指标的变化规律。[方法]实验所用实验动物均选自黑龙江地区某奶牛场,常规水平饲养管理,TMR全混合日粮自由采食。根据DHI数据随机选择体重、胎次(2~3次)、泌乳期(0~10d)、体况和饲养管理高度相似的泌乳奶牛50头。[结果]实验奶牛血清铜水平与IL-2的相关性为R=0.355,显著性为P=0.011。实验奶牛血清铜水平与IL-2呈显著正相关,泌乳奶牛血清中的IL-2会随着铜水平的升高而有所升高。实验奶牛血清铜水平与IL-1的相关性为R=0.215,显著性为Ρ=0.133,P>0.05。实验奶牛血清铜水平与IL-1不相关。实验奶牛血清铜水平与TNF-α的相关性为R=0.185,显著性为P=0.198,P>0.05。[结论]实验奶牛血清铜水平与TNF-α不相关。     

Concentrations of IL-6 in Serum and Whey from Healthy and Mastitic Cows

Inflammatory cytokines, such as interleukin (IL)-6, have been shown to reflect clinical signs in certain conditions in diseased animals. In this study, we quantified the IL-6 concentrations in the serum and milk whey from 94 dairy cows with acute clinical mastitis and 55 healthy lactating cows. The IL-6 concentrations in serum from mastitic cows were significantly higher on the first day of illness compared to those of normal cows. Higher concentrations of IL-6 were also detected in the whey from mastitic cows, whereas low concentrations of IL-6 were detected in both serum and whey samples from normal cows. IL-6 concentrations in the serum taken at the onset of illness from cows that later required euthanasia were significantly higher than those in samples from cows that later recovered. These results suggest that serum IL-6 concentrations may be of prognostic value in identifying cows with severe mastitis.     

A luteinizing hormone-releasing hormone-induced serum luteinizing hormone surge is not detectable in the milk of cows

Six lactating Holstein cows were used to determine whether a serum luteinizing hormone (LH) surge induced by luteinizing hormone-releasing hormone (LHRH) could be detected in milk. A double antibody radioimmunoassay was evaluated for measuring LH in whole milk. Cows (d 10 of the estrous cycle) were injected with saline (time zero), followed by LHRH 12 h later. Blood samples were collected hourly for 12 h via jugular cannula following each injection; milk removal was accomplished every 2 h by a portable milking machine. On d 10 of the next estrous cycle, treatment, order was switched, with the same cows receiving LHRH at time zero and saline 12 h later. Approximately 2 h following LHRH treatment, serum LH levels peaked at 29 ng/ml and remained elevated for 5 h. There was no corresponding change in milk LH detected during the 12-h to 24-h period following the induced serum LH surge. Our conclusion is that the measurement of LH in the milk of cows shows little promise for predicting ovulation time in the cow.     

Ceruloplasmin as an indicator of copper status in cattle and sheep.

The relationship between ceruloplasmin, a metalloenzyme with oxidase activity, and copper was investigated in cattle and sheep. The oxidase activity of ceruloplasmin correlated closely with the serum or plasma copper concentrations in cattle. The respective correlation coefficients were 0.83 and 0.60. In sheep serum, a correlation coefficient of 0.92 was obtained. In each instance, the relationship remained linear from the deficient to the high normal ranges of copper. Comparison of the linear regression relationships indicated the ceruloplasmin activity in bovine serum was statistically lower than the activity in bovine plasma (P less than 0.0001), through the intercepts from the regression lines of the two relationships were similar (P = 0.412). Comparisons of ovine and bovine serum-ceruloplasmin relationships indicated that a significant species difference was present. Ovine ceruloplasmin activity increased more rapidly as compared to the corresponding bovine activity over the range of copper concentrations investigated (P less than 0.0001). The intercept from the ovine regression relationship was also lower (P less than 0.0001). A correlation coefficient of 0.35 was observed between the serum ceruloplasmin activity and hepatic copper concentrations in cattle indicating that the mathematical relationship was not as well defined. Ceruloplasmin activity appears to correlate more closely with serum or plasma copper concentrations as compared to corresponding liver copper concentrations.     

Serum calcium response following oral zinc oxide administrations in dairy cows

Six non-pregnant cows were allocated into 3 groups. Group 1 comprised a pair of lactating cows, whereas groups 2 and 3 each comprised a pair of non-lactating cows. The cows in groups 1 and 2 were dosed intraruminally by stomach tube with zinc oxide at 120 mg Zn per kg of bodyweight at weekly intervals for a period of 33 days. Each cow received a total of 4 doses of zinc oxide. Group 3 served as non-treated control group. Blood samples were collected from all 6 cows daily. Serum was analysed for concentration of calcium. Within 12-24 h of each zinc oxide administration the serum calcium of the lactating cows dropped dramatically indicating the existence of an antagonistic effect between Zn and Ca. The first Zn induced hypocalcaemic episode in the lactating cows was followed by a rise in serum calcium to a level above the pre-dosing level and above the mean value of the control group. The depth of the hypocalcaemic response decreased with the number of zinc oxide dosings. This effect was explained as a response from the stimulation of the calcium homeostatic mechanisms. In the Zn dosed non-lactating cows responses were similar but less clear. The perspective of these findings is discussed in relation to resistance towards parturient hypocalcaemia.     

Serum paraoxonase activity in dairy cows during pregnancy

Preparturient dairy cows are at high risk of metabolic and reproductive disorders and oxidative stress is considered to be involved in these events. We investigated the serum paraoxonase activity in dairy cows during pregnancy and alterations in lipid and lipoprotein patterns in this period. The relation between paraoxonase activity and HDL-cholesterol concentration was also compared. The study was carried out on 76 pregnant lactating and 26 pregnant dry Holstein dairy cows. The serum paraoxonase activity was determined by the method of hydrolysing of paraoxon, while triglyceride, cholesterol and HDL-cholesterol concentrations were measured by the enzymatic kit methods. A significantly higher serum triglyceride concentration (P<0.001) was observed in dry cows compared to lactating cows. The total cholesterol and HDL-cholesterol concentrations were significantly lower (P<0.001) in dry cows than in lactating ones. In dry cows, paraoxonase activity was significantly lower than in those lactating (P<0.001). There was no significant difference in paraoxonase/HDL-cholesterol ratio between the investigated groups. It seems that the lower HDL concentration could be one of the causes of reduced paraoxonase activity considering the role of HDL as a carrier of most paraoxonase molecules in the blood. A decreased serum paraoxonase activity could diminish the effectiveness and total capacity of the whole antioxidative system during prepartum period in dairy cattle.     

Concentration of serum amyloid A and ceruloplasmin activity in milk from cows with subclinical mastitis caused by different pathogens

The aim of the present study was to determine the concentration of serum amyloid A (SAA) and the activity of ceruloplasmin (Cp) in milk from cows with subclinical mastitis caused by different pathogens. Eighty-four milk samples from cows with subclinical mastitis and fourteen milk samples from healthy cows were examined. SAA concentration was determined using the commercial ELISA kit (Tridelta Development Ltd., Greystones, Wicklow, Ireland). Cp activity was assessed spectrophotometrically, using the Rice method. The results reveal that the concentration of SAA (with exception of CNS) and activity of Cp in cow milk can be regarded as markers of subclinical mastitis, irrespective of the microorganism inducing the disease. In conclusion, measurement of SAA and Cp in milk samples could be a useful method in diagnosing subclinical mastitis in cows, but the method should be adapted for field use.