乳酶LDH作为奶牛隐性乳房炎早期诊断指标的研究

为了筛选敏感的奶牛隐性乳房炎早期诊断指标,选择220头荷斯坦泌乳奶牛,分别采集乳汁进行体细胞计数和乳酸脱氢酶(LDH)活性测定.结果显示,隐性乳房炎奶牛乳汁中LDH活性显著高于健康奶牛(P＜0.05),乳汁体细胞数(SCC)与LDH活性呈正相关(r2=0.93).选择LDH活性>100 IU/L作为隐性乳房炎的判定阈值,诊断的敏感性为70%,特异性为82.3%,Jouden指数为0.52.结果提示,LDH可作为奶牛隐性乳房炎早期诊断指标.     

The effect of experimentally induced subclinical mastitis on milk yield of ewes and on the growth of lambs

In each of two experiments, subclinical mastitis was induced by inoculating both mammary glands of Welsh-Mountain and Dorset-Horn ewes with a coagulase-negative staphylococcus; groups of control ewes were also included. After inoculation, the somatic cell counts of milk of the inoculated ewes increased (P less than 0.01) and the milk yield decreased (P less than 0.01). The lambs of the inoculated ewes had a poorer growth than lambs of the control ewes (P less than 0.01).     

不同前作对杂交狼尾草产量和品质的影响

对长江流域农区不同粮草前作下杂交狼尾草的草产量、再生情况和营养品质进行了研究。结果表明,多花黑麦草茬的杂交狼尾草长势好、再生植株高、分蘖多、叶面积指数大、干物质积累多、产量较高。而且茎叶比较小、鲜干比较大、适口性较好。黑麦茬茬口较早,杂交狼尾草产量高,小麦茬表现最差。但是不同前作对杂交狼尾草的营养品质的影响较小。为了达到高产优质,杂交狼尾草应与多花黑麦草或黑麦进行复种。     

Cow milk yield and composition before development of Escherichia coli mastitis

High milk yield, low milk fat and low milk protein were considered as possible predisposing factors to bovine Escherichia coli mastitis. Morning and afternoon milk yields were recorded in 46 Friesian cows later developing E coli mastitis and compared with 92 uninfected controls. Animals developing E coli mastitis gave a significantly higher milk yield than controls. The overall morning: afternoon ratio was (mean +/- se) 1.66 +/- 0.41, with no difference in ratio for the two groups. Further studies on 85 animals later developing E coli mastitis, and 192 controls, in four Friesian herds did not reveal differences in milk fat content (except as related to yield), milk protein or in the interrelationship of days of lactation, milk protein or in the interrelationship of days of lactation, milk fat and milk protein in the two groups. Again there was a correlation between high milk yield and a tendency to develop E coli mastitis but this may have been an age effect in both investigations. No correlation between milk yield and mastitis severity was detected. High yielders which succumbed to E coli mastitis in three herds were producing less milk than mastitis-free controls in the fourth herd which suggests that the correlation is not with yield per se.     

不同粮食和牧草前作对水稻生长、产量和品质的影响

为了探讨长江流域农区冬季种植牧草和粮食作物对后作水稻Oryza sativa生产的影响,对种植多花黑麦草Lolium multiflorum、黑麦Secale cereal和小麦Triticum eastivum的水田土壤理化性状以及水稻的生长发育、稻谷产量和稻米品质进行了研究.结果表明:冬季种植多花黑麦草和黑麦后土壤理化性状得到了改善,降低了土壤pH值,增加了土壤全氮含量和速效养分.种植小麦的土壤pH值降低,全氮含量增加,但速效养分增加较少或减少.相应地,多花黑麦草茬和黑麦茬水稻生长得到了明显的促进,单位面积有效穗数和产量显著高于小麦茬水稻,但对每穗粒数、千粒重和稻米品质的影响不大.可见,冬季种植牧草在生产大量青饲料的同时,还起到了改良土壤的作用,为提高农田生产力提供了有效途径.同时促进了农业种植业和畜牧业的有机结合,形成了包括土壤、粮食作物、牧草、家畜等多因子的生态农业系统.     

温湿度对乳牛产乳量的影响

研究了夏季高温中温、湿度对中国黑白花乳牛生产性能的影响。结果表明,夏季气温27℃、温湿指数(THI)超过69时,导致该品种牛产乳量下降     

Influence of milk components in establishing biofilm mediated bacterial mastitis infections in cattle: A fractional factorial approach

Biofilm formation is one of the factors responsible for antibiotic resistance. The involvement of biofilm formation in bacterial mastitis is well known. Milk composition varies during the lactation period and certain pathogens are producing more number of mastitis cases during particular periods of lactation. The present study elucidates the effects of different milk components on biofilm formation and the persistence of infection. The Plackett Burman screening design has been chosen for assessing the significance. Biofilm production of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were assessed by crystal violet assay. Dipotassium hydrogen phosphate had a significant effect on biofilm formation by S. aureus (MTCC 1430) whereas it was pH in the case of biofilm formation by P. aeruginosa (NCIM 5029). Other independent factors were found to be insignificant.     

