鹿茸Ca^2＋含量与塔里木马鹿收茸期的关系研究

为了确定不同年龄段塔里木马鹿鹿茸的最佳收茸时间,保证鹿茸的药用价值,试验选取老、中、青3个年龄段的塔里木马鹿各6头,采用火焰原子吸收分光光度法,分别测定不同生茸时期鹿茸中Ca2＋的含量。结果表明：青年组至6月17日鹿茸上段Ca2＋含量增加显著,确定其最佳收茸时间以6月17日为宜;中年、老年组的最佳收茸时期在6月3日左右,三者存在时间差异。     

野生高乌头开花习性及种子灌浆特性研究

利用甘肃永登县野生高乌头植株为研究材料,标记初花期一致的植株,每天测定单株开花数和蓇葖果数,并每隔3 d测定蓇葖果种子数、粒重和体积,对其开花结果动态和种子灌浆特性系统研究,旨在揭示其开花结果习性及其种子灌浆规律,为探寻高乌头种子发育规律及适宜采收期提供科学依据。结果表明,野生高乌头植株主花序花蕾自下而上依次开放。单花开放后第3天形成蓇葖果,第15天种子成形,并开始脱水形成干物质积累。单株开花数等于蓇葖果数,基本不落花,但仅主花序中部及以下部位蓇葖果具成熟种子。在种子整个灌浆过程中,百粒鲜重和干重的变化动态均呈“S”型曲线,符合Logistic方程。籽粒鲜重快增期在花后7～21 d,最大增长速率出现在花后14 d,在花后27 d达到最大,而干物质积累快增期在花后16～30 d,最大积累速率出现在花后23 d。开花36 d后蓇葖果脱落,种子灌浆和株上脱水中断,导致种子含水量达50%以上,采收后种子在快速脱水过程中可能形成深休眠特性,说明高乌头种子适宜采收期为开花后第36天左右(8月中下旬),蓇葖果尚未开裂时及时分批采收为宜。     

Effect of time delay and storage temperature on blood gas and acid-base values of bovine venous blood

The aim of this study was to investigate possible changes in the gas composition and acid-base values of bovine venous blood samples stored at different temperatures (+4, 22 and 37 degrees C) for up to 48 h. Five healthy cattle were used in the study. A total of 15 blood samples collected from the animals were allocated into three groups, which were, respectively, then stored in a refrigerator adjusted to +4 degrees C (Group I, n=5), at a room temperature of about 22 degrees C (Group II, n=5) and in an incubator adjusted to 37 degrees C (Group III; n=5) for up to 48 h. Blood gas and acid-base values were analysed at 0 (baseline), 1, 2, 3, 4, 5, 6, 12, 24, 36 and 48 h of storage. A significant decrease (p<0.001) was found, in the pH of the refrigerated blood after 5 h and its maximum decrease was recorded at 48 h as 0.04 unit. There were also significant alterations (p<0.001) in the blood pH of the samples stored at room temperature and in the incubator after 2 and 3 h, respectively. The maximum mean alteration in pCO(2) value for Group I was -0.72 kPa during the assessment, while for groups II and III, maximum alterations in pCO(2) were detected as +2.68 and +4.16 kPa, respectively. Mean pO(2) values increased significantly (p<0.001) for Group I after 24 h and for Group II after 6 h, while a significant decrease was recorded for Group III after 24 h (p<0.001). Base excess (BE) and bicarbonate (HCO(3)) fractions decreased significantly for all the groups during the study, compared to their baseline values. In conclusion, acid-base values of the samples stored at 22 and +4 degrees C were found to be within normal range and could be used for clinical purposes for up to 12 and 48 h, respectively, although there were small statistically significant alterations.     

两种早熟禾超氧物歧化酶活性测定的适宜条件

以冷地早熟禾 (Poacrymophila)和草地早熟禾 (P .pratensis)为材料 ,探讨光照反应时间、酶浓度以及酶反应体系等对NBT光化还原反应的影响。随着光照反应时间的延长 ,最大光还原值直线上升。 2 5min后光化还原值逐渐趋于稳定。光照反应开始后 ,酶液对NBT光化还原反应速率的抑制百分率迅速升高 ,在 15～ 2 5min时 ,酶液对NBT光化还原反应的抑制百分率保持稳定 ,2 5min后下降速率较大。光照反应时间对SOD酶活性测定的影响较大 ,确定为 2 5min较为适宜。酶浓度在 4 0～ 6 0mg/mL时光化还原值变化速率较一致。测定中反应体系NBT、核黄素的加样量以及光照强度在一定范围内时光化还原值较为稳定     

交配时间长短对家蚕卵质卵量的影响

通过不同蚕品种不同交配时间产卵成绩比较,交配3 h拆对,多数品种显示对增加产卵量及减少不受精卵为好,缩短或延长时间均不利于提高产卵成绩。     

结构基因座和微卫星标记应用于绵(山)羊群体遗传分化的比较研究

对湖羊、同羊及长江三角洲白山羊的随机样本分别进行14个结构基因座和7个微卫星标记的遗传检测,比较由两种遗传标记获得的群体基因平均杂合度(H)、多态信息含量(PIC)及群体有效等位基因数(Ne);分别根据两种类型的基因频率资料,计算3个群体间的标准遗传距离并加以比较。结果表明:由微卫星等位基因频率获得的群体基因平均杂合度、多态信息含量及有效等位基因数显著大于结构基因座获得的,但在三群体中变化趋势是一致的;由结构基因座资料计算的3个群体间标准遗传距离为0 0268～0 2487,微卫星标记资料计算的3个群体间标准遗传距离为:0 2321～1 2313,绵山羊间显著大于绵羊群体之间。提示:结构基因座和微卫星标记一致揭示3群体内的遗传变异;同羊>湖羊>长江三角洲白山羊;微卫星标记较结构基因座标记更能表达近缘种间进化趋异水平,可将FCB11、MAF33、AE101、FCB128及FCB304位点作为研究绵山羊近缘种间遗传分化的标志性位点。     

