激素剂量、超排间隔及重复超排次数对和牛重复超排效果的影响

试验旨在探讨激素剂量、超排间隔及重复超排次数对和牛重复超排效果的影响，为建立稳定、高效的和牛供体重复超排方案提供依据。本试验共选取63头15~18月龄的和牛供体母牛进行超排处理，其中17头和牛供体随机分成2组，分别以200、200、200 mg的FSH注射总剂量和200、220、240 mg的FSH注射总剂量进行3次重复超排，每次超排间隔30 d，研究激素剂量对和牛重复超排的影响；24头和牛供体随机分成3组，每组分别以60、45、30 d的超排间隔，每次200 mg的FSH注射总剂量进行3次重复超排，研究超排间隔对和牛重复超排的影响；22头和牛供体采用每次200 mg的FSH注射总剂量进行连续7次重复超排，每次超排间隔30 d，研究重复超排次数对和牛重复超排的影响。结果显示，采用FSH注射总剂量为200、220、240 mg获得的头均胚胎总数和头均可用胚胎数显著高于每次均为200 mg的FSH注射总剂量（P<0.05）；与超排间隔60 d组相比，超排间隔45 d组获得的头均可用胚胎数显著降低（P<0.05），而超排间隔30 d组获得的头均可用胚胎数也降低，但差异不显著（P>0.05）；重复超排在6次以内，获得的头均可用胚胎数无显著差异（P>0.05）。结果表明，注射FSH总剂量为200、220、240 mg连续超排3次的超排效果优于注射FSH总剂量为200、200、200 mg组；超排间隔越长，越有利于母牛生殖道的恢复，获得的可用胚胎数越多，但超排间隔30 d，也可获得良好的超排效果；高强度重复超排以30 d为超排间隔，超排5~6次为宜。     

影响绵羊超数排卵效果因素的研究

通过对绵羊超数排卵技术的主要环节进行研究,得出适用于规模化生产的一套简便、稳定、低成本、高效、实用的羊胚胎生产技术.其结果如下①超排处理的499只供体羊平均排卵、回收胚、可用胚分别是14.41枚±4.34枚、12.56枚±4.05枚、9.13枚±4.03枚,育成羊组的此3项指标均高于经产羊组(P＜0.01);②对6个品种的412只供体羊进行超排处理,罗米利希尔斯羊的排卵、回收胚胎及可用胚胎平均数均高于其他品种(P＜0.01),其他品种之间无显著差异(P＞0.05),帮德羊的可用胚胎平均数显著低于其他品种(P＜0.01);③舍饲和放牧条件下供体羊排卵黄体平均数没有显著差异(P＞0.05).但是,舍饲羊的回收胚和可用胚胎平均数显著高于放牧羊(P＜0.01);④3种方式发情羊的排卵黄体平均数无显著差异(P＞0.05),但是,自然发情羊的回收胚及可用胚平均数均明显高于其他两组(P＜0.01);⑤用宁波和加拿大生产的FSH制剂进行超排处理,黄体平均数并无差别(P＞0.05),但回收胚胎平均数前者低于后者(0.01＜P＜0.05),尤其是后者的可用胚胎平均数明显高于前者(P＜0.01);⑥宁波生产的FSH制剂分为4个剂量等级进行超数排卵,4组之间无显著差异(P＞0.05).150 u剂量组的回收胚胎平均数均低于其他剂量组(0.01＜P＜0.05),180 u剂量组可用胚平均数显著低于其他3个剂量组(P＜0.01); ⑦超排1次或2次,排卵数无显著差异(P＞0.05);但超排2次以上,黄体数明显下降(P＜0.01).超排3次以上回收胚胎数明显低于其他两组(P＜0.01);⑧精液质量直接影响超排效果,精液活力越高效果越好.     

