健康仔猪口服亚硒酸钠后血液中药代动力学的研究

本实验按 0 .6 mg/ kg BW单剂量对健康仔猪口服亚硒酸钠溶液后 ,首次系统地研究了其在血液中药物代谢动力学。实验结果表明 :血液动力学特征符合一级吸收二室开放模型 ,其理论方程为 :C=0 .0 82 0 e- 0 .0 4 2 1 t 0 .10 5 0 e- 0 .0 0 1 4t- 0 .1870 e- 2 .2 541 t。主要动力学参数为 :吸收半衰期 (t1 / 2 Ka)为 0 .30 75 h;达峰时间 (tmax)为 2 .15 17h;消除半衰期 (t1 / 2β)为 5 10 .2 70 6 h;曲线下面积 (AU C)为 75 .14 6 0 mg/ L· h;表观分布容积 (Vd)为 5 .5 74 2 L/ kg。根据单剂量药动学参数 ,计算多剂量给药参数 ,为临床治疗制订给药方案。先导剂量 (D* )为 1.2 2 6 2 mg/ kg BW,维持剂量(D0 )为 0 .6 m g/ kg BW,给药间隔 (τ)为 4 80 h,平均稳态血药浓度 (с)为 0 .15 6 6 μg/ m l     

健康仔猪口服亚硒酸钠的血液中药代动力学的研究

本实验按0.6mg/kgBW单剂量对健康仔猪口服亚硒酸钠溶液后，首次系统地研究了其在血液中药物代谢动力学。实验结果表明，血液动力学特征符合一级吸收二室开放模型，其理论方程为：C＝0.0820e^-0.0421t 0.1050e^-0.0014t-0.1870e^-2.2541t。主要动力学参数为：吸收半衰期（t1/2Ka)为0.3075h，达峰时间（tmax)为2.1517h；消除半衰期（t1/2β）为510.2706h，曲线下面积（AUC）为75.1460mg/L.h；表观分布容积（Vd)为5.5742L/kg。根据单剂量药动学参数，计算多剂量给药参数，为临床治疗制订给药方案，先导剂量（D^*)为1.2262mg/kg BW，维持剂量（D0）为0.6mg/kgBW，给药间隔（τ）为480h，平均稳态血药浓度（c)为0.1566μg/ml。     

亚硒酸钠在低硒雏鸭体内的血液动力学研究

选用健康雏鸭作试验动物,通过人工复制硒缺乏模型,研究亚硒酸钠在雏鸭体内的药物代谢动力学。结果表明:亚硒酸钠在低硒雏鸭血液中的代谢动力学过程符合一级吸收二室开放模型,其动力学方程为:C=-0.0439e-2.6925t+0.1085e-0.0053t-0.0646e-0.1174t。其主要动力学参数为:吸收半衰期(T12Ka)为5.9026h,达峰时间(Tmax)为23.03h,消除半衰期(T12β)为131.13h,曲线下面积(AUC)为19.93mgL·h,表观分布容积(Vd)为7.60389Lkg。根据单剂量给药参数计算多剂量给药参数,为临床制定给药方案,首次先导剂量(D)为1.7046mgkg·BW,维持剂量(D0)为0.8mgkg·BW,给药间隔为120h,血药平均稳态浓度(C)为0.1664μgmL。这一结果为临床科学合理地用药预防雏鸭缺硒病提供了试验依据。     

恩诺沙星在眼斑拟石首鱼体内的药物代谢动力学

应用反相高效液相色谱法 (RP- HPL C)研究了恩诺沙星在眼斑拟石首鱼 (Sciaenops ocellatus)体内的药物代谢动力学。实验数据经 DAS药代动力学分析软件分析后得出 :腹腔注射组血浆的药时数据符合一级吸收二室模型 ,动力学方程为 :C =4 .92 5 e- 1 .4 52 t +2 .730 e- 0 .0 75t ,其主要药代动力学参数 :AU C37.5 33mg· L- 1· h、Cmax 4 .74 7mg/ L、Tmax0 .75 0 h、t α0 .4 77h、t β9.2 92 h、Vd/ F 1 .6 76 L / kg、t Ka0 .1 70 h、Ka 4 .0 81 / h、K 6 .71 4 / h、K1 0 0 .1 91 / h、K1 2 0 .76 9/h、K2 1 0 .5 6 6 / h;灌服组血浆的药时数据符合一级吸收一室模型 ,动力学方程为 :C =6 .4 82 (e- 7.0 92 t- e- 1 0 .356 t) ,其主要药代动力学参数 :AU C1 5 .80 5 mg· L- 1 · h、Cmax2 .770 mg/ L、Tmax1 .5 0 0 h、t α4 .989h、Vd/ F2 .0 72 L/ kg、Ka7.0 92 /h、K 1 0 .35 6 / h。结果表明 ,腹腔注射给药比灌服给药吸收快 ,血药浓度达峰时间短于灌服给药 ,但血药浓度峰值明显高于灌服给药 (P<0 .0 5 ) ,血浆中恩诺沙星的回收率为 94 .5 79%。     

