226 Effect of the presence or absence of corpus luteum in females with small antral follicles at the beginning of a progesterone-based oestrus synchronization protocol on superovulatory response and embryo yields in sheep

2020 ◽  
Vol 32 (2) ◽  
pp. 241
Author(s):  
M. S. D. Lima ◽  
G. B. Vergani ◽  
K. M. Silva ◽  
A. W. U. Monteiro ◽  
L. M. C. Pereira ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Animal Health ◽  
Cervical Dilation ◽  
Antral Follicles ◽  
Embryo Recovery ◽  
Multiple Ovulation ◽  
Flunixin Meglumine ◽  
Oestradiol Benzoate ◽  
Intravaginal Device ◽  
Synchronization Protocol

The high variability of responses to multiple ovulation and embryo transfer (MOET) programs is related to several factors, including the ovarian population present at the beginning of hormonal protocols. Thus, our objective was to evaluate the effect of the presence or absence of corpus luteum (CL) in females presenting small antral follicles (SF) at the beginning of a progesterone (P4)-based oestrus synchronization protocol on superovulatory response and embryo yields. The study was conducted during September and October in northeast Brazil (03°40′26″S and 40°14′20″W) using 15 adult Santa Inês ewes, in which the ovarian population present were SF (≤3.75mm, n=5) or SF plus CL (SF+CL, n=10) at the beginning of P4-based oestrus synchronization protocol. The females received a new or reused intravaginal device of progesterone (CIDR Eazi-breed, Zoetis) on Day 0, which remained for 9 days. On Day 7, the pFSH (133mg, Folltropin V, Vetoquinol) treatment was begun, with 6 decreasing doses (25, 25, 15, 15, 10, and 10%) injected IM at 12-h intervals. On Day 9, two equal doses of D-cloprostenol were injected at a 12-h interval (37.5μg, Prolise, Agener União). Flunixin meglumine (24.9 mg; Banamine, MSD Animal Health) was administered IM on Days 13 to 15. All ewes showed oestrus and were mated with fertile rams. On Day 16 non-surgical embryo recovery (NSER) was performed after cervical dilation using D-cloprostenol and oestradiol benzoate at 16h and ocytocin at 20min before. Transrectal B-mode ultrasound evaluations (Z5 Vet, Mindray) were performed on Day 0 and just before NSER to evaluate the ovarian population present. Data are showed in mean±s.d. and compared by t-test for independent samples (P<0.05). The number of CL present on NSER day (21.5±4.4 and 4.0±8.5) and the number of viable embryos (11.1±14.9 and 4.0±8.5) differed (P<0.05) between SF+CL ewes and SF ewes, respectively. However, the number of luteinizing unovulated follicles present on NSER day (4.5±2.5 and 12.4±7.8) and the number of recovered structures (i.e. embryos plus unfertilized eggs; 14.2±15.6 and 4.2±8.2) did not differ (P>0.05) between SF+CL ewes and SF ewes, respectively. In conclusion, the presence of a CL at the beginning of the oestrous synchronization protocol used for superovulation treatment affects responses to the MOET program. Financial support for this study was provided by Embrapa (02.13.06.026.00.02 and 02.13.06.026.00.04) and FAPEMIG (PPM 00201-17).

227 Is the antral follicle count on a random day of the oestrous cycle correlated with superovulatory responses in Santa Inês ewes?

2020 ◽  
Vol 32 (2) ◽  
pp. 241
Author(s):  
M. Pupin ◽  
G. Vergani ◽  
M. Lima ◽  
K. Silva ◽  
A. Monteiro ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Animal Health ◽  
Antral Follicle ◽  
Antral Follicle Count ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Embryo Recovery ◽  
Flunixin Meglumine ◽  
Santa Inês ◽  
Synchronization Protocol

