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1.
选择从澳大利亚购进的2岁左右、发情周期为21天的育成母牛10头,用放射免疫测定法(RIA)测定了发情周期血清中促卵泡素(FSH)和促黄体素(LH)的浓度,用B-型超声波诊断仪检测发情周期卵巢卵泡发育变化。结果显示:FSH和LH浓度在奶牛发情周期中主要表现出两个波峰,其中一个波峰较小,这与卵泡两个发育波态势相似。  相似文献   

2.
选择从澳大利亚购进的2岁左右发情周期为21天的育成母牛10头,用放射免疫测定法(RIA)测定发情周期血清中孕酮(P_4)和17β-雌二醇(E_2)的浓度,用B-型超声波诊断仪检测发情周期卵巢卵泡发育变化,结果显示:E_2浓度在奶牛发情周期中主要表现出两个波峰,只是其中一个波峰较小,这与卵泡两个发育波态势相似,而P_4在发情周期中却只表现出一个波峰,与卵泡两个发育波部分相似。  相似文献   

3.
在牛的发情周期中,卵泡是以卵泡波的形式周期性地发生的;每个发情周期中出现2—3个卵泡活动波。在每个卵泡活动波中,一般只有一个卵泡发育较快,成为优势卵泡。在黄体溶解时存在的那个优势卵泡排卵,其它卵泡则发生闭锁。这种理论可以应用于兽医产科实践的许多方面,如同期发情、超数排卵、发情鉴定。  相似文献   

4.
在影响奶牛繁殖的诸多因素中,卵巢疾病性不孕导致奶牛发情周期异常、繁殖性能低下,是引起奶牛不孕的重要原因之一,包括卵巢机能减退(卵巢静止)、持久黄体、卵巢囊肿、卵泡交替发育、排卵延迟等多种疾病。笔者应用自拟组方治疗奶牛卵巢静止、持久黄体和卵巢囊肿等卵巢性不孕症71例,平均发情率为94.4%,受孕率为81.7%。  相似文献   

5.
奶牛定时排卵、输精技术试验初报   总被引:2,自引:0,他引:2  
<正>母畜周期性发情的实质是卵泡与黄体的交替发育。奶牛定时排卵、输精技术是根据卵泡发育波理论,在发情周期的初期(第7天),第一批卵泡已发育至排卵前大小时注射GnRH(LRH),既能促进这些卵泡排卵并形成黄体,又可以促进新一波卵泡的发育。  相似文献   

6.
<正>母畜周期性发情的实质是卵泡与黄体的交替发育。奶牛定时排卵、输精技术是根据卵泡发育波理论,在发情周期的初期(第7天),第一批卵泡已发育至排卵前大小时注射GnRH(LRH),既能促进这些卵泡排卵并形成黄体,又可以促进新一波卵泡的发育。  相似文献   

7.
青年母牛在发情周期中卵泡发育波变化规律的研究   总被引:1,自引:0,他引:1  
为揭示青年母牛卵泡生长发育的动态模式,作者利用B-型超声波诊断仪,对青年母牛在发情周期中卵泡生长发育的过程进行了连续观察。结果表明,卵巢上小卵泡(1~4 mm)、中卵泡(5~7 mm)和大卵泡(≥8 mm)的数量和直径均呈动态变化。大、中、小卵泡的数量、卵泡的发育要经历征集期、选择期、优势化、成熟期和闭锁退化的过程。青年母牛在整个发情周期中,优势卵泡的平均直径为13.6 mm,成熟卵泡的平均直径为13.80 mm,一个发情周期有3~4个卵泡发育波,其中有3个卵泡发育波的为多数(71.43%),有4个的为28.57%。  相似文献   

8.
动物发情周期内卵泡的发育都要经过卵泡募集、卵泡选择、卵泡优势化和卵泡周转(排卵或闭锁),这种周期性的卵泡发育模式即为卵泡发育波.试验应用B超探查20只大足黑山羊连续2个周期卵泡发育波模式,不仅可以进一步了解反刍动物卵泡发育波理论,同时通过分析山羊卵泡发育波对发情周期、卵泡募集、卵泡排卵数的影响,为提高同期发情和超数排卵技术效果、通过调控卵泡波数增强山羊繁殖力提供理论基础.  相似文献   

