奶牛蹄病的发病调查与分析

为了引起奶牛养殖者对奶牛蹄病的重视,减少因奶牛蹄病而造成的经济损失,笔者对临洮城郊几个奶牛场的四百多头不同胎次奶牛的蹄病的发病情况进行了调查。结果表明,奶牛1～6胎次内随着胎次的增加,蹄病的发病率逐渐上升,并且3胎以上产奶牛的发病率明显要高于1～2两胎。从发病程度来看,1～5胎随着胎次的增加"中+,重"程度发病产奶牛比例逐渐加大,而"轻"度发病呈现逐渐降低的变化,而6胎次的奶牛发病程度的变化与前者刚好相反。     

奶牛蹄病的调查分析

为了引起奶牛养殖者对奶牛蹄病的重视,减少因奶牛蹄病造成的经济损失,笔者对临洮城区两个奶牛场472头不同胎次奶牛蹄病的发病情况进行了调查。结果表明:产奶牛1～6胎次发病率分别为11.63%,12.77%,16.00%,25.00%,26.67%和35.71%。说明随着胎次的增加,奶牛蹄病的发病率逐渐上升,并且3胎以上产奶牛的发病率明显要高于1～2胎。从发病程度来看,1～5胎奶牛随着胎次的增加",中+,重"程度发病产奶牛比例逐渐加大,而"轻"程度发病呈现逐渐降低的变化,而6胎次的奶牛发病程度的变化与前者刚好相反。     

奶牛蹄病的调查分析

为了引起奶牛养殖者对奶牛蹄病的重视,减少因奶牛蹄病造成的经济损失,笔者对临洮城区两个奶牛场472头不同胎次奶牛蹄病的发病情况进行了调查。结果表明：产奶牛1～6胎次发病率分别为11.63%,12.77%,16.00%,25.00%,26.67%和35.71%。说明随着胎次的增加,奶牛蹄病的发病率逐渐上升,并且3胎以上产奶牛的发病率明显要高于1～2胎。从发病程度来看,1～5胎奶牛随着胎次的增加＂,中＋,重＂程度发病产奶牛比例逐渐加大,而＂轻＂程度发病呈现逐渐降低的变化,而6胎次的奶牛发病程度的变化与前者刚好相反。     

淮南地区荷斯坦奶牛隐性乳房炎的检测及分析

随机抽取473头荷斯坦奶牛1892个乳区进行奶牛隐性乳房炎的检测及分析。结果表明：淮南地区荷斯坦奶牛隐性乳房炎的乳区阳性率为25．42％。奶牛阳性率为52．64％。在1、2、3、4、5胎以及5胎以上的乳区阳性率分别为23．12％、24．53％、25．88％、22．41％、23．03％和44．08％；奶牛阳性率分别是47．95％、52．34％、52．33％、51．72％、52．63％及73．68％。1～5胎乳区阳性率的变异范围是22．41％～25．08％，差异不显著（P〉0．05），而5胎以上乳区阳性率为44．08％，极显著（P〈0．01）地高于前5个胎次。同样，奶牛阳性率随胎次发生变化的趋势与乳区阳性率是一致的，只是在前5个胎次中第1胎47．95％的奶牛阳性率分别低于2～5胎次各5个百分点左右，但也均未达到显著水平（P〉0．05）。不同胎次不同泌乳月隐性乳房炎的乳区阳性率及奶牛阳性率无明显的变化规律。     

荷斯坦奶牛非本意淘汰的原因及分析

目的:探讨荷斯坦奶牛非本意淘汰的原因及对策。方法:统计非本意淘汰奶牛数,检测奶牛隐性乳房炎,分析奶牛腐蹄病发病情况。结果:①奶牛非本意淘汰率为73.3%。②奶牛1胎～叟6胎各胎次隐性乳房炎的奶牛阳性率分别是47.82%、52.03%、52.11%、51.06%、52.84%及75.00%;乳区阳性率分别为23.07%、24.59%、25.70%、22.34%、23.08%和43.75%。③奶牛1～叟6胎各胎次腐蹄病的奶牛发病率分别为26.09%、27.64%、60.56%、68.09%、73.08%和81.25%,病蹄率分别是7.61%、8.13%、18.31%、23.40%、23.08%和23.44%,均在3胎以后明显大于1、2胎次。     