Antral follicle count (AFC) performed after an oestrus synchronization protocol has been studied as a tool to select ewes with high potential for invivo embryo production (Pinto et al. 2018 Theriogenology 113, 146-152). However, it would be interesting to know whether AFC assessed on a random day of the oestrous cycle correlates with the superovulatory response. The present study was conducted to evaluate the correlation between AFC at the beginning of progesterone (P4)-based oestrus synchronization protocol used as basis of superovulatory treatment and the number of corpora lutea (CL) 12h before recovery of embryos in Santa Inês ewes. The study was conducted during September and October in northeast Brazil (03°40′26″S and 40°14′20″W) using 8 adult Santa Inês ewes. On a random day of oestrous cycle (Day 0) all ewes received an intravaginal device (CIDR) of progesterone (0.3g, Eazi-breed, Zoetis), which remained for 9 days. On Day 7, the pFSH (133mg, Folltropin V, Vetoquinol) treatment began, with 6 decreasing doses (25, 25, 15, 15, 10, and 10%) injected IM at 12-h intervals. On Day 9, 2 equal doses of D-cloprostenol were injected at a 12-h interval (37.5µg, Prolise, Agener União). All ewes showed oestrus and were mated by fertile rams. Flunixin meglumine (24.9 mg; Banamine, MSD Animal Health) was administered IM on Days 12, 13, and 15. On Day 16, non-surgical embryo recovery (NSER) was performed after cervical dilation using D-cloprostenol and oestradiol benzoate at 16h and oxytocin 20min before. Transrectal B-mode ultrasound evaluations (Z5 Vet, Mindray), frequency 7.5MHz, were performed on Day 0 and 7 and 12h before NSER to evaluate the ovarian population present. Pearson correlation analysis (P<0.05) was performed using Bioestat 5.3 software. The number of AFC per ewe at the beginning of the protocol and on Day 7 were 9.9±2.7 and 11±3.2, respectively. The numbers of CL, recovered embryos, and viable embryos were 14.0±3.5, 8.2±10.9, and 6.0±11.0, respectively. There was no correlation of AFC on a random day of oestrous cycle with the number of AFC on Day 7 (P=0.42), number of corpora lutea (P=0.44), number of recovered embryos (P=0.18), or number of viable embryos (P=0.11) in superovulated ewes. In conclusion, we did not find significant correlations between AFC on a random day of oestrous cycle and the superovulatory/embryos response in Santa Inês ewes. Financial support for this study was provided by Embrapa (02.13.06.026.00.02 and 02.13.06.026.00.04) and FAPEMIG (PPM 00201-17).

225 Evaluation of superovulatory response in Brazilian native sheep by B-mode ultrasonography

2020 ◽  
Vol 32 (2) ◽  
pp. 240
Author(s):  
G. B. Vergani ◽  
M. S. D. Lima ◽  
K. M. Silva ◽  
A. W. U. Monteiro ◽  
A. F. Ramos ◽  
...  
Keyword(s):  
Recovery Rate ◽  
Pearson Correlation ◽  
Animal Health ◽  
Device Removal ◽  
Embryo Recovery ◽  
Flunixin Meglumine ◽  
Ultrasound Evaluation ◽  
Release Device ◽  
Linear Probe ◽  
Santa Inês