不同温度下甲砜霉素在鲫体内的药物动力学及残留研究

本文对鲫以15 mg/kg·bw的剂量单次口灌甲砜霉素进行药物动力学参数模拟研究,以15 mg/kg·bw的剂量连续口灌给药3 d进行药物残留研究。结果表明甲砜霉素的药—时曲线均较符合有吸收一室开放模型,10℃水温条件下甲砜霉素在鲫体内的主要药物动力学参数为:吸收半衰期(t1/2ka)4.63 h;峰浓度(Cmax)5.71μg/m L;达峰时间(Tmax)10.94 h;消除半衰期(t1/2β)13.68 h;表观分布容积(Vd/F)1.53 L/kg;清除率(CLb)0.08 L/(h·kg);药时曲线下面积(AUC)195.99μg·h/m L。25℃水温条件下甲砜霉素在鲫体内的药物动力学参数为:吸收半衰期(t1/2ka)2.72 h;峰浓度(Cmax)5.60μg/m L;达峰时间(Tmax)6.98 h;消除半衰期(t1/2β)9.87 h;表观分布容积(Vd/F)1.6 4L/kg;清除率(CLb)0.12 L/(h·kg);药时曲线下面积(AUC)130.16μg·h/m L。不同水温条件下甲砜霉素在鲫鱼各组织中的代谢明显不同,表现为水温升高甲砜霉素消除则加快,水温降低甲砜霉素消除则变慢。结果还显示在两个温度下,甲砜霉素在鲫鱼主要组织中消除均较慢,在给药72h后,仍可在在皮肤、肌肉、肾脏组织中检测到甲砜霉素。同时,皮肤中的药物代谢速率相对于其他组织较慢,因此,建议把皮肤作为甲砜霉素药物残留的靶组织。若以15 mg/kg·bw的剂量连续口灌给药甲砜霉素后,建议甲砜霉素在鲫鱼体内的休药期定为:在10℃至少为10d,在25℃至少为6 d。     

环丙沙星和磺胺二甲嘧啶在大菱鲆体内的药代动力学比较

采用高效液相色谱法,在(23.1±0.8)℃水温条件下,对环丙沙星和磺胺二甲嘧啶两种抗菌药物在健康大菱鲆体内的代谢动力学规律进行了比较研究。结果显示,单次口服环丙沙星和磺胺二甲嘧啶后,药物在血浆中的经时过程均符合一级吸收二室开放模型,表达方程分别为CCIP=14.811e-0.337t+4.028e-0.063t-18.839e-0.616t、CSM2=64.981e-0.141t+4.59e-0.004t-69.571e-0.19t;静脉注射这两种药物后,药物在血浆中经时过程均符合无级吸收二室开放模型,表达方程分别为CCIP=21.784e-1.098t+1.514e-0.043t、CSM2=33.028e-5.687t+8.674e-0.013t。口服相同剂量(20 mg/kg)药物后,对血浆的药代动力学参数进行比较,环丙沙星的Tmax(6 h)、Cmax(5.385μg/mL)、t1/2Ka(1.125h)、t1/2α(2.057 h)和t1/2β(11.028 h)均小于磺胺二甲嘧啶给药(8 h、13.990μg/mL、3.647 h、4.923 h和173.407 h),且F(60.57%)大于磺胺二甲嘧啶给药F(47.13%)。证实环丙沙星在大菱鲆体内的吸收、分布、消除速度,达峰时间均快于磺胺二甲嘧啶给药,且比磺胺二甲嘧啶给药吸收完全。根据本实验的结果,环丙沙星和磺胺二甲嘧啶的合理给药方案分别为28.01 mg/kg和18.32 mg/kg,均为每日1次给药,连用3～5 d。     

