173 ESTRADIOL-17β CONCENTRATIONS IN BLOOD AND MILK DURING SUPEROVULATORY TREATMENT IN DAIRY COWS

2010 ◽  
Vol 22 (1) ◽  
pp. 245
Author(s):  
R. Dupras ◽  
J. Dupras ◽  
Y. Chorfi

In cows, estradiol-17β is usually used to synchronize follicular wave emergence during superovulatory treatment. This approach, however, raises some concerns about the presence of estrogens in bovine products and their possible association with some human estrogen-sensitive cancers. The objective of this study was to determine estradiol-17β concentrations in blood and milk of dairy cows after i.m. injection of estradiol-17β and to compare these concentrations to those obtained during standard superovulation protocols. Six cows were used for this experiment. On Day 0, corresponding to Day 7 of their ensuing cycle, cows received 4.5 mg of estradiol-17β (Gentes et Bolduc, St-Hyacinthe, Québec, Canada) via i.m. injection and a progesterone-releasing vaginal insert (1.9 g of progesterone, CIDR, Pfizer Animal Health, Kirkland, Québec, Canada). Blood and milk samples were taken at 0, 24, 48, and 72 h after injection. From Day 4 evening to Day 8 evening, the cows received a total of 380 mg of NIH-FSH-P1 (Folltropin-V, Bioniche Animal Health, Belleville, Ontario, Canada) administered i.m. through 9 injections of decreasing dose (from 70 to 20 mg) at 12-h intervals. On Day 7, the cows received 2 injections consisting of 500 μg of cloprostenol (prostaglandin F2 α analogue, Estrumate, Shering-Plough, Pointe-Claire, Québec, Canada) given approximately 12 h apart and vaginal inserts were removed 12 h after the last injection. Artificial insemination was performed on Day 9 and 10 after treatment with 100 μg of GnRH i.m. (Cystorelin, Merial Canada Inc., Baie Urfe, Québec, Canada). A second batch of blood and milk samples was taken at Day 8, 9, 10, and 11. Measurement of estradiol-17β was performed with an IMMULITE chemiluminescent counter using an IMMULITE Estradiol Kit (Siemens Diagnostic Products Corporation, Los Angeles, CA, USA). Concentrations of estradiol-17β in blood (37.1 ± 15.6 pg mL-1 at 24 h, 19.1 ± 14.2 pg mL-1 at 48 h) and milk (38.4 ± 29.5 pg mL-1 at 24 h, 9.3 ± 4.9 pg mL-1 at 48 h) were significantly higher after i.m. injection of 4.5 mg of estradiol-17β. In comparison, superovulation heat (Day 9 to 11) increased estradiol-17β concentrations in blood (20 ± 13.6 pg mL-1 at 24 h, 32.5 ± 16.3 pg mL-1 at 48 h) but not in milk.

