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对高锰酸钾滴定法测定乳钙的方法进行了改进；以４％草酸铵直接沉淀乳中钙，以稀氨水洗去多余的草酸铵，再加入０．５ｍｏｌ／Ｌ硫酸使草酸游离，然后以标准高锰酸钾液滴定草酸，间接求出钙含量。２０份乳样用改进的方法和国家标准方法测定结果之间无显著差异（Ｐ＞０．１）；改进方法的重复试验结果的Ｃ．Ｖ％为２．８８％，回收率为（９３．０６±４．８８）％。改进的方法省略了消化过程，使乳钙测定简便化。 相似文献
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<正> 近20多年来,许多国家已把改进泌乳母牛的排乳速度、提高挤奶效率提到科研和生产日程上,国外已有不少人对这一性状进行了研究,均指出排乳速度的改进,可增加泌乳期产奶量,节约挤奶时间,提高劳动效率,其遗传力较高,对它选择是有效的。国内这方面研究很少见报道。陈幼春等〔1979〕曾测定平均流速与当次奶量的相关为0.47。本试验目的是研究我国南方黑白花奶牛不同胎次、不同泌乳阶段排乳速度的差异, 相似文献
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本文采用国家标准法中高效液相色谱法检测了乳及乳制中的三聚氰胺,经过反复使用和多次试验,从样品处理、净化、仪器测定3个方面,对国家标准中要求不详之处,进行了补充和改进。对用液相色谱法检测三聚氰胺所用色谱柱和流动相进行了优选,将乳及乳制品中与三聚氰胺出峰时间重叠的组分进行了完全分离。 相似文献
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现如今,我国在微生态制剂的研究和开发中已经取得了明显的成效。为了研究植物乳杆菌的增值发酵的具体条件,本文主要通过实验的方式来进行研究。首先是采用一定的方法来对植物乳杆菌发酵的培养基进行改进和优化,通常情况下都是采用单因素的方式。然后,对培养工艺进行深入探讨。通过此次试验,可以证明,在蔗糖、酵母膏或者是蛋白胨等浓度和数量达到相应标准的时候,可以得到大量的植物乳杆菌。说明,这种方式具有一定的现实意义。可以得到广泛地推广和应用。 相似文献
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为了探讨新疆石河子南山地区牧草绢蒿对正常小鼠和环磷酰胺所致免疫低下小鼠的免疫调节作用,采用脾脏系数测定法、脾脏淋巴细胞ANAE染色法、姬姆萨-瑞特氏染色法、MTT法、抗支原体抗体ELISA法及大肠杆菌攻毒试验分别对小鼠脾脏指数、T淋巴细胞数量、巨噬细胞吞噬活性、脾脏淋巴细胞增殖、抗体分泌功能及抗致病性大肠杆菌感染能力等指标进行研究。结果表明,高、低浓度的绢蒿水煎剂均能不同程度提高免疫低下小鼠和正常小鼠的T淋巴细胞数量及腹腔巨噬细胞吞噬功能;高、低浓度的绢蒿水煎剂均能不同程度提高正常小鼠的脾脏淋巴细胞增殖能力;低浓度的绢蒿水煎剂能提高正常小鼠对大肠杆菌的抗感染能力;高浓度的绢蒿水煎剂能下调免疫低下小鼠和正常小鼠的脾脏指数,下调正常小鼠的血清抗体效价。提示,绢蒿水煎剂对免疫低下小鼠有一定的增强免疫作用,对正常小鼠具有双向免疫调节作用。本研究结果为进一步开发绢蒿免疫调节剂提供了依据。 相似文献
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目的：研究新疆石河子南山地区牧草绢蒿对正常小鼠和环磷酰胺所致免疫低下小鼠的免疫调节作用。方法：采用脾脏系数测定法、脾脏淋巴细胞ANAE染色法、姬姆萨-瑞特氏染色法、抗支原体抗体ELISA法及大肠杆菌攻毒试验,分别对小鼠脾脏指数、T淋巴细胞数量、巨噬细胞吞噬活性、抗体分泌功能及抗致病性大肠杆菌感染能力等指标进行研究。结果：高、低浓度的绢蒿水煎剂均能不同程度地提高免疫低下小鼠和正常小鼠的T淋巴细胞数量及腹腔巨噬细胞吞噬功能;低浓度的绢蒿水煎剂能提高正常小鼠对大肠杆菌的抗感染能力;高浓度的绢蒿水煎剂能下调正常小鼠血清抗体效价和脾脏指数。结论：绢蒿水煎剂对免疫低下小鼠有一定的免疫增强作用;对正常小鼠具有双向免疫调节作用。研究结果为进一步开发绢蒿免疫调节剂提供了依据。 相似文献
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薛长安 《青海畜牧兽医杂志》2012,42(3):5-6
对150头当年产母牦牛在发情季节进行犊牛断乳,同时对166头隔年产干乳母牦牛进行对照,观察了犊牛断乳后母牦牛发情周期恢复的规律。结果表明断乳组母牦牛发情率为69.33%,发情持续期为15d;隔年产母牦牛发情率为89.94%,发情持续期为62d。 相似文献
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The effect of acrosomal aberrations of the spermatozoa of Finnish Ayrshire bulls on the corrected non-return rate within 60 days of the first 500 inseminations was studied. The material consisted of sperm samples examined by the artificial insemination societies. All samples had been accepted for use in artificial insemination. One Giemsa-stained slide was studied for each of the 95 bulls concerned. Samples showing distinct acrosomal defects were studied by electron microscopy. Three different types of acrosomal aberration were found. One was obviously associated with subfertility in all 6 bulls in which it was detected. 相似文献
