体细胞数在奶牛乳房卫生保健工作中的应用

编者的话： 体细胞 (Somatic Cell Count)简称 SCC、是奶牛乳房健康状况的一个重要指标，牛奶中体细胞含量愈高，说明被感染的可能性就愈大，乳房炎的发病率也就愈高，但一般人们对体细胞的作用不太清楚，故本期刊出陈华林先生写的“体细胞数在奶牛乳房卫生保健工作中的应用”一文，供参阅。 《中国奶牛》编辑部 中图分类号： S857.26文献标识码： C文章编号： 1004－ 4264(2000)06－ 0049－ 02 收稿日期： 2000－ 07－ 24 (北京市农工商联合总合司，北京市 100009) 　　牛奶中的体细胞，多数是白细胞， (即巨噬细胞，噬中性白细胞和淋…     

南方地区中国荷斯坦牛乳中体细胞数变化规律的研究

为探索南方地区中国荷斯坦牛乳中体细胞数的变化规律,利用最小二乘法对南方地区某奶业集团2003—2006年7个牛场2063头中国荷斯坦牛92133次奶牛群改良计划(DHI)测定日记录进行了分析。结果表明:乳中体细胞数(SCC)为(399×1000±909×1000)个/mL,不同牛场、年份、月份、产犊季节、泌乳月和胎次对乳中体细胞数的影响均达到极显著水平(P<0.001)。SCC随着胎次和泌乳月的增加有升高的趋势。我国南方地区独特的气候特点和该乳业集团内部各牛场的饲养管理制度与本研究较高的乳中体细胞数均有一定的关系。     

南方地区中国荷斯坦牛乳中体细胞数变化规律的研究

采用最小二乘法分析了南方地区某奶业集团2006年7个牛场2063头中国荷斯坦牛22 377次SCC测定日记录。结果表明SCC为459.49×1000±924.66×1000个/mL,不同牛场、月份、泌乳月和胎次对乳中体细胞数的影响均达到极显著水平(p<0.001),而产犊季节对乳中SCC的影响未达到显著水平(p>0.05)。SCC随着胎次和泌乳月的增加有升高的趋势。     

南方地区荷斯坦牛乳中体细胞数及乳房性状与泌乳性能相关性的研究

对192头成年荷斯坦牛乳中体细胞数及乳房性状与泌乳性能的相关性进行研究,结果表明:乳中体细胞数较高,9月份达到最高水平;乳房性状评分偏低。体细胞数与月产奶量、月乳脂产量及月乳蛋白产量等性状有极显著负相关(p<0.01),与乳脂率和乳蛋白含量无显著相关关系(p>0.05);后乳房宽度与月产奶量、月乳脂产量及乳蛋白产量有极显著正相关(p<0.01)。     

南方地区中国荷斯坦牛乳中体细胞数变化规律的研究

采用最小二乘法分析了南方地区某奶业集团2006年7个牛场2 063头中国荷斯坦牛22 377次乳中体细胞数(SCC)测定日记录,以揭示SCC的变化规律.结果表明乳中SCC为459.49×103士924.66×103个/mL,不同牛场、月份、泌乳月和胎次对乳中体细胞数的影响均达到极显著水平(P＜0.01),而产犊季节对乳中SCC的影响未达到显著水平(P＞0.05).SCC随着胎次和泌乳月的增加有升高的趋势.     

褪黑素与奶牛牛乳体细胞数防控研究进展

奶牛牛乳体细胞数偏高问题一直是困扰世界奶牛养殖业的难题,现在对于奶牛高体细胞数的防控手段也是多种多样,有药物注射防控、饲养管理防控、加入中草药防控等。褪黑素作为一种重要的生殖激素,不仅和生物节律有关,还与调节免疫力和动物繁殖性能有关,褪黑素具有清除活性氧、抗衰老、抗炎症和增强机体抵抗力的功能。本文综述了奶牛牛乳体细胞数过高的危害及其防控手段,褪黑素在奶牛产业中的应用,以及褪黑素降低奶牛牛乳体细胞数的研究进展。     

