297 LACK OF IMPROVEMENT ON EMBRYO PRODUCTION BY THE REPLACEMENT OF THE LAST TWO DOSES OF pFSH BY eCG IN SUPERSTIMULATED NELORE HEIFERS

2009 ◽  
Vol 21 (1) ◽  
pp. 245 ◽  
Author(s):  
R. Sartori ◽  
M. M. Guardieiro ◽  
C. M. Barros ◽  
M. R. Bastos ◽  
G. M. Machado ◽  
...  

Results from a previous experiment have shown that the replacement of pFSH by eCG on the last day of the superstimulatory treatment in Nelore (Bos indicus) cows resulted in a greater superovulatory (SOV) response as compared to the treatment exclusively with pFSH (Barros CM et al. 2008 Repr. Fertil. Dev. 20, 152 abst). The aim of this study was to investigate if a similar approach would be beneficial for embryo production in nulliparous Nelore heifers. Forty heifers were randomly divided into two SOV groups: FSH Group: eight pFSH injections or FSH-eCG Group: six pFSH injections followed by two eCG injections. Each female received both treatments 65 days apart in a cross-over design. The SOV protocols consisted of an IM injection of 2 mg estradiol benzoate (Estrogin, Farmavet, São Paulo, Brazil) and insertion of an intravaginal progesterone releasing device (1.9 g progesterone, CIDR, Pfizer, Hamilton, New Zealand) on Day 0. On Day 4.5, the superstimulatory treatments (70 mg pFSH; Folltropin-V, Bioniche Animal Health; Belleville, ON, Canada) were initiated and given in decreasing doses of 28, 21, 14, and 7 mg twice a day, over a 4-day period. The FSH-eCG Group had the last two doses of pFSH replaced by two doses of 150 IU eCG (Folligon, Bioniche). At the time of the fifth and sixth injections of FSH, 25 mg dinoprost tromethamine (Lutalyse, Pfizer, Paulinia, Brazil) was injected IM. The CIDR was removed at the time of the seventh superstimulatory injection. Ovulation was induced with an IM injection of 0.05 mg GnRH (gonadorelin acetate; Gestran Plus; ARSA S.R.L., Buenos Aires, Argentina) 12 h after the last superstimulatory injection. All heifers were artificially inseminated with frozen/thawed semen from the same bull 12 and 24 h after GnRH. Seven days after the first AI, embryos/ova were recovered using a nonsurgical uterine flushing technique and classified according to IETS standards. To determine the superstimulatory (number of follicles ≥6 mm 12 h prior to GnRH) and SOV (number of ovulated follicles 48 h after GnRH, confirmed by CL number at the time of embryo collection) responses, transrectal ultrasonography was performed. Data were analyzed by paired t test and are presented as mean ± SEM. There was no difference between FSH and FSH-eCG groups regarding superstimulatory (23.2 ± 1.9 v. 22.3 ± 1.6 follicles ≥6 mm, P = 0.56) or SOV (15.2 ± 1.1 v. 17.5 ± 1.4 CL, P = 0.21) responses. Treatments were also similar for number of total embryos/ova (9.6 ± 0.9 v. 9.5 ± 1.0, P = 0.91), viable embryos (4.9 ± 0.7 v. 3.7 ± 0.5, P = 0.17), or degenerate embryos (3.0 ± 0.6 v. 4.3 ± 0.7, P = 0.10) recovered. Contrasting with the results using Nelore cows, the present study did not observe improvement on embryo production by replacing of the last two doses of pFSH by eCG in superstimulated heifers. Financial support from CNPq, FAPESP, EMBRAPA and Pfizer of Brazil.

