中国林蛙产业存在的问题及发展对策

林蛙是我国重要的集食用和药用为一体的珍贵两栖类动物,具有较高的经济价值。林蛙药用历史悠久,我国很多地区林蛙资源丰富。林蛙产业在国民经济中占有重要地位,中国的林蛙产业在发展过程中,在林蛙科研、养殖及产品开发等方面取得了许多显著的成绩,但也存在很多问题。本文对中国林蛙产业存在的问题进行综述,并提出其发展对策,即中国的林蛙产...     

中国林蛙真伪品的PCR鉴别

本研究根据GenBank发表的哺乳类SRY核酸序列和禽类EcoRI家族序列设计1对引物,对中国林蛙真伪品进行了PCR扩增,并对特征条带进行了克隆测序。结果表明,PCR扩增产物有明显的区别,中国林蛙、黑龙江林蛙、黑斑蛙和中华大蟾蜍分别扩增出约1000、250、450、750bp的特征条带,通过对中国林蛙1000bp条带的克隆序列进行BLAST比对分析,找到了一些禽类的WZ染色体上的相关基因片段。     

中国林蛙卵的药理作用及开发利用

中国林蛙具有很高的药用价值与经济价值,是东北地区重要的经济蛙种,因而一直受到人们的重视。长期以来人们对中国林蛙资源的开发仅局限于中国林蛙油,而对中国林蛙其他资源开发利用不够充分,文章对中国林蛙卵的营养价值、药理作用及开发利用现状进行了综述。     

中国林蛙胚胎发育的研究进展

论文对中国林蛙胚胎发育时期的划分、胚胎期的性腺发育和性别分化、环境温度对胚胎发育的影响等研究进行了综述.根据胚胎的外部形态特征和生理特性,中国林蛙早期胚胎发育划分为25个时期.中国林蛙胚胎发育到31期时生殖腺开始性别分化.在15～30 ℃之间,温度越高,雄性比例越大.适量的雌激素可以提高中国林蛙的雌性比例.在7～22 ℃的温度范围内中国林蛙胚胎均能正常发育,温度越高,发育越快,发育历期越短.这些研究结果为中国林蛙的保护及养殖提供了科学依据.     

中国林蛙温室大棚全人工养殖技术

中国林蛙全人工养殖，就是根据林蛙的生物学特性，模拟林下生态环境条件，从林蛙抱对产卵、孵化、蝌蚪变态、幼蛙、成蛙的饲养及越冬等完全在人工条件下进行的一种集约化养殖方法。全人工养殖林蛙使林蛙生产走向高密度、集约化、快速化、科学化的道路，提高了林蛙的回收率，稳定了林蛙的收成；扩大了林蛙饲养区域，在庭院、平原地区都可以用全人工方式养殖中国林蛙。     

几种生态因素对人工养殖中国林蛙的影响

为了提高中国林蛙个体生长速度和雌性比例及林蛙的群体产量,试验研究了温度对中国林蛙卵孵化率、成活率、变态率及林蛙性别的影响,盐度对中国林蛙的影响,pH值对中国林蛙变态蝌蚪的影响,光照对蝌蚪的影响。结果表明:蝌蚪最适生长发育温度为18～24℃,可利用光照调节水温,在15～25℃条件下中国林蛙蝌蚪的变态率最高,蛙卵孵化水温在13～18℃之间变雌率可达70%,变态蝌蚪饲养池水体pH值应控制在6.5～8.5,盐度控制在2 g/L以下,蝌蚪养殖水环境Ca2+、Mg2+质量浓度及Ca2++Mg2+总质量浓度应分别控制在20～50 mg/L、20～80 mg/L、50～150 mg/L。     

中国林蛙南移人工养殖的生态适应性研究

观察并研究了中国林蛙从东北迁移到浙江之后 ,在人工养殖过程中出现的生长变缓、死亡率增高、行为习性改变和幼蛙的发育过程不良等现象。分析了南方环境生态因子变化对林蛙所造成的环境胁迫 ,及由此带来林蛙在冬眠和繁殖上的影响。认为饲料供应、光周期和环境温度是决定林蛙在南方生长发育的限制因子 ,并从技术上提出了改进措施。     

中国林蛙蝌蚪不同营养水平日粮的饲喂效果比较

中国林蛙是东北地区具有较高经济价值的两栖动物之一,其雌性输卵管的干制品即中药学上的哈士蟆油,无论食用还是药用均具有较高价值.目前在东北地区已经广泛开展了中国林蛙的人工养殖和半人工养殖.在养殖林蛙时,蝌蚪的饲养管理极为重要,特别是饲料的营养结构合理与否,直接影响蝌蚪的生长发育和养殖的经济效益.本试验利用营养结构不同的4组饲料,在中国林蛙蝌蚪期进行喂养,研究其对中国林蛙蝌蚪生长发育速度、体长、体重及成活率的影响. 　　……     