Effects of 2 concentrations of sodium citrate on coagulation test results, von Willebrand factor concentration, and platelet function in dogs

BACKGROUND: Blood collection tubes containing 3.2% (0.109 M) sodium citrate, instead of 3.8% (0.129 M) sodium citrate, have recently become available in the United States. These tubes are visually indistinguishable from the traditional 3.8% sodium citrate tubes, except for wording on the label. Consequently, samples for hemostatic evaluation are frequently collected in tubes containing the lower concentration of sodium citrate. HYPOTHESIS: Results of hemostasis assays are different in samples collected in 3.2% versus 3.8% sodium citrate. ANIMALS: Twenty healthy dogs. METHODS: This study aimed at determining whether results of standard coagulation tests, von Willebrand factor concentration (vWF:Ag), and platelet function with the platelet function analyzer PFA-100a were affected by the different concentrations of sodium citrate. Blood samples were collected in tubes containing either 3.2% or 3.8% sodium citrate concentrations and processed routinely for coagulation assays (one-stage prothrombin time [OSPT], activated partial thromboplastin time [aPTT], fibrinogen concentration, and platelet count), vWF:Ag, and platelet function assays with a PFA-100. RESULTS: There was no significant difference between samples collected in 3.2% versus those collected in 3.8% sodium citrate for OSPT, aPTT, fibrinogen concentration, platelet count, or vWF:Ag. The closure times with collagen/adenosine diphosphate were significantly shorter (66 +/- 8.1 versus 74.8 +/- 9.7 seconds; P < .0001) with the 3.2% than with 3.8% sodium citrate concentration, and the hematocrit was significantly higher (47.9 +/- 5.6 versus 46.0 +/- 4.7 seconds; P = .03) in samples collected in 3.2% than in those collected in 3.8% sodium citrate. CONCLUSIONS AND CLINICAL IMPORTANCE: There is no clinically relevant effect of collection of blood into 3.2% or 3.8% sodium citrate.     

The effects of l‐DOPA and sulpiride on growth hormone secretion at different injection times in Holstein steers

The effects of l ‐DOPA, a precursor of dopamine (DA), and sulpiride, a D₂‐type DA receptor blocker, on growth hormone (GH) and prolactin (PRL) secretion were investigated in steers. Eight Holstein steers (212.8 ± 7.8 kg body weight) were used. Lighting conditions were 12:12 L:D (lights on: 06.00–18.00 hours). Blood samplings were performed during the daytime (11.00–15.00 hours) and nighttime (23.00–03.00 hours). Intravenous injections of drugs or saline were performed at 12.00 hour for the daytime and 00.00 hour for the nighttime, respectively. Plasma GH and PRL concentrations were determined by radioimmunoassay. l ‐DOPA did not alter the GH secretion when it was injected at 12.00 hour (spontaneous GH level at its peak). On the other hand, l ‐DOPA increased GH secretion at 00.00 hour (GH level at its trough). Injection of sulpiride suppressed GH secretion at 12.00 hour but did not affect GH levels at 00.00 hour. l ‐DOPA inhibited and sulpiride stimulated PRL release during both periods. These results suggest that dopaminergic neurons have stimulatory action on GH secretion and inhibitory action on PRL secretion in cattle. In addition, injection time should be considered to evaluate the exact effects on GH secretion due to its ultradian rhythm of GH secretion in cattle.     

刈割对牧草生物量和品质影响的研究进展

刈割是一种常见的草地利用和管理方式,它可以通过两方面途径来影响牧草产量及品质。首先,刈割可以利用植物的补偿性生长,促进牧草生长并提高牧草产量。其次,刈割可以利用植物均衡性生长特性,改变牧草营养物质的沉积和分配方向,进而影响牧草品质。常见的刈割包括刈割频次、刈割时间和刈割方式。全面综述3种刈割对牧草产量及品质影响和相应作用机理,为适当利用刈割提高牧草产量及品质提供参考。     

圈养秦岭羚牛夏季昼间活动时间分配研究

为了对秦岭羚牛进行有效的迁地保护和揭示圈养条件下秦岭羚羊的夏季昼间的时间分配状况,更好地加强饲养管理,2006年7月,在陕西省珍稀野生动物抢救饲养研究中心内采用瞬时扫描取样法对13头圈养秦岭羚牛(Budorcas taxicolor bedfordi)的活动规律进行了观察。结果表明,夏季白昼羚牛的活动以休息为主,采食次之,同时,羚牛的饮水、排尿、排便量均较低,分别为每头每天1.92次、0.54次、0.92次。羚牛每天的活动节律与气温的变化相关。年龄对羚牛活动节律的影响主要表现在羚牛的活动节律和时间分配方面的差异。此外,从羚牛群体进行观察,同一群中的羚牛个体的活动具有不完全同步性。