兽药的科学使用及注意事项

正科学合理地使用兽药,不但能及时预防和治疗动物疾病,提高养殖效益,而且对控制和减少药物残留,提高产品质量具有重要意义。1.科学选择药物使用兽药一定要注意病情需要,不要贪图价格便宜或只认准某种新药。一般,微生物感染性疾病应依据药敏试验结果选择药物,尽量选用效能多样或有特效的敏感     

禾·西乳油的气相色谱分析

本文采用气相色谱法,用１ｍ×３ｍｍ的玻璃色谱柱,内装５％ＯＶ－１７／ＣｈｒｏｍｏｓｏｒｂＷ－ＨＰ（６０－８０目）固定相,正二十烷作内标物,测定禾·西乳油中有效成分的含量。禾草特和西草净的回收率分别为９９．２９％和９９．０２％,变异系数为０．６１％和０．４９％。     

Effects of cotton field management practices on soil CO2 emission and C balance in an arid region of Northwest China

Changes in both soil organic C storage and soil respiration in farmland ecosystems may affect atmospheric CO2 concentration and global C cycle. The objective of this field experiment was to study the effects of three crop field management practices on soil CO2 emission and C balance in a cotton field in an arid region of Northwest China. The three management practices were irrigation methods（drip and flood）, stubble managements（stubble-incorporated and stubble-removed） and fertilizer amendments（no fertilizer（CK）, chicken manure（OM）, inorganic N, P and K fertilizer（NPK）, and inorganic fertilizer plus chicken manure（NPK＋OM））. The results showed that within the C pool range, soil CO2 emission during the whole growing season was higher in the drip irrigation treatment than in the corresponding flood irrigation treatment, while soil organic C concentration was larger in the flood irrigation treatment than in the corresponding drip irrigation treatment. Furthermore, soil CO2 emission and organic C concentration were all higher in the stubble-incorporated treatment than in the corresponding stubble-removed treatment, and larger in the NPK＋OM treatment than in the other three fertilizer amendments within the C pool range. The combination of flood irrigation, stubble incorporation and application of either NPK＋OM or OM increased soil organic C concentration in the 0-60 cm soil depth. Calculation of net ecosystem productivity（NEP） under different management practices indicated that the combination of drip irrigation, stubble incorporation and NPK＋OM increased the size of the C pool most, followed by the combination of drip irrigation, stubble incorporation and NPK. In conclusion, management practices have significant impacts on soil CO2 emission, organic C concentration and C balance in cotton fields. Consequently, appropriate management practices, such as the combination of drip irrigation, stubble incorporation, and either NPK＋OM or NPK could increase soil C storage in cotton fie     

不同土壤含水量对大白菜莲座期生长影响的研究

本试验研究了不同土壤含水量对大白菜莲座期生长的影响，结果表明：土壤相对含水量在４０％～８０％的范围内，大白菜的光合速率、净同化率（ＮＡＲ）、叶面积、植株干重都随土壤含水量的增加而增加，超过８０％则略有下降。不同土壤含水量直接影响到植株体内的水分状况和常量元素的吸收量。大白菜莲在期生长最适宜的土壤相对含水量为７０％～８５％。     

奥奶净对奶牛生产性能和血液生化指标的影响

选择45头泌乳前期奶牛,根据年龄、胎次、泌乳时间和产奶量进行配对,随机分为对照组、试验Ⅰ组和试验Ⅱ组,各组均饲喂奶牛场配制的全混合饲料,另外,试验Ⅰ组每天每头奶牛日粮中添加45g奥奶净,试验Ⅱ组每天每头奶牛日粮中添加60g奥奶净,研究奥奶净对奶牛生产性能和血液生化指标的影响。结果表明,与对照组相比,补饲45g／d和60g／d奥奶净的奶牛产奶量分别提高了2．34％和2．96％（P〈0．05）;乳脂率分别提高2．63％和6．72％;体细胞数分别下降了35．92％和42．55％（P〈0．05）;磷酸肌酸激酶有提高的趋势,乳酸脱氢酶呈下降趋势;奶牛血清IgG、SOD和GSH-Px含量均有不同程度的提高,而MDA呈下降趋势。表明饲喂奥奶净能够促进奶牛泌乳、提高机体免疫力和机体抗应激能力．并有促进营养物质代谢的趋势。     

三元杂交牛12和18月龄肉用性能研究

选择健康无病、发育正常、膘情中等的夏洛来×西门塔尔×本地牛(夏西本)、皮埃蒙特×西门塔尔×本地牛(皮西本)、利木赞×西门塔尔×本地牛(利西本)、西门塔尔×西门塔尔×本地牛(西杂二代)各10头,从6月龄开始育肥,测定其增重、饲料消耗及其12和18月龄的屠宰成绩。结果表明:平均日增重以皮西本、利西本较高,分别为0.96kg、0.90kg,并与西杂二代差异显著(P<0.05);饲料消耗以皮西本较少,每kg增重消耗精、粗饲料分别为4.03kg和5.98kg。以皮西本和利西本2个杂交组合的屠宰成绩较好,18月龄屠宰率分别为61.50%、61.17%,净肉率分别为52.59%、49.21%。各组试验牛的高档肉块比例随着年龄的增长相应增加。     

33%纹霉净与益微混配防治小麦纹枯病的药效试验

在小麦播种前，１ｋｇ种子用３３％纹霉净２ｇ＋益微１ｇ处理后，纹枯病株发病率下降７８．８６％，病指下降７９．４５％，即解决了单纯用纹霉净或三唑酮拌种出现苗迟、难齐苗的问题，又达到了保健、控病、增产的目的，增产幅度达１０％以上。     

阔叶净防除麦家公的效果

麦家公是本地区麦田恶性杂草之一,其繁殖力强、危害严重,一般除草剂很难防除,严重威胁着小麦的安全生长。为了探索麦家公的防除技术,由省植保站提供美国杜邦公司生产的75％阔叶净,1989年冬季及1990年春季在我场进行防除试验,并取得成功。一、材料与方法 (一) 供试药剂 75％阔叶净干悬浮剂(美国杜邦公司产品):48％百草敌水剂(瑞士山德士农药公司产品);20％2甲4氯水剂(天津人民农药厂产品);25％苯达松水剂(建湖农药厂产品);