不同粗饲料对奶牛乳产量和乳成分的影响

选择18头荷斯坦奶牛,设置3个处理,每个处理6个重复,每个重复1头奶牛,研究不同粗饲料对奶牛泌乳性能和乳成分的影响,3个处理的粗饲料分别为玉米秸(Ⅰ组)、玉米秸+青贮玉米秸(Ⅱ组)、羊草(Ⅲ组)。试验结果表明:①试验Ⅱ组与试验Ⅲ组平均产奶量差异不显著(P>0.05),试验全期分别比Ⅰ组提高了8.82%(P<0.05)和9.57%(P<0.05);②不同处理间的乳糖、乳脂含量差异不显著(P>0.05);对于乳蛋白,在试验40d时3个试验组差异不显著(P>0.05),在第15d时Ⅱ组、Ⅲ组分别比Ⅰ组降低了7.43%(P<0.05)和8.57%(P<0.05)。对于乳干物质,Ⅱ组与Ⅲ组差异不显著(P>0.05)。根据上述生产性能指标综合评定,玉米秸+青贮玉米秸可有效替代羊草饲喂奶牛,而不降低泌乳性能。     

基因芯片法检测奶牛乳房炎主要致病菌

奶牛乳房炎不但严重影响乳的品质,而且危害人类健康.目前已知的奶牛乳房炎致病菌大约有220多种,其中常见的有20多种[1],基因芯片技术以其集成化、微型化、可对靶致病菌实现平行化检测的特点在动物疫病诊断方面显示出强大的优势[2-4],本试验旨在建立快速、灵敏、特异、准确检测奶牛乳房炎5种主要致病菌的基因芯片检测技术,为乳业生产上有效预防控制奶牛乳房炎提供检测依据.     

复合酶制剂对奶牛产奶量和乳品质的影响

30头产奶量和泌乳天数相近的泌乳高峰期(32～100d)头胎中国荷斯坦奶牛[BW=(520±6.44)kg],随机分为3组,每组10头,分别为对照组(不添加复合酶制剂),试验Ⅰ组[添加复合酶制剂500g(/t精料)]和Ⅱ组[添加复合酶制剂1000g(/t精料)]。基础日粮为TMR日粮,试验期共45d,预饲期15d,正式试验期30d,饲喂制度按牛场规定统一进行。试验结果表明:①复合酶制剂的两个不同水平的添加量(1000和500g/t)可显著提高奶牛产奶量(P<0.01)、乳中乳脂率(P<0.05)和乳糖(P<0.05)含量,显著降低乳中体细胞数(P<0.01);②在本试验条件下,使用复合酶制剂可显著增加经济效益。     

Effect of premilking teat disinfection on mastitis incidence, total bacterial count, cell count and milk yield in three dairy herds.

An iodophor teat disinfectant was applied before milking by dip or spray to 50 cows and 50 cows were left untreated in each of three commercial herds. The mean incidence of clinical mastitis was reduced by 57 per cent, the total bacterial count by 70 per cent and the count of thermoduric organisms by 32 per cent. These results were not statistically significant, except that one herd showed a significant decrease in total bacterial count. There was no effect on somatic cell count, milk production or milk iodine residues. Atmospheric iodine concentrations increased in the two herds which applied the treatment as a spray, but the levels attained were not likely to be detrimental to human health.     

体细胞数对牛奶品质及产量的影响

根据宁夏地区某奶牛场的DHI检测获得的体细胞数据(SCS),利用SAS软件实现单因素方差分析,探讨不同乳中SCS对产奶量和乳中主要成分的影响,并对它们之间的相关性进行分析。结果表明:乳中SCS与日产奶量呈显著负相关(P0.01);与乳糖和胎次呈正相关(P0.01);乳中SCS水平与乳脂率、乳蛋白率和尿素氮没有明显的相关性。本试验通过对SCS的研究为乳品质的测定提供一定依据和参考。     

高产母猪营养策略

过去20年,猪的生产性能得到了快速的提高。如今,每头母猪每年能够生产30头或更多的断奶仔猪已司空见惯。猪场管理部门是否为达到这一目标做好了准备呢?饲喂策略和饲料组成是否与母猪的生产水平相匹配?     

关于高产母猪饲养管理及饲粮的几个问题

近些年来,母猪的繁殖性能已经得到很大程度地提高。目前,养殖发达国家的PSY已经超过30头。母猪如此高产,养猪生产者如何保障其泌乳的质和量?饲养管理能否跟上?饲喂策略和饲粮的组成是否相匹配?原文作者对上述问题进行了简单论述。