9.
作者旨在通过B超技术探讨产后奶牛子宫的恢复情况和卵巢的变化情况,研究奶牛繁殖性能的变化规律,为更好地指导奶牛产后配种、繁育等工作提供试验依据。根据试验方案选择8头中国荷斯坦产后奶牛(其中4头初产、4头经产),从产后第1天开始到下次发情配种,持续利用B超观察其子宫的恢复情况和卵巢的变化情况。结果表明,子宫颈和子宫壁恢复正常的平均时间初产奶牛分别大约为25和32 d,经产奶牛均为27 d;经产和初产奶牛卵泡的发育都经历了6个卵泡波,前3个卵泡波为1个发情周期,后3个卵泡波为1个发情周期。因子宫未恢复完全,故要到第2个发情周期末(即要到第6个卵泡波)配种;初产和经产奶牛产后发情配种的平均时间分别大约为90和53 d。由此可看出初产奶牛的子宫颈恢复正常的平均时间要比经产奶牛早2 d,而子宫壁恢复正常的平均时间要比经产奶牛晚5 d;初产奶牛发情配种的平均时间要比经产奶牛晚37 d。  相似文献   

10.
[目的]动物的繁殖启动都以促性腺激素释放激素(GnRH)为基础,奶牛等非季节性发情动物的GnRH释放受黄体酮(孕酮)的负反馈控制,即奶牛的发情周期变化受孕酮水平的调节。孕酮不仅控制奶牛发情,还影响优势卵泡期内卵母细胞质量、优势卵泡体积大小、排卵、受孕、双胎率及促进子宫内膜发育、抑制宫缩、妊娠维持等生理变化。出于食品安全考虑,生产中注射用黄体酮制剂已在奶牛的泌乳期被禁用。在国内泌乳牛允许使用的孕酮制剂为黄体酮阴道缓释栓。目前使用的该类产品主要是进口孕酮栓产品。为支持我国奶业发展,降低用药成本,国内开始研发生产该类产品。2019年6月,开展试验对比了国产黄体酮硅胶缓释栓(喜达)与同类进口原研产品差异。[方法]通过检测试验组(喜达栓)与对照组(原研孕酮栓)奶牛在放栓前、放栓后48 h、放栓后7天(撤栓时)血中孕酮水平变化,使用后硅胶栓内孕酮残留比例。同时对比了旧栓第2次使用时上述各时间点的血药浓度变化及输精后受胎情况。[结果]两种产品各自使用后的血中孕酮浓度变化和栓内孕酮残留比例均无差异(P>0.05),两组产品在首次使用及二次重复利用时的受胎率对比均差异不显著(P>0.05)。...  相似文献   

11.
Ovarian function in 91 dairy cows with cystic ovarian disease was assessed by rectal palpation and by plasma hormone analysis before and after treatment. Plasma analysis showed that 84% of the cysts were correctly classified clinically and only these cows are considered further. Luteinised cysts occurred in 59 cows whereas only 18 had non-luteinised cysts. The mean plasma concentrations of luteinising hormone (LH), follicular stimulating hormone (FSH), progesterone, oestradiol and testosterone were not significantly different when compared with values at relevant stages of the oestrous cycle in normal cows. Success of treatment with progesterone, a synthetic prostaglandin, human gonadotrophin (HCG), or gonadotrophin releasing hormone (GnRH) was not dependent upon prior hormone concentrations, except for the prostaglandin which required active luteal tissue. LH and FSH concentrations in cows with luteinised cysts were not significantly different before and after successful treatment with GnRH or progesterone. Normal luteal function was not always established after treatment of non-luteinised cysts with GnRH.  相似文献   

