基于Nemerow法的森林土壤肥力综合指数评价

以广西国有大桂山林场用材林林地为研究区域,以土壤pH值、全量氮、全量磷、全量钾、速效氮、速效磷、速效钾、有效铜、有效锌、有效硼和有效铁作为评价指标,利用Nemerow法进行土壤肥力综合评价。结果表明,不同样地土壤养分因子变异系数在5.02%~65.69%。有机质平均值为28.75g/kg,处于中等偏下水平。全量N平均含量为1.64g/kg,速效N为135.5mg/kg,处于中等或中等偏上水平。全量P2O5平均含量为0.82g/kg,速效P为1.5mg/kg,均处于贫乏水平。全量K2O平均含量为23.76g/kg,速效K为51.8 mg/kg,均处于中等偏下水平。大量元素氮磷钾因子可以概括为"富氮、缺磷、中等钾"。微量元素方面,有效Zn和有效Fe林地平均含量分别为2.03mg/kg和32.11mg/kg,处于中等水平,有效B和有效Cu平均含量分别为0.18mg/kg和0.41mg/kg,属于贫或极贫水平。大桂山林地土壤肥力综合指数为0.85,桉树、松树林地肥力综合指数分别为0.77和0.82,肥力等级均属于Ⅲ级,杉木林地肥力综合指数为0.90,肥力等级属于Ⅱ级。速效P、有效B、有效Cu均处于贫或极贫水平,是影响研究区域土壤肥力的主要限制因子。     

万州玫瑰香橙果园土壤养分含量现状分析

摘%20%20%20要：为了解万州区玫瑰香橙果园的土壤养分含量分布状况，共采集果园土样97份，分析土壤pH、有机质、氮、磷、钾和中微量元素含量，结果表明：92.79%的土壤pH适宜柑橘生长，土壤有机质平均含量为12.76g/kg，67.01%的土壤有机质含量不足，32.99%的土壤有机质含量适宜生长；土壤碱解氮含量缺乏（<100%20mg/kg）、有效磷含量缺乏（<15%20mg/kg）和速效钾含量缺乏（<100%20mg/kg）的样品比例分别为58.77%、66.67%和38.14%，土壤中有效铁、有效铜、有效锌、交换性钙和交换性镁的平均含量分别为88.98%20mg/kg、1.31%20mg/kg、1.79%20mg/kg、3.28%20g/kg%20和0.32%20g/kg。土壤有效铁、有效铜、交换性钙、交换性镁含量过高比例分别达93.81%、92.78%、93.81%和84.45%，存在过量现象，而有24.74%的样品有效锌缺乏。因此，在玫瑰香橙的生产中，需有机无机配施，针对性补充N、P、K，增施有机肥，提高土壤有机质，改良土壤，实现高产优质。     

玉米/紫花苜蓿间作对土壤化学性质的影响

为了解玉米/紫花苜蓿间作对土壤肥力的影响,试验设置了3种种植模式,分别为玉米单作、紫花苜蓿单作和玉米/紫花苜蓿间作,玉米单作行距分别为30,50,70 cm(DY30、DY50和DY70);紫花苜蓿单作行距为30 cm(DZ30);玉米与紫花苜蓿间作,紫花苜蓿行距为30 cm,玉米行距分别为30,50,70 cm(JYZ30、JYZ50和JYZ70),玉米与紫花苜蓿的行距均为30 cm,分别在玉米抽穗期、灌浆期和蜡熟期测定各处理土壤中有机质、全氮、碱解氮、全磷、有效磷、全钾、速效钾7个化学指标含量,并采用平均隶属函数对土壤肥力进行综合评价。结果表明:玉米单作随着行距的增加,土壤有机质、全氮、碱解氮、全磷及有效磷含量呈先减少后增加趋势,均在DY50处理时降到最低,各指标值分别介于31.98～40.31 g/kg、1.57～1.77 g/kg、108.42～143.50 mg/kg、0.67～0.84 g/kg及11.09～20.56 mg/kg之间;全钾与速效钾大致呈先增加后减少趋势,在DY50处理时含量达到最大,介于7.93～9.86 g/kg与85.00～140.33 mg/kg之间;与紫花苜蓿单作相比,间作土壤中的养分含量大致呈下降趋势,尤其土壤中的有效磷含量下降最为明显,含量介于14.50～23.03 mg/kg之间;与玉米单作相比,间作土壤中各指标含量变化不同,但均呈增加趋势;玉米/紫花苜蓿间作随着玉米行距的增加土壤全氮和速效钾含量呈先减少后增加趋势,均在JYZ50处理时降到最低,各指标值分别介于1.60～1.78 g/kg、70.00～110.00 mg/kg之间;此外,无论玉米单作还是间作,灌浆期土壤中的有机质、全氮、全磷及碱解氮含量大致低于抽穗期和蜡熟期。隶属函数分析表明相应行距的单作玉米土壤肥力小于间作(除玉米行距为70 cm外)。说明玉米与紫花苜蓿间作可提高土壤肥力。     