中国林蛙消化道解剖学观察

中国林蛙属脊椎动物门、两栖纲蛙科蛙属，是一种药肉兼用的珍稀两栖动物。因此，近年来对林蛙的研究也日益增多，但目前对林蛙的研究主要集中在人工繁殖及养殖技术方面，而对其形成学方面的研究非常少见。所以，为进一步研究林蛙的消化吸收机制及对疾病防治方面提供确实可靠的形态学理论依据，现对中国林蛙消化道的形态特征及消化道管壁的组织结构特点进行了观察。     

中国林蛙南移养殖效益高

近年来，苏州大学水产学院、江苏省苏州望湖中国林蛙研究所进行了中国林蛙南移养殖试验，结果表明：中国林蛙不仅能在南方正常生长繁殖，而且在南方养殖还具有生长期长、饵料资源丰富等特点。 中国林蛙是我国著名的集药用、食用、保健于一身的珍贵蛙种，与猴头、熊掌、飞龙并称“四大山珍”，被誉为深山老林珍品。中国林蛙的全身均可入药。目前林蛙的南移养殖刚刚兴起，养殖中国林蛙的经济效益十分可观。 (车铁崔勇华成长勇缪建海 )     

中国林蛙蝌蚪期饲料配方的研究

为研究一种适合林蛙蝌蚪生长的饲料配方,试验选用林蛙蝌蚪受精卵共800只,分为4个大组,每大组设两个重复,共8个小组,分别饲养在8个水盆中,每盆100只。试验对比研究了蛋白质含量分别为37.765%、31.628%、23.535%及11.562%的4种饲料。试验结果表明,饲喂蛋白质含量为23.535%的一组蝌蚪重量最大,体长最长,发育的也最为良好。同时通过试验分析证明,从蝌蚪发育到变态前的饲料应以植物性饲料为主并适当的加入部分动物性饲料,这样才有利于蝌蚪的生长发育。此外,还提出用传统方法配制蝌蚪饲料的不足及解决的办法。     

Periovulatory changes in peripheral plasma progesterone and estrogen concentrations in the mare.

Concentrations of progesterone and estrogen were measured in peripheral blood plasma samples from mares around the time of ovulation. Samples were collected every 2 hours from 36 hours before, to 26 hours after, ovulation and assayed by radioimmunoassay. Progesterone concentrations were between 60 and 100 pg/ml for the period 24 hours before ovulation through 8 hours after ovulation. By 10 hours after ovulation, concentrations increased to 140 pg/ml and, by 26 hours after ovulation, reached 346 pg/ml. Plasma estrogen concentrations did not change significantly throughout the same period.     

Plasma concentrations of immunoreactive (ir)-inhibin, gonadotropins and steroid hormones during the ovulatory cycle of the duck

The present study was undertaken to determine changes in circulating levels of immunoreactive (ir)-inhibin, FSH, LH, estradiol-17beta, progesterone, and testosterone during the ovulatory cycle of Shao ducks. Serial blood samples were taken from two groups of laying ducks for measurement of ir-inhibin, gonadotropins, and steroid hormones at 2 h intervals for 24 h. Plasma concentrations of ir-inhibin did not change significantly during the ovulatory cycle. The highest level of plasma ir-inhibin was observed 6 h prior to ovulation, which coincided with a decreased level of plasma FSH. One FSH surge was found 12 h after ovulation. Estradiol-17beta, progesterone, and testosterone were also determined during the ovulatory cycle. Two peak values were detected for estradiol-17beta 8 h before ovulation and 4 h after ovulation, while progesterone started to increase 4 h before ovulation and reached a peak at ovulation. The highest level of plasma testosterone was detected around the time of ovulation. These results suggest that inhibin may be involved in the control of FSH secretion during the ovulatory cycle. In addition, both LH and progesterone are of importance in the ovulation process of Shao ducks.     

Plasma LH and progesterone levels before and after ovulation and observation of ovarian follicles by ultrasonographic diagnosis system in dogs

Recently, canine frozen semen has been attracting attention for breeding purposes, and methods of judging ovulation and optimum timing for insemination have become important. As methods of predicting the canine ovulation, vaginal smear, plasma sex hormone levels and ultrasonographic diagnosis system (US) have been investigated in combination, but a standard technique has not yet been established. Therefore, we investigated a method of predicting canine ovulation in dogs by US, and by measuring plasma LH and progesterone (P) levels three times a day. Ovulation could be observed by detecting irregularly shaped ovarian follicles by US in six of 11 dogs (54.5%). In these dogs, the time between the LH peak and ovulation was 24-48 hr, 38.0 hr on average. The P level on the ovulation day was 1.88-2.81 ng/ml, 2.34 ng/ml on average. A value of 1.88 ng/ml was detected in one dog, but the other five dogs showed P levels of 2 ng/ml or higher. The P level on the day before ovulation was 0.8-1.56 ng/ml, 1.12 ng/ml on average. Assuming that ovulation occurred two days after the LH peak in the 11 experimental dogs, the P level was 2.12-4.06 ng/ml, 2.78 ng/ml on average. The period of a high LH level, not less than 10 ng/ml, continued for 12 hr around the LH peak. Based on these findings, to predict ovulation using US and LH level, it would be necessary for the tests to be performed several times a day. In contrast, it was shown that the day on which a plasma P level of 2 ng/ml or higher was detected by the test performed once a day corresponded to the ovulation day.     