新疆褐牛与荷斯坦牛隐性乳房炎与体细胞数、病原菌种类的比较

本试验以新疆乌鲁木齐市地区一大中型奶牛场的新疆褐牛、荷斯坦牛奶样为研究对象,对奶样进行了病原菌分离培养,同时对不同品种牛体细胞数与菌落形成单位（colony-forming unit, CFU）、体细胞数与不同年龄进行了统计分析。结果表明,2个品种牛感染病原菌种类稍有差别且新疆褐牛感染葡萄球菌的机率明显高于荷斯坦牛;荷斯坦牛比新疆褐牛更容易患乳房炎;新疆褐牛、荷斯坦牛体细胞在小于20万/mL时均与体细胞大于50万/mL时的CFU值呈显著差异（P＜0.05）,而这2个品种牛的体细胞在20～50万/mL时分别与体细胞小于20万/mL、大于50万/mL时的CFU值均无显著差异（P＞0.05）,初步推测体细胞数和细菌总数之间没有必然联系,还受其它因素影响;此外,随着年龄增长,褐牛和荷斯坦牛的体细胞评分（somatic cell score,SCS）都呈上升趋势,且不同品种间的SCS差异显著。     

补充蛋氨酸锌对荷斯坦奶牛乳中体细胞数和乳房炎的影响

该研究选取240头不同泌乳阶段、1~8胎次的荷斯坦奶牛,探讨影响牛奶中体细胞数以及产奶量和乳成分的某些因素。同时,12头健康奶牛、15头亚临床乳房炎奶牛以及15头临床乳房炎奶牛分别分为3组,第1组不添加蛋氨酸锌,第2、3组分别添加蛋氨酸锌5g/d·头和10g/d·头。亚临床和临床性乳房炎奶牛乳房内注射抗生素(100mg),直到完全康复。研究结果显示,冬季乳中体细胞数最高(P0.05),接着是夏季,最低的是秋季。体细胞数的变化是随着泌乳开始产奶量上升到高峰期的过程中呈现下降趋势,之后显著升高(P0.05),并且随着泌乳期的增加也在升高。正常奶牛、亚临床乳房炎奶牛和临床乳房炎奶牛的比例分别为77.71%、15.82%以及6.46%。产奶量和乳成分以及产奶收入都随着体细胞数的增加而显著降低(P0.05)。补充蛋氨酸锌导致乳中体细胞数显著下降(P0.05)。亚临床和临床乳房炎补充蛋氨酸锌显著降低了乳中体细胞数、导电性、康复时间以及与未添加组奶牛相比消耗的费用(P0.05)。     

奶牛体型和体细胞数（乳房炎）之间关系的研究进展

奶牛体型和体细胞数（乳房炎）之间关系的研究进展储明星，师守堃（北京农业大学动物科技学院）有效的牛奶生产是奶牛育种方案的主要目标。牛奶生产的效率受收入和生产成本的影响，生产中因疾病而增加的扰乱是费钱的，且对经济管理和伦理几乎是不能接受的。其中使奶牛身体...     

乳房炎对中国荷斯坦牛测定日泌乳性能及体细胞数变化的影响

旨在研究乳房炎及病原菌组成对中国荷斯坦牛测定日泌乳性能及体细胞数变化的影响.本研究于2009年9月对江苏某奶牛场140头成年中国荷斯坦泌乳牛进行乳房炎检测和DHI测定,同时对隐性乳房炎阳性乳区进行病原菌分离鉴定,并分析了不同乳房炎类型和隐性乳房炎病原菌组成对测定日泌乳性能和乳中SCC变化的影响.结果表明,该牛场临床乳房炎、隐性乳房炎和正常奶牛比例分别为10.00％、51.10％和37.90％,其中隐性乳房炎以大肠杆菌和链球菌混合感染最多(19头,占26.00％),其次为链球菌单独感染(17头,占23.30％).由1种细菌单独感染的比例为26头(占36.11％),2种或2种以上细菌混合感染为44头(占61.11％).乳房炎类型对测定日产奶量、乳糖含量、体细胞数和体细胞评分4个指标影响达到极显著水平(P＜0.01),临床乳房炎和隐性乳房炎奶牛日产奶量和乳糖含量极显著低于正常奶,同时体细胞数和体细胞评分极显著高于正常奶,而临床乳房炎奶和隐性乳房炎奶在所有检测指标上均无显著差异,但临床乳房炎奶比隐性乳房炎奶体细胞数高出约100万·mL-1.不同病原菌组成类型对乳中体细胞数和体细胞评分有极显著影响(P＜0.01),而对其它性状无显著影响(P＞0.05).混合感染奶牛测定日产奶量极显著低于单独感染奶牛(P＜0.01),同时乳中体细胞数显著高于单独感染奶牛(P＜0.01).乳房炎类型对乳中SCC的变化趋势有显著影响(P＜0.01),正常奶牛维持较低SCC的能力较强,隐性乳房炎奶牛在下一泌乳月体细胞增加的可能性较大.不同隐性乳房炎病原菌组成类型对乳中SCC的变化无显著影响.奶牛生产中隐性乳房炎发病率高,危害性也最大,不同病原菌混合感染引起的隐性乳房炎对测定日产奶量和乳中体细胞数影响最大.该结果为奶牛场采取合理措施,降低隐性乳房炎发生率提供了参考.     