The objective of this study was to evaluate the correlation between the number of corpora lutea (CL), as determined by B-mode ultrasonography, and the total number of structures recovery by non-surgical embryo recovery (NSER) from superovulated ewes. Somali (n=18), Santa Inês (n=18), and Morada Nova (n=16) ewes received an intravaginal device with progesterone (0.33g, controlled internal drug release device, CIDR, Zoetis), which was maintained for 9 days. The superovulatory protocol started 60h before device removal, with 6 decreasing doses (25, 25, 15, 15, 10, and 10%) of p-FSH (IM 133mg, Folltropin V, Vetoquinol) injected every 12h. D-Cloprostenol (IM 37.5μg, Prolise, Agener Union) was injected 12h before and at the moment of device removal. Ewes in oestrus were mated by fertile male rams three times after the onset of oestrus with a 12-h interval. Flunixin meglumine (24.9 mg; Banamine, MSD Animal Health) was injected IM on Days 12, 13, and 15. One day before NSER, B-mode ultrasound evaluations were performed using portable equipment (Z5 Vet, Mindray) with a stiffened multifrequency linear probe to evaluate the number of structures present in the ovaries. Embryo recovery was performed 7 days after progesterone CIDR removal (Day 16). The number of CL and the number of recovered structures were determined and their association evaluated using the Pearson correlation test (P<0.05). Only 17 Somali, 16 Santa Inês, and 15 Morada Nova ewes were submitted to NSER; the other 4 ewes could not be flushed because of low cervical dilation or cervical puncture. After B-mode ultrasound evaluation, 168, 217, and 131 CL were observed, with an average of 9.9 (range: 1 to 12), 13.5 (range: 2 to 47), and 8.7 (range: 3 to 18) CL per donor for Somali, Santa Inês, and Morada Nova ewes, respectively. The recovery rates (i.e. structures recovered by the number of CL counted) were 60.1% (101/168), 96.3% (209/217), and 103.5% (135/131) for the 3 breeds, respectively. There was a positive correlation (r=0.69; P<0.01) between the number of recovered structures and number of CL. Those findings confirm results from other studies, in which the recovery rate varied from 35 to 91%. In some cases, recovery rate can be overestimated because of the difficulty in quantifying CL. In conclusion, B-mode ultrasonography can be used to estimate superovulatory response in ewes and thus as a criterion to decide whether a donor will undergo embryo flushing. Financial support for this study was provided by Embrapa (02.13.06.026.00.04) and Fapemig (CVZ-PPM 00201-17).

226 INCLUSION OF BOVINE SOMATOROPIN ON MULTIPLE-OVULATION EMBRYO TRANSFER TREATMENTS FOR LOW-RESPONDING BEEF DONOR COWS

2012 ◽  
Vol 24 (1) ◽  
pp. 225
Author(s):  
S. Kmaid ◽  
J. M. Saldaña ◽  
Z. Ramos ◽  
R. Ungerfeld
Keyword(s):  
Animal Health ◽  
Control Treatment ◽  
Embryo Production ◽  
Multiple Ovulation ◽  
Oestradiol Benzoate ◽  
Pfizer Animal Health ◽  
Universal Laboratory ◽  
To Receive ◽  
Test Treatment ◽  
Donor Cows

An experiment was designed to determine if embryo production of Angus donors could be improved by including a single dose of bovine somatotropin (bST) before starting the superovulatory treatment (SPO). Thirty-three multiparous Angus cows (body condition = 4.6 ± 0.6, range = 1–8) were submitted to 2 SPO treatments at random stages of the oestrous cycle in a crossover design (60 days apart). On Day 0, cows were divided at random to receive either 500 mg of bST (n = 18; Lactotropin, Elanco Saude Animal, Brasil) or remain without bST (control, n = 15). At the same time, all cows received 2 mg of oestradiol benzoate, 50 mg of progesterone and a CIDR (Pfizer Animal Health, Uruguay). On Day 2, all cows received 200 IU of eCG (Inducel, Universal Laboratory, Uruguay) and on Day 4 were superstimulated with 425 IU of FSH (Pluset, Calier, Spain) in twice-daily decreasing doses over 4 days. On Day 6, all cows received 2 doses (a.m. and p.m.) of a PGF analogue (800 μg, Delprostenate, Glandinex, Universal Laboratory, Uruguay) and the CIDRs were removed in the morning of Day 7. Cows were injected with 10 μg of GnRH (Receptal, Intervet, the Netherlands) on Day 8 (a.m.) and were inseminated 12, 24 and 36 h later. On Day 15, ova/embryos were collected nonsurgically and evaluated in accordance to IETS guidelines. For statistical analysis, cows were categorized according to the number of transferable embryos obtained in control treatment (without bST) in terciles: low-responding cows (LR, ≤6; n = 11), middle-responding cows (7–9, n = 12), or high-responding cows (HR ≥ 10; n = 10). Data were analysed by a paired t-test. Treatment with bST increased the total ova and embryos and the number of transferable embryos in LR cows (Table 1). However, the number of transferable embryos and the percentage of transferable embryos werereduced in HR cows. The inclusion of a single bST dose 4 days before initiating SPO with FSH treatments may be a useful alternative to improve embryo production in low-responding cows. Table 1.Response of low-responding and high-responding Angus cows to superovulatory treatments with or without bST (mean ± SD)