2009 ◽  
Vol 21 (1) ◽  
pp. 246 ◽  
Author(s):  
R. G. Steel ◽  
J. F. Hasler

Traditionally, successful superstimulation of cattle depended on initiating injections of gonadotrophin at mid-cycle, approximately at second follicular wave emergence. This approach limited the convenience of scheduling donors for superstimulation. With the use of intravaginal progesterone-releasing devices and estradiol 17β, superstimulation can be initiated successfully at any time of the estrous cycle. However, because estradiol cannot be legally injected into cattle in an increasing number of countries, the efficacy of GnRH as an estradiol substitute was investigated. A retrospective analysis was performed on data collected in a commercial bovine embryo transfer program over a period of several years. All donors were lactating dairy cows at least two years of age; approximately 75% were comprised of Holstein and the remainder of Jersey, Guernsey, or Brown Swiss breeds. The three treatments employed were (1) Controls injected twice daily for 4 days with a total of 240 to 400 mg of porcine FSH (Folltropin-V, Bioniche Animal Health, Inc.) in decreasing doses starting between day 7 and day 14 of diestrus, with PG (Lutalyse, Pfizer Animal Health) given at the time of FSH injections no. 5 (35 mg) and 6 (25 mg); (2) Estradiol females received a CIDR (Pfizer Animal Health), 5.0 mg estradiol 17β and 100 mg progesterone in oil on random days of the estrous cycle; FSH was initiated 4 days later as described for controls with CIDR removal at the time of FSH injection no. 6; (3) GnRH females received a CIDR on random days of the estrous cycle and 100 μg GnRH on day 1.5 following CIDR insertion; FSH was initiated 60 h after GnRH injection as described for controls with CIDR removal at the time of FSH injection no. 6. All donors were inseminated with one straw of frozen semen 12 and 24 h after the onset of estrus. Embryos were nonsurgically recovered 7 to 8 days after onset of estrus. Only embryos of grades 1 to 3 (IETS classification) were included in the data. Data were analyzed by ANOVA and Tukey’s hsd test was used to distinguish significance among means as shown in Table 1. Estradiol females produced approximately 2 more ova/embryos per procedure than Control and GnRH groups and an average of 0.8 more embryos per female than did the Control group, but there was no difference compared to the GnRH group. Similar to what has been shown in other commercial embryo transfer data sets, nearly 25% of the donors in each group failed to produce at least one good embryo. Clearly, all three treatments resulted in efficacious superstimulation. In light of the legality issues surrounding the use of estradiol, this study shows that GnRH can be used quite successfully to superstimulate dairy cattle at random times of the estrous cycle. Table 1.Average numbers of ova and embryos recovered from dairy cows superstimulated with three different protocols We thank G.E. Seidel, Jr. and S.C. Purcell for assistance with statistical analysis.


2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Desiye Tesfaye Tegegne ◽  
Gezahegne Mamo ◽  
Hika Waktole ◽  
Yohannes Equar Messele

Abstract Purpose Staphylococcus aureus (S. aureus) is the most important pathogen involved in bovine mastitis in dairy production. S. aureus produces a spectrum of extracellular protein toxins and virulence factors which are thought to contribute to the pathogenicity of the organism. The aim of this work was to isolate and molecular characterize S. aureus associated with bovine subclinical mastitis in the central part of Ethiopia. Methods A total of 265 lactating dairy cows from various dairy farms in four different geographical locations were screened by the California mastitis test (CMT) for bovine subclinical mastitis. One hundred thirty CMT-positive milk samples were collected and transported to the laboratory. Different biochemical tests and polymerase chain reaction (PCR) were used for the identification of S. aureus isolates. Finally, PCR was performed for molecular detection of virulence genes. Results From a total of 265 lactating dairy cows screened, 49% (n = 130) were positive for bovine subclinical mastitis. One hundred thirty mastitic milk samples were subjected to bacterial culturing, and one hundred (76%) S. aureus isolates were identified based on phenotypic characters. Sixty-eight confirmed S. aureus isolates were obtained using PCR. The confirmed S. aureus isolates were tested for six virulence genes (tsst-1, hlb, eta, sea, clfA, and icaD) using PCR. Of the six virulence genes screened from all the isolates, only two (clfA and eta) were detected in the isolates. Out of 68 isolates, 25% and 22% were possessed the eta and clfA genes, respectively. Conclusion The presence of Staphylococcus aureus having virulence genes (eta and clfA) revealed that mastitis is a major concern nowadays affecting animal health, milk quality, and yield. Further genomic study of these isolates will provide broad new insights on virulence.


2013 ◽  
Vol 25 (1) ◽  
pp. 229
Author(s):  
J. W. Thorne ◽  
C. R. Looney ◽  
J. F. Hasler ◽  
D. K. Hockley ◽  
D. W. Forrest

