364 DISTRIBUTION OF OVULATION AND SUBSEQUENT EMBRYO PRODUCTION USING LUTROPIN AND ESTRADIOL-17β FOR TIMED AI OF SUPERSTIMULATED BEEF FEMALES

2006 ◽  
Vol 18 (2) ◽  
pp. 289 ◽  
Author(s):  
W. Larkin ◽  
P. Chesta ◽  
C. Looney ◽  
G. Bo ◽  
D. Forrest

This experiment was designed to compare timing of ovulation and embryo production between traditional superstimulatory and AI methods and the use of additional treatments of Estradiol-17β and pLH (Lutropin; Bioniche Animal Health, Belleville, Ontario, Canada) to facilitate timed AI in beef cows. A total of 31 mature cross-bred beef cows were randomly assigned three treatments. On Day 0, experimental cows were selected upon transrectal ultrasound evaluation for corpus leutum (>10 mm) prior to CIDR insertion plus 2.5 mg estradiol-17β and 50 mg Progesterone i.m. Superstimulatory treatments with Folltropin-V (Bioniche Animal Health) began on Day 4 for 3.5 days (236 mg NIH-FSH-P10) in decreasing dosages (7 injections at 0700 and 1900). All cows received prostaglandin F (PGF) treatments of 625 mcg D-cloprostenol i.m. (Estrumate; Schering-Plough, Union, NJ, USA) in both AM and PM on Day 6, and CIDRs were removed in AM of Day 7, followed by the final injection of Folltropin. In addition, Heat Watch patches (Heat Watch; Cow Chips, Denver, CO, USA) were applied to optimize heat detection. Donors selected as control treatment were AI at 12 and 24 h post-onset of estrus (first mount) with frozen semen from the same bull. Donors selected on the Estradiol-17β treatment received 1 mg i.m. 12 h after CIDR removal and timed AI at 24 and 36 h. Donors selected for Lutropin treatment received 12.5 mg (5cc i.m.) 24 h after CIDR removal and were timed AI at 12 and 24 h. All AI procedures used 2 units from the same bull. All cows were examined by ultrasonography every 8 h beginning 24 h post-CIDR removal and ending at 60 h to determine the time and distribution of ovulation. Ovulation was determined by the disappearance of follicles (>12 mm) from the prior examination. All AI and ultrasound procedures were performed by the same technician. There were no differences detected between the three treatments as evaluated by all the variables we studied (Table 1). However, donors treated with Lutropin tended to produced more viable embryos per collection and had a tighter degree of distribution of ovulations. Donors treated with Estradiol-17β tended to have fewer viable embryos. More research is needed to determine if donors can be timed AI without regard to estrus. Table 1. Mean onset of estrus, distribution of ovulation, and embryo production in superstimulated beef donors treated with Estradiol-17β, and Lutropin

2006 ◽  
Vol 18 (2) ◽  
pp. 115
Author(s):  
H. Davis ◽  
M. Colazo ◽  
M. Rutledge ◽  
J. Small ◽  
J. Kastelic ◽  
...  