锰在肉鸡体内药代动力学研究

实验研究了30日龄肉鸡按55.38mg/kg·bw剂量灌服10%硫酸锰溶液后不同时间采血,应用石墨炉原子吸收分光光度法测定血药浓度,经微机处理得出血药浓度及药动学参数,血药浓度-时间曲线符合一级吸收一室开放模型,最佳药时方程:C=80.8013(e-0.0709t-e-0.4402t)。主要药动学参数:t1/2Ka为1.5747hrs,t1/2Ke为9.7698hrs,tp为5.6617hrs,Cmax为48.3581ug/L,AUC为967.9305(μg/L)·h。根据单剂量给药参数,计算出多剂量给药参数。τ定为12h,(C∝)max为95.997μg/L,为80.6609μg/L,(C∝)min为4.0668μg/L,D为3.2794mg/kg·bw,D0为1.8789mg/kg·bw,R为1.7454。     

磺胺间甲氧嘧啶在猪体内的药代动力学及生物利用度

健康猪只5头,按50 mg.kg-1剂量分2个阶段分别给猪静注、肌注,研究其在猪体内的药代动力学规律。采用高效液相色谱法测定血浆中的药物浓度。采用3P97药代动力学程序软件处理药时数据。结果静注药时曲线符合一室开放模型,其理论方程为C=139.6 e-0.24 t,V(c)为(0.38±0.02)L.kg-1,AUC为(537.7±37.6)μg.h.mL-1,t1/2Ke为(2.84±0.08)h,CL(s)为(0.09±0.005)L.kg-1.h-1。肌注药时数据符合一室开放模型,其理论方程为C=19.2(e-0.04 t-e-0.73 t),t1/2Ka为(0.87±0.14)h,t1/2Ke为(16.3±1.9)h,C(m ax)为(15.4±0.6)μg.mL-1,AUC为(427±43)μg.h.mL-1,F为(79.5±8.0)%。表明本制剂肌注后在猪体内吸收较好,具有较长的半衰期,为一种长效制剂。以化脓链球菌为例,肌注剂量有效浓度维持时间为72 h。     

氧氟沙星(Ofloxacin)在鲤鱼体内的药代动力学

应用 HPL C法测定了单次混饲口服氧氟沙星 (10 mg/ kg)后 ,鲤鱼体内不同时间的血浆药物浓度。利用 MCPKP药代动力学软件分析数据 ,其药代动力学特征符合一级吸收一室开放模型 ,动力学方程为 C=3.2 94 31(e- 0 .0 4 34 1 t-e- 1 .1 1 474 t )。主要药代动力学参数 :吸收半衰期 (T1 /2 ka) 0 .6 2 16 7h,半衰期 (T1 /2 k) 15 .96 4 0 5 h,最高血药浓度 (Cmax)2 .775 89mg/ L ,出现最高血药浓度时间 (TPP,血药浓度时间曲线下面积 (AUC) 72 .934mg/ L· h,血浆治疗浓度维持时间 TCP(ther) 5 .4 4 10 h。结果表明 ,氧氟沙星在鲤鱼体内吸收较迅速 ,达峰时间较短 ,血药峰浓度高 ,消除缓慢 ,保持有效杀菌浓度时间长 ,适用于鱼类细菌性疾病的预防和治疗     

盐酸沙拉沙星在蛋鸡体内的血液动力学的研究

为研究盐酸沙拉沙星在蛋鸡体内血液动力学 ,选用成年健康蛋鸡 6 5只进行试验。按 10mg/kg体重口服给药后 ,测定血清中盐酸沙拉沙星的含量。结果表明 :盐酸沙拉沙星在血液中经时过程符合一级吸收一室模型 ,其理论方程为Cb=1.0 36 (e-0 .173 5t-e-2 .0 57t)。Ka 为 1.6 0 2 5h-1、Cmax为 0 .74 2 9μg/mL、tmax为 1.5 80 7h。由抗生素后效应及药动学参数 ,建议临床给药口服方案为 10 .12mg/kg。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。