A strain of Haemonchus contortus resistant to thiophanate

The occurrence of a field strain of Haemonchus contortus resistant to thiophanate is reported for the first time in New Zealand. In a controlled anthelmintic trial with experimentally infected animals, thiophanate at 50-100 mg/kg had no appreciable effect on the Haemonchus burden. Albendazole reduced faecal strongylate egg counts by 95% in animals with naturally acquired 59 infections.     

The efficacy of albendazole against some gastrointestinal nematodes in goats

On the basis of worm counts in naturally infected Angora-X goats, albendazole at either 3.8 mg/kg repeated after 24 hours or as a single dose at 7.6 mg/kg, was >99% effective in removing adult Ostertagia and Trichostrongylus spp. Small numbers of adult Haemonchus contortus, Cooperia sp. and Chabertia ovina were present in control but not treated animals. The single dose of 7.6 mg/kg removed >99% of adult Oesophagostomum venulosum whereas the repeated dose of 3.8 mg/kg removed only 96%.     

The effect of repeated doses of toltrazuril on coccidial oocyst output and weight gain in suckling lambs

Coccidial oocyst output and liveweight were monitored in 43 pairs of lamb twins over a 10-week period during September-November 1992. One of each set of twins was treated orally with toltrazuril (20 mg/kg) weekly while the other was an untreated control. The oocyst output was significantly lower (P < 0.01) and the weight gain over the trial period was significantly greater (P < 0.05) in the treated group than in the control group.     

CD4+ and CD8+ T- lymphocytopenia in a filly with Pneumocystis carinii pneumonia

Decreased proportion of CD4+ and CD8+ T lymphocytes in peripheral blood likely contributed to susceptibility to Pneumocystis carinii in a foal. Cytological evaluation of bronchoalveolar lavage was required for identification of the pathogen and serial flow-cytometric analysis of peripheral blood lymphocytes documented transient low expression of CD4+ and CD8+ T lymphocytes. Although immunodeficiency is uncommon, it must be included in the differential diagnosis for patients suffering from chronic or opportunistic infections and may provide an indication for immunostimulant therapy.     

Anthelmintic usage on goat farms in New Zealand: results of a postal survey

A nationwide postal survey in New Zealand of about 3850 goat farmers was conducted in 1988 to determine gastrointestinal nematode control practices. The analysis of 848 replies revealed that at least 16.9%, 20.0% and 34.4% were drenching their adults, yearlings and kids respectively 10 or more times per year. During 1987-88, 42.0% used only ivermectin, 9.0% only a benzimidazole and 1.9% only levamisole or morantel; 42.7% used anthelmintics from two different action families and 3.5% used all three action families. In total, 85.8% had used ivermectin at some stage during the preceding 12 months. Ivermectin was used by 46.5% during the 1987-88 season and also for the 3 preceding years. Sixty percent estimated the weight of their goats only by eye. Twenty-seven percent set the dose volume of the drench gun for the average weight of the goats in the mob, not the heaviest. Drenching frequency was positively correlated with the ratio of goat stock units to total stock units and also with the actual stocking rate of kids and yearlings.     

紫色丘陵区小流域典型降雨径流氮磷流失特征

对2007年盐亭小流域两场典型降雨(施肥后首场大雨和大暴雨)的径流过程进行了连续监测,同步测定了径流量、氮磷浓度,旨在阐明农业小流域典型降雨氮磷流失随降雨径流的变异规律.结果表明,流量曲线与浓度过程线变化趋势一致.整个径流过程中的氨态氮(AN)与磷酸盐(PO3-4-P)浓度较低且波动较小.初期径流颗粒态氮(PN)、颗粒态磷(PP)与总磷(TP)的浓度高于后期径流,初期冲刷效应明显.颗粒态氮(PN)是氮素在径流初期迁移的主要形态,而后期以硝态氮(NN)为主;但PP是整个径流过程中的主要迁移形态.初期径流中AN、PN、TP、PP及泥沙(SS)负荷分布较大,而硝态氮(NN)、总氮(TN)和PO3-4一P则主要分布在径流后期.污染物初期冲刷和NN后期淋溶是暴雨径流氮素流失的主要原因,而施肥后首场降雨氮素流失的主要原因是NN淋溶.暴雨径流产生氮磷负荷巨大,TN与TP分别为167.04kg和20.75 kg;而施肥后首场大雨径流氮磷流失负荷较小,分别为12.07 kg(TN)、1.04 kg(TP),其中60%的TN以NN流失.     

瓠瓜新品种‘越蒲1号’

‘越蒲1号’为早熟瓠瓜一代杂种。商品瓜棒形,淡绿色,表面密生白色短茸毛,粗细均匀,长25～35cm,直径5～7cm,脐部较平,果肩微凸,单瓜质量350～500g,肉质致密,口感糯,味微甜。从播种到始收,春季95～105d,秋季45～50d,一般春季产量45.0t.hm-2以上,秋季产量22.5t.hm-2以上。     

不同灌溉方式对制种玉米产量及水分利用效率的影响

通过田间试验,研究了畦灌、常规沟灌、隔沟交替灌3种灌溉方式对制种玉米产量及水分利用效率的影响,结果表明,不同灌溉方式下,制种玉米产量为8.73~10.87 t/hm~2,耗水量为349.7~625.0 mm,WUE为1.40~3.01kg/m~3。隔沟交替灌溉方式耗水量最低,畦灌方式最高,常规沟灌居中。相同灌溉定额条件下,隔沟交替灌制种玉米产量较常规沟灌增减幅度在-2.43%~10.24%。常规沟灌方式若能保证作物需水关键期的灌溉,适度减少灌水不会造成制种玉米减产。产量构成要素结果表明,行粒数、出籽率、穗长、穗粗、秃尖长、千粒重产量构成要素对产量的累积贡献率达85.54%。在甘肃河西地区,制种玉米全生育期灌水8次(苗期1次,拔节期2次,抽穗期1次,灌浆期2次,乳熟期2次),灌溉定额2 250 m~3/hm~2的隔沟交替灌溉方式(T6处理)能稳定提高产量和水分利用效率。