365 THE EFFECT OF ADMINISTERING PROGESTERONE AND ESTRADIOL PRIOR TO eFSH ON THE SUPEROVULATORY RESPONSE OF MARES

2006 ◽  
Vol 18 (2) ◽  
pp. 290 ◽  
Author(s):  
N. Logan ◽  
P. McCue ◽  
M. Alonso ◽  
E. Squires
Keyword(s):  
Embryo Quality ◽  
Animal Health ◽  
T Test ◽  
Exact Test ◽  
Embryo Recovery ◽  
Multiple Ovulation ◽  
Fisher’S Exact Test ◽  
Good For ◽  
Group 2 ◽  
Group 1

eFSH has been used to induce multiple ovulation in cycling mares. However, the response to eFSH is variable. Generally, eFSH is initiated 5 to 7 days after ovulation at a time when the follicular population on the ovaries may be variable. The objective of this study was to determine whether administration of progesterone and estradiol for 10 days prior to eFSH (Bioniche Animal Health, Athens, GA) would enhance the response to eFSH administration. Thirty normal cycling mares were assigned to 1 of 2 groups. Group 1: Control eFSH treatment - mares were examined daily with ultrasonography beginning 5 days after ovulation. Once the follicles in these mares reached 20 to 25 mm in size, eFSH treatment (12.5 mg, i.m.) was administered twice a day. Cloprostenol (Schering-Plough, Union, NJ, USA) treatment (250 �g) was administered on the second day of eFSH treatment. eFSH treatment continued until the majority of the cohort of follicles reached e35 mm. Treatment was stopped and after approximately 36 h hCG (2500 IU, i.v.; Chorulon; Intervet, Millsboro, MD, USA) was administered. Group 2: Injectable progesterone + estradiol (150 mg of progesterone and 10 mg of estradiol; P+E) treatment was initiated in diestrus (5 to 7 days post-ovulation) for 8 mares and in early estrus for 7 mares in this group. Injectable progesterone was continued for 10 days and Cloprostenol (250 �g) was administered on Day 10. Mares were then examined daily with ultrasonography and, once they had acquired 20- to 25-mm follicles, eFSH treatment was initiated. Twice-daily injections of eFSH (12.5 mg, i.m.) were continued until a majority of the cohort of follicles was e35 mm. hCG was administered approximately 36 h later. All mares were inseminated with 1 billion progressively motile spermatozoa from one of two stallions on the day of hCG administration and on the following day with cooled semen (1 billion progressively motile spermatozoa) from the same stallion. Data were analyzed by t-test and Fisher's Exact Test. The number of days of eFSH treatment was similar for the P+E (2) vs. the control (1) group (4.2 � 2.0 vs. 4.9 � 1.3 days, respectively). However, the number of ovulations induced in response to eFSH was greater for mares in the eFSH control (1) group (5.6 � 2.0) than for those in the P+E (2) group (3.0 � 1.9). Embryo recovery per flush was also greater for eFSH control (1) mares (2.7) vs. P+E (2) mares (1.1). Embryo quality was excellent or good for all embryos in both groups. Seventy-three percent of the mares (11 of 15) in both groups gave at least one embryo at each recovery attempt. However, more mares in the eFSH control (1) group gave two or more embryos (60%) compared to those in the P+E (2) group (20%). In summary, treatment of mares with P+E prior to eFSH treatment resulted in fewer ovulations, fewer embryos recovered, and fewer mares providing e2 embryos. Thus, there was no advantage in pretreating mares with P+E prior to eFSH treatment.