This study was performed to test the viability of administering Folltropin-V® (FSH, Bioniche Animal Health) diluted in hyaluronan (MAP-5 50 mg, sodium hyaluronate, Bioniche Animal Health) to beef cows enrolled in a recipient synchronization protocol to evaluate its effect on recipient fertility. All recipients were administered an estradiol 17β (2.5 mg, IM) and progesterone (50 mg, IM) combination injection on Day 0, a CIDR® (progesterone 1.34 g, Pfizer Animal Health, Groton, CT, USA) was inserted for 7 days. Lutalyse® (dinoprost tromethamine, Pfizer Animal Health, 25 mg, IM) was administered at the time of CIDR removal on Day 7, and estradiol 17β (1 mg, IM) was administered on Day 8. On Day 16, the presence of at least one corpus luteum, detected via ultrasound, resulted in the recipient receiving an embryo (both fresh and frozen–thawed embryos were used). Embryos were not transferred into cows that did not show ultrasonic evidence of a CL. Dependent variables for which data were collected included circulating progesterone levels at the time of transfer and CL diameter, area, and circumference; measured in millimeters. The total study (n = 274) consisted of both wet (n = 85) and dry (n = 189) cows and included both Bos indicus (Brahman-influenced) crossbred (n = 93) and Bos taurus (Angus-based) cows (n = 181). The experiment consisted of cows being placed in either the treated or control groups, with treated cows receiving a single 40 mg (1 mL) IM injection of Folltropin-V in hyaluronan on Day 5 and control cows receiving no additional injections. Results are shown in Table 1. Transfer rate, conception rate, and pregnancy rate were tested for significance with chi-square analysis and remaining statistics were analyzed with a t-test: two-sample assuming equal variances. There were no significant differences found between the treated and control groups for transfer rate, conception rate, or pregnancy rate. Corpus luteum diameter was shown to be larger in control cows (P < 0.05); however, CL area and circumference did not differ significantly. Folltropin-V given with hyaluronan at a 40-mg dose on Day 5 did not improve fertility, induce a larger CL, or increase circulating progesterone levels in synchronized beef recipients as hypothesized. Further work is needed with Folltropin-V in hyaluronan to determine if an alternative dose or timing of administration would be more appropriate for improving fertility in recipients. Table 1.Fertility data in beef recipients following synchronization for fixed-time embryo transfer with a protocol that included (Treated) or did not include (Control) FSH in hyaluronan


2013 ◽  
Vol 25 (1) ◽  
pp. 156
Author(s):  
D. Romero ◽  
G. Romero ◽  
G. Veneranda ◽  
L. Filippi ◽  
D. Racca ◽  
...  

An experiment was designed to compare pregnancy rates in lactating dairy cows synchronized with a 7-day CIDR-Synch or a 5-day CIDR-Synch program and to determine if the addition of a second prostaglandin F2α (PGF) injection to the 7-day CIDR-Synch program would improve pregnancy rates following fixed-time AI (FTAI). The experiments were performed on 2 dairy farms in Argentina, with year-round calving and a mixed feeding system (35% grazing plus 65% corn silage and grain). Cows (n = 621) were 39.3 ± 6.5 days in milk (DIM, mean ± SD) when they were enrolled in the program, had 2.4 ± 1.5 lactations and a body condition score (BCS) of 3.1 ± 0.2 (range: 2.7 to 4.0). All cows received a pre-synchronization treatment with 2 doses of prostaglandin (PGF, 25 mg of dinoprost, Lutalyse, Pfizer Animal Health, Argentina) 14 days apart, and 11 days after the second PGF (Day 0) received 10 µg of Buserelin (GnRH, Receptal, MSD-Intervet, Argentina) and a CIDR device (1.9 g of progesterone, Pfizer Animal Health). Cows were randomly allocated to 1 of 3 groups. The CIDR devices were removed and PGF was administered to cows in Groups 1 and 2 on Day 7. A second GnRH was given 56 h later and cows experienced FTAI 16 h after gonadotropin-releasing hormone (GnRH) injection (i.e. 72 h after CIDR removal). Cows in Group 2 also received a second PGF injection on the afternoon of Day 7. Cows in Group 3 had the CIDR removed and received 2 PGF injections 12 h apart on Day 5. A second dose of GnRH was given and FTAI was performed at the same time, on Day 8 (i.e. 72 h after CIDR removal). All cows were examined by ultrasonography (Aloka 500V, Aloka, Tokyo, Japan) on the day of the first PGF injection and at CIDR removal to determine the presence and number of corpora lutea (CL), and 30 days after FTAI to determine pregnancy status. Data were analyzed by logistic regression to determine the effects of treatment, parity, days postpartum, milk production, BCS, presence of a CL at enrollment, and number of CL at the time of CIDR removal on pregnancy rates. Overall pregnancy rates did not differ among groups: 32.9% (68/207), 38.2% (78/204), and 38.3% (80/209) for Groups 1, 2, and 3, respectively (P = 0.2). Although the number of CL present at CIDR removal did not significantly affect pregnancy rates (P = 0.4), pregnancy rates in cows with 1 CL in Groups 1 and 2 tended to differ [29.0% (11/38) v. 48.9% (21/43); P < 0.07], but neither differed from that in Group 3 [37.2% (16/43)]. No differences were detected among groups in cows without a CL at CIDR removal [overall pregnancy rate: 29.4% (5/17)] and those with ≥2 CL [overall pregnancy rate: 36.1% (173/479)]. Among the other variables evaluated, first-parity cows had 1.96 (1.38–2.78) times more chance of getting pregnant than second-or-more-parity cows (P = 0.002) and cows with BCS >3 had 1.63 (1.16–2.28) times more chance of getting pregnant than those with BCS <3 (P = 0.003). Finally, herd, days postpartum, milk production, and presence of a CL at enrollment did not significantly affect pregnancy rates. We concluded that the 3 treatments resulted in similar pregnancy rates for lactating dairy cows and that the benefit of adding a second PGF injection to the 7-day protocol was only marginal in cows with 1 CL at CIDR removal.


