Increased production of sheep embryos following superovulation of Merino ewes with a combination of pregnant mare serum gonadotrophin and follicle stimulating hormone

1991 ◽  
Vol 3 (5) ◽  
pp. 551 ◽  
Author(s):  
JP Ryan ◽  
JR Hunton ◽  
WM Maxwell
Keyword(s):  
Follicle Stimulating Hormone ◽  
Ovarian Response ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Embryo Recovery ◽  
Designed Experiment ◽  
The Mean ◽  
Mean Concentration ◽  
Pregnant Mare Serum Gonadotrophin ◽  
Stimulating Hormone

In a factorially designed experiment (N = 321), 0, 800 or 1600 I.U. pregnant mare serum gonadotrophin (PMSG) were administered in combination with 0, 12 or 18 mg follicle stimulating hormone (FSH-P) to superovulate Merino ewes in autumn and spring. A moderate dose of PMSG (800 I.U.) in conjunction with 12 or 18 mg FSH-P increased the ovulation rate above that observed when FSH-P was used alone. This was accomplished by (i) increasing the proportion of ewes that exhibited a superovulatory response (greater than 3 corpora lutea (CL) or persistent large follicles (LF): 69/70 (99%) v. 55/74 (74%), P less than 0.001), and (ii) in those ewes that exhibited a superovulatory response, by an additive effect of exogenous gonadotrophin (14.8 +/- 0.9 CL (69) v. 11.3 +/- 0.9 CL (55), P less than 0.01) without increasing the incidence of LF. The use of 1600 I.U. PMSG in conjunction with 12 or 18 mg FSH-P was characterized by an increase in the number of LF and, in comparison with 800 I.U. PMSG, a reduction in ovulation rate. Season had no effect on the numbers of CL, but total ovarian response (CL + LF) was higher in autumn than in spring (P less than 0.01), because of a greater incidence of LF (P less than 0.001). The proportion of ewes with regressed CL was higher in autumn than in spring (53/143 (37%) v. 32/156 (21%), P less than 0.01), and increased with increased dose of gonadotrophin. Furthermore, a nutritional component to the incidence of ewes with regressed CL was suggested by the observation that the mean concentration of plasma glucose was higher for ewes with normal CL than for ewes with regressed CL (P less than 0.05). Rates of ova or embryo recovery, fertilization and embryo development generally declined with an increase in the incidence of LF as a result of increases in the dose of gonadotrophin and season of administration.

407 SUPERSTIMULATORY RESPONSE WITH DECREASING DOSES OF FOLLICLE-STIMULATING HORMONE v. A SINGLE DOSE OF FOLLICLE-STIMULATING HORMONE - EQUINE CHORIONIC GONADOTROPIN DURING BREEDING AND NONBREEDING SEASON IN SHEEP

2010 ◽  
Vol 22 (1) ◽  
pp. 360
Author(s):  
M. I. Cueto ◽  
F. Pereyra-Bonnet ◽  
P. Silvestre ◽  
A. E. Gibbons
Keyword(s):  
Single Dose ◽  
Breeding Season ◽  
Recovery Rate ◽  
Follicle Stimulating Hormone ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Nonbreeding Season ◽  
Embryo Recovery ◽  
The One ◽  
Stimulating Hormone