不同FSH对和牛超数排卵效果的影响

[目的]以16~18月龄青年日本和牛为供体,研究不同FSH和剂量对青年日本和牛超排效果的影响。[方法]超排采用CIDR+FSH+PG方法进行。[结果]进口FSH和国产FSH超排和牛后头均获胚胎数、头均获可用胚胎数、头均退化胚胎数和头均未受精卵数差异均不显著(P0.05);3种不同剂量的国产FSH处理日本和牛,头均获胚胎数、头均获可用胚胎数、头均退化胚胎数和头均未受精卵数差异均不显著(P0.05)。[结论]进口FSH和国产FSH超排青年和牛效果相当,同时适当降低国产FSH注射总剂量不影响青年和牛供体超排效果。     

绵羊超数排卵技术的初步研究

以乌珠穆沁蒙古绵羊及无角道赛特羊为供体,采用FSH-LH法,对73只供体羊实施超排处理,有效率为94.5%,平均获卵8.12枚,平均获可用胚7.22枚.结果表明:在9～11月超排效果最佳;发情周期正常且易受孕,母羊可提高超排效果和胚胎可用率;FSH剂量150IU可获较好的超排效果;适龄羊超排效果最佳,平均获卵和可用胚胎数高于育成和老龄羊组.     

红安格斯牛超数排卵效果研究

为探讨红安格斯牛超数排卵的效果,选择9头红安格斯牛作为供体,采用CIDR＋PG以及FSH递减法进行超数排卵处理,以快速获得红安格斯牛胚胎,统计胚胎回收数及可利用率.结果表明：有效超排供体9头,共回收胚胎150枚,平均回收胚胎16.67枚/头;回收可利用胚胎80枚,平均可用胚胎8.89枚/头,可利用率达53.33％.     

冬季不同激素处理对高山美利奴羊胚胎移植效果的影响

为了快速扩大高山美利奴优质种羊群体、提高供种能力,试验采用卵泡刺激素(follicle stimulating hormones,FSH)不同使用剂量、给药方式,在冬季不同畜舍温度下进行超数排卵及胚胎移植,分析胚胎移植的效果。结果表明:在冬季畜舍内温度为-8℃时,按照6次递减法肌肉注射12.5 mL Folltropin-V进行超排处理时(对照组),黄体数及回收可用胚胎数最高,胚胎移植后产羔率为41.67%;减少Foltrpin-V使用量,采用6次递减法肌肉注射10 mL Folltropin-V时(试验1组),黄体数及可用胚胎数显著下降(P0.05),胚胎移植后产羔率为56.67%;增加注射次数,采用8次递减法注射12.5 mL Folltropin-V时(试验2组),可用胚胎数极显著下降(P0.01),移植后产羔率为52.17%;当不改变剂量及给药方式,仅将畜舍内温度降至-18℃时(试验3组),卵巢反应及胚胎回收率未受影响,但胚胎移植后产羔率仅为14.70%。手术时与FSH浓度关系研究中,手术时间为外源性FSH浓度下降期,排卵结束。说明畜舍内温度为-8℃,按照6次递减法肌肉注射10 mL Folltropin-V进行超排,于供体第1次配种后40小时时进行胚胎回收及移植手术,为冬季高山美利奴羊胚胎移植最优方案。     

核心群奶牛超数排卵技术影响因素的研究

[目的]为进一步研究核心群奶牛超数排卵技术影响因素。[方法]试验使用3个FSH剂量和4 个公牛精液对27头青年奶牛进行超数排卵。对供体牛胚胎生产情况和受体胚胎移植妊娠率进行统计。[结果]结果显示供体2次超排获得7.8枚平均可用胚胎显著高于1次超排获得的5.7枚平均可用胚胎(P<0.05);260,280 mg FSH超排供体获得6.0和7.7 枚平均可用胚胎显著高于300 mg FSH超排供体获得的4.6枚平均可用胚胎(P<0.05);供体使用4个公牛精液人工授精后获得的平均可用胚胎数和平均未受精卵数差异不显著(P>0.05);移植前接种疫苗的受体胚胎移植妊娠率显著降低(P<0.05）。[结论]核心群奶牛超排适宜FSH剂量为260-280 mg,使用高受精力公牛精液和对超排反应好的供体重复超排能够提高超排效率,受体移植前避免疫苗接种能够提高胚胎移植妊娠率。     