奶牛隐性乳房炎的流行病学调查

为了降低奶牛隐性乳房炎对奶牛养殖业的危害,采用中国农业科学院兰州畜牧与兽医研究所研制的奶牛隐性乳房炎诊断液（LMT）．随机对某奶牛场的400头奶牛进行乳房炎调查,结果表明：④该场奶牛隐性乳房炎的阳性率为55．00％,乳区阳性率为49．81％;②隐性乳房炎的发病率随季节的变化而变化,以第2季度最高,达71％,与其他季节相比差异显著（P〈0．05）：③该场奶牛隐性乳房炎主要以左前乳区的发病率最高（53．41％）,但4个乳区的差异不显著;（4）被检奶牛中,头4胎发病率随胎次的增加而降低,4胎以上发病率随胎次的增加有上升的趋势。2胎和5胎以上的差异不显著（P〉0．05）,与其他胎次差异显著（P〈0．05）;（5）泌乳期各月隐性乳房炎的阳性检出率以产后1～2月内差异极显著（P〈0．01）．以后随泌乳月份的增加呈上升趋势;（6）日泌乳量在20kg以下奶牛的患病率为68．00％,显著高于日产奶量20kg以上奶牛（42．00％,P〈0．05）的患病率。     

奶牛乳房炎的临床学调查

本研究对济南郊区卫生和管理条件较好的大型奶牛场临床型奶牛乳房炎和隐性奶牛乳房炎与胎次之间的关系进行了调查。结果表明,该奶牛场1～5胎次奶牛隐性乳房炎发病率高于临床型奶牛乳房炎发病率,而两种不同型的奶牛乳房炎发病率在6～9胎次奶牛表现相同,均为28.00%。临床型乳房炎除第3胎次稍有降低外,其余随胎次增多,发病率呈上升趋势。1胎、2胎、3胎、4胎、6～9胎的临床型乳房炎发病率分别为3.86%、8.04%、5.26%、9.00%、10.00%、28.00%,不同胎次间存在显著差异(P<0.05);不同胎次奶牛隐性乳房炎的发病率依次为16.49%、29.15%、31.58%、20.07%、22.22%、28.00%,其中第3胎次奶牛隐性乳房炎发病率显著高于其它胎次发病率,且各组间也具有差异显著性(P<0.05)。总之,该奶牛场随奶牛胎次的增加,乳房炎总发病率呈上升的趋势,6～9胎次奶牛乳房炎发病率最高,其次为2、3胎次。     

奶牛产后瘫痪的诊断及其综合防治方法

产后瘫痪又称乳热症,是母畜在分娩前后突然发生以肌肉松弛、昏迷和低血钙为主要特征的代谢病。本病多发生于高产奶牛,奶产量越高,发病越多,年发病率在3．5％～8．8％,有些农场发生率很低,约为1．2％;但有些可高达25％～30％。本病的发生与奶牛年龄、胎次、产奶量及品种有关。青年母牛很少发病,95％以上的病牛是5-9岁或第3～7胎;易患病牛的乳产量均高于平均产乳量,为未发病牛的2-3倍。     

寒冷地区奶牛多汗症的治疗

龙江县景星镇畜牧站于2001~2009年共诊治奶牛多汗症34例,占奶牛发病总数的28%。1发病情况1.1胎次在景星镇畜牧站所诊治的34例多汗病奶牛中,有3胎牛6例、4胎牛18例、5胎以上的牛10例。1.2产奶量据34例多汗病牛的产奶量统计,奶量均在20千克/天以上的奶牛多发,产奶量越高,多汗病出现的越早,而且汗量也多。     

奶牛腐蹄病的防治

蹄病是奶牛的常见病,对牛的利用有很大影响,而在蹄病中腐蹄病又占有相当高的比例。据调查,在山东省规模在１００头以上的奶牛场,腐蹄病的发病率在２５％左右,农户奶牛蹄病的发病率近４０％,而腐蹄病牛占蹄病牛的比例高达４５％。牛蹄病的发生对奶牛饲养场、户造成的...     

