scholarly journals 133 One versus two prostaglandin F2α injections on progesterone concentrations and luteolysis in suckling beef cows subjected to a 5-day controlled internal drug release-Cosynch protocol.

2018 ◽  
Vol 96 (suppl_3) ◽  
pp. 347-347 ◽  
Author(s):  
J Spencer ◽  
S Menegatti Zoca ◽  
M Reynolds ◽  
W Price ◽  
B Shafii ◽  
...  
Keyword(s):  
Drug Release ◽  
Prostaglandin F2α ◽  
Beef Cows

166 Comparison of the 7 and 7 Synch protocol and the 7-day CO-Synch + controlled internal drug release protocol among recipient beef cows in an embryo transfer programme

2020 ◽  
Vol 32 (2) ◽  
pp. 210
Author(s):  
R. C. Bonacker ◽  
K. R. Gray ◽  
C. A. Breiner ◽  
J. M. Anderson ◽  
D. J. Patterson ◽  
...  
Keyword(s):  
Drug Release ◽  
Embryo Transfer ◽  
Body Condition Score ◽  
Prostaglandin F2α ◽  
Beef Cows ◽  
Corpora Lutea ◽  
Frozen Embryos ◽  
Condition Score ◽  
Recommended Guidelines ◽  
Mixed Groups

An experiment was designed to evaluate the effectiveness of the recently developed 7 and 7 Synch protocol to synchronise oestrus and ovulation among recipients before embryo transfer (ET). Postpartum beef cows (n=1358) across 13 locations were assigned to either the 7-day CO-Synch + controlled internal drug release (CIDR) protocol or the 7 and 7 Synch protocol before oestrus detection and subsequent ET. Cows were pre-assigned to balanced treatments within location based on age and days postpartum, and body condition score was recorded at ET. Cows assigned to the 7-day CO-Synch + CIDR protocol were administered gonadotrophin-releasing hormone (GnRH; 100µg of gonadorelin acetate) on Day 0, an intravaginal CIDR insert (1.38g of progesterone) from Day 0 to 7, and prostaglandin F2α (PG; 25mg of dinoprost tromethamine) coincident with CIDR removal on Day 7. Cows assigned to the 7 and 7 Synch protocol were administered PG (25mg of dinoprost tromethamine) coincident with CIDR insertion on Day −7, GnRH (100µg of gonadorelin acetate) on Day 0, and PG (25mg of dinoprost tromethamine) coincident with CIDR removal on Day 7. The 7 and 7 Synch protocol was hypothesised to enhance response to GnRH administration on Day 0 among mixed groups of oestrous cycling and anestrous cows, ultimately resulting in improved oestrous response and synchrony of oestrus before ET. Cows were observed for visible signs of oestrus following oestrus synchronisation, with GnRH (100µg of gonadorelin acetate) administered to cows failing to express oestrus during the detection period. Length of the detection period varied among locations but was consistent across treatments within location. Embryo transfer was performed approximately 7 days after oestrus or GnRH administration. Presence of corpora lutea (CL) was determined via transrectal palpation by a single veterinarian blinded to treatment, and embryos were transferred only to cows with palpable CL. Embryo transfer was performed using fresh or frozen embryos staged and graded according to IETS recommended guidelines, with embryo information recorded for each recipient. Data were analysed using the PROC GLIMMIX procedure of SAS (SAS Institute Inc.). Proportion of cows expressing oestrus was improved (P<0.0001) among cows assigned to the 7 and 7 Synch protocol (86% (529/615) vs. 76% (488/640)). The proportion of recipient females with palpable CL tended to be greater (P=0.07) among cows assigned to the 7 and 7 Synch protocol (82% (478/586) vs. 80% (451/565)). Among cows that expressed oestrus, a greater proportion (P<0.01) had palpable CL following the 7 and 7 Synch protocol (88% (466/529) vs. 86% (418/488)). Consequently, irrespective of embryo type received, the proportion of recipients pregnant to ET was greater (P<0.01) following the 7 and 7 Synch protocol (39%; 263/668) compared with the 7-day CO-Synch + CIDR protocol (33%; 228/690). In summary, the 7 and 7 Synch protocol improved the likelihood of oestrus expression in recipient cows, increased the proportion eligible to receive an embryo, and resulted in greater pregnancy rate to ET.

scholarly journals 35 Vaginal pH changes due to the use of a controlled internal drug release (CIDR) and its effects on fertility of beef cows

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 25-26
Author(s):  
Nicholas W Dias ◽  
Claire L Timlin ◽  
Stefania Pancini ◽  
Nicholas W Dias ◽  
Zackary Seekford ◽  
...  
Keyword(s):  
Drug Release ◽  
Scoring System ◽  
Beef Cows ◽  
Ph Changes ◽  
Ph Values ◽  
Vaginal Ph ◽  
Pregnancy Status ◽  
System 1