2013 ◽  
Vol 25 (1) ◽  
pp. 306
Author(s):  
M. E. F. Oliveira ◽  
C. C. D'Amato ◽  
C. S. Oliveira ◽  
F. F. P. C. Barros ◽  
A. P. Perini ◽  
...  

This study was designed to investigate if the time of onset of FSH treatment [near the emergence of first or last follicular wave on progesterone (P4) protocol] influenced the superovulatory response and embryo yield in Santa Ines ewes during breeding season. Days of emergence of the follicular waves were defined in a previous study that evaluated the follicular dynamic in oestrus synchronization treatments (Oliveira et al. 2011 Acta Sci. Vet. 40). We observed emergence of the first and last follicular wave on 5.69 ± 0.42 and 11.25 ± 0.39 days of protocol, respectively. Twenty Santa Ines ewes were submitted to 2 superovulatory protocols according to the time that FSH treatments were initiated (G-first wave, n = 10; G-last wave, n = 10). On Day 0, all ewes received a P4 device (CIDR®; Pfizer Animal Health, New York, NY, USA) and injection of 37.5 µg of d-cloprostenol, IM. The FSH treatments started on Day 6 and Day 11 of protocol for G-first and G-last, respectively. The superovulatory regimen consisted of 8 IM injections of pFSH administrated twice daily (40, 40, 30, 30, 20, 20, 10, and 10 mg of pFSH). The P4 device was removed on Day 8 and Day 13 for G-first and G-last, respectively. At these times, all ewes received another injection of 37.5 µg of d-cloprostenol and a dose of 200 IU of eCG. During 4 days after the P4 device removal, ewes were mated by a fertile ram. Embryo collections were accomplished 7 days after CIDR withdrawal. The ovaries were evaluated by ultrasonography (3 times daily, during the mating period) and laparotomy (concomitantly with embryo collection). The superovulatory response was observed by classified by score: 0 = 4 or fewer corpora lutea (CL); 1 = between 5 and 10 CL; and 2 = 11 or more CL. Data were analysed by GLIMMIX using SAS software (SAS Institute Inc., Cary, NC, USA). All donors from G-first had superovulatory response classified as score 2, whereas 60% of ewes from G-last were classified as score 2, 20% as score 1, and 20% as score 0 (P < 0.05). There were effects between treatments (P < 0.05) for ovulation rate (G-first: 97.9 ± 1.4% v. G-last: 88.5 ± 4.4%) and number of ovulations (G-first: 17.0 ± 2.3 v. G-last: 12.5 ± 2.6). The numbers of luteinized unovulated follicles were 0.7 ± 0.5 for G-first and 1.2 ± 0.4 for G-last (P > 0.05). There was no difference between G-first and G-last (P > 0.05) in the rate of ova/embryos recovered (54.9 ± 5.7% v. 49.3 ± 8.5%), mean number of ova/embryos recovered (9.0 ± 1.4 v. 6.3 ± 1.1), number of viable embryos (3.8 ± 1.5 v. 3.4 ± 0.8), or viability rate (40.3 ± 10.8 v. 53.4 ± 12.1). In conclusion, the FSH treatment started near the emergence of the first follicular wave of progesterone protocol in Santa Ines ewes during the breeding season resulted in a higher superovulatory response than that started near the last follicular wave; however, no improvements in embryo yield were observed. Financial support: FAPESP.