Effects of subclinical bovine leukemia virus infection on some production parameters in a dairy farm in southern Turkey

Some production parameters of seropositive cows (age, first calving age, 305 day mature equivalent last milk yield production, lifetime mature equivalent milk yield production, lifetime total milk production, lifetime total milking period, lifetime monthly milk production, lifetime daily milk production, lifetime total days of milking, number of inseminations per pregnancy (for last pregnancy), number of calves and calving interval (for last pregnancy)) were analysed in the current study. The study population was clinically healthy Holstein cows from a commercial dairy herd in southern Turkey. Of 109 animals, 65 cows were seropositive by ELISA and the prevalence of bovine leukemia virus (BLV) infection was 59.6%. The prevalence of seropositive cows in 2nd (62.8%), 3rd (64.7%), 4th (61.5%), and 5th (66.6 %) lactations was slightly higher than that of cows in 1st (52.6%) lactations. No statistical differences were observed between BLV seronegative and seropositive cows for production and reproduction parameters analysed in this study (P > 0.05).     

饲料营养对母牛繁殖率影响效果研究

通过对妊娠后期（后１４２ｄ）母牛、带犊哺乳母牛的不同阶段饲料营养配合试验,探讨母牛的饲养技术方案。选择条件大致相同的妊娠后期母牛３６头,随机分为试验１、２组和对照组各１２头。试验１组和试验２组根据妊娠月份及粗饲料种类不同,粗饲料日喂量各有所调整,对照组牛则采用当地的传统饲养方式。试验结果,试验１组母牛产仔成活１１头,哺乳期平均１１７ｄ,断奶成活１０头,繁殖成活率８３．３％,母牛产后开始发情时间平均     

奶牛卵巢囊肿分布调查及形成原因分析

为了探讨北京市规模化奶牛场奶牛卵巢囊肿的发病情况、致病因素及形成机制,本研究采用直肠检查及B超诊断,结合奶牛的胎次、分娩季节及血清生化指标、激素水平等分析了奶牛卵巢囊肿的分布情况、影响因素及形成原因。结果表明,卵巢囊肿在所试奶牛场的发病率为10.73%,不同胎次奶牛卵巢囊肿发病率不同;在所有卵巢囊肿奶牛中,夏季分娩奶牛（51.06%）明显高于春季（8.51%）和冬季（17.02%）;胰岛素、胰岛素样生长因子1（IGF-1）及雌二醇（E₂）等与奶牛卵巢囊肿的发生密切相关,其中患有卵巢囊肿奶牛血清胰岛素和IGF-1的平均浓度均显著低于正常奶牛血清值（P < 0.05）,而血清E₂的平均浓度却显著高于正常奶牛血清值（P < 0.05）。该研究结果为奶牛场奶牛卵巢囊肿的预防和治疗提供了可靠的依据。     