Modeling lactation curves and estimation of genetic parameters in Holstein cows using multiple‐trait random regression models

We compared the goodness of fit of three mathematical functions (including: Legendre polynomials, Lidauer‐Mäntysaari function and Wilmink function) for describing the lactation curve of primiparous Iranian Holstein cows by using multiple‐trait random regression models (MT‐RRM). Lactational submodels provided the largest daily additive genetic (AG) and permanent environmental (PE) variance estimates at the end and at the onset of lactation, respectively, as well as low genetic correlations between peripheral test‐day records. For all models, heritability estimates were highest at the end of lactation (245 to 305 days) and ranged from 0.05 to 0.26, 0.03 to 0.12 and 0.04 to 0.24 for milk, fat and protein yields, respectively. Generally, the genetic correlations between traits depend on how far apart they are or whether they are on the same day in any two traits. On average, genetic correlations between milk and fat were the lowest and those between fat and protein were intermediate, while those between milk and protein were the highest. Results from all criteria (Akaike's and Schwarz's Bayesian information criterion, and ?2*logarithm of the likelihood function) suggested that a model with 2 and 5 coefficients of Legendre polynomials for AG and PE effects, respectively, was the most adequate for fitting the data.     

2005年上海地区乳牛球虫感染的季节动态

为了解上海地区乳牛球虫感染的季节变化情况，对上海地区3个牧场乳牛抽样直肠采集粪便，检查了718头乳牛粪样。结果，查出球虫阳性牛269头，平均感染率为37．46％，其中1月龄以内牛的感染率为33．89％，1～12月龄牛的感染率为42．33％，12月龄以上牛的感染率为25．95％。平均感染率最高的4月份为44．44％，最低的8月份为28．57％。3个牧场球虫阳性牛的感染强度（OPG值）为0～169000个，平均OPG值为9477个，其中1月龄以内牛的OPG值为8270个，1～12月龄牛的OPG值为4318个，12月龄以上牛的OPG值为145个。调查发现了6种球虫，分别是牛艾美球虫（Eimeria boris）、椭圆艾美球虫（E．ellipsoidalis）、邱氏艾美球虫（E．zurnii）、怀俄明艾美球虫（E．wyomingensis）、柱状艾美球虫（E．cylindrica）、亚球形艾美球虫（E．subspherica）。结果表明，2005年上海地区乳牛球虫感染率无明显季节差异，12月龄内乳牛的球虫感染率与感染强度均明显高于12月龄以上乳牛，乳牛球虫的优势虫种为牛艾美球虫、椭圆艾美球虫、邱氏艾美球虫。     

Characterizing rumination patterns of dairy cows using spectral analysis

Spectral analysis techniques were used to characterize the cyclical variation in rumination behavior of cows. Four Holstein cows were fed twice daily a diet of 60% high-moisture shelled corn-based concentrate, 15% first-cut alfalfa-grass hay and 25% second-cut alfalfa silage. The number of minutes that each cow spent ruminating was determined for 15-min intervals during six consecutive days. Rumination data then were characterized using Fourier harmonic analysis to decompose the total sum of squares into 288 orthogonal components due to different rumination wavelengths. Rumination patterns for all cows consisted mainly of wavelengths that were harmonics of a 24-h cycle, indicating a circadian pattern of rumination. Differences in rumination patterns between cows occurred mainly at wavelengths of less than 2 h. Rumination patterns of two of the four cows were more complex, and consisted of high-frequency, non-24-h harmonic wavelengths in addition to the circadian pattern. Spectral analysis can be used to identify the component cycles of rumination patterns of individual animals, which can then be used to determine the effects of dietary or other manipulations on rumination behavior.     