12.
Patterns of concentrations of luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone (P4) and estradiol-17 beta (E2) during an estrous cycle were compared between 15 lactating beef cows 5 to 7 years of age (young) and 15 cows greater than or equal to 12 years of age (old). Length of estrous cycle did not differ between young and old cows (P = .06). No differences due to age were found for LH. Patterns of concentrations of P4 during the first 15 days of the cycle, of FSH during days 6 through 12 and of E2 during the follicular phase differed with age (P less than .05). An earlier (P less than .025) midcycle elevation of FSH was associated with an earlier rise and greater concentration of E2 (P less than .05) during the follicular phase in old than in young cows. Differences in FSH and P4, although subtle, were consistent with an earlier or more advanced follicular development in old cows, leading to greater secretion of E2 from the preovulatory follicle.  相似文献   

13.
The aim of this study was to validate a direct time-resolved fluoroimmunoassay (TR-FIA) for quantifying progesterone concentrations in milk during the bovine oestrous cycle. Holstein-Friesian and suckled and non-suckled Japanese Black cows were used to demonstrate the relationship between milk and plasma progesterone concentrations and to monitor progesterone profiles in milk and plasma during the oestrous cycle. The minimum detection level of the assay was 1.53ng/mL. Progesterone concentrations in milk and plasma changed in a similar manner throughout the oestrous cycle in dairy and beef cows, and milk and plasma progesterone profiles were significantly correlated (P<0.001). The study confirmed that a direct TR-FIA can be used to monitor the oestrous cycle in cattle and to quantify progesterone concentrations in whole milk.  相似文献   

14.
本研究以青年荷斯坦母牛为试验对象,在供体母牛发情周期的任意一天(发情当天除外),于供体牛阴道放置CIDR(孕酮的缓释装置).同时肌注Eb 2 mg和P4激素100 mg,在放置阴道栓的第五天开始按常规4天递减法肌肉注射FSH超数排卵.结果发现,应用进口FSH超排组,有23头发生卵巢囊肿,同时乳房有不同程度的发育,应用国产FSH超排组,只有3头牛发生卵巢囊肿,且其乳房并无发育.表明在超数排卵时,应根据所选药物及超排牛群内牛只个体的不同,选择适宜的超排剂量.  相似文献   

15.
This study investigates the changes in endometrial thickness between ipsilateral and contralateral uterine horns, diameter, blood flow area and hormonal concentrations in cows during natural and induced oestrus. In the induced group, six cows received a controlled internal device insert for 7 days. In the normal and induced oestrous group (n = 12), Doppler was performed day after day from day 5 till day 15. Oestradiol, progesterone and nitric oxide metabolites (NOMs) were measured. Results showed that dorsal, ventral and cross-section diameter of the ipsilateral horn increased during the induced oestrous group to reach a maximum on day 2 than during normal one. The total coloured area in both horns in a normal and induced group was also affected (p < .001), as the total coloured area in the ipsilateral horns, increased in the induced group, reach a maximum on day 2 after ovulation, while in normal it reaches a maximum on day of ovulation. Oestradiol increased during the induced cycle than during the normal one, but progesterone increased during days after ovulation reaches a higher value on day 10 in both groups. Nitric oxide showed two peaks, one on the day 3 and another peak on day 5. Conclusion: The ipsilateral uterine horn different diameters and thickness increased more rapidly in the induced oestrous group than the natural oestrus group. A complete analysis of variations in P4 and E2 concentrations and endometrial thickness suggested that decreases in P4 concentrations were related to an increase in endometrial thickness and that increases in E2 concentrations enhanced these endometrial changes.  相似文献   