Abstract The objective of this study was to evaluate changes in vaginal pH of beef cows enrolled in a 7-d CO-Synch+controlled internal drug release (CIDR) protocol and its effects on pregnancy. A total of 46 multiparous beef cows with no signs of vaginitis were enrolled. Individual vaginal flushes were collected from cows on D0, D7 and D10. Individual flushes were immediately analyzed for pH with a portable pH meter. As evidence of vaginitis, a CIDR score was determined at CIDR removal (D7), following a 1 to 4 scoring system: 1 = clean, no secretion; 2 = clean, clear secretion; 3 = purulent secretion; 4 = purulent secretion and blood. Pregnancy status was determined by rectal ultrasonography approximately 40 days after TAI. No cows had CIDR scores of 1 or 4, 19.6% of cows had a score of 2 and 80.4% a score of 3. Vaginal pH increased from D0 (6.88±0.007) to D7 (7.32±0.047), regardless of CIDR score (P < 0.001). Cows with a CIDR score 2 had greater pH on D7 (7.35±0.084) than on D0 (6.90± 0.14; P = 0.001), and pH on D10 was intermediate (7.14±0.14; P = 0.14). Cows with CIDR score 3 had reduced pH on D10 (7.09±0.07) when compared to D7 (7.29±0.04; P = 0.003), but greater pH on D10 than on D0 (6.87±0.07; P = 0.007). There was a pregnancy by day interaction for pH values (P = 0.046). Pregnant cows had greater vaginal pH in comparison with non-pregnant cows on D0 (6.99±0.081 and 6.68±0.09, respectively; P = 0.01) and D10 (7.26±0.08 and 6.89±0.09, respectively; P = 0.006), but not on D7 (7.34±0.05 and 7.27±0.06, respectively; P = 0.38). Non-pregnant cows had reduced vaginal pH on D10 in comparison to D7 (6.89±0.09 and 7.27±0.06, respectively; P < 0.001), whereas pregnant cows had similar vaginal pH on D10 and D7 (7.26±0.08 and 7.34±0.05, respectively; P = 0.35). We conclude that CIDR increases vaginal pH overtime and greater pH at TAI is beneficial to fertility.

Determination of the appropriate delivery of prostaglandin F2α in the five-day CO-Synch + controlled intravaginal drug release protocol in suckled beef cows1

2012 ◽  
Vol 90 (13) ◽  
pp. 4814-4822 ◽  
Author(s):  
G. A. Bridges ◽  
J. K. Ahola ◽  
C. Brauner ◽  
L. H. Cruppe ◽  
J. C. Currin ◽  
...  
Keyword(s):  
Drug Release ◽  
Prostaglandin F2α

scholarly journals The effects of gonadotrophin releasing hormone in prostaglandin F2α-based timed insemination programs for beef cattle

2001 ◽  
Vol 81 (3) ◽  
pp. 335-343 ◽  
Author(s):  
J. A. Small ◽  
J. D. Ambrose ◽  
W. P. McCaughey ◽  
D. R. Ward ◽  
W. D. Sutherland ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Key Words ◽  
Prostaglandin F2α ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Progesterone Concentration ◽  
Gender Ratio ◽  
Plasma Progesterone ◽  
Estrous Synchronization ◽  
Gonadotrophin Releasing Hormone

Trials were conducted in the spring (May; n = 324) and fall (October; n = 132) with crossbred continental-type beef cows assigned on the basis of parity and postpartum interval to one of three timed-AI treatments and one of two post-AI treatments. The timed-AI treatments were: (DPG) double (14 d apart) PGF2α (Lutalyse®) and AI (day = 0) 72 h after the second PGF2α (day –3); (OVS) Ovsynch® with the second GnRH (Factrel®) at 48 h and AI at 66 h; and (BRC) the same as OVS except that the second GnRH was given at the time of AI. Half of the cows within each treatment were given GnRH on day 14. Plasma progesterone concentrations were determined for the day of the first injection and on days –3, 0, 14, and 21. Timed-AI pregnancy was diagnosed by ultrasonography at day 42 and confirmed at calving. For DPG, OVS and BRC, PGF2α responder rates were 75.9, 51.4 and 71.3%, respectively, in spring (P < 0.05) and 70.4, 70.4 and 59.1% in fall (P > 0.05), and AI pregnancy rates were 28.7, 44.9 and 44.4% in spring (P< 0.05) and 25.0, 40.9 and 43.2% in fall (P > 0.05). Post-AI GnRH had no significant effect on pregnancy or conception rates or day 21 progesterone. The use of GnRH in the PGF2α based timed-AI program improved pregnancy rates and the BRC treatment was as effective as OVS. Neither postpartum interval nor initial progesterone concentration influenced (P >0.05) the effect of GnRH on AI pregnancy rate, and GnRH had no effect (P > 0.05) on twinning rate or gender ratio. Key words: Beef cows, estrous synchronization, pregnancy, timed-AI, progesterone

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