鸵鸟和鸸鹋血清生化指标参考值研究

鸵鸟血液化学研究较少,并且鸵鸟的血液生化值与鸸鹋的不一致.本研究的目的是:建立鸸鹋的血液生化各指标的参考值范围与鸵鸟的对应指标进行比较,并且分析各指标值受性别与月龄的影响.     

奶牛早孕诊断乳汁孕酮临界值的确定

随机选择健康荷斯坦母牛６３头，其中发情周期牛５头，配后１８－２４天牛３０头和通过直接确定的怀孕牛２８头，按程序采集末乳乳样。用放射免疫测定法（ＲＬＡ）测定乳汁孕酮（ＭＰ４）浓度。以发情第３天ＭＰ４浓度加上２倍标准差为未孕临界值的土限，以配后１８－２４天怀孕牛ＭＰ４浓度的平均值减去１倍标准差为怀孕临界值的下限。结果表明，奶牛ＭＰ４早孕诊断临界值为：≥７．１９ｎｇ／ｍｌ为怀孕，〈４．７２ｎｇ／ｍｌ为未     

Use of an ELISA for plasma progesterone to facilitate rabbit husbandry

There is a need for a simple and accurate method for detecting pregnancy in rabbits; the available methods are not ideal and may not provide the diagnosis at an appropriate time for the early remating of non-pregnant animals. This paper describes the use of an ELISA kit to measure progesterone concentrations in rabbit plasma; a qualitative assessment of the results appears to be sufficiently accurate for pregnancy diagnosis, as does the use of serum instead of plasma. The technique can be used to predict ovulation and to distinguish between pregnant and pseudopregnant animals.     

Direct enzyme immunoassay of progesterone in bovine plasma

The present study was undertaken to develop a novel, practical and simple procedure for enzyme immunoassay (EIA) of plasma progesterone in cows. Diluted plasma was heated for 70°C for 30 min and applied directly to wells of a microtitre plate without extraction. Then plasma was incubated with antiprogesterone antibody and horseradish peroxidase‐labeled progesterone. The sensitivity of the assay was estimated as 4.4 pg/mL (0.11 pg/well). The intra‐assay and interassay coefficients of variation were 5.7–19.1% and 6.6–19.3%, respectively. When 0.3, 1 and 3 ng of progesterone were added to plasma, the recovery rates ranged between 79.9 and 108.4%. Only 4 h were needed to complete an assay to measure progesterone concentration. To apply the present direct EIA, progesterone concentration in plasma was assayed in crossbred cows used for the embryo transfer program. During insertion of controlled‐internal drug release (CIDR), progesterone concentrations were kept at a high level, although the removal of CIDR with treatment of dinoprost trometamine reduced progesterone concentration drastically. These results suggest that the present direct EIA is a practical and suitable method for measuring the plasma concentration of progesterone.     

Measurement of progesterone in sheep using a commercial ELISA kit for human plasma

Determination of serum or plasma progesterone (P4) concentrations is important to recognize pregnant and non-pregnant ewes, and also to predict the number of carried lambs. The 2 most common methodologies for the detection of plasma P4 are radioimmunoassay (RIA) and enzyme immunoassay (EIA). RIA is very expensive, and not all laboratories are equipped to perform this test; EIA is commercially available for human use, but only a few companies produce species-specific kits, which are expensive. We verified for ovine plasma a less expensive and easily available ELISA kit (DiaMetra) designed to quantify P4 in humans. Pools of ovine and human plasma were used to compare repeatability, accuracy, sensitivity, and stability of P4 measured by the DiaMetra kit. Repeatability data were within 15%, and accuracy values were ~90% for both plasma matrices. Stability data showed a loss of <20% for freeze–thaw and <30% for 30-d storage. All parameters were acceptable under international guidelines for method validation. The human ELISA kit was used successfully to quantify plasma P4 in 26 ewes during pregnancy until delivery. P4 concentrations were also correlated with the number of carried lambs.     

Rapid radioimmunoassay of progesterone in unextracted bovine plasma.