2010 ◽  
Vol 22 (1) ◽  
pp. 357
Author(s):  
R. H. Alvarez ◽  
A. C. Martinez ◽  
R. M. L. Pires

Breed differences in ovarian function were found among beef Bos indicus and Bos taurus cows maintained in a subtropical environment (Alvarez P et al. 2000 J. Anim. Sci. 78, 1291-1302). The aim of this study was to compare ovarian response to superovulation and embryo production of tropical-adapted Bos taurus and Bos indicus cows. The experiment was carried out in a tropical wet climate at the experimental station of Instituto de Zootecnia (latitude 22°46′S, longitude 47°17′W) from November to February (average maximum temperature = 30.0 ± 0.8°C and average absolute precipitation = 153.1 ± 78.8 mm3). Forty Caracu (a local Bos taurus breed) and 50 Nelore (Bos indicus breed) lactating cows were treated with an intravaginal device containing progesterone (1.38 mg; CIDR-B®, Pfizer Animal Health, Montreal, Québec, Canada) and 2.5 mg i.m. of estradiol benzoate (Estrogin®, Farmavet, São Paulo, Brazil). Four days later, the animals were superovulated with multiple i.m. injections of 400 IU of FSH (Pluset®, Calier, Spain) in decreasing doses (75-75, 75-50, 50-25, and 25-25 IU) at 12-h intervals over 4 days. The CIDR-B® device was removed 3 days after the first superovulatory injection and cows received i.m. 150 μg of cloprostenol (Veteglan®, Calier, Spain). Cows were inseminated 48 and 62 h after the cloprostenol injection and embryos were recovered nonsurgically 7 days after insemination. Differences in the number of CL (assessed by ultrasound scanning), total number of ova/embryos, and number of transferable embryos were analyzed by ANOVA. Differences in the number of animals with low response (<3 CL) to superovulation were analyzed by chi-square test. All donors (with the exception of 1 Caracu and 2 Nelore) with ovarian response >3 CL showed estrus at insemination. Three (8.9%) Caracu and 5 (10.0%) Nelore cows had <3 CL following the superovulation treatment (P = 0.68). There was no difference (P > 0.05) in the mean (± SEM) CL counts of Caracu (11.4 ± 3.3) and Nelore (12.0 ± 4.1) cows. Similarly, there were no differences (P > 0.05) between Caracu and Nelore cows for total number of ova/embryos collected (8.6 ± 2.6 v. 9.0 ± 4.3) or transferable embryos (6.0 ± 2.4 v. 5.1 ± 2.9). In conclusion, the superovulation of Caracu and Nelore cows carried out in a tropical climate resulted in similar ovarian responses and embryo production. Supported by FAPESP.


2007 ◽  
Vol 19 (1) ◽  
pp. 309
Author(s):  
C. M. Martins ◽  
H. Ayres ◽  
J. R. S. Torres-Junior ◽  
A. H. Souza ◽  
G. A. Bó ◽  
...  

In embryo transfer programs, 2 inseminations per superstimulated donor are usually recommended. Based on studies of follicular dynamics in Bos indicus donors (Baruselli et al. 2006 Theriogenology 65, 77–88), we tested the hypothesis that a single fixed-time AI (FTAI) at 16 h after pituitary luteinizing hormone (pLH) treatment is as efficacious as 2 FTAI at 12 and 24 h after the pLH treatment. Suckling Nelore cows (n = 10), 60 � 12 days postpartum, were equally distributed in 2 experimental groups: G-1TAI vs. G-2TAI, in a crossover design. All animals received an intravaginal progesterone device (DIB; Syntex S.A., Buenos Aires, Argentina) and 2 mg of estradiol benzoate (IM, Ric Be; Syntex) at random stages of the estrous cycle (Day 0). Superstimulatory treatments started on Day 4 with pFSH (133 mg; Folltropin-V; Bioniche Animal Health Canada, Inc., Belleville, Ontario, Canada) in 8 decreasing doses, given IM 12 h apart. On Day 6, all cows received 2 (AM and PM) treatments of 0.15 mg of d-cloprostenol (Prolise; Syntex). The DIB devices were removed 36 h after the first PGF2� injection. The pLH treatment (25 mg IM; Lutropin-V; Bioniche) was given 48 h after the first PGF2� treatment (12 h after the last pFSH treatment). In the G-2TAI group, all cows received 2 inseminations (12 and 24 h after the pLH). Cows in the G-1TAI group received a single insemination (16 h after the pLH). All inseminations were done with the same batch of semen from a single bull. Ultrasound examinations (PIE Medical Scanner 200; Pie Medical Equipment, Maastricht, The Netherlands) were performed every 12 h from 0 to 72 h after pLH treatment to evaluate the number of ovulatory follicles (&lt;8 mm), the ovulation rate, and the time of ovulation. Variables were analyzed by ANOVA and chi-square test. The homogeneity of the variances (distribution of ovulations) was analyzed by Bartlett&apos;s test. Conclusions were based on a 5% level of significance. The results for G-1TAI and G-2TAI were, respectively: number of follicles &gt;8 mm at the time of pLH administration (16.2 � 1.4 vs. 14.8 � 1.2; P &gt; 0.05), ovulation rate (63.8 � 3.8% vs. 64.2 � 4.3%; P &gt; 0.05), interval from the first to the last ovulation (32.4 � 1.8 vs. 33.6 � 1.6 h; P &gt; 0.05), total ova/embryos (8.2 � 0.9 vs. 7.2 � 0.8; P &gt; 0.05), Grade 1 embryos (2.0 � 0.5 vs. 2.3 � 0.4; P &gt; 0.05), transferable embryos (Grades 1, 2, and 3) (4.3 � 0.7 vs. 4.2 � 0.6; P &gt; 0.05), freezable embryos (Grades 1 and 2) (2.9 � 0.6 vs. 2.8 � 0.4; P &gt; 0.05), unfertilized ova (0.6 � 0.2 vs. 0.8 � 0.2; P &gt; 0.05), and degenerated embryos (3.3 � 0.9 vs. 2.2 � 0.3; P &gt; 0.05). These results suggest no significant differences in embryo production between superstimulated Nelore donors inseminated once or twice by fixed time following administration of pLH. This work was supported by Tecnopec, Brazil.