阴山北麓不同土地利用类型土壤养分特征分析与评价

采用野外实地调查采样、室内样品分析和数理统计相结合的方法,研究了阴山北麓4种不同利用类型土地的土壤养分特征,并对土壤肥力进行了综合评价。结果表明,1) 研究区土壤有机质、全氮、全磷、全钾含量分别为(25.12±6.56),(0.63±0.08),(0.76±0.10),(31.99±1.07) g/kg;速效氮、速效磷、速效钾含量分别为(39.87±9.14),(6.72±3.75),(175.83±105.45) mg/kg;pH为(7.74±0.14)。2) 土地利用方式对有机质、全氮、全磷、速效磷和速效钾的影响极显著(P<0.01),而对速效氮、全钾和pH的影响不显著(P>0.05)。3) 土壤全氮、磷、钾含量和pH值在垂直剖面上(0~25 cm自上而下)表现为无规律的波动状态,但整体上变幅不大;而速效氮、磷、钾和有机质含量整体上表现为下降趋势。4) 土壤肥力综合评价值的排序为封育草地(0.506)>放牧草地(0.417)>耕地(0.361)>弃耕地(0.357),封育草地与放牧草地的土壤肥力为中等级水平,而耕地和弃耕地的肥力为低等级水平,说明草地比耕地更有利于土壤保肥。总体而言,研究区土壤肥力水平较低,存在的主要问题是土壤中全氮和速效氮含量严重偏低。     

分析土壤养分状况提出施肥建议

通过对土壤养分的测定,了解掌握土壤中各种养分含量状况,进行科学的评价分析,提出合理施肥数量和施肥方法。结论如下:土壤有机质平均含量为16.2g/kg,比第二次普查结果 12.1 g/kg上升了4.1 g/kg,属于三级地力水平;碱解氮平均含量为115.12mg/kg,比第二次普查结果 78.9mg/kg上升了36.22mg/kg,从四等地力级别上升到三等地力级别,为中等地力;有效磷平均含量为18.65mg/kg,比第二次普查结果 8.51mg/kg上升10.14mg/kg,达到了较丰水平;速效钾平均含量为122.12mg/kg,比第二次普查结果 118.3mg/kg上升了3.82mg/kg,为中等地力,地力级别没有太大变化。根据土壤肥力高低,土壤养分丰缺程度,提出合理的施肥建议:每亩增施有机肥2000—3000kg;每亩施用氮素8—15kg;有效磷每亩施用P2O53—8kg;速效钾每亩施用K2O5—10kg。对贫磷和严重缺钾地区,要因地制宜地侧重施用磷肥和钾肥。     

免耕春小麦套种牧草土壤养分动态研究

研究免耕春小麦Triticum aestivum套种牧草土壤养分的动态变化,分析了小麦套种白花草木樨Melilotus albus、野豌豆Vicia villosa、英吉沙豌豆Pisum sativum、玉米Zea mays、毛苕子V.villosa对土壤有机质、碱解氮和速效磷的影响。结果表明,套种牧草能提高土壤有机质、碱解氮和速效磷的含量,特别是套种白花草木樨和套种野豌豆增加更为明显,其中套种白花草木樨土壤碱解氮含量增加4.8 mg/kg,增幅19.4%,套种野豌豆土壤有机质增加0.39 g/kg,增幅1.6%,土壤速效磷含量增加了8 mg/kg,增幅23.9%;土壤有机质、碱解氮和速效磷含量随土层深度的增加而降低。     

紫花苜蓿生长年限对土壤理化性状的影响

2003～2005年在内蒙古民族大学试验农场连续3年测定了紫花苜蓿试验田土壤理化性状的变化.结果表明,随生长年限的增加,紫花苜蓿地0～30cm土层的土壤容重减小了0.026g/cm3,总孔隙度增加了1%,有机质的含量增加了0.8g/kg,碱解氮的含量增加了33.69 mg/kg,速效磷的含量下降了6.94 mg/kg,速效钾的含量下降了121.04 mg/kg.有机质的增加以10～20cm土层最为明显,碱解氮的增加在0～10cm和10～20cm两个土层均较明显,速效磷的减少在0～10cm土层最大,速效钾的减少在各土层均较为明显.说明紫花苜蓿高产栽培中必须重视磷、钾肥的施用,特别是要提高追施钾肥的水平.     