Ketonuria in dairy cows

In 3337 dairy cows, urine was examined for ketone bodies by help of Bililabstix during the first and second phase of lactation and in the eighth to the ninth and a half month of pregnancy; at the same time needed supply of energetic nutrients in 175 summer and 308 winter feed rations was calculated. Intensity and frequency of ketonuria in lactating cows fed winter rations is significantly higher than in those fed green feeds; it decreases significantly with a phase of lactation and with milk production. On the contrary, cows in late pregnancy have higher intensity and frequency of ketonuria (32.9%) when fed green feeds than when fed winter rations (30.7%). In winter feed rations energy input was significantly lower, percentage of deficient feed rations at a relatively broader caloric-protein ratio was higher than in summer season. The highest deficits of energy and digestible nitrogen compounds were observed in cows in the first phase of lactation. Discussion concerns the causes and mechanisms of different ketonuria in groups of dairy cows in relation to deficit of energetic nutrients, caloric-protein ratio, to the level of glycaemia, non-esterified fatty acids in plasma, triglycerides of plasma and to the state of liver function.     

Heritability and genetic correlations between rumination time and production traits in Holstein dairy cows during different lactation phases

So far, rumination has been used as a proxy for monitoring dairy cow health at farm level. However, investigating its genetic aspects as well as its correlation with other important productive traits may turn this management tool into a new informative selection criterion. However, scientific evidences on genetic correlation among rumination time (RT) and milk production and milk composition are still scarce. Therefore, the objective of this study was to estimate the heritability of RT across three lactation phases and its genetic correlation with milk production, milk composition and somatic cell count (SCC). Results of our study showed that heritability for RT was 0.34 and was constant across lactation. The mean genetic correlations between RT and milk production and composition traits were 0.07 (milk production), ?0.07 (protein yield), ?0.31 (fat yield), and ?0.32 (fat/protein ratio). The mean genetic correlation between RT and the SCC was 0.05.     

Blindness in dairy cows

Extract

Blindness in dairy cows due to various causes has often been observed. This report instances threecases occurring on one property within a period of two months. Of the animals concerned, all Jersey cows, one was home bred and the other two were purchased.     

Oestrus prediction in dairy cows using an ELISA progesterone test

The commercially available test kit for assaying milk progesterone was used in the practice laboratory on samples taken daily from cows 17 to 24 days after service. Improved oestrus detection rates and accuracy were achieved by predicting the onset of oestrus. Similar results were obtained by sampling on days 18, 20, 22 and 24 or on days 19, 21 and 23 after service. Calving to conception intervals improved from 115 to 84 days in one herd and from 85 to 74 days in another and the potential economic benefits in these two herds outweighed the costs by 7.4:1 and 3.4:1, respectively.     

Cow effects and estimation of success of first and following inseminations in Dutch dairy cows

The objective of this research was to determine the contribution of cow factors to the probability of successful insemination accounting for the serial number of inseminations in analysis. The investigation was performed with 101,297 insemination records in 51,525 lactations of different cows from 1368 herds obtained from the Dutch milk production recording database. Cows that had a first insemination (AI) between 40 and 150 days post-partum with one or more inseminations (≤6 inseminations) were selected. An insemination was defined successful when not followed by another insemination and when the cow calved between 267 and 295 days after insemination, or when the cow was culled between 135 and 295 days after the last insemination. Breed, parity, days in milk, lactation curve characteristics, milk production traits, moment of AI related to peak milk yield time (before or after peak milk yield), the last calf (female, male, twin or stillbirth) and season of insemination were selected as independent parameters for a model with successful rate of insemination as dependent parameter. A multivariable logistic regression model was used within cow and farm as a random effect. The probability of successful insemination was the highest in the first insemination and decreased in the following inseminations. However, the success rate of all inseminations increased in a later stage of lactation. The improvement in the successful inseminations in a later stage of lactation was better in multiparous cows than in first parity cows. Insemination in summer and before peak milk yield time reduced the success of insemination. The success rate was the lowest in 100% Holstein Friesian cows compared with other breeds and was the highest when the last calf was a female calf compared to a male calf, twin or stillbirth. In conclusion, the success of first and following inseminations depended on parity, breed, season of insemination, last calf status, daily milk yield at insemination date, serial insemination number and days in milk at insemination date.