2010 ◽  
Vol 22 (1) ◽  
pp. 364
Author(s):  
M. C. C. Mattos ◽  
M. R. Bastos ◽  
M. M. Guardieiro ◽  
J. O. Carvalho ◽  
G. B. Mourão ◽  
...  

Results from a previous experiment (Barros C et al. 2008 Reprod. Fertil. Dev. 20, 152 abst) have shown that the replacement of porcine FSH (pFHS) by eCG on the last day of the superstimulatory treatment in Nellore (Bos indicus) cows resulted in a greater superovulatory (SOV) response as compared with treatment exclusively with pFSH. However, another study (Sartori R et al. 2009 Reprod. Fertil. Dev. 21, 245-246 abst) in Nellore heifers did not corroborate those observations. The aim of this study was to evaluate the SOV response of Sindi (Bos indicus) donors submitted to this protocol. Forty-eight SOV treatments were performed in a crossover design in 19 nulliparous and primiparous females that were randomly divided into 2 groups: FSH (n = 24), which consisted of 8 pFSH injections (Folltropin®-V, Bioniche Animal Health; Belleville, Ontario, Canada), or FSH-eCG (n = 24), which consisted of 6 pFSH injections followed by 2 eCG injections (Folligon®, Intervet Schering-Plough Animal Health, Brazil). Each female underwent 2 or 3 SOV treatments that consisted of an i.m. injection of 2 mg of estradiol benzoate (Gonadiol®, Intervet) and the insertion of an intravaginal progesterone-releasing device (DIB®, Intervet) on Day 0. On Day 4, the superstimulatory treatments (100 or 150 mg of pFSH, based on previous history of SOV responses) were initiated and given in decreasing doses twice a day over a 4-day period. In the FSH-eCG group, the last 2 doses of pFSH were replaced by 2 doses of eCG (150 or 200 IU of eCG each). At the time of the fifth and sixth injections of FSH, 0.150 mg of PGF2 (Preloban®, Intervet) was injected i.m. The DIB® device was removed at the time of the last FSH or eCG injection and ovulation was induced with 0.2 mg of GnRH (Fertagyl®, Intervet) 12 h later. All females were artificially inseminated with frozen-thawed semen from the same bull 12 and 24 h after GnRH treatment. Seven days after the first AI, embryos/ova were recovered. Superstimulatory (number of follicles ≥6 mm at the time of the last FSH or eCG injection) and SOV (CL number) responses were determined by transrectal ultrasonography. Data were analyzed using generalized linear models and results were presented as least squares means ± standard error. The FSH-eCG group had higher superstimulatory (33.3 ± 3.9 v. 24.2 ± 3.0 follicles; P ≤0.06) and SOV (16.8 ± 2.9 v. 10.8 ± 2.1 CL; P ≤ 0.10) responses. Although the number of total ova/embryos recovered was not different between groups (8.2 ± 1.8 v. 5.9 ± 1.4 for FSH-eCG and FSH groups, respectively; P > 0.25), the number (6.5 ± 1.2 v. 2.4 ± 0.7; P ≤ 0.008) and percentage (75.2 ± 6.6 v. 52.8 ± 8.6%; P ≤ 0.05) of viable embryos was greater for the FSH-eCG females. Contrasting with the results in Nellore heifers, this study observed improvement in superstimulatory and SOV responses and embryo quality by replacing the last 2 doses of pFSH by eCG in Sindi donors. Financial support from FAPESP, EMBRAPA, Intervet Schering-Plough Animal Health, Nutricell, and Sindi do ACS of Brazil.