Effect of lameness on the calving-to-conception interval in dairy cows

OBJECTIVE: To examine the relationship between lameness and the duration of the interval from calving to subsequent conception in lactating dairy cows. DESIGN: Cohort study. ANIMALS: 837 dairy cows. PROCEDURE: Cows affected with lameness were classified into 1 of 4 groups on the basis of types of disease or lesions observed, including foot rot, papillomatous digital dermatitis, claw lesions, or multiple lesions. Cows not affected with lameness were classified as healthy. Time from calving to conception was compared between lame cows and healthy cows. RESULTS: 254 (30%) cows were affected with lameness during lactation. Most lame cows (59%) had claw lesions. Lame cows with claw lesions were 0.52 times as likely to conceive as healthy cows. Median time to conception was 40 days longer in lame cows with claw lesions, compared with healthy cows. Number of breedings per conception for lame cows with claw lesions was significantly higher than that for healthy cows. CONCLUSION AND CLINICAL RELEVANCE: Claw lesions were the most important cause of lameness, impairing reproductive performance in dairy cows, as indicated by a higher incidence of affected cows and a greater time from calving to conception and a higher number of breedings required per conception, compared with healthy cows.     

Postpartum reproductive performance in dairy cows. I: Influence of animal, breed and parity

The purpose of this study was to evaluate the influence of animal, breed and parity on postpartum reproductive functions in dairy cows. A total of 141 cows were included in the experiment, which was carried out as part of a study on traits affecting longevity in Swedish dairy cows. The cows belonged to 4 different breed-groups and were 1st to 5th calvers. The duration of the study was 3 years and 44 cows were followed during 1 postpartum period, 49 cows during 2 consecutive periods, 43 cows during 3 periods and 5 cows during 4 periods.The cows were clinically examined, by rectal palpation, at 10-day intervals between calving and first AI, which was at first normal oestrus more than 50 days after calving. External signs of heat were checker and recorded three times daily by the herdsmen. Blood samples for progesterone assay were taken at days 10, 15 and 20 after calving and thereafter every 10th day until first AI. Samples taken at days 10, 15 and 20 were also assayed for content of 15-keto-13,14-dihydro-PGF_2α.Heat detection records, records from clinical examinations and plasma progesterone assays were chronologically compiled for each postpartum period and based on this, intervals between calving and postpartum ovulations, recorded uterine involution, 1st and subsequent oestrus and regular reproductive functions were estimated. Least-squares methods were used for the statistical evaluation of data.The results indicate a large variation within and between cows in postpartum reproductive performance. In the total material 1st ovulation occurred before recorded uterine involution and there was a close relationship between 1st ovulatory oestrus and the onset of regular reproductive functions. The interval between calving and 1st ovulation significantly influenced the length of the first cycle in the sense that a large proportion of the early ovulating cows had a short interval between 1st and 2nd postpartum ovulations. The large variations were also evident in the plasma levels of 15-keto-13,14-dihydro-PGF_2α. There was a marked decline between days 10 and 15 postpartum and most cows were close to basal levels at 20 days postpartum.The individual cow had a significant influence on intervals from calving to recorded uterine involution, 1st ovulatory oestrus, regular reproductive functions and conception. The breed influence was significant for intervals between calving and 1st ovulation and recorded uterine involution whereas the parity of the cow only influenced the interval between calving and recorded uterine involution.     

Investigation on the Distribution and Analysis on Formation Cause of Cystic Ovarian Disease in Dairy Cows

In order to explore the incidence,pathogenic factors and the formation mechanism of cystic ovarian disease (COD) in Beijing scale dairy farm,we used the rectal examination and ultrasound diagnosis,combined with the dairy parity,calving season and serum biochemical indices and hormone levels to investigate the distribution,influencing factors and formation cause of cow ovarian cysts.The results showed that the incidence of cystic ovarian disease (COD) was 10.73% in the testing dairy herds and the incidence of COD was associated with the parities.The incidence rate of ovarian cyst in the cows calving in the summer (51.06%) was higher than those calving in the spring (8.51%) and winter (17.02%).Insulin,IGF-1 and E₂ were closely related with the formation of the cow ovarian cyst.The average concentrations of serum insulin and IGF-1 in cows with ovarian cysts were significantly lower than those of normal cows(P < 0.05),but the average concentration of serum E₂ was significantly higher than that of normal cows(P < 0.05).This study provided reliable basis for the prevention and treatment of cow ovarian cyst.     