16.
Several studies have clarified that the follicular cysts degenerate and are replaced by newly growing follicles that develop into new follicular cysts without ovulation, i.e., turnover of ovarian follicular cysts in cows. However, the relativity of endocrinological changes, including the inhibin profile during turnover of spontaneous follicular cysts in dairy cows, is still unclear. In the present study, the relationship between turnover of follicular cysts and changes in the peripheral blood concentrations of progesterone (P), estradiol-17beta (E(2)), luteinizing hormone (LH), follicle stimulating hormone (FSH) and inhibin were examined in lactating dairy cows. Five cows diagnosed with follicular cysts (follicles of more than 25 mm in diameter in the absence of a corpus luteum) were investigated. Their ovarian dynamics were monitored using ultrasonography, and blood samples were collected at 2- or 3- day intervals throughout the experiment. The day when a follicle fated to become a follicular cyst reached more than 8 mm in diameter was defined as the start of a cystic follicular wave. Four of the 5 cows exhibited a similar patterns of cystic follicular changes and hormone profiles. The data from the 4 cows was used for analysis of the relationships between turnover of cystic follicles and the hormone profiles. Two or three new cystic follicular waves occurred in each cow during the experimental period. The mean diameter of the cystic follicles was more than 25 mm 13 to 15 days after the start of the cystic follicular wave, and it began to decrease 1 to 6 days before the start of the subsequent cystic follicular wave. The levels of E(2) and inhibin tended to decrease for 7 to 9 days before the start of a new cystic follicular wave and to increase concomitantly with new follicular cyst growth. The levels of FSH rose for 1 to 3 days before the start of a new cystic follicular wave. The present study clarified the relationship between FSH and inhibin during turnover of spontaneous follicular cysts in dairy cows and found that it was very similar to previous results for cows. The present results suggest that an increase in FSH secretion following a reduction in inhibin secretion triggers turnover of cystic follicles in cows with spontaneous follicular cysts.  相似文献   

17.
Changes in consecutive estimates of milk progesterone concentrations and serum steroid hormone and sex hormone-binding globulin (SHBG) concentrations in the postpartum period were examined in Finnish Ayrshire and Friesian dairy cows which were divided according to feeding into a hay group and a silage group. Milk progesterone concentrations rose above 10 nmol/l, indicating the start of ovarian luteal activity, slightly earlier in the silage group (28.4 +/- 8.7 (S.D.) days, n = 19) than in the hay group (33.4 +/- 10.3, n = 28) after calving. Likewise, the first normal oestrous cycles began slightly earlier in cows fed with silage. On the other hand, no differences in the beginning of ovarian luteal activity were observed between the breeds. Serum oestradiol-17 beta, oestrone, testosterone, 5 alpha-dihydrotestosterone (5 alpha-DHT), pregnenolone and progesterone concentrations were fairly unchanged during postpartum anoestrus after uterine involution and before ovarian cyclic activity. After first ovulation, considerable increases in milk and serum progesterone concentrations were observed. The increase was accompanied by elevations in serum pregnenolone and 5 alpha-DHT concentrations. In the late luteal phase, progesterone, 5 alpha-DHT and pregnenolone concentrations rapidly declined, leading to low hormone levels in pro-oestrus. Thereafter, serum pregnenolone and 5 alpha-DHT concentrations slightly increased during the follicular phase. On the other hand, oestradiol-17 beta concentrations were elevated in pro-oestrus and decreased after that, being lowest at met-oestrous. Serum testosterone concentrations appeared to be unchanged during postpartum anoestrus and over the oestrous cycle. Serum SHBG concentrations were unchanged during postpartum anoestrus and over the oestrous cycle, as well as in pregnant animals. The serum SHBG concentrations were about double those found in women with normal menstrual cycles, whereas oestradiol concentrations were much lower. At present, it cannot be explained how the biological effects of oestradiol become evident under such conditions.  相似文献   