2007 ◽  
Vol 19 (1) ◽  
pp. 242 ◽  
Author(s):  
L. U. Gimenes ◽  
N. A. T. Carvalho ◽  
M. F. Sá Filho ◽  
H. Ayres ◽  
J. R. S. Torres-Júnior ◽  
...  

In Holstein cows, the diameter of the dominant follicle (DF) at the time of follicle deviation is 8.5 mm and the subordinate follicle (SF) is 7.2 mm (Ginther et al. 1996 Biol. Reprod. 55, 1187–1194). However, follicular responsiveness to an ovulatory treatment occurs only with 10.0-mm-diameter follicles (Sartori et al. 2001 Biol. Reprod. 65, 1403–1409). The current study tested the hypothesis that, in Bos indicus (Nelore and crossbred Nelore � Gir) females, the follicular diameters at the time of deviation and ovulation responsiveness are smaller than those in Holstein cows. The experiment was performed in two phases. In the first phase, 12 Nelore heifers were previously synchronized with a protocol using progestagen and estradiol benzoate. After implant removal, all heifers were evaluated by transrectal ultrasonography (Aloka SSD-500, Tokyo, Japan) every 12 h until Day 5 of the estrous cycle (Day 0 = Day of the ovulation) to assess the time of ovulation, the time of follicle deviation, and the follicular diameter at the deviation. In the second phase, 29 Bos indicus heifers (Nelore and crossbred Nelore � Gir) were previously synchronized with the same protocol as cited above. After the ovulations (Day 0), the follicles were evaluated by transrectal ultrasonography every 24 h, until they reached the diameter of 7.0–8.4 mm (n = 9); 8.5–10.0 mm (n = 10); and &gt;10.0 mm (n = 10). In order to assess the ovulatory capacity, all animals were treated with 25 mg of LH (Lutropin-V�; Bioniche Animal Health, Inc., Belleville, Ontario, Canada) at these follicle diameter ranges. After the LH treatment, all animals were monitored by ultrasonography every 12 h for 48 h. ANOVA, Bartlett, and chi-square tests were used in the statistical analyses. In the first phase, the diameters of the DF and SF at the time of follicular deviation (61.9 � 4.9 h after ovulation) were 6.2 � 0.2 and 5.8 � 0.2 mm, respectively. In the second phase, the the average follicular diameters at the time of LH administration in the groups 7.0–8.4 mm, 8.5–10.0 mm, and &gt;10.0 mm were 7.6a � 0.1 mm, 9.6b � 0.1 mm, and 10.9c � 0.2 mm; and their ovulation rates were 33.3%a (3/9), 80.0%b (8/10), and 90.0%b (9/10), respectively (P &lt; 0.05). The interval from LH treatment to ovulation was 38.0 � 4.0 h, 31.5 � 2.7 h, and 30.0 � 2.0 h, respectively (P &gt; 0.05). In conclusion, in Bos indicus heifers, follicle deviation occurred with smaller diameters than previously reported in Bos taurus breeds. In addition, Bos indicus heifers are able to ovulate in response to 25 mg of LH with smaller diameters compared to those of Bos taurus breeds. Moreover, in Bos indicus heifers, ovulatory capacity is acquired by follicles as small as 7.0–8.4 mm, but this responsiveness significantly increases after follicles reach 8.5–10.0 mm. This work was supported by FAPESP (Proc:03/10203-4); Bioniche Animal Health, Inc., Belleville, Ontario, Canada; and Tecnopec, S�o Paulo, Brazil.