2010 ◽  
Vol 22 (1) ◽  
pp. 171
Author(s):  
M. F. Martínez ◽  
D. Tutt ◽  
L. Proctor ◽  
J. L. Juengel

An experiment was designed to evaluate the effect of different doses of eCG on ovarian follicular dynamics in heifers treated with a Ovsynch plus progesterone protocol. Twenty-five cyclic yearling Black Angus heifers (373.0 ± 35.7 kg), in 2 replicates, received an injection of 100 μg of GnRH (Ovurelin, Bomac Laboratories Ltd., Auckland, New Zealand) i.m. and an intravaginal progesterone device (1.38 g of progesterone; Eazi-Breed CIDR, Pfizer Animal Health, New Zealand) on Day 0 (beginning of the experiment), followed by 500 μg of cloprostenol (PGF, Estrumate, Intervet/Schering-Plough Animal Health, Auckland, New Zealand) i.m. on Day 7, and a second 100 μg of GnRH injection given i.m. on Day 9 (56 h after PGF). At the time of PGF treatment, heifers were randomly assigned to 5 treatment groups to receive 0, 300, 500, 700, or 1000 IU of eCG (Folligon, Intervet/Schering-Plough Animal Health) i.m. Heifers were monitored by ultrasonography (Aloka 900-SSD equipped with a 7.5-MHz linear-array transducer; Aloka, Tokyo, Japan) daily from Day 0 to 9 (GnRH), and then every 12 h until ovulation. Data were analyzed by one-way ANOVA or Kruskall-Wallis test, and means or ranks were compared with LSD or Wilcoxon rank sum tests, respectively. Because a replicate effect was observed (P < 0.05) in the size of the dominant follicle at the second GnRH and prior to ovulation, replicate effect was included in the analysis. The luteal area at PGF treatment was significantly greater (P < 0.01) in heifers that ovulated (750.0 ± 97 mm2) in response to the first GnRH treatment than in those that did not (301.6 ± 42.7 mm2). The diameter of the dominant follicle at the time of PGF treatment was also greater (P < 0.05) in ovulating (11.2 ± 0.4 mm) than in nonovulating (9.7 ± 0.5 mm) heifers. The interval from the first GnRH treatment to the emergence of the next follicular wave was longer (P = 0.50) and more variable in heifers that did not ovulate (2.9 ± 0.4 d; n = 27) than in those that ovulated (1.9 ± 0.2 d; n = 23). There was no effect (P < 0.37) of eCG on the interval from PGF to ovulation (86 ± 1.9 h). The number of ovulations after the second GnRH was higher (P = 0.01) in the group of heifers treated with 1000 IU of eCG (1.8 ± 0.4) than in the other groups (1.0 ± 0.0; 1.1 ± 0.1; 1.2 ± 0.1; 1.0 ± 0.1). There was an effect of day of follicular wave emergence on the number of ovulations (P < 0.01). Heifers with a wave emerging 1 to 3 days after the first GnRH (n = 37), had one ovulation (1.0 ± 0.0), whereas heifers with a wave emerging on Day 4 (3 out of 4 heifers) and Days 5 to 7 (n = 9), ovulated 2 or more follicles. In summary, the multiple ovulation effect occurred when eCG was given to heifers with a follicular wave emerging on or after Day 4, and was potentiated when heifers received 1000 IU of eCG. Although the dose of eCG given at the time of PGF treatment in an Ovsynch program has a significant effect on follicular development, the time of emergence of the dominant follicle appeared to be more important in the ovulation of preovulatory follicle/s after the eCG and the second GnRH treatment.