Two experiments were conducted to determine the effects of plasma progesterone (P4) concentrations on LH release and ovulation in beef heifers and lactating beef cows given gonadotropin-releasing hormone (GnRH). Previously autoclaved, once-used CIDR inserts (Colazo et al. 2004 Anim. Reprod. Sci. 81, 25-34) were used for experimental purposes to induce differential plasma progesterone concentrations. In Experiment 1, postpubertal heifers received 25 mg of dinoprost i.m. (prostaglandin F (PGF); Lutalyse; Pfizer Animal Health, Montreal, Quebec, Canada). On Day 4 (estrus = Day 0), heifers were randomly assigned (10/group) to receive no treatment (control) or 1 or 2 autoclaved once-used CIDR (Pfizer Animal Health) inserts (1CIDR and 2CIDR, respectively). On Day 5, heifers in the 1CIDR group were given PGF twice 12 h apart. On Day 6, all heifers received 100 �g of GnRH i.m. (Cystorelin; Merial Canada, Inc., Victoriaville, Quebec, Canada). Once daily on Days 4 to 9, a blood sample was collected and ultrasonography was performed. On Day 6, heifers in the control (3.0 � 0.4 ng/mL; mean � SD) and 1CIDR groups (3.0 � 0.3 ng/mL) had lower (P < 0.01) plasma progesterone concentrations than those in the 2CIDR group (5.7 � 0.4 ng/mL). However, the diameter of the dominant follicle was larger (P < 0.001) in heifers in the control and 1CIDR groups than in the 2CIDR group (12.1 � 1.0, 11.5 � 0.7, and 10.1 � 0.7 mm, respectively). More (P < 0.01) heifers ovulated in response to GnRH in the control and 1CIDR groups than in the 2CIDR group (10/10, 9/10, and 3/10, respectively). In Experiment 2, ultrasound-guided follicular ablation (FA) was performed (to synchronize ovarian follicular wave emergence) 4 to 6 days after estrus in 20 postpubertal heifers and 20 mature lactating cows. Cattle were randomly and equally assigned to receive an autoclaved, once-used CIDR, either with no further treatment (High-P4) or with two PGF treatments 12 h apart (Low-P4) given after FA. All cattle received 100 �g of GnRH either 6 days after FA or the day after the dominant follicle reached 9 mm in diameter. Ultrasonography was performed daily (from 4 days after FA to ovulation or to 3 days after GnRH treatment). In three cows and three heifers per group, blood samples were collected every 30 min for 12 h after GnRH. The dominant follicle at GnRH treatment was larger in cows than heifers (11.0 � 1.1 vs. 10.3 � 0.9 mm, respectively; P = 0.05) and tended to be smaller in the High-P4 group vs. the Low-P4 group (10.3 � 1.0 vs. 11.0 � 1.0 mm; P = 0.06). Ovulatory response was not different (P = 0.9) between heifers (77.7%) and cows (78.9%), but combined for heifers and cows, was lower in High-P4 vs. Low-P4 cattle (61.1 vs. 94.7; P < 0.01). The GnRH-induced LH surge did not differ (P = 0.23) between cows and heifers, but it was lower and of shorter duration (P < 0.001) in the High-P4 group than in the Low-P4 group. In summary, higher plasma P4 concentrations resulted in decreased LH release and the proportion of cattle ovulating in response to GnRH treatment. There was no significant difference between heifers and cows in LH release or ovulatory response.


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.


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


2012 ◽  
Vol 24 (1) ◽  
pp. 225
Author(s):  
S. Kmaid ◽  
J. M. Saldaña ◽  
Z. Ramos ◽  
R. Ungerfeld

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)


2010 ◽  
Vol 22 (1) ◽  
pp. 367 ◽  
Author(s):  
A. Tríbulo ◽  
H. Tríbulo ◽  
R. Tríbulo ◽  
D. Carballo Guerrero ◽  
P. Tríbulo ◽  
...  

Two experiments were designed to determine the superovulatory response of Angus donors treated with a single injection of Folltropin®-V diluted in a slow release formulation (SRF; Bioniche Animal Health Inc., Belleville, Ontario, Canada). Experiment 1 was designed to compare superovulatory response in Angus donor cows (n = 29 per group) treated with a single i.m. injection of Folltropin®-V diluted in SRF with cows treated using the traditional twice-daily i.m. injection treatment schedule. On Day 0, all cows received 5 mg of estradiol-17β plus 50 mg of progesterone and a Cue-Mate® (Bioniche Animal Health). On Day 4, cows were superstimulated with 400 mg of NIH-FSH-P1 Folltropin®-V in twice-daily decreasing doses over 4 days or in a single i.m. injection in the neck. The single injection was prepared by diluting the Folltropin®-V lyophilized powder in 1 mL of saline for injection and mixed with 9 mL of the SRF in the syringe immediately before administration. In the am and pm of Day 6, all cows received PGF2 and Cue-Mates® were removed in the pm. In the am of Day 8, cows received 12.5 mg of porcine LH (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 recommendations. Means were compared between groups by t-test Mean (±SEM) number of ova/embryos and transferable embryos were 13.7 ± 2.1 and 7.1 ± 1.3 v. 12.3 ± 1.5 and 5.3 ± 0.8 for donors treated with the single v. twice-daily injections, respectively (P > 0.4). Experiment 2 was designed to confirm the results of Experiment 1 and to compare the effect of different dosages of Folltropin®-V on embryo production in Angus cows. Cows (n = 23) were superstimulated by 6 treatment protocols (2 × 3 factorial) in a crossover design (i.e. all cows received the 6 treatments and all treatments were represented on each collection day). Cows received the same treatments as cows in Experiment 1 except that the dosages of Folltropin®-V used were 200, 300, or 400 mg. Statistical analysis (ANOVA) revealed a significant effect of dosage of Folltropin®-V on embryo production, but there was no effect of treatment (i.e. single v. twice-daily injections; P > 0.2), nor was there a treatment by dosage interaction (P > 0.7). Mean (± SEM) number of ova/embryos and transferable embryos were 10.3 ± 0.9 and 5.4 ± 0.6 v. 11.3 ± 0.6 and 5.6 ± 0.5 for donors treated with the single or twice-daily injections, respectively (P > 0.2). Furthermore, the mean number of ova/embryos and transferable embryos were higher in cows treated with 400 mg (13.9 ± 1.1 and 6.5 ± 0.7) and 300 mg (12.0 ± 1.0 and 6.1 ± 0.7) of Folltropin®-V than those treated with 200 mg (6.6 ± 0.7 and 4.0 ± 0.5). In summary, superstimulation of Angus donor cows with a single i.m. injection of Folltropin®-V diluted in an SRF resulted in comparable embryo production to the traditional twice-daily i.m. administration of Folltropin®-V over 4 days. Although response did not differ between 300 and 400 mg, results suggest that 300 mg of Folltropin®-V given i.m. by a single or twice-daily injections is the most appropriate dose for Angus donor cows.


