不同硒水平对生长育肥猪生产性能的影响

试验研究了宁夏常用饲粮中不同硒水平(添加硒0，0．15，0．30，0．45，0．60mg／kg)对生长育肥猪生产性能的影响。结果表明：(1)在饲粮中添加不同水平的硒，对各个饲养阶段生长育肥猪的日增重、日采食量和饲料报酬没有明显影响。但从全期来看。饲粮中添加硒0．30mg／kg时日增重最高。料重比最低。(2)综合肉质品质各项指标的测定结果。饲粮中添加硒0．30，0．45，0．60mg／kg时，肌肉保水性、嫩度较好。以饲粮中添加硒0．30mg／kg时为最好。补硒组肉色评分、肌肉新鲜度和抗应激能力均较缺硒组高，肉色评分以饲粮中添加硒0．30mg／kg时最为理想。(3)在宁夏缺硒地区的玉米-豆粕、胡麻饼型饲粮中。从满足正常生长发育的代谢需要、改善肉的品质及降低发病率等方面综合考虑。在15～90kg体重的生长育肥猪基础饲粮中建议添加0．30mg／kg硒为宜，饲粮硒水平为0．33mg／kg，特别是在15～30kg体重的仔猪阶段。从降低发病率的角度考虑。硒的添加量可适当提高。     

Transport of 14C-Sucrose and 14C-Benzyl Adenine in Winter Wheat (Triticum aestivum L.) in the Pre-Anthesis Period

A lysimeter trial is described in which the fate of ¹⁵N was monitored in a sand, loam and clay soil by using it over a period of 6 years. The following results were obtained.
1. The uptake of fertilizer nitrogen by plants, determined by using ¹⁵N, is lower than by using the conventional method ("difference method"). Nitrate ¹⁵N is better utilized by the plants than is ammonium ¹⁵N. The total nitrogen uptake only gives hints of these differences.
2. The extent to which plants utilize fertilizer ¹⁵N is between 38 and 58%; in the case of the method of differences this figure is between 48 and 68%.
3. Plants remove more nitrogen from the soil when fertilizer N is applied than when without fertilization. The influence of these two nutrient forms is of subordinate significance.
4. After a trial period of six years between 26 and 54 % of the fertilizer ¹⁵N remains in the soil. The resulting sequences are clay > loam > sand > and ammonium > nitrate.
5. The immobilization of the fertilizer ¹⁵N is most pronounced in the first four years but then decreased considerably; in the case of the sandy soil it is then even slightly regressive.
6. The biggest part of the ¹⁵N is deposited in the uppermost layer of the soil. The amount of ¹⁵N in the deeper layers is diminished appreciably. The type of soil has a greater influence than the form of nitrogen.
7. If the amount of fertilizer N left in the soil is compared with the N losses from the soil's reservoir (plants' uptake, leaching) there is a negative balance for the soil nitrogen which mainly is determined by the type of soil.     

Parasitological and Clinico‐pathological Profiles in Friesian Cattle Naturally Infected with Theileria annulata in Saudi Arabia

Clinico‐pathological profiles were studied in adult and young Friesian cattle naturally infected with Theileria annulata in the Qassim Region, Saudi Arabia. Sixty‐two clinical cases of T. annulata infection in adult and young Friesian cattle were diagnosed during the period from August 1999 to July 2000. Symptoms observed were marked fever, swelling of superficial lymph nodes, inappetance, tachycardia, dyspnoea and weakness. The most prominent gross pathological features were jaundice, petechial and ecchymotic haemorrhages involving mucosal and serosal surfaces of many organs as well as body fat. A number of young and adult Friesian cattle undergoing lethal T. annulata infection developed lymphoma‐like lesions in a manner similar to that of T. parva. The main histological findings were necrosis and severe lymphocytic infiltration. The spleen, lymph nodes and Peyer's patches were devoid of typical lymph nodules.     