The aim of the study was to assess possible variations in superovulatory yields due to different FSH treatments at 2 times of the year. Superovulation and embryo recovery were performed during the breeding (n = 63) andnonbreeding (n = 46) seasons in Merino ewes located at 41°S latitude. Animals were kept under the same conditions, housed outdoors in a sheltered and covered pen, and were fed a liveweight maintenance ration. All animals received 60-mg medroxyprogesterone acetate intravaginal sponges (Progespon®, Syntex, Buenos Aires, Argentina) for 14 days. Ewes were then randomly assigned to 2 different superovulatory treatments: classic (n = 74) and one shot (n = 35) in both seasons. Classic superovulatory treatment consisted of 7 decreasing doses (2 × 48 mg, 2 × 24 mg, 2 × 20 mg, and1 × 16 mg NIH-FSH-P1)ofFSH (Folltropin®-V, Bioniche, Belleville, Ontario, Canada), administered twice daily from 48 h before to 24 h after pessary removal. A dose of eCG (300 IU; Novormon®, Syntex) was administered at progestagen removal. One shot superovulatory treatment consisted of a single dose of FSH (70 mg NIH-FSH-P1) plus 300 UI of eCG injected at pessary withdrawal. Embryo donors were inseminated by laparoscopy with frozen-thawed semen (100 × 106 spz) 12 h after the onset of estrus. Surgical embryo recovery was done on Day 7 after sponge withdrawal and embryos were graded for quality according to morphology (Grade 1 = excellent or good; Grade 2 = fair; Grade 3 = poor; and Grade 4 = dead or degenerated; IETS 1998). A 2 × 2 factorial ANOVA was used to test the main effects (season and superovulatory treatment) and interactions. There were no significant differences in the proportion of responding ewes (>3 corpora lutea), ovulation rate, and recovered Grades 1 to 2 embryos between the breeding and nonbreeding season (Table 1; P > 0.05). However, number of recovered ova/embryos and ova/embryo recovery rate were higher during the breeding season compared with the nonbreeding season, whereas the percentage of nonfertilized ova was lower in the breeding season than in the nonbreeding season (P < 0.05). Analysis of data comparing superovulatory treatments showed that the proportion of responding ewes, ovulation rate, recovered embryos, and recovered Grades 1 to 2 embryos were lower for the one shot treatment than for the classic treatment (P < 0.05). Embryo recovery rate and nonfertilization rate did not differ between treatments (P > 0.05). It was concluded that there was an increase in the number of total recovered ova/embryos during the breeding season compared with the nonbreeding season, although the number of recovered good-quality embryos was not affected. The use of multiple FSH injections produced a higher number of total recovered and viable embryos in Merino sheep than the one shot superovulatory treatment. Table 1.Embryo yields in ewes submitted to superovulation

MAINTENANCE OF PREGNANCY RELATIVE TO THE PRESENCE OF FEW EMBRYOS IN THE RABBIT

1970 ◽  
Vol 48 (2) ◽  
pp. 243-249 ◽  
Author(s):  
C. E. ADAMS
Keyword(s):  
Pregnancy Rate ◽  
Follicle Stimulating Hormone ◽  
Uterine Horn ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
The Mean ◽  
Stimulating Hormone

SUMMARY Either one or two 60-h morulae were transferred to one uterine horn of Polish, Dutch or Strain A rabbits in which the mean number of ovulations was 4·3, 6·4 and 10·8. The pregnancy rate, as determined by palpation on day 10, varied from 45–65% (mean 53%) in recipients of one egg to 69–71% with two eggs. Only 20% of the does carrying one foetus maintained pregnancy to term compared with 87% of those with two implants. If pregnancy failed this usually occurred between days 15 and 20. In a further experiment, in which additional eggs were transferred to the contralateral horn, it was shown that all single conceptuses were inherently capable of surviving to term. It is concluded that irrespective of breed and ovulation rate, two conceptuses are normally required to prevent regression of corpora lutea on about day 17. Treatment with follicle-stimulating hormone in mid-pregnancy or removal of the barren uterine horn on day 13 failed to maintain pregnancies involving only one conceptus.

THE RELATION BETWEEN NATURAL FECUNDITY AND RESPONSE TO FOLLICLE-STIMULATING HORMONE

1962 ◽  
Vol 25 (1) ◽  
pp. 137-144 ◽  
Author(s):  
ANNE McLAREN
Keyword(s):  
Artificial Selection ◽  
Response Curve ◽  
Follicle Stimulating Hormone ◽  
Ovarian Response ◽  
Ovulation Rate ◽  
The Other ◽  
Principal Effect ◽  
Low Levels ◽  
Selection For ◽  
Stimulating Hormone

SUMMARY A study was made of the response to induced ovulation of female mice from strains in which the spontaneous ovulation rate had increased as a result of artificial selection for litter size. In response to standard doses of follicle-stimulating hormone (FSH) within the physiological range, the number of eggs shed differed significantly among the three strains tested, in the direction expected on the basis of their spontaneous ovulation rates. This indicates that the principal effect of selection has been to increase the sensitivity of the ovary to FSH. In one strain, the possibility remains open that there may also have been some increase in the amount of FSH available. In response to larger doses of FSH, females from the strain with the highest spontaneous ovulation rate shed significantly fewer eggs than the other two groups. Selection must therefore have altered the shape of the dose-response curve, increasing the ovarian response at low levels of hormone and decreasing it at high levels.