2010 ◽  
Vol 22 (1) ◽  
pp. 167 ◽  
Author(s):  
D. B. Carwell ◽  
J. A. Pitchford ◽  
G. T. Gentry Jr ◽  
H. Blackburn ◽  
K. R. Bondioli ◽  
...  

Artificial insemination has proven to be a valuable asset to the cattle industry. It is assumed that once good quality semen is frozen in liquid nitrogen it should remain viable indefinitely; however, semen viability has not been systematically evaluated after being stored for several decades. In this experiment, frozen semen from 25 purebred Angus bulls processed during 3 time periods (1960-1975 = 5 bulls; 1976-1991 = 11; 1992-2002 = 9 bulls) was used to randomly inseminate purebred lactating Angus cows and heifers and lactating crossbred beef cows. In experiment 1, Angus cows (n = 24) and Angus heifers (n = 16) and in experiment 2, crossbred cattle (n = 88) of 5 breeds (Beefmaster, Romosinuano, Bons Mara, Brangus, Brangus F1) were artificially inseminated with frozen-thawed Angus bulls semen from the 3 time periods. All females were in good body condition and at least 45 days postpartum and were synchronized using the SelectSynch protocol. Briefly, on treatment Day 0, females received an Eazi-Breed CIDR (Pfizer Animal Health, New York, NY, USA) implant and were administered GnRH (Factryl, 100 μg im), on Day 7, prostaglandin (Lutalyse, 25 mg im, Pfizer Animal Health) was administered and the CIDR removed. Cattle not responding to synchronization were subjected an additional prostaglandin treatment 8 to 10 days later. Estrus detection was conducted using the HeatWatch™ system for the Angus females and with Estrotect™ patches for the crossbred females. Females fitted with HeatWatch transponders that were successfully mounted 4 times within a 6-h period were considered to be in standing estrus and were inseminated 12 to 14 h later. Females fitted with Estrotect patches were observed twice daily (morning and evening) to identify females whose patch was scratched. Females were inseminated by an experienced technician 12 to 14h after the patch were observed as being scratched a minimum of 50%. Response to synchronization in Angus cows and heifers was 76% (n = 40), whereas in the crossbred cattle the response was 74% (n = 88). Cows and heifers were confirmed pregnant via transrectal ultrasonography 45 days postinsemination. Pregnancy rates confirmed by chi-square analysis were not different for Angus cows and heifers (58% and 43%, respectively). Also, pregnancy rates for the Angus females were not different across time periods 1, 2, and 3 (58, 43, and 53%, respectively). Pregnancy rates for crossbred females were not different across time periods 1, 2, and 3 (35, 60, and 44%, respectively). Overall pregnancy rates (experiments 1 and 2) were 47, 52, and 40% across time periods 1, 2, and 3 respectively. It is concluded from this study that semen units processed and frozen from Angus bulls from time periods 1, 2, and 3 (from the 1960s through to 2002) are still viable and produce similar pregnancy rates in artificially inseminated beef females. Thanks to Jared Pitchfordfor inseminating all of the cattle; Harvey Blackburn for providing the semen to make the project possible; and my advisors Dr. Gentry and Dr. Godkefor assisting throughout the entire project. I also thank all of the graduate students who have helped me throughout the project.


2010 ◽  
Vol 22 (1) ◽  
pp. 365 ◽  
Author(s):  
D. Rogan ◽  
A. Tríbulo ◽  
H. Tríbulo ◽  
R. Tríbulo ◽  
D. Carballo Guerrero ◽  
...  