2009 ◽  
Vol 21 (1) ◽  
pp. 171
Author(s):  
M. E. F. Oliveira ◽  
I. C. C. Santos ◽  
J. S. P. Pieroni ◽  
R. M. Ferreira ◽  
M. F. Cordeiro ◽  
...  

The aim this study was to evaluate the effect of the addition of LH in superovulatory response and embryo production in Santa Inês sheep. Ten donors with 60.3 ± 10.7 kg and BCS of 3.9 ± 0.3 were superovulated in a cross-over design, with a 60-day interval. Estrus was synchronized with a progesterone-releasing intravaginal device (CIDR™; Pfizer Animal Health, Brazil) inserted on Day 0 and replaced by a new one on Day 7, that was maintained to Day 14. Two doses of 37.5 g of D-cloprostenol (Prolise™, Arsa, Buenos Aires, Argentina) were administered, on Days 7 and 14. Donors also receive 256 mg of pFSH (Folltropin™, Bioniche, Belleville, ON, Canada) in 8 decreasing doses, starting on Day 12. On Day 14, all females received 200 IU of eCG (Novormon ™, Syntex, Argentina). On Day 15, the animals were homogeneously allocated in 1 of 2 groups: Control (GC, n = 10) and treated (G-LH, n = 10). Ewes in GC did not receive exogenous LH, whereas ewes in G-LH were treated with 7.5 mg of LH (Lutropin™, Bioniche), on Day 15. All females were inseminated by laparoscopy, with frozen–thawed semen, 42 and 48 h after CIDR removal. On Day 21, the embryos were surgically collected. The superovulatory response was classified in scores: (0) 4 or fewer CL; (1) between 5 and 10 CL, and (2) 11 or more CL. Means were compared using Kruskal-Wallis test and percentages using chi-square (P < 0.05). Most of donors (70%, 7/10) from G-LH presented a superovulatory response classified as score 2, and the remaining (30%, 3/10) as score 1, whereas, half of the controls were classified as score 2 and half as score 1. Ovulation rate tended to be greater in G-LH (135/158, 85.4% v. 105/135, 77.7%, P = 0.08). The number of CL (mean ± SD) was 10.5 ± 3.8 in GC and 13.5 ± 4.84 in G-LH, but was not statistically different. The number of anovulatory follicles (AF) did not differ between groups (GC: 3.0 ± 3.2; G-LH: 2.3 ± 1.6), but the proportion of AF tended to decrease in G-LH (30/135, 22.2% v. 23/158, 14.5%, P = 0.08). Considering embryo production, there was no difference between GC and G-LH (P > 0.05) related to number of recovered ova/embryos (6.1 ± 4.6 v. 8.4 ± 5.2), viable embryos (3.8 ± 4.3 v. 4.2 ± 5.2), unfertilized (1.7 ± 3.4 v. 2.0 ± 2.9) and degenerated embryos (0.7 ± 0.7 v. 2.2 ± 2.9), respectively. Data showed that the addition of LH tended to increase ovulation rate and to decrease the proportion of AF, but did not affect the number of viable embryos.


2012 ◽  
Vol 24 (1) ◽  
pp. 224 ◽  
Author(s):  
R. L. Davis ◽  
A. Arteaga ◽  
J. F. Hasler