230 SUPEROVULATORY RESPONSE OF BEEF COWS WITH OR WITHOUT A CORPUS LUTEUM AT THE TIME OF INSERTION OF A PROGESTERONE RELEASING DEVICE

2012 ◽  
Vol 24 (1) ◽  
pp. 227
Author(s):  
A. Tríbulo ◽  
J. Garzón ◽  
H. Tríbulo ◽  
R. Tríbulo ◽  
D. Rogan ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Mixed Models ◽  
Animal Health ◽  
Treatment Protocol ◽  
Random Variable ◽  
Beef Cows ◽  
Embryo Production ◽  
Transfer Programs ◽  
Intravaginal Device ◽  
Donor Cows

Commercial embryo transfer programs require frequent superovulation of embryo donors. Although early reports suggested that donor cows require 60 to 90 days to recover from superovulation, recent information suggests that this interval could be reduced to 25 to 30 days. Because donor cows reovulate at variable intervals after embryo collection, some donors do not have an ultrasonically detectable corpus luteum (CL) when frequent superovulation programs are initiated. A retrospective study was performed to evaluate the influence of the presence of a CL at the time of initiating treatments on superovulatory response of beef donors that had been previously collected once and then were collected every 28 to 35 days 2 or 3 times. The data were from 190 collections performed in 48 Angus, 36 in 10 Brangus and 74 in 20 Bonsmara donors. On Day 0, all cows were ultrasonically examined for the presence of a CL (Falco 100 Vet, 8-MHz transducer, Pie Medical, the Netherlands) and were treated with 5 mg of oestradiol-17β and 50 mg of progesterone IM and a progesterone-releasing intravaginal device (Cue-Mate, Bioniche Animal Health, Belleville, Ontario, Canada). On Day 4, donors were superstimulated with Folltropin-V (Bioniche Animal Health), in twice-daily injections over 4 days or diluted in 20 mg mL–1 hyaluronan and given by a single IM injection. Folltropin-V dosages used were 300 or 400 mg (Angus), 260 or 300 mg (Brangus), or 200 or 300 mg (Bonsmara). On Day 6, all cows received 2 doses of PGF2α 12 h apart and Cue-Mates were removed in the p.m. In the a.m. of Day 8, cows received 12.5 mg pLH (Lutropin-V; Bioniche Animal Health) and were inseminated 12 and 24 h later. Ova/embryos were collected nonsurgically on Day 15 and evaluated following IETS guidelines. For each breed, superovulatory response (i.e. mean number of CL) and embryo data were evaluated by ANOVA for mixed models, using CL, FSH dose and treatment as fixed variables and cow identification as a random variable. Forty-six (24.2%) Angus donors, 4 (11.1%) Brangus donors and 5 (6.8%) Bonsmara donors did not have a CL at the time of initiating FSH treatment. There was no significant effect of FSH dose or treatment protocol on superovulatory response and the presence or absence of a CL did not influenced embryo production (P > 0.31). Mean (± SEM) number of CL, ova/embryos and transferable embryos were 13.2 ± 0.5, 12.4 ± 0.7 and 6.1 ± 0.4 in Angus donors with a CL vs 13.0 ± 0.7, 11.5 ± 0.9 and 5.6 ± 0.7 for those without a CL (P > 0.37); 14.8 ± 1.2, 14.2 ± 1.6 and 8.4 ± 1.1 for Brangus donors with a CL vs 15.2 ± 3.1; 11.2 ± 3.3 and 5.7 ± 2.8 for those without a CL (P > 0.34); and 13.2 ± 0.8, 11.2 ± 1.0 and 7.4 ± 0.5 for Bonsmara donors with a CL vs 17.4 ± 3.7, 13.6 ± 6.5 and 9.2 ± 4.3 for those without a CL (P > 0.16). In summary, the presence or absence of a CL did not affect embryo production in donor cows superstimulated every 28 to 35 days using a progesterone-releasing device and FSH. Study was supported by Bioniche Animal Health, Belleville, Ontario, Canada.