Two experiments were designed to evaluate the superovulatory response of Brangus and Bonsmara donor cows to different dosages of Folltropin®-V (Bioniche Animal Health Inc., Belleville, Ontario, Canada) given by a single i.m. injection or twice-daily i.m. injections. In Experiment 1, Brangus cows (n = 12) were superstimulated by 6 treatments (2 × 3 factorial) in a crossover design (i.e. all cows received the 6 treatments and all treatments were represented on each day). On Day 0, cows received 5 mg of estradiol-17β plus 50 mg of progesterone and a Cue-Mate® (Bioniche Animal Health Inc.). On Day 4, cows were superstimulated with 300, 260, or 200 mg of NIH-FSH-P1 Folltropin®-V (Bioniche Animal Health Inc.) in twice-daily decreasing doses over 4 days or diluted in a slow release formulation (SRF; Bioniche Animal Health) and given in a single i.m. injection. The single injection was prepared by diluting the Folltropin®-V lyophilized powder in 1 mL of saline followed by mixing with 9 mL of the SRF in the syringe immediately before administration. In the am and pm of Day 6, all cows received PGF2, and Cue-Mates® were removed in the pm. Cows received 12.5 mg of porcine LH (Lutropin®-V; Bioniche Animal Health Inc.) in the am of Day 8 and were inseminated 12 and 24 h later. Ova/embryos were collected on Day 15 and data were analyzed by ANOVA. There was no effect of treatment (i.e. single v. twice-daily injections; P > 0.2) nor a treatment by dosage interaction (P < 0.6) on the mean (± SEM) number of total ova/embryos or transferable embryos (13.1 ± 1.9 and 7.5 ± 1.2 v. 15.5 ± 1.7 and 7.6 ± 1.0 for single v. twice-daily injections, respectively). The total number of ova/embryos did not differ among Folltropin®-V dosages (15.0 ± 2.3, 15.7 ± 2.0, and 12.1 ± 2.5 for 300, 260, and 200 mg, respectively; P > 0.4). However, the number of transferable embryos tended (P < 0.09) to be higher in donors receiving 260 mg (9.5 ± 1.6) than 200 mg (5.2 ± 0.8), with 300 mg (7.9 ± 1.5) intermediate. In Experiment 2, Bonsmara cows (n = 16) were superstimulated by 4 treatments (2 × 2 factorial) in a crossover design similarly to Experiment 1, except that 2 dosages of Folltropin®-V (200 and 300 mg) were evaluated. There were no significant effects of dosage of Folltropin®-V (P > 0.9), treatment (P > 0.3), or interaction (P < 0.4) on embryo production. The total number of ova/embryos and transferable embryos were 11.9 ± 2.0 and 7.2 ± 1.1 v. 11.1 ± 1.1 and 7.6 ± 0.7 for single and twice-daily injections, respectively, and 11.9 ± 1.9 and 7.6 ± 1.0 v. 11.1 ± 1.3 and 7.2 ± 0.8 for 300 and 200 mg of Folltropin®-V, respectively. Superstimulation of Brangus and Bonsmara cows with a single i.m. injection of Folltropin®-V diluted in a SRF resulted in comparable embryo production to twice-daily administration of Folltropin®-V over 4 days. While 260 mg seems to be the most appropriate dosage for Brangus donors, 200 mg seems to be adequate for Bonsmara donors.


2012 ◽  
Vol 24 (1) ◽  
pp. 227
Author(s):  
A. Tríbulo ◽  
J. Garzón ◽  
H. Tríbulo ◽  
R. Tríbulo ◽  
D. Rogan ◽  
...  

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.


2020 ◽  
Vol 4 (4) ◽  
Author(s):  
Pedro H V Carvalho ◽  
Mariana F Westphalen ◽  
Jonathan A Campbell ◽  
Tara L Felix