Ovulation rate and survival of fertilized ova in Merino ewes selected for and against multiple births

1972 ◽  
Vol 23 (5) ◽  
pp. 851 ◽  
Author(s):  
AO Trounson ◽  
NW Moore
Keyword(s):  
Ovulation Rate ◽  
The Other ◽  
Multiple Births ◽  
Corpora Lutea ◽  
Significant Difference ◽  
The Mean ◽  
Selection Group ◽  
Pregnant Mare Serum Gonadotrophin

Peppin Merino ewes selected for (T group) and against (0 group) multiple births over a number of generations were used in an experiment designed to study the effect of selection on ovulation rate, response to exogenous gonadotrophin (1300 i.u. pregnant mare serum gonadotrophin—PMSG), and their ability to support one or more embryos of their own or the other group. Fertilized eggs, collected following treatment of donors with PMSG, were transferred within and between groups at a rate of one and three per recipient. Recipients were not treated with PMSG. The mean ovulation rates of T and 0 recipients were 2.03 and 1.13, and the mean ovulatory response to PMSG of T ewes was almost 50 % greater than that of O ewes (4.76 v. 3.29 corpora lutea). The survival to birth of transferred eggs was affected by both the selection group of the egg and the selection group of the recipient, and by the number of eggs transferred. More O than T recipients lambed (77 % v. 45 %); and within O recipients, intergroup transfers were more successful than intragroup transfers (94 % v. 54% ewes lambed). A similar but not significant difference was observed in T group recipients (54% v. 38% lambed). Where three eggs were transferred, neither the selection group of the recipient nor that of the egg had any effect upon the incidence of multiple births. It is concluded that selection has operated primarily on ovulation rate, and there was some evidence of heterosis in intergroup transfers.

SERUM FOLLICLE-STIMULATING HORMONE, LUTEINIZING HORMONE AND PROGESTERONE CONCENTRATIONS IN PSEUDOPREGNANT RATS TREATED WITH MEDROXYPROGESTERONE ACETATE

1976 ◽  
Vol 70 (3) ◽  
pp. 465-471 ◽  
Author(s):  
W. J. DE GREEF ◽  
J. DULLAART ◽  
G. H. ZEILMAKER
Keyword(s):  
Luteinizing Hormone ◽  
Medroxyprogesterone Acetate ◽  
Follicle Stimulating Hormone ◽  
Corpora Lutea ◽  
Progesterone Concentration ◽  
Vaginal Smears ◽  
The Mean ◽  
And Control ◽  
Stimulating Hormone

SUMMARY Pseudopregnant rats were treated early in pseudopregnancy with 1 or 10 mg medroxyprogesterone acetate (MPA). Serum FSH, LH and progesterone concentrations were determined on days 2–20 of pseudopregnancy in treated and control rats. The mean duration of pseudopregnancy was 13·5 days in the control animals, but when animals were treated with 1 mg MPA a dioestrous period of 21·4 days was observed. A period with leucocytic vaginal smears of at least 2 months was observed after treatment with 10 mg MPA. Injection with MPA on day 3 of pseudopregnancy did not affect the serum FSH concentrations during the subsequent days. The progesterone pattern was alike in the three groups of animals, i.e. the duration of the activity of the corpora lutea was similar in all groups. However, 10 mg MPA slightly lowered progesterone concentrations on days 4–8 of pseudopregnancy. In the saline-treated rats, LH concentrations decreased from days 2–5, and remained low until they increased after day 11 of pseudopregnancy. This increase was delayed until day 20 in the animals treated with 1 mg MPA, and was not observed in the animals treated with 10 mg MPA. It is argued that the increase of LH concentration at the end of pseudopregnancy is not instrumental in the decrease of peripheral progesterone concentration but rather that the decrease in the progesterone concentration leads to the increase in the LH concentration.

Successful embryo transfer following artificial insemination of superovulated fallow deer (Dama dama)

1994 ◽  
Vol 6 (2) ◽  
pp. 181 ◽  
Author(s):  
HN Jabbour ◽  
VS Marshall ◽  
CM Argo ◽  
J Hooton ◽  
AS Loudon
Keyword(s):  
Ovarian Response ◽  
Fallow Deer ◽  
Corpora Lutea ◽  
Dama Dama ◽  
Cell Stage ◽  
Embryo Recovery ◽  
Dama Mesopotamica ◽  
Morula Stage ◽  
The Mean ◽  
Follicular Response