This study examined the superovulatory responses of Bos taurus beef cows maintained in a commercial embryo transfer facility. Donors were superovulated 1 to 3 times each with either a traditional 8 injection FSH protocol (controls, n = 126) or 6 injections of FSH with the seventh or eighth FSH treatments replaced by 2 injections of eCG (treatment, n = 134). During the 5-month study, 132 donors were alternatively assigned to a control or treatment group for a single superovulation and an additional 62 animals were superovulated 2 (n = 58) or 3 times (n = 4) in a crossover design. Although 14 beef breeds were represented in the study, 87% of the cows were Angus, Red Angus, Polled Hereford, or Charolais. All donors were synchronized on Day 0 with a CIDR, 5 mg of oestradiol-17β and 100 mg of progesterone. Starting on Day 4 (p.m.), controls were injected twice daily for 4 days with descending doses of porcine FSH (Folltropin-V®, Bioniche Animal Health, Belleville, Ontario, Canada). Cows received 750 μg of cloprostenol (Estrumate®, Intervet Schering-Plough, Summit, NJ, USA) at the seventh FSH injection and the CIDR was removed at the eighth FSH injection. Based on previous experience with specific, individual animals, total FSH dose per donor ranged from 240 to 400 mg. However, 74% of treatments involved 380 mg for controls and 310 mg for treated donors that received eCG. In addition, donors that were superovulated more than once received the same FSH dose in the crossover, treatment-control design. In the treatment group, 200 IU of eCG (Pregnecol™ 6000, Bioniche Animal Health) was substituted for the seventh and eighth FSH injections. Inseminations were conducted on a timed AI basis, with one unit of semen 32 h and a second 48 h following CIDR removal. Results were analysed by ANOVA as shown in Table 1. Although more ova/embryos and unfertilized ova (UFO) were recovered in the control group, the control and treatment groups did not differ in the number of grade 1, 2, or 3 embryos or in the number of degenerate embryos. Previous superovulation studies in South America using eCG to replace the last 2 injections of FSH resulted in more total ova/embryos in Nelore cows but not heifers and in more embryos in Brangus and Sindhi cows. The mean embryo production for the control cows in this study was high and the addition of eCG in the protocol did not improve embryo production. Failure of eCG to increase the number of embryos for Bos taurus cows in this study compared with previous studies may be due to differences with Bos taurus versus Bos indicus breeds or differences in management factors between Canada and South America. The high response rate in the controls may also have contributed to the failure of any advantage of adding eCG to the treatment protocol. Table 1.Mean numbers (± SEM) of ova and embryos recovered from Bos taurus females superovulated with 2 different protocols


2007 ◽  
Vol 19 (1) ◽  
pp. 311
Author(s):  
J. L. M. Vasconcelos ◽  
D. T. G. Jardina ◽  
C. A. Rodrigues ◽  
V. C. Guerreiro

The aim of this study was to evaluate effects of season and lactation status on embryo production in Holstein donors (n = 51). Data from 195 embryo collections (94 from lactating cows and 101 from non-lactating cows), at a dairy farm located in Descalvado, Sao Paulo, Brazil, in 2005, were analyzed. The superstimulation protocol included two 3-mg norgestomet ear implants (Crestar�; Intervet, Sao Paulo, Brazil) and an injection of 3 mg of estradiol benzoate IM (EB) on random days of the estrous cycle. Four days later, 500 IU FSH IM (Pluset�; Calier, Buenos Aires, Argentina) were divided into 8 decreasing doses given 12 h apart. With the seventh FSH injection, 0.530 mg IM of sodium cloprostenol (PGFα Ciosin�; Coopers-Brazil, Sao Paulo, Brazil) was given, and implants were removed with the eighth FSH injection. Twelve hours later, 250 �g IM of gonadorelin (Fertagyl�; Intervet) was given, followed by two AI 12 and 24 h later. Ova/embryos were recovered 6.5 days after the first insemination. The total number of ova/embryos, IETS grades 1, 2, and 3 (viable) and grade 4 plus unfertilized (non-viable), were analyzed by General Linear Model (GLM). Effects of donor, lactation status (lactating or non-lactating), sire, season (1: January through March, n = 56; 2: April through June, n = 37; 3: July through September, n = 50; 4: October through December, n = 52), and their interactions were included in the model. There was an effect of donor on all outcome variables (P &lt; 0.01). There was an effect of season on the total number of ova/embryos (1: 10.2 � 1.2; 2: 6.6 � 1.0; 3: 10.0 � 1.1; 4: 11.2 � 1.2; P &lt; 0.02) and of viable embryos (1: 3.7 � 0.5; 2: 2.4 � 0.5; 3: 5.9 � 0.9; 4: 4.4 � 0.7; P &lt; 0.001). Lactation status influenced the total number of ova/embryos (lactating: 10.9 � 0.9 vs. non-lactating: 8.7 � 0.7; P &lt; 0.001) and the number of non-viable embryos (lactating: 6.7 � 0.8 vs. non-lactating: 4.4 � 0.5; P &lt; 0.01). However, there was no effect of lactation status on the number of viable embryos (lactating: 4.14 � 0.5 vs. non-lactating: 4.29 � 0.5; P &gt; 0.10). In summary, the number of viable embryos in Holstein cows was influenced by season and donor, but not by lactation status.