11 Conception rate of high-producing dairy cows at first service using prostaglandin F2α and oestradiol benzoate

2019 ◽  
Vol 31 (1) ◽  
pp. 131
Author(s):  
M. Yamaguchi ◽  
M. Takayama ◽  
H. López ◽  
O. Dochi
Keyword(s):  
New York ◽  
Dairy Cows ◽  
Corpus Luteum ◽  
Animal Health ◽  
Prostaglandin F2α ◽  
Conception Rate ◽  
Chi Square ◽  
Average Interval ◽  
Oestradiol Benzoate ◽  
Days Open

We have shown that a simplified oestrus synchronization protocol using prostaglandin F2α (PG) and oestradiol benzoate (EB) resulted in a satisfactory conception rate, similar to that obtained in high-producing dairy cows with natural oestrus (Yamaguchi et al. 2018 Reprod. Fertil. Dev. 30, 147 abstr). However, we found no significant effect of PG+EB protocols on the first-service conception rates (CR) of dairy cows. This study investigated the effect of the first-service CR by using PG+EB protocols in the high-producing dairy cows that had not exhibited oestrus expression after calving. Data concerning the first-service CR were obtained for 481 Holstein cows from 4 commercial dairy herds in Hokkaido and Ibaraki, Japan, from 2014 to 2017. The average number of parity, average interval between calving and the first service, and average milk yield (at 305 days) of the cows were 2.2±1.3, 89.7±26.1 days, and 10314±1994kg, respectively. We carried out the PG+EB protocols on cows not showing evident standing heat from Days 50 to 150 postpartum regardless of the presence of a corpus luteum in the ovary. The statuses of ovaries of cows were confirmed using ultrasonography before starting the treatment. Prostaglandin F2α (25 mg; Lutalyse, Pfizer, New York, NY, USA) was injected into cows with a >20mm cutoff for functional corpus luteum diameter at a random stage of oestrus, and EB (1 mg; Ovahormon®, Aska Animal Health Co., Tokyo, Japan) was injected 24h later, and AI was carried out 24 to 48h after EB injection. Cows with a natural oestrus service from Days 50 to 150 postpartum were used as control. All the cows were inseminated after the onset of standing heat or removal of the tail chalk. Pregnancy diagnoses were performed using ultrasonography 30 to 45 days after AI. The CR and intervals of partum to conception were analysed using a chi-square test and ANOVA. The first-service CR (i.e. the number of pregnant cows/total number of cows in the treatment group) of the natural oestrus (n=330) and PG+EB (n=151) groups were 42.7 and 41.1%, respectively, and there were no significant differences between these 2 groups (P=0.7). The average interval between calving and the first service of the PG+EB groups was significantly longer than that of the natural oestrus groups (86.4±1.5 days v. 96.9±1.9 days; P<0.01). The average days open of the natural oestrus and PG+EB groups were 88.5±3.2 days and 98.1±2.3 days, respectively (P<0.05). These results confirmed that the first-service CR in the PG+EB and natural oestrus groups of high-producing dairy cows were similar. We suggest that conducting PG+EB protocols was effective in the high-producing dairy cows that had not exhibited oestrus expression after calving. Moreover, using PG+EB protocols could prevent the further increase in the number of days open.

Combined treatment with oestradiol benzoate, d-cloprostenol and oxytocin permits cervical dilation and nonsurgical embryo recovery in ewes

2018 ◽  
Vol 54 (1) ◽  
pp. 118-125 ◽  
Author(s):  
Jeferson Ferreira da Fonseca ◽  
Fabiana Nunes Zambrini ◽  
José Domingos Guimarães ◽  
Marcio Roberto Silva ◽  
Maria Emilia Franco Oliveira ◽  
...  
Keyword(s):  
Combined Treatment ◽  
Cervical Dilation ◽  
Embryo Recovery ◽  
Oestradiol Benzoate

GONADAL HORMONES AND THE CONTROL OF OVULATION IN THE GUINEA-PIG

1972 ◽  
Vol 55 (3) ◽  
pp. 599-607 ◽  
Author(s):  
B. T. DONOVAN ◽  
A. N. LOCKHART
Keyword(s):  
Guinea Pig ◽  
Corpus Luteum ◽  
Acute Treatment ◽  
Gonadal Hormones ◽  
Time Of Day ◽  
Gonadal Steroids ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Gonadotrophin Secretion ◽  
Oestradiol Benzoate