波尔山羊和本地山羊超数排卵和胚胎移植试验初报

采用常规超排方法，使用促卵泡素(FSH)对波尔山羊进行超排处理，其结果如下：用300IU的FSH对波尔山羊逐日渐量递减注射，在第一次配种的同时注射人绒毛膜促性腺激素(HCG)，2只波尔山羊卵巢上卵泡数和黄体数分别为50个和32个，回收的卵子数为22个，排卵率为64％，回收率为68．7％，可用胚胎率为0。本地羊超排处理后，3只羊卵巢上卵泡数和黄体数分别为66个和24个，排卵率为36．3％，回收的数为16个，回收率为66．7％，可用胚胎率为0。一以上结果表明：以300IU的FSH结合HCG对波尔山羊进行超排处理是有效的。而以相同的FSH剂量结合HCG处理本地山羊时。超排效果不甚理想。     

波尔山羊重复超排FSH用量的调整方法与效果

根据218只2～5岁经产波尔山羊的第1次超排反应及回收胚胎数将第2次超排母羊分为5个组（1组只有卵泡未排卵;2组母羊处理后未发情;3组黄体数≤4个;4组黄体数5～14个;5组黄体数≥15个）,2次连续超排时间间隔60 d以上,采用递减法用FSH（Folltropin V）进行超排处理,第2次FSH给量根据第一次的超排效果进行调整。结果表明,1～5组的有效供体利用率分别为100%、75%、71.88%、93.10%和93.65%,5组有效供体比例差异不显著（P＞0.05）;1～5组的总胚胎数分别为14.00±5.73、12.10±6.78、11.77±7.26、13.84±7.04、18.03±9.06枚,5组的总胚胎数极显著高于其他4组(P＜0.01);1～5组的回收可用胚胎数分别为12.81±6.04、10.33±8.12、10.08±7.14、11.34±6.58和15.37±7.64枚,5组超排后可用胚胎数显著高于2、3、4组(P＜0.05),与1组间差异不显著（P＞0.05）。根据供体首次超排效果调整波尔山羊重复超排FSH给量方案可行,首次超排无反应或超排反应差的个体,重复超排时增加FSH给量,可以使70%以上的个体成为有效供体。     

澳洲和牛超数排卵与体内胚胎生产的影响因素研究

旨在研究不同发育阶段（青年和经产牛）、同期方法、促卵泡素（follicle-stimulating hormone,FSH）剂量、超排次数等因素对澳洲和牛供体超数排卵（简称超排）和体内胚胎生产效率的影响。本试验共选用38头青年和牛（16~20月龄）和42头经产和牛（胎次=1）进行超排处理,分别统计每头供体牛回收的总胚胎数、可用胚胎数、不同等级胚胎数以及不可用胚胎数,然后分别根据不同发育阶段、同期方法、FSH剂量以及超排次数对各试验组的超排效率、胚胎生产等数据进行比较分析。结果表明：1）经产牛的超排有效率（（95.46±2.58）%）显著高于青年牛（（77.55±6.02）%）（P<0.05）,胚胎总数（12.30 vs 10.37枚）、可用胚胎数（8.97 vs 7.66枚）、A级胚胎数（3.86 vs 2.50枚）均高于青年牛,但组间差异不显著（P>0.05）;2）超排前不同同期处理方法（自然发情、PG和埋植CIDR）的超排有效率差异不显著,但是自然发情组供体牛头均可用胚胎总数（（11.22±2.33）枚）显著高于PG处理组（（6.09±1.05）枚）（P<0.05）;3）不同剂量FSH可显著影响供体的超排效率和头均不可用胚胎数,青年牛120 mg FSH组的超排有效率（（55.56±17.57）%）显著低于200 mg FSH （（88.00±6.63）%）和220 mg FSH组（（73.33±11.82）%）（P<0.05）,经产牛220 mg FSH组的头均不可用胚胎数（（2.28±0.65）枚）显著低于250 mg FSH组（（5.00±1.38）枚）（P<0.05）;4）超排次数显著影响青年牛超排有效率和经产牛头均不可用胚胎数,青年牛第一次超排有效率（（70.27±7.62）%）显著低于第二次超排有效率（100%）（P<0.05）,经产牛第二次超排回收的不可用胚胎数（（4.44±0.92）枚）显著高于第一次超排（（2.39±0.40）枚）（P<0.05）。因此,在华北地区现有的生产管理水平下,和牛超排供体宜选用经产母牛,超排处理FSH总剂量宜为240 mg,这对和牛体内胚胎高效生产和核心群的建立具有一定的参考价值。     

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。