Immunohistochemical study on the endocrine cells in gut of the stomachless teleost, Zacco platypus (Cyprinidae)

The regional distribution and relative frequency of neurohormonal peptides-producing cells were demonstrated in the gut of the stomachless teleost, Zacco platypus (Temminck et Schegel), using 10 types of specific antisera raised against mammalian regulatory peptides. The gut of Z. platypus was divided into five portions from proximal to distal (segment I-V). Most of immunoreactive cells in the epithelial lining portion, between epithelial cells, were generally spherical or spindle shape having long cytoplasmic process that was reached via the lumen while cells round in shape were found in the basal portions of epithelial lining occasionally. Serotonin-, somatostatin-, glucagon-, cholecystokinin (CCK)-8 and pancreatic polypeptide (PP)-immunoreactive cells were observed in this study. However, no chromogranin A-, secretin-, vasoactive intestinal peptide (VIP)-, substance P- and bombesin-immunoreactive cells were found. Serotonin-immunoreactive cells were demonstrated throughout the entire gut tract and occurred more frequently than other cells. Somatostatin-immunoreactive cells were restricted to proximal segments of the gut (segment I-III) with rare frequencies, and glucagon-immunoreactive cells were demonstrated in the proximal segments of the gut (segment I, II) with moderate to few occurrences. CCK-8-immunoreactive cells were found throughout the whole intestinal tract except for most proximal segment (segment I) with moderate to few frequencies and PP-immunoreactive cells were demonstrated in the proximal to middle segments, segment I-III, with a few, rare and rare frequencies, respectively.     

Atlantic deep-sea stratigraphy: extension of absolute chronology to 320,000 years

Thorium-230 measurements on a core of globigerina ooze from the Caribbean Sea substantiate the prediction of Ericson et al. that the paleontological boundary U-V (Sangamon-Illinoian boundary in their scheme) in the Atlantic sediments has an age of close to 320,000 years. As the ages derived by Ericson et al. were based on extrapolations of mean sedimentation rates established by carbon-14 and protactinium-231 dating of the upper sections of this and other cores, this result confirms the assumption that sedimentation rates in the Caribbean Sea have not changed significantly during the past several hundred thousand years. The uranium content of the ocean as indicated by the deposition rate of thorium-230 was no more than 30 percent higher during glacial than during interglacial periods.     

一起猪炭疽的诊断与处理

2005年4月初我市某猪场有2头猪发病死亡,经临床诊断和实验室菌体检查确诊为猪炭疽病。现将诊断与处理的情况报告如下:     

Purification and characterization of two larval glycoproteins from the cattle tick, Boophilus annulatus

The present study was conducted to identify new target immunogenic molecules from the larval stage of the cattle tick, Boophilus annulatus (Acari: Ixodidae). Two specific larval glycoproteins (GLPs) were isolated by two-step affinity chromatography. The larval immunogens were first purified with CNBr-Sepharose coupled to rabbit anti-larval immunoglobulins, and the glycoproteins were then purified with Con-A Sepharose. These glycoproteins have molecular weights of approximately 32 and 15 kDa with isoelectric points between 6.8 and 7.2. Antibodies against the two GLPs, labeled I and II, were detected in the anti-whole tick, -whole larval, and -gut antigens through immunoblot analysis. These results suggest that these GLPs are good immunogens and can be useful in the vaccination of cattle against tick infestation.     

Emergence en Tunisie de nouveaux pathotypes de Verticillium tricorpus pouvant attaquer la tomate, l'aubergine et la pomme de terre

Durant les campagnes agricoles 2002/2003 et 2003/2004, plusieurs isolats de Verticillium , différents de ceux de V. dahliae et de V. albo-atrum , ont été obtenus. Ils ont été isolés à partir de plants de tomate, situés dans la région de Chott-Mariem, montrant des symptômes typiques d'une maladie vasculaire. Ces isolats ont été identifiés comme étant Verticillium tricorpus en se basant sur leurs caractéristiques morphologiques. Ils montrent une pigmentation jaune en début d'incubation sur milieu potato dextrose agar et possèdent trois formes de conservation: chlamydospores, mycélium noir et microsclérotes. L'optimum thermique de leur croissance mycélienne est de 20°C. Leur virulence a été vérifiée chez trois solanées maraîchères: tomate, aubergine et pomme de terre. Ces nouveaux pathotypes ont montré un pouvoir pathogène élevé, surtout chez l'aubergine et la tomate. Ils ont entraîné non seulement le flétrissement et l'altération du feuillage des plants inoculés mais aussi une réduction de la croissance végétative, comparativement aux témoins sains. Ces résultats confirment la présence pour la première fois en Tunisie de nouveaux pathotypes de V. tricorpus pouvant attaquer aussi bien la tomate que l'aubergine et la pomme de terre.