Abstract The objectives of the study were to determine the effect of coated or noncoated hormone implants on growth performance, carcass characteristics, and serum estradiol-17β (E2) concentrations of Holstein steers fed a grain-based diet for 112 d. Seventy-nine Holstein steers [average initial body weight (BW) = 452 ± 5.5 kg] were stratified by BW and allotted to one of two treatments: 1) Holstein steers implanted with a coated implant containing 200 mg of trenbolone acetate (TBA) and 40 mg E2 (Revalor-XS (Merck Animal Health; Summit, NJ)] on day 0 (XS) or 2) Holstein steers implanted two times (days 0 and 56) with a noncoated implant containing 80 mg of TBA and 16 mg of E2 [(2IS) Revalor-IS (Merck Animal Health)]. Data were analyzed using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC). There was no effect (P ≥ 0.71) of implant strategy on initial, middle, and final BW. No effect (P ≥ 0.12) of implant strategy was observed on average daily gain, dry matter intake, or gain-to-feed ratio. There were no effects (P ≥ 0.11) of implant strategy on carcass characteristics. There was an implant × day interaction (P &lt; 0.01) for the circulation of serum E2 concentrations. Serum E2 concentration increased similarly 14 d after Holstein steers were implanted, regardless of implant strategy. At 28 d, after steers were implanted, steers in the XS group had less serum E2 concentration than Holstein steers in the 2IS group. However, at 56 d after the first implantation, both groups, once again, had similar serum E2 concentrations and E2 concentrations were less on day 56 than day 28 for both strategies. Holstein steers implanted with 2IS had greater serum E2 concentration on day 70 and E2 concentrations remained greater than serum E2 of Holstein steers implanted XS for the duration of the trial (day 112). In summary, there was no effect of coated or two doses of noncoated implant on growth performance or carcass characteristics of Holstein steers.


2004 ◽  
Vol 16 (2) ◽  
pp. 213 ◽  
Author(s):  
J. Small ◽  
M. Colazo ◽  
D. Ambrose ◽  
R. Mapletoft ◽  
J. Reeb ◽  
...  

The objective was to evaluate the effect of pLH treatment on pregnancy rates in recipients receiving in vivo- or in vitro-produced bovine embryos. Heifers (n=37) and lactating (n=28) and non-lactating (n=150) beef cows were treated at random stages of the cycle with 100μg GnRH i.m. (Cystorelin, Merial Canada Inc., Victoriaville, Quebec, Canada) on Day −9, 500μg cloprostenol i.m. (PGF; Estrumate, Schering Plough Animal Health, Pointe-Claire, Quebec, Canada) on Day —2 and GnRH on Day 0 (66h post-PGF; without estrus detection). Cattle were placed at random, by class, into three groups: no further treatment (Control; n=71), or 12.5mg pLH (Lutropin-V, Bioniche Animal Health, Belleville, Ontario, Canada) on Day 5 (n=72) or on Day 7 (n=72) after the second GnRH. On Day 7, cattle with a CL &gt;10mm in diameter (determined ultrasonically) received in vivo-produced, fresh (Simmental) or frozen (Holstein), or in vitro-produced frozen (Holstein) embryos (embryo type balanced among groups). Embryos were cryopreserved in 10% ethylene glycol; in vivo-produced frozen embryos were thawed 5 to 10s in air, 15s in a water-bath at 30°C and then “direct-transferred” nonsurgically. In vitro-produced frozen embryos (donated by IND Lifetech Inc., Delta, British Columbia, Canada) were thawed in a water-bath at 27°C for 10s and placed in ViGro Holding Plus medium (AB Technology, Pullman, WA, USA) at room temperature, evaluated and then transferred nonsurgically. Pregnancy was determined by ultrasonography on Day 35. Data were analyzed with CATMOD, chi-square and GLM procedures (SAS Institute, Cary, NC, USA.). Twenty cattle (9.3%) did not receive embryos; five heifers had cervical problems, and five heifers and 10 cows did not have a CL &gt;10mm. Overall, 7.1% of the recipients had two CL on the day of embryo transfer. There was no effect (P&gt;0.05) of treatment, embryo type (or interaction) or class of recipient on pregnancy rate (overall, 44.1%, 86/195; Table 1). Similarly, mean (±SD) CL diameter and luteal area did not differ (P&gt;0.05) among groups or between pregnant and open recipients (overall, 22.0±3.4mm and 352.0±108.7mm, respectively). However, recipients with a CL diameter ≥18mm tended (P&lt;0.1) to have a higher pregnancy rate (45.8 vs 25.0%). In a subset of 40 recipients examined ultrasonically on Day 12, 50% of those treated on Day 5 and 70% of those treated with pLH on Day 7 had two CL. In summary, overall pregnancy rate in GnRH-synchronized recipients receiving in vitro- or in vivo-produced embryos by nonsurgical transfer was 44.1%. Embryo survival to Day 35 was not affected by type of embryo or treatment with pLH 5 or 7 days after ovulation. Table 1 Pregnancy rate in recipients on Day 35 based on pLH treatment and embryo-type


Sign in / Sign up

Export Citation Format

Share Document