Thirty-four European fallow deer (Dama dama dama) were randomly allocated into embryo donor (n = 12) or embryo recipient (n = 22) groups. All does were treated with controlled internal drug release (CIDR) devices for 14 days. Animals in the embryo donor group were further treated with 200 I.U. pregnant mare serum gonadotrophin (PMSG) and 0.5 units ovine follicle-stimulating hormone (FSH). PMSG was administered 72 h before withdrawal of CIDR devices and FSH was given in eight 0.063 unit injections at 12-hourly intervals starting at the time of PMSG administration. All embryo donor animals were inseminated, by laparoscopy in both uterine horns, 36 h after withdrawal of CIDR devices with 25 x 10(6) fresh spermatozoa collected from Mesopotamian fallow deer (Dama dama mesopotamica). Embryos were recovered by laparotomy on Day 3 (n = 6) or Day 6 (n = 6) after withdrawal of CIDR devices and the ovarian response was determined. In total, 22 embryos were transferred into the oviduct (2-4-cell stage, n = 14) or uterine horn (morula stage, n = 8) on Day 3 or Day 6 after withdrawal of CIDR devices respectively. The overall means (+/- s.e.m.) of total follicular response and corpora lutea were 24.2 +/- 3.5 and 14.1 +/- 3.6 respectively. The mean number of large unruptured follicles was higher on Day 6 than on Day 3 (13.5 +/- 2.9 v. 6.7 +/- 1.3, P < 0.05). The overall embryo recovery rate was 45.8%. There was no difference in pregnancy rate following transfer of embryos on either Day 3 or Day 6 (7/14 v. 5/8 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of lupin (Lupinus angustifolius) supplementation on ovarian and pituitary activity in ewes

1991 ◽  
Vol 3 (1) ◽  
pp. 109 ◽  
Author(s):  
BH Pearse ◽  
NP McMeniman ◽  
KF Dowsett
Keyword(s):  
Direct Effect ◽  
Anterior Pituitary ◽  
Follicle Stimulating Hormone ◽  
Nutrient Status ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Releasing Hormone ◽  
Gonadotrophin Releasing Hormone ◽  
Pregnant Mare Serum Gonadotrophin ◽  
Maintenance Ration

In each of three experiments, thirty seasonally anoestrous Border Leicester ewes were fed on a maintenance ration of oaten chaff. Fifteen of them were given a supplement of 500 g lupin grain per head per day. The ewes were treated with 10 mg follicle stimulating hormone (Expt 1), 600 I.U. pregnant mare serum gonadotrophin (Expt 2) and either 150 or 300 micrograms gonadotrophin releasing hormone (Expt 3) to determine whether the ovaries and/or the anterior pituitary were capable of responding to the nutrient status of the animals and influencing ovulation rate. In each experiment, the number and size of corpora lutea and follicles in the lupin-supplemented and -unsupplemented groups were similar. It was concluded that the mechanism by which lupins increase the ovulation rate is probably neural and not a result of direct effect on either the pituitary or the ovaries.

Relationships between follicle-stimulating hormone, follicle growth and ovulation rate in sheep

1996 ◽  
Vol 8 (2) ◽  
pp. 279 ◽  
Author(s):  
RC Fry ◽  
MA Driancourt
Keyword(s):  
Follicle Stimulating Hormone ◽  
Follicular Phase ◽  
Oestrous Cycle ◽  
Ovulation Rate ◽  
Follicle Growth ◽  
Group I ◽  
Group 3 ◽  
Group 2 ◽  
Group 1 ◽  
Stimulating Hormone

The changes in follicle-stimulating hormone (FSH) concentration required to affect follicle growth and ovulation rate within individual ewes were examined. Relationships between peripheral FSH concentrations during the late-luteal and follicular phase and subsequent ovulation rates were investigated in 22 ewes from 4 breeds over 3 successive cycles (Experiment 1). Ewes were grouped as follows: Group 1 (n = 6), ewes exhibiting the same ovulation rate at each oestrous cycle: Group 2 (n = 5), ewes with three different ovulation rates at each oestrous cycle; and Group 3 (n = 11), ewes with the same ovulation rate at two oestrous cycles and a different ovulation rate on one occasion. Data from ewes in Group 1 and 3 provided estimates on the variation in FSH concentrations between cycles which were not large enough to alter ovulation rate (range, 0-67% variation in FSH concentration). In Group-2 ewes, there was no consistent association between increases in ovulation rate and the proportional increases in FSH concentrations. Differences in FSH concentrations were often less than those that did not alter ovulation rate in Group-I ewes. Furthermore, only 3 of 11 Group-3 ewes demonstrated high FSH concentrations associated with high ovulation rate (or low FSH concentrations and low ovulation rate) when compared with the concentrations found at the two cycles in which ovulation rate was similar. Hence, there was little evidence that FSH concentrations during the late-luteal and follicular phase are associated with changes in ovulation rate within individual ewes. In Experiment 2, follicles of similar size obtained from the same ewe (FecBFec+ and Romanov) showed markedly different responses in vitro to graded doses of FSH as measured by aromatase activity. It is concluded that, within a ewe, the large variability between gonadotrophin-dependent follicles in their requirement for FSH prevented the expression of any thresholds of ovarian response to FSH.

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