SUMMARY The release of ovulating hormone after acute treatment with gonadal steroids, or corpus luteum removal on different days of the oestrous cycle, was studied in the guinea-pig. Injection of 25, 50 or 100 μg oestradiol or 2·5 mg progesterone on day 13 of the cycle had no effect upon gonadotrophin secretion as judged by follicular histology, but markedly altered the sizes of the corpora lutea of the previous ovulation. Treatment with oestradiol on day 14 did not elicit gonadotrophin secretion. However, administration of the same hormones to animals given 10 μg oestradiol benzoate 24 h earlier caused ovulation or follicular luteinization. Progesterone (2·5 mg) appeared least effective in stimulating gonadotrophin release; 25 μg oestradiol were more effective when given at 12.00 h than at 24.00 h but treatment with both hormones caused ovulation when given at either time of day. Luteal volumes were not affected. Removal of corpora lutea during the second half of the cycle advanced the time of expected ovulation to day 15 or earlier when the procedure was carried out on days 8 or 9, but not on days 10–13. It is concluded that 4–5 days must elapse between the fall in plasma progesterone level associated with corpus luteum regression and the release of ovulating hormone.

122 TIMED ARTIFICIAL INSEMINATION IN WOOD BISON USING FROZEN-THAWED SEMEN

2016 ◽  
Vol 28 (2) ◽  
pp. 191 ◽  
Author(s):  
G. P. Adams ◽  
S. X. Yang ◽  
J. M. Palomino ◽  
M. Anzar
Keyword(s):  
Animal Health ◽  
Egg Yolk ◽  
Ovulation Rate ◽  
Chi Square ◽  
Semen Cryopreservation ◽  
Wood Bison ◽  
The Mean ◽  
Intravaginal Device ◽  
Synchronization Procedure

Recent progress with methods to control ovulation and semen cryopreservation in Wood Bison was the impetus to test the feasibility of timed AI to facilitate reclamation of this threatened species. A 2 × 2 design was used to compare the efficacy of 2 ovulation synchronization techniques and 2 semen cryopreservation protocols. Female Wood Bison were assigned randomly to 2 groups (n = 24/group) in which ovarian synchronization was induced by ultrasound-guided ablation of follicles >5 mm or intramuscular treatment with 2.5 mg of estradiol 17B + 50 mg of progesterone (E+P) in canola oil. A progesterone-releasing intravaginal device (PRID) was placed at the time of follicle ablation (for 5 days) or E+P treatment (for 8 days) in the respective groups. A luteolytic dose of prostaglandin was given at the time of PRID removal, and 2500 IU of hCG was given IM 3 days later. Bison were inseminated 24 and 36 h after hCG treatment using frozen-thawed semen. The semen was collected by electro-ejaculation from 4 Wood Bison bulls, pooled, and divided into aliquots diluted in either egg-yolk extender (EY) or cholesterol-loaded cyclodextrin extender (CLC). Half the bison in each synchronization group were inseminated with either EY- or CLC-extended semen. Bison were examined by ultrasonography every 12 h beginning on the day of hCG treatment for 3 days or until ovulation was detected, whichever occurred first. Pregnancy diagnosis was made by ultrasonography 34–36 days after insemination. Two bison were excluded during the experiment because of handling difficulty; therefore, the total number of bison used was 46. Ovulation rate and interval to ovulation were compared between synchronization groups by chi-square and t-test, respectively. Pregnancy rates were compared among groups by 2-way ANOVA after transforming data to arcsin. The ovulation rate was not different between synchronization groups [combined mean, 37/46 (80%)], nor was the degree of synchrony, as assessed by the residuals (variation from the mean) in the respective groups. However, the diameter (mean ± standard error of the mean) of the dominant follicle at the time of hCG treatment was smaller in the follicle ablation group than in the E+P group (10.5 ± 0.6 v. 13.9 ± 0.6; P < 0.04), and the interval from hCG treatment to ovulation tended to be longer (35.3 ± 1.6 v. 31.8 ± 1.3 h; P ≤ 0.10). Pregnancy rate was not affected by synchronization procedure, but pregnancy was detected only in the EY-inseminated group (9/23 v. 0/23; P < 0.01). Despite that post-thaw sperm motility was similar for EY and CLC semen (41.7 ± 2.9 and 44.6 ± 3.3%; respectively), CLC-treated semen failed to impregnate bison in vivo. We concluded that synchronization and timed insemination with frozen-thawed semen is feasible in Wood Bison. Of the 23 bison inseminated with EY-extended semen, 21 ovulated (91%), and of those that ovulated 9 became pregnant (43%). Both synchronization schemes were effective, but the ablation protocol may be improved by an additional day between ablation and hCG treatment. We thank Vetoquinol Canada and Merck Animal Health for providing hormone treatments.