Author(s):  
A. Srikandakumar ◽  
A. Mohammed ◽  
A. AI-Abri

Estrus was synchronized in dairy cattle using the synthetic prostaglandin F2a (PG) analog Estnunate (Coopers Animal Health Ltd., Berkhamsed, England. UK; 250 ug/ml of cloprostenol). PG was administered by two routes at two different doses, 500 ug by im route (control) and 125 pg by intravulval lip (ivu) route (treatment). All animals were bred by artificial insemination (AI) to detected estrus using the am-pm breeding rule (BR). First service conception rate (FSCR) for all dairy cows and heifers was 70% for the control and 54% for the treatment groups (P>0.05). The FSCR was also not different (P>0.05) between Holstein (HOL) and Australian Milking Zebu (AMZ) breeds (HOL 52% and AMZ 78%). Moreover, all the animals in this study were confirmed pregnant by the end of the breeding season. In conclusion, dairy cows and heifers can be successfully synchronized using only 125 pg of cloprostenol without impairing fertility. This dose corresponds to only one fourth of the recommended dose of 500 pg of cloprostenol by the manufacturer.  


2007 ◽  
Vol 19 (1) ◽  
pp. 126 ◽  
Author(s):  
D. Rogan ◽  
M. F. Martinez ◽  
G. A. Bo ◽  
P. Chesta ◽  
F. Feresin ◽  
...  

Various intravaginal progesterone-releasing devices are commercially available and each is impregnated with different amounts of progesterone. An experiment was designed to characterize plasma progesterone release profiles from Cue-Mate in comparison with other commercially available progesterone-releasing devices. Cycling, lactating Holstein cows (n = 60; BCS between 2.0 and 3.0 out of 5) from commercial dairy farms in Argentina were used in 2 replicates. All cows received 2 injections of D+ cloprostenol (PGF, Bioprost-D�; Biotay, Buenos Aires, Argentina) 14 days apart and were randomly assigned to one of four groups to receive intravaginal devices as follows: Cue-Mate (1.56 g progesterone; Bioniche Animal Health, A/Asia Pty, Armidale, Australia; n = 10), DIB (1 g progesterone; Syntex SA, Argentina; n = 10), CIDR with 1.9 g progesterone (Pfizer Salud Animal S.A., Buenos Aires, Argentina; n = 10), or CIDR with 1.38 g progesterone (Pfizer Animal Health, Groton, CT, USA; n = 10). All devices were inserted 24 hours after the second PGF and were left in place for 31 days. Blood samples were taken for progesterone analysis at 6-hour intervals for the first 24 hours, then daily for a week, and every 2 days for an additional 25 days. Plasma progesterone concentrations were measured with a modified human double-antibody RIA kit (DPC Coat-A-Count�; Diagnostic Products Corporation, Los Angeles, CA, USA). Cows were observed twice daily to confirm that vaginal inserts were still in place. Time-series hormone data were analyzed using the MIXED procedure for repeated measures (SAS Institute, Inc., Cary, NC, USA). Main effects of device and time, the highest mean concentration of progesterone, and the mean day on which this occurred were compared by a protected LSD test. There was no evidence of cow discomfort with any of the vaginal devices, and loss rates did not differ. There was an effect of group (P &lt; 0.001) and day (P &lt; 0.001) for progesterone concentrations, but there was no interaction (P = 0.89). Peak concentrations of progesterone (ng mL-1) did not differ among groups (Cue-Mate: 5.0 � 1.1; DIB: 3.9 � 0.6; 1.9-g CIDR: 4.6 � 0.6; 1.38-g CIDR: 3.7 � 0.4; P = 0.51). Mean (� SEM) concentrations of progesterone over the 31-day insertion period differed between 1.9-g CIDR (1.8 � 0.2 ng mL-1) and DIB (1.5 � 0.1 ng mL-1, P &lt; 0.006), with Cue-Mate (1.5 � 0.2 ng mL-1) and 1.38-g CIDR (1.6 � 0.1 ng mL-1) intermediate and not different from either. When data were evaluated from insertion until Day 7, mean plasma progesterone concentrations did not differ among groups (Cue-Mate: 2.2 � 0.2 ng mL-1; DIB: 2.2 � 0.1 ng mL-1; 1.9-g CIDR: 2.6 � 0.2 ng mL-1; 1.38-g CIDR: 2.1 � 0.1 ng mL-1). However, progesterone concentrations from insertion until Day 21 were higher (P &lt; 0.03) in cows with a 1.9-g CIDR (2.1 � 0.1 ng mL-1) than in those with a DIB (1.6 � 0.1 ng mL-1) or a 1.38-g CIDR (1.6 � 0.1 ng mL-1), with Cue-Mate (1.7 � 0.1 ng mL-1) intermediate and not different. Based on progesterone release patterns, it was concluded that Cue-Mate intravaginal devices can be used in protocols for synchronization of estrus and ovulation as with other progesterone-releasing devices.