干奶后期饲喂阴离子盐对奶牛离子平衡和产奶的影响

采用28头荷斯坦经产牛按配对试验设计研究了添加阴离子盐对奶牛血液离子浓度、胎衣不下发病率及产后6个月泌乳性能的影响。结果表明,饲喂阴离子盐饲粮5天使尿液pH值显著降低(P<0.01),产前血清氯离子浓度提高(P<0.05),钙离子浓度趋于上升,并使分娩后胎衣不下的发病率降低31.2个百分点P=0.05)。第1、2、3、4泌乳月校正乳产量提高,且趋向提高乳脂率,但对乳蛋白、乳糖、非脂乳固体含量等乳成分没有明显影响(P<0.2)。饲喂阴离子盐能够显著降低产奶牛第2、3、4个泌乳月乳中的体细胞数P=0.03(0.09)。本试验结论:产前饲粮中添加阴离子盐能够改善奶牛产后的健康状况,提高泌乳性能。     

牛奶中超氧化物歧化酶(SOD)活性的研究

本试验采用邻苯三酚自氧化法,对牛奶中ＳＯＤ活性进行了研究。结果表明：在泌乳期４间ＳＯＤ活性是初乳〉本乳〉常乳。其测定值分别为１１．４、８．０和６．９ｕ／ｍｌ。在泌期内随泌乳时间呈规律性变化,初乳是产后第一天最高,以后迅速下降（Ｃ．Ｖ．１６．５％）;常乳是第一、二泌乳月下降,第三、四泌乳月最低,第五、六泌乳月回升,第七、八泌乳月稳定（Ｃ．Ｖ;２６．０％）;末乳相对比较稳定,在不同个体间有一定程度的差     

荷斯坦牛产后前60 d患隐性乳房炎次数对各泌乳月SCS的影响

荷斯坦牛产后前60 d患隐性乳房炎(SCM)次数反映了泌乳牛产后乳房的生理健康状况.本研究旨在探究荷斯坦牛产后前60 d患SCM次数对各泌乳月体细胞评分(somatic cell score,SCS)的影响,以期为牧场及时采取相关措施进行隐性乳房炎防控提供科学依据.本研究收集江苏地区12个奶牛场2017-2019年荷斯...     

Heifer rearing conditions affect length of productive life in Swedish dairy cows

Associations between rearing conditions and the risk of culling in dairy cows were studied by survival analysis. Data were collected from 1039 Swedish Red cows, 1029 Swedish Holsteins, and 56 cows of other milk or cross-breeds, representing all female animals born in 109 Swedish herds during 1998. Length of productive life was defined as the number of days from 1st calving to culling. The applied Weibull proportional hazards model included time-independent effects of breed, housing from 3 to 7 months of age, number of housing changes before calving, grazing before 1st calving, herd median age at 1st calving, age at 1st calving, cow housing, herd lactational incidence risk of veterinary-reported clinical mastitis, and the random effect of herd. Time-dependent effects were year, month, the interaction year by month, parity, number of breedings, pregnancy status, the interaction parity by pregnancy status, herd mean milk-production level, relative milk yield within breed-parity, and veterinary-reported clinical mastitis. The lactation was divided into six stages in which pregnancy status was assumed to be known by the farmer and culling could occur. Median productive life time in culled cows was 780 d and 14% of the records were censored due to terminated data collection. An individual calving age of 28.2–30.9 months was associated with the highest culling risk, 1.2-fold higher than calving at ≤25.3 months, whereas the risk decreased almost linearly with a higher herd median age at 1st calving. Housing in slatted pens with >7 calves from 3 to 7 months was associated with a 1.7-fold increase in risk, relative to litter pens. If a cow had changed housing system 4 times before 1st calving it increased the risk of culling 1.4 times, relative to two housing changes. These results show that rearing factors affect the productive life time of dairy cows in Swedish family operations.