2010 ◽  
Vol 22 (1) ◽  
pp. 174
Author(s):  
V. A. Nascimento ◽  
G. S. Moura ◽  
M. Dias ◽  
F. A. Oliveira ◽  
A. R. Dias ◽  
...  

The objective of this study was to evaluate the administration of the follicle-stimulating hormone (FSH-p) or equine chorionic gonadotropin (eCG) in protocols of ovulation synchronization. One hundred forty-nine crossbred Holstein-Gyr cows were used in 2 properties in Minas Gerais and 3 treatments: TControl (n = 49 cows), Day 0: insert of a progesterone device (Primer®, Tecnopec, São Paulo, Brazil) + 2 mg of estradiol benzoate (RIC-BE®); Day 8: removal of Primer + 112 mg of D-cloprostenol (Prolise®, ARSA SRL, Buenos Aires, Argentina) + 1 mg of estradiol benzoate and fixed-time artificial insemination (FTAI) accomplished 44 h after the removal of Primer; TFSH (n = 50 cows), similar to TControl, but on Day 8, 15 mg of FSH-p (Folltropin®, Bioniche Animal Health) was administered; TeCG (n = 50 cows), similar to TControl, with administration on Day 8 of 300 IU of eCG (Novormon®, Syntex SA, Buenos Aires, Argentina). Cows that returned to estrus 14 to 28 days after the FTAI were inseminated once again. For all statistical analysis, we used the program SAS 9.0 (2002; SAS Institute Inc., Cary, NC, USA) at 5% probability. Quantitative variables (live weight, days postpartum, follicular average per cow) were analyzed by variance, and body condition score by Friedman test. The pregnancy rates were submitted to logistic analysis considering the effect of local experimental factors and were analyzed by Spearman correlation among the variables studied and the pregnancy rate. There was no difference (P > 0.05) between treatment for pregnancy rate in FTAI protocols (TControl = 40.82%; TFSH = 38.00%; TeCG = 26.00%), in the first insemination after FTAI (TControl = 56.25%; TFSH = 70.59%; TeCG = 68.42%), and in FTAI plus first insemination after FTAI (TControl = 59.18%; TFSH =62.00%; TeCG = 52.00%), as well as for the estrus repetition (TControl = 55.17%; TFSH = 54.84%; TeCG = 51.35%) and the correlation (P > 0.05) among the pregnancy rate and postpartum period, milk production, body weight and body condition. No effect was observed on the pregnancy rate by the addition of the hormones FSH and eCG in the protocol of ovulation synchronization in crossbred Holstein-Gyr cows; however, reinsemination in the period from 14 to 28 days after FTAI increased the pregnancy rate. CNPq; FAPEMIG; TECNOPEC/São Paulo, Brazil.


2018 ◽  
Vol 30 (1) ◽  
pp. 203
Author(s):  
P. Tiwari ◽  
S. Zawar ◽  
J. H. Pryor ◽  
C. R. Looney ◽  
R. Kaushik ◽  
...  