A rapid radioimmunoassay for determining progesterone levels in unextracted bovine plasma has been developed. Two antisera have been tested, anti-deoxycorticosterone-21-hemisuccinate human serum albumin and antiprogesterone-11-hemisuccinate bovine serum albumin. The usefulness of an antiserum for rapid assays has been based on its agreement with assays of organic extracts or chromatographically purified extracts of selected bovine samples. To avoid large blank effects and non-specific interference, a plasma volume of 20 microliter that provided adequate sensitivity was not exceeded. All correlations between rapid assays, assays using organic extraction or assays after chromatographic purification were greater than 0.9 and showed regression slopes approximating unity. It was concluded that individual lots of antisera should be evaluated thoroughly before use in a rapid assay.     

The effects of progesterone and oestrogen treatment in heifers on oestrous cycle control and plasma progesterone levels

Data are presented on the effects of a short-term progesterone treatment for oestrous cycle control in cattle. Progesterone was administered by intravaginal sponge pessaries inserted for a 10-day period. Progesterone pessaries alone did not affect oestrous cycle length or corpus luteum function at either early (day 2) or midluteal (day 12) cycle stages. However, when progesterone (250 mg) and oestradiol benzoate (7-5 mg) were given intramuscularly on the day of pessary insertion corpus luteum development was inhibited in animals treated at day 2 and was regressed in animals at day 12. This combined oestrogen-progesterone treatment efficiently controlled oestrous cycle length.     

Effects of selenium supplementation on plasma progesterone concentrations in pregnant heifers

It is known that selenium (Se) has various functions in animals. Many investigations on the biochemical and physiological effects of Se have been previously reported; however, the detailed function of Se in reproduction is not yet clear. We proposed the possibility that Se plays a notable role in progesterone production. The aim of this study was to clarify the effects of Se supplementation on progesterone levels of pregnant Holstein heifers. Eight Holstein heifers (?Se) were fed basal diet (containing 0.022 ppm of Se) throughout the experiment. While a 0.3 ppm diet of Se (sodium selenite) was fed to another seven animals (+Se) with basal diet. Blood sampling was carried out every week. Plasma Se concentrations were higher in Se‐supplemented cows compared with controls (?Se) (P < 0.01) throughout the experiment. Se supplementation increased plasma progesterone in the 29–39 weeks of pregnancy from 4.98 ± 0.64 to 6.86 ± 0.49 ng/mL on average (P < 0.05). The present findings suggest that Se contributes to maintaining the function of the corpus luteum and/or placenta in the latter period of pregnancy.     

The effect of handling methods on subsequent plasma progesterone levels in sheep

The mean progesterone concentration in the plasma of 10 adult Ethiopian Highland sheep obtained immediately after slaughter was 10.56±3.98 ng/ml. Samples were subsequently incubated at 4°C, room temperature (19–22°C) or 26°C as either plasma or intact but citrated blood. Failure to separate plasma affected the progesterone content at 2–72 h at room temperature or 26°C (p<0.01-p<0.0001). Incubation temperature affected the plasma concentration at 18 h (p<0.05) and 24 h (p<0.001). Although progesterone values were generally higher in separated plasma, disparity with the values from plasma separated from incubated citrated blood was small (r=0.76–0.98). Progesterone concentration declined haphazardly after collection but sometimes exceeded the initial readings. This kept the average concentration of progesterone in plasma separated immediately after collection fairly constant and within 15% of zero time samples during the first 48 h.     

The sensitivity and specificity of postbreeding plasma progesterone levels as a pregnancy test for dairy cows.

Plasma progesterone levels on day 4 and day 8 postbreeding were measured for one hundred and eighty-four dairy cows. These two parameters (PPD4, PPD8), their absolute difference (PPDIFF) and their ratio (PPRATIO) were assessed for their ability to identify cows not conceiving, using the principles of sensitivity and specificity. PPD4 was significantly higher (p less than 0.10) and PPD8, PPDIFF and PPRATIO were significantly lower (p less than 0.01) in cows remaining open than in pregnant cows. Evaluating each parameter separately, PPDIFF greater than 3.00 units had the highest specificity, 85.7%, but a low sensitivity (27.0%). Combining two parameters using series interpretation to increase specificity resulted in the best combination of specificity (87%) and sensitivity (27%). Maximum specificity was 97% for PPD4 less than or equal to 1.00 units and PPD8 greater than 4.00 units, and also for PPD4 less than or equal to 1.00 units and PPDIFF greater than 3.00 units, but sensitivity was very low (7% and 10% respectively). Predictive values of the test results with the best specificity were evaluated; given the population pregnancy rate of 54%, none exceeded 50%, indicating that the plasma progesterone parameters were not very useful for identifying open dairy cows.