2009 ◽  
Vol 21 (1) ◽  
pp. 169
Author(s):  
R. Dupras ◽  
Y. Chorfi

The objective of this study was to evaluate the use of a second flush for bovine embryo recovery. A total of 319 clinically healthy Holstein cows (247 lactating, 53 dry, 19 nulliparous) with an average age of 5.5 ± 2.5 years were used for this experiment. Superovulation was performed according to a modified method of Baracaldo et al. (2000). On Day 0 (beginning of the experiment), each cow received 3 mg of estradiol-17β intramuscularly (i.m.) and a progesterone-releasing vaginal insert (1.9 g of progesterone, CIDR, Pfizer Animal Health, Kirkland, QC, Canada) at random stages of the estrous cycle. From Day 4 evening to Day 8 evening, the cows received a total of 380 mg of NIH-FSH-P1 (FolltropinV, Bioniche Animal Health) administered im through 9 injections of decreasing dose (from 70 to 20 mg) at 12-h intervals. On Day 7, the cows received 2 injections consisting of 500 μg of cloprostenol (prostaglandin F2α analogue Estrumate, Schering-Plough, Pointe-Claire, QC, Canada) given approximately 12 h apart and vaginal inserts were removed 12 h after the last injection. Artificial insemination was performed on Day 10 after treatment with 100 μg, GnRH im (Cystorelin, Merial Canada Inc, Baie d’Urfe, QC, Canada). Embryos were flushed from the uterus of donor cows 6 days after AI. The method consisted of using simultaneously 1 catheter (18Fr Silicone 2-way, Bioniche Animal Health) per uterine horn. Catheters were maintained in place to perform 2 flushes 1 h apart. A total of 1000 mL of flushing media (Complete flush, Bioniche Animal Health) were used, 700 mL and 300 mL for the first and the second flush, respectively. Embryos were assessed for viability immediately after collection using IETS classification. Data were analyzed using the SAS MIXED procedure (SAS Institue, Cary, NC). The mean (±SD) number of embryos collected at the first flushing was 5.87 ± 5.1, 0.92 ± 2.2 and 2.9 ± 4.4 for transferable, degenerate and unfertilized oocytes, respectively. The second flushing yielded 2.32 ± 2.6 transferable embryos, 0.28 ± 0.83 dead embryos and 1.2 ± 2.2 unfertilized oocytes. There was no significant effect of age, day in milk, or stage of lactation on transferable or degenerate embryos or nonfertilized oocytes in each flushing. The embryo recovery method used in this experiment could be used to recover more transferable embryos. The authors want to thank Dr Vincent Girard for his help in statistics.


2008 ◽  
Vol 88 (3) ◽  
pp. 457-461
Author(s):  
M. Aali ◽  
T. Pretheeban ◽  
G. Giritharan ◽  
R. Rajamahendran

Peripheral progesterone (P4) concentrations as well as pregnancy rates (PR) between cows treated with Ovsynch or CIDR ovulation synchronization/TAI protocols were compared. Two hundred and twenty-seven postpartum lactating Holstein cows were randomly assigned to Ovsynch (n = 111) or CIDR (n = 116) ovulation synchronization/TAI protocols. Pregnancy was diagnosed by ultrasonography at day 35 after TAI and later confirmed by rectal palpation at day 60 post TAI. Milk samples were taken from the beginning of treatment (day -10) until day 35 after TAI (day 0) for P4 determination. Pregnancy rates for Ovsynch and CIDR groups of cows were 31 and 41%, respectively. The PR of ovulation synchronized cows for Ovsynch and CIDR groups were 49 and 69%, respectively. Progesterone levels during the sampling period were similar (P > 0.05) between Ovsynch and CIDR treated cows. Key words: Pregnancy rate, progesterone, Ovsynch, CIDR, cows


Sign in / Sign up

Export Citation Format

Share Document