Ongole, also known as Nelore (Bos indicus) cattle, are indigenous to the Andhra region in the Prakasam District in the State of Andhra Pradesh in India. A better understanding and utilisation of follicular wave dynamics within this breed would ultimately enhance oocyte and potential embryo production. Therefore, the aim of this study was to evaluate the differences between coasting periods of 24 h (S1) and 36 h (S2) on oocyte recovery, the rate of viable oocytes, cleavage, and Day 7 blastocyst rates of Nelore cattle in India. A total of 58 ovum pick-up (OPU) sessions (29 per treatment) were performed on 32 healthy donor cows that were randomly assigned to 1 of 2 coasting treatments (S1 or S2). Donors were stimulated as follows: 2.5 mL of gonadotropin-releasing hormone (GnRH; Receptal, MSD Animal Health, New Zealand) given IM on Day 1 followed by once-daily descending dose of Folltropin® (FSH, Vetoquinol, Canada) on Days 3 to 5 for a total of 180 mg. Cumulus-oocyte complexes were collected following OPU on Day 6 either at 24 (S1) or 36 h (S2) following the last FSH injection (coasting period). Donors were subject to OPU 1 to 3 times with a minimum interval of 15 days between procedures from March to April 2017. All 32 donor cows were non-lactating at the time of aspiration and divided equally between treatment groups. A total of 1492 follicles produced 850 total oocytes with oocyte recovery numbers for treatments S1 and S2 (785, 707; 441, 409; respectively). All data were analysed by ANOVA (P < 0.05). The mean number of follicles aspirated from S1 (27 ± 20.2) was not significantly different from that of S2 (24.4 ± 14.4). For S1, 393/441 (89%) quality oocytes were utilised for culture compared with 323/409 (78.9%) for S2, with no differences between rates. Additionally, there were no differences between mean number of oocytes, cleaved embryos, and blastocysts for S1 (15.2 ± 12.7; 9.9 ± 9.2; 4.3 ± 5.4) and S2 (14.1 ± 10; 7.4 ± 6.0; 3.6 ± 3.3; respectively). In conclusion, there were no differences found between 24- or 36-h coasting periods of Nelore cattle undergoing OPU for follicle counts, oocyte recovery, viable oocyte rates, cleavage, and blastocyst rates. Further research is needed to determine whether different stimulation protocols, the use of lactating cows, or coasting periods could alter outcomes.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12077
Author(s):  
Khalid Mahmood ◽  
Muhammad Zahid Tahir ◽  
Mahboob Ahmad Butt ◽  
Shazia Mansoor Qureshi ◽  
Amjad Riaz

Multiple Ovulation and Embryo Transfer (MOET) technology is a potential technique to upgrade livestock species’ genetics. The varied response to super-stimulatory treatments remains one of the limiting factors to this technology’s widespread use. The present study was aimed to improve the superovulation response and in-vivo embryo production by using controlled internal drug release (CIDR)-GnRH or CIDR-EB (Estradiol Benzoate) along with conventional superovulation protocol in Holstein Frisian (HF): Bos taurus; n = 42) and Crossbred (XB: Cholistani (Bos indicus) × HF; n = 28) cows. In the CIDR-GnRH/CIDR-EB treatment, CIDR was implanted in the cows after confirming the presence of a corpus luteum (CL) on the 8th day after estrus. 2 ml GnRH (Lecirelin acetate 0.0262 mg/ml) or 2 mg EB was also administered in CIDR-GnRH/CIDR-EB groups, respectively. Both groups were given super-stimulatory treatment from the 11th day after estrus (FSH in tapering doses twice a day for four consecutive days). On day 13, two doses of 2 ml prostaglandin (75 µg/ml of dextrorotatory cloprostenol) were administered (am: pm), and CIDR was removed the following day. Two artificial inseminations (AI) of the cows were performed (12 h apart) on the 15th day. No CIDR and GnRH/E.B were given in the control group, but the remaining superovulation protocol was the same. Later on, seven days after the first AI, non-surgical embryo flushing was done. The transferable embryos produced from three different superovulation protocols were then transferred into the recipient cows (n = 90) for determining their fertility. Statistical analysis revealed that the number of super-estrus follicles (SEF), multiple corpora lutea (MCL), ovulation/fertilization percentage, fertilized structures recovered (FSR), and transferable embryos (TEs) remained significantly higher (p < 0.05), and days taken for return to estrus (RTE) after embryo collection remained significantly lower (p < 0.05) in CIDR-GnRH (n = 18) and CIDR-EB (n = 15) groups as compared to the control (n = 37). The comparison between XB and HF cows revealed that the TEs production in CIDR-GnRH (XB = 5 vs HF = 13) and CIDR-EB (XB = 6 vs HF = 9) based superovulation protocols were 11.60  ±  4.08 vs 04.31  ±  0.98 and 09.33  ±  1.78 vs 05.22  ±  1.36, respectively. TEs production in XB cows (n = 5) of the CIDR-GnRH group was significantly higher (11.60  ±  4.08) than other groups. On the other hand, the days taken for RTE after embryo collection remained significantly lower (p < 0.05) in HF cows of treatment groups. However, the fertility of TEs was neither affected significantly (p > 0.05) by the superovulation protocol used nor by breed differences among donor cows. In conclusion, using CIDR-GnRH or CIDR-EB along with conventional superovulation protocol may enhance the efficiency of MOET programs in cattle. Furthermore, XB donor cows demonstrated a better performance than HF donor cows under subtropical conditions.


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