18.
Exogenous hormonal manipulation of ovarian activity in cattle   总被引:1,自引:0,他引:1  
To achieve precise control of the oestrous cycle in cattle it is necessary to control both the life span of the corpus luteum and the follicle wave status at the end of the treatment. Antral follicle growth in cattle occurs in distinct wavelike patterns during the ovarian cycle and the postpartum anoestrous period. The emergence of each new wave is stimulated by a transient increase in FSH. Each follicle wave has an inherent life span of 7-10 days as it progresses through the different stages of development, viz., emergence, selection, dominance and atresia or ovulation. The dominant follicle (DF) is distinguishable from other subordinate follicles by its enhanced capacity to produce oestradiol, maintenance of low intrafollicular concentrations of insulin-like growth factor binding proteins-2, -4 and -5 and follistatin and an increase in free intrafollicular concentrations of IGF-I as well as an increase in size. Three approaches can be taken to control ovarian activity and regulate the oestrous cycle in cattle: (i) use of the luteolytic agent prostaglandin F2alpha (PGF2alpha) alone or one of its potent analogues, (ii) administration of exogenous progesterone-progestagen treatments combined with the use of exogenous oestradiol or gonadotrophin releasing hormone (GnRH) to control new follicle wave emergence and shorten the life span of the corpus luteum, and (iii) prior follicle wave synchrony followed by induced luteolysis. A number of different oestrous synchronisation regimens, viz., PGF2alpha-based only, short-term progesterone with prior follicle wave synchrony using oestradiol or GnRH have been developed but the problem of obtaining good follicle wave synchrony and CL regression limit their widespread application. GnRH-prostaglandin-GnRH regimens have recently been developed for beef and dairy cows. However, their success is variable. A better understanding of the hormonal control of follicle growth is a prerequisite in order to obtain more precise control the oestrous cycle allowing one AI at a predetermined time giving high pregnancy rates without recourse to detection of oestrus.  相似文献   

19.
Contents: Superovulation in cattle: Hormonal profdes during superovulation with PMSG or pituitary FSH.: Hormonal profiles for LH, FSH, PMSG, progesterone in peripheral blood and oestrogens in urine during superovulation with PMSG (1500–3100 IU i. m.) or pituitary porcine FSH (5 mg i.m. 2 times daily for 5 days) were evaluated radioimmunologicaly. Two days after the begin of treatment luteolysis was induced by means of 0.5 mg Estrumat® i. m. The experiments were performed with 14 heifers and 2 cows. Blood samples were taken in 6 or 12 h intervals. Preovulatory LH and FSH peaks occurred coinciding with the onset o f oestrus in good responding animals instead of a few hours later, as in weakly responding animals or during normal oestrous cycle. PMSG could be still measured in peripheral blood 10 days after application. Preovulatory gonadotropin peaks are preceded in good responding animals by clear oestrogen peaks contrary t o weak responding ones. Progesterone concentrations of good responding animals increase faster after the preouulatory LH peak and reach higher absolute values compared t o bad responding ones or during normal oestrous cycle. Furthermore there was a clear difference in progesterone values between both stimulation methods. Progesterone concentrations after induction of superovulation with PMSG are significantly higher f o r about the same number of corpora lutea as after stimulation with pituitary FSH. For judgement of the success of stimulation the determination of progesterone can be considered as parameter. From the hormonal profiles no conclusion can be drawn why some animals don't respond to the stimulation.  相似文献   

20.
This experiment was conducted to 1) determine whether chronic cystic-ovarian-diseased (CCOD) cows fail to respond to luteinizing hormone (LH) treatment because of a lack of adequate ovarian LH receptors and 2) determine the effect of follicle stimulating hormone (FSH) treatment on ovarian LH and FSH receptors in ovaries of CCOD cows. The CCOD cows were those that did not resume cyclic ovarian activity after repeated treatment with human chorionic gonadotropin (hCG) and(or) LH-releasing hormone (LHRH) and were considered chronic by veterinarians. Thirteen CCOD cows were purchased from producers; six of them were injected with 5 mg FSH twice daily for 3 or 5 d (TCCOD) and the remaining seven remained untreated. Seven control (noncystic) cows in the luteal phase of the estrous cycle were injected with Lutalyse approximately 48 to 50 h before slaughter so they would be in the follicular phase (FP) of the cycle at the time of slaughter. Analysis of serum and pituitaries showed no differences (P greater than .05) in mean concentrations of serum or pituitary LH and FSH or pituitary LHRH receptor concentration and affinity among FP, CCOD and TCCOD cows. Ovarian follicle wall concentrations of receptors for LH (3.2 +/- .6; 13.0 +/- 2.5; 22.4 +/- 5.1 fmol/mg protein) and FSH (10 +/- 2.6; 43 +/- 7.2; 29 +/- 6.7 fmol/mg protein) were lower (P less than .05) in CCOD cows compared with FP and TCCOD cows, respectively. The same pattern was observed for concentrations of granulosa cell LH and FSH receptors.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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