Hourly water consumption and egg formation in the domestic fowl

Observations on the water intake of four laying hens indicate that consumption is related to the egg formation. The maximum intakes occur just after the oviposition (50 ml/h) and during the albumen plumping (37 ml/h). Data obtained around the time of oviposition suggest that at this moment water intake is connected to oviposition rather than ovulation. A comparison between water and food intake is also presented.     

虎纹蛙蝌蚪几种饵料的比较试验

以藻类，蛋黄，水蚤和异种蝌蚪为饵料，饲喂人工养殖下的虎纹蛙蝌蚪。结果表明虎纹蛙蝌蚪喜食活动的动物性饵料，且生长率高。我们认为水蚤是一种较为适宜的饵料。     

Influence of Sperm Cell Dose and Post-insemination Backflow on Reproductive Performance of Intrauterine Inseminated Sows

This study was carried out to evaluate the effects of the sperm cell dose and semen backflow on the pregnancy rate and number of embryos of sows inseminated once at 0-24 h before ovulation, using an intrauterine technique. The results were analysed from a total of 211 sows assigned to three groups inseminated with doses of 0.25 x 10(9) (T1), 0.5 x 10(9) (T2) and 1.0 x 10(9) (T3) spermatozoa. Semen backflow was observed in 95% of the females (143/151) evaluated for this purpose. The percentage of semen backflow is close to two-third of the volume and the percentage of sperm is around 15% of the infused sperm dose. Intrauterine insemination can be successfully performed provided that at least 0.5 billion of sperm cell dose is infused at an interval of 0-24 h before ovulation.     

Ultrasonographic characteristics of the preovulatory follicle preceding and during ovulation in mares

Changes in appearance of preovulatory follicles were observed with real-time ultrasonography prior to and during ovulation in mares. Preovulatory follicles of 15 mares were scanned at < 1 hr intervals for 12 hr or more frequently if displaying signs of impending ovulation. If ovulation was not imminent at the end of 12 hr (n = 2), mares were removed from the trial. Mean follicular diameter decreased 13% from 30 minutes prior to ovulation until the beginning of ovulation. Fifteen to 77 minutes (mean = 41 min) prior to ovulation, a break in or a protrusion of the follicular wall toward the ovulation fossa was visualized in all follicles and was a consistent indicator of impending ovulation. A rapid decrease in size of follicles (ovulation) occurred within a period of 5 to 90 seconds (mean = 42 sec). Little or no fluid remained in the antrum following ovulation. An increase in echogenicity (whiteness) of the follicular wall and echogenic “spots” within the follicle were frequently visualized (13/13, 100% and 7/13, 54% respectively) prior to ovulation; however, prediction of time of ovulation could not be based solely on these individual changes.     

The relation between ultrasonographic observations in the oviduct and plasma progesterone, luteinizing hormone and estradiol during the egg laying cycle in ostriches

In this study we investigated the temporal relationship between ovulation, egg formation, oviposition and the changes in plasma concentrations of progesterone, luteinizing hormone and estradiol-17beta during the egg laying cycle in farmed ostriches. In 10 egg-producing birds, transcutaneous ultrasound scanning was performed at 3h intervals and blood sampling at hourly intervals during a period of at least 48h (one egg laying cycle). In hens (n=8) that ovulated during the observational period, the ovulated egg was first detected 2h after oviposition; thus, ovulation occurred shortly after oviposition in all birds. During the period between two consecutive ovipositions, the developing egg remained for 9h in the proximal part (infundibulum, magnum or isthmus) and for 39h in the distal part of the oviduct (uterus). In ovulating hens, plasma progesterone concentrations showed a characteristic and consistent profile: from basal levels of around 0.1ng/ml concentrations started to increase 12h before oviposition, reached an average maximum of 3.5ng/ml at 3h before oviposition and returned to basal levels 3h and 30min after oviposition. Changes in plasma luteinizing hormone and estradiol-17beta concentrations showed comparable patterns of elevation and decline relative to the timing of oviposition and ovulation. However, variation in their individual basal concentrations was generally larger and peak values were less conspicuous than those of progesterone. In non-ovulating hens (n=2) neither progesterone, nor luteinizing hormone nor estradiol-17beta showed elevations to peak concentrations before oviposition. These data demonstrate that during the egg laying cycle of ostriches, events such as ovulation, egg development and oviposition evolve according to a rather strict time schedule, and that progesterone, luteinizing hormone and estradiol-17beta reach peak concentrations shortly before ovulation. Additionally, our findings also show that on-farm ultrasound scanning is a useful technique to discriminate between ovulating and non-ovulating hens.