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Gastric motility, secretion and structure were studied in piglets which were weaned at two weeks of age and reared in iron-free cages on a low-iron diet. Piglets which were not given iron parenterally rapidly developed iron deficiency anaemia. Gastric motility was studied fluoroscopically after dosing the piglets with barium sulphate. Gastric secretion was studied in piglets with gastric cannulae after stimulation with betazole hydrochloride. There was no difference between iron-treated and iron-deprived pigs in the motility of the stomach but in iron-deprived animals there was marked impairment of acid and chloride secretion from an early age and histological evidence of atrophic gastritis. 相似文献
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The activity of a mixture of sulphadimethoxine and pyrimethamine (10:3) as prophylactic medication and prophylactic and therapeutic medication was studied in rabbits experimentally infected with Eimeria stiedai. The haematocrit index (packed cell volume) and haemoglobin levels were studied for assessment of drug toxicity. The activity in serum of aspartate aminotransferase (AST) and alanine aminotransferase, alkaline phosphatase and gamma-glutamyltranspeptidase were studied as indicators of hepatic lesions. Parasite development was followed on the basis of the presence of oocysts; other parameters were analysed in order to monitor the performance of infected animals. All the parameters studied showed that the chemoprophylactic medication provided efficient control of the infection and of the hepatic lesions. Serum AST activity was seen to be a good indicator of the effect of the drugs on the liver. 相似文献
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为了降低玉米压片加工的成本,采用对辊式压片机对北方新收获的玉米进行了热风加热压片的试验研究.以影响玉米热风加热压片的热风加热温度、热风加热时间、压辊间距及压辊转速4个因素进行正交旋转组合设计,以玉米片糊化度为评价指标进行了试验.结果表明:高水分玉米经热风直接加热压片对提高玉米的糊化度有利,研究的较佳工艺技术参数组合为:热风温度为121～126℃、热风加热时间为64～67 min、压辊的间距为0.5-0.7 mm、压辊的转速为160～171r/min. 相似文献
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V Cigánková 《Veterinární medicína》1983,28(10):613-620
The morphological picture of Sertoli cells was studied in view of development. The testicular tissue of rams was studied from the 80th to the 140th day of intrauterine development and the testes of ram-lambs were studied from the 1st to the 40th day from birth; further, the testes were studied in adult rams. The development and differentiation of Sertoli cell precursors were examined, including their change into differentiated mature Sertoli cells. The electron-microscopic picture of these cells was described with special emphasis on those morphological changes in cells which are closely related with their functional activity during the development of the testes. The findings obtained so far in this field are incomplete and concern mainly laboratory animals and man. The results of the study extend the theoretical knowledge in the fields of histology, embryology, physiology, endocrinology and andrology. At the same time, they may serve as starting material for the study of the control of spermatogenesis under experimental conditions. 相似文献