108 COMPARATIVE EFFICIENCY OF GONADOTROPIN-RELEASING HORMONE AND LUTEINIZING HORMONE IN THE INDUCTION OF OVULATION IN SUPEROVULATED ALPACAS

2014 ◽  
Vol 26 (1) ◽  
pp. 168
Author(s):  
H. W. Vivanco-Mackie ◽  
M. D. Ponce Salazar ◽  
M. M. Gonzales ◽  
M. A. Tapia
Keyword(s):  
Gnrh Agonist ◽  
Recovery Rate ◽  
Pearson Correlation ◽  
Animal Health ◽  
Gonadotropin Releasing Hormone ◽  
Corpora Lutea ◽  
Peruvian Andes ◽  
Releasing Hormone ◽  
Induction Of Ovulation ◽  
Embryo Recovery

Alpacas are induced ovulators, responding to copulation and (or) exogenous application of ovulation-inducing hormones. The objective of this study was to determine the efficiency of the injection of a gonadotropin-releasing hormone (GnRH) agonist versus LH in the induction of ovulation and the presence and size of non-ovulated follicles at the time of embryo collection and its relationship to the yield of transferable embryos in superovulated alpacas. Twenty-one adult (3 to 7 years old) female alpacas under extensive grazing at 4300 m elevation in the Peruvian Andes that had been synchronized and treated for superovulation were induced to ovulate 6 days after the application of the superovulatory hormone (1000 IU of eCG, Folligon®, Intervet International BV, Boxmeer, the Netherlands) by mating with fertile males and injection immediately after copulation of either an IM dose of 0.0084 mg of buserelin acetate (Buserelina Zoovet®, Laboratorio Zoovet, Santa Fe, Argentina) to 10 alpacas (T1) or an IM dose of 5-mg Armour standard of LH (Lutropin®, Bioniche Animal Health, Belleville, ON, Canada) to 11 alpacas (T2). All alpacas had a second mating 12 h after the first mating and were subjected to ovarian inspection by ultrasonography and previous embryo collection by nonsurgical transcervical embryo flushing 6.5 days after the first mating. On average, the embryo recovery rate for T1 was 34.6% and there were 7.8 ± 3.99 corpora lutea (CL), 2.7 ± 4.08 collected embryos, and 3.6 ± 2.95 total, 0.5 ± 0.85 small (<6 mm), 1.8 ± 1.99 medium (≥6 but ≤14 mm), and 1.3 ± 2.11 large (≥15 mm) non-ovulated follicles. For T2, the embryo recovery rate was 59.4% and there were 6.73 ± 1.49 CL, 4.0 ± 2.57 collected embryos, and 0.64 ± 0.81 total, 0.0 ± 0.0 small, 0.36 ± 0.67 medium, and 0.27 ± 0.47 large non-ovulated follicles. The differences between treatments were nonsignificant (P > 0.05) for all the parameters; however, there was a clear tendency for a better recovery rate, more embryos collected, and lower number of non-ovulated follicles in T2. The Pearson correlation coefficient between the presence of large follicles in the ovaries at the time of embryo collection and the total number of embryos collected was negative (r = –0.26) and highly significant (P ≤ 0.001). The use of LH for ovulation induction of superovulated alpacas seems to be more advisable than the use of GnRH agonist; further comparisons with larger number of observations per treatment are recommended. This study was financed by the Peruvian Fund for Innovation, Science and Technology (FINCYT).

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