黄土高原沟壑区苜蓿生产力及养分特性的研究

在长期定位试验的基础上,研究了黄土高原沟壑区粮草轮作中苜蓿产草量及其养分变化特性。结果表明,苜蓿产草量一年生最低,为8 763 kg/hm²,3年生产草量达到最高,为12 020 kg/hm²,4年生产草量为9 665 kg/hm²,开始出现下降。1年生苜蓿对氮、磷、 钾的吸收量最低,分别为218 kg/hm²,11 kg/hm²,105 kg/hm²,3年生苜蓿对磷、钾的吸收量最高,分别为23 kg/hm²和185 kg/hm²,比1年生苜蓿吸磷量高109.1%、吸钾量高76.2%;而4年生苜蓿对氮的吸收量最高,为351 kg/hm²,比1年生苜蓿吸氮高61%。土壤有机质、全氮和碱解氮含量逐年增加,有机质由15.60 g/kg增至18.26 g/kg,全氮由1.20 g/kg增至1.50 g/kg,碱解氮由64.74 mg/kg增至88.02 mg/kg;土壤全磷、速效磷及速效钾含量逐年下降,全磷由0.86 g/kg降至0.76 g/kg,速效磷由14.00 mg/kg降至9.27 mg/kg,速效钾由70.51 mg/kg降至54.35 mg/kg。建议在生产中施适量钾肥满足苜蓿高品质、高产量的需要。     

甘肃省不同区域人工草地土壤肥力特征研究

以甘肃省不同区域人工草地土壤样品为研究对象,测定12个不同区域[民乐县(ML1、ML2)、安定区(AD)、通渭县(TW1、TW2、TW3、TW4)、宁县(NX1、NX2)、靖远县(JY1、JY2、JY3)]人工草地土壤的pH值、有机质、全氮、速效磷、速效氮、速效钾。结果表明:AD的p H值最大,JY3的pH值最小;TW2有机质含量最高,AD有机质含量最低,TW2较AD提高了78.95%,在TW2种植陇东苜蓿对土壤有机质影响大;TW2、TW3速效氮含量较高,约为AD速效氮含量的3倍,在TW2、TW3种植陇东苜蓿对土壤速效氮影响大;JY2速效钾含量是AD的3倍,TW2速效钾的含量最低,在JY2种植陇东苜蓿对速效钾影响大;ML1、ML2速效磷含量较高,NX1、NX2速效磷含量较小,在NX1、NX2种植陇东苜蓿对土壤速效磷影响小;TW2全氮含量最高,较AD提高了85.07%,在TW2种植陇东苜蓿对土壤全氮影响大。综合分析结果显示,TW2土样的关联度值最大(0.787 9),综合肥力最好,为最优土样;NX2土样的关联度最小(0.500 7),综合肥力最差。     

海南荔枝主产区果园土壤养分状况分析

调查分析海南荔枝主产区荔枝园土壤养分状况,为荔枝的养分管理与合理施肥提供理论依据和科学指导。选择具有一定种植规模、有代表性的荔枝园 49 个,采集0~30 cm土层土壤样品进行养分丰缺状况的测试分析各种性质。结果表明,海南荔枝园土壤pH大部分呈酸性,16.3 % 荔枝园土壤pH适宜荔枝生长,土壤阳离子交换量为中等水平,63.3 % 果园土壤有机质含量处于适宜值及以上;土壤全氮、碱解氮、有效磷、速效钾含量丰富;土壤交换性钙、有效硫含量丰富,42.7 % 果园土壤交换性镁含量缺乏,4.1 % 果园极缺乏;土壤微量元素铁、锰、铜、锌、钼含量较为丰富,但73.5 % 果园土壤有效硼含量低于适宜值。不同产区荔枝园土壤养分状况存在差异,海口果园土壤有机质和有效养分氮、钾、钙、镁含量最高,约2/3产区果园土壤偏缺交换性镁,仅海口、澄迈、定安土壤交换性镁含量在适宜值以上,各产区荔枝园土壤有效铁、锰、铜、锌、钼微量元素丰富,土壤有效硼在琼海果园含量丰富,澄迈、万宁、陵水、儋州、白沙荔枝园土壤有效硼偏缺。综合分析可知,各产区土壤肥力由高到低依次为：海口>定安>澄迈>文昌>琼海>儋州>万宁>陵水>白沙。综上所述,海南荔枝园应根据土壤养分情况平衡施肥,改良土壤酸度,增施有机肥,重视镁、硼肥施用,适当减施化肥以获得更好的产量效应。     

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。     

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.     

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.     

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.     

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。     

Microsporidial keratopathy in two dogs

A microsporidial keratopathy is described in two dogs. Both dogs presented with a unilateral stromal keratopathy characterized by multifocal coalescing opacities, and the diagnosis was made on histopathologic examination of keratectomy specimens. Transmission electron microscopy (TEM) on formalin‐fixed, paraffin‐embedded corneal tissue was performed in one dog, and the morphologic features were consistent with Nosema species infection. Both dogs were initially diagnosed and treated by superficial keratectomy. One dog received additional antifungal medication and underwent a penetrating keratoplasty following local recurrence two years later. No other systemic lesions attributable to the microsporidial infection were identified clinically. The clinical and diagnostic pathology findings, treatment, and follow‐up are discussed.