scholarly journals PSVIII-42 Effect of presynchronization using prostaglandin F2α prior to a shortened progesterone exposure in fixed-timed AI of crossbred beef cows nursing calves

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 260-260
Author(s):  
Whitney L Rook ◽  
Jeremy Powell ◽  
Reagan Cauble ◽  
Rick Rorie
Keyword(s):  
Statistical Difference ◽  
Prostaglandin F2α ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
University Of Arkansas ◽  
Estrous Synchronization ◽  
Frozen Semen ◽  
To Receive ◽  
Fall Calving ◽  
Synchronization Protocol

Abstract Presynchronization has been shown to improve AI pregnancy rates in dairy cattle, by improving the effectiveness of the initial GnRH treatment required for follicular control in estrous synchronization protocols. An experiment was designed to evaluate the effect of prostaglandin presynchronization in a fixed-timed AI (FTAI) protocol with a shortened progesterone exposure in beef cows. A total of 135 fall calving (September-November) crossbred beef cows from two locations were randomized to receive either: A) prostaglandin (25mg; Lutalyse, Zoetis, Kalamazoo, MI) administered two days prior to synchronization with GnRH (100mg; Factrel, Zoetis) and progesterone (1.38g P4; CIDR, Zoetis) for 6 days, or B) Control, the same synchronization protocol without Lutalyse pretreatment. On day 6 (Day 0: CIDR insertion) CIDR was removed and 25mg of prostaglandin was administered and 72 hours later fixed-timed AI with concurrent injection of 100mg of GnRH. Conventional frozen semen from Simmental-Angus sires was used for AI and fertile Angus bulls were used for pasture exposure. Pregnancy was determined by ultrasound 30 days after AI and again 30 days after clean-up bull exposure for 30 days. Statistical analysis was performed using the frequency procedure of SAS (Cary, NC) and significance was set at X2 < 0.05. Pregnancy rate to timed AI was 71.4% for Treatment A compared to 80.3% for Treatment B (Control). Although these results were greater than previously reported at these research stations, there was no statistical difference (X2=0.23) between treatments. Overall pregnancy rates tended to be different (X2=0.06) and were potentially influenced by treatment or shortened exposure to progesterone in synchronization. Research supported by University of Arkansas Division of Agriculture.

Setting the Cycle for Reproductive Success with a Pre-synchronization Program in Postpartum Beef Cows

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 23-23
Author(s):  
Macy M Massengill ◽  
Thiago V Silva ◽  
Daniel H Poole
Keyword(s):  
Body Condition Score ◽  
Statistical Significance ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Estrous Synchronization ◽  
Condition Score ◽  
Pregnancy Status ◽  
Timed Artificial Insemination ◽  
To Receive ◽  
Synchronization Protocol

Abstract Previous experiments from our laboratory determined that postpartum beef cows with a functional corpus luteum (CL) at the start of an estrous synchronization protocol have greater pregnancy success to FTAI than those that did not have a CL. Therefore, it was hypothesized that incorporation a presynchronization program prior to FTAI in postpartum cows will improve pregnancy rates. The goal of this project was to compare the effectiveness of a presynchronization program prior to the 7-d CO-Synch+CIDR fixed timed artificial insemination (FTAI) protocol in postpartum cows. Postpartum cows (n = 310) at two locations were randomly assigned to receive either the presynchronization program, consisting of 2 PGF2α injections 14 d apart and 11 d prior to the start of the 7-d CO-Synch+CIDR protocol, or the 7-d CO-Synch + CIDR protocol. Following estrus synchronization, all cows were inseminated by trained technicians using semen from bulls of known fertility. Pregnancy status to FTAI was assessed using ultrasonographic diagnosis at 30 d post insemination. Data were analyzed using a MIXED procedure of SAS and examined for effects of inseminator, body condition score (BCS), and location and age. Statistical significance was determined at P < 0.05 and a tendency at 0.05< P < 0.10. Age, BCS, and location did not affect (P > 0.05) pregnancy rates. Cows exposed to the pre-synchronization program tended to have greater AI pregnancy rates compared to cows that did not receive the pre-synchronization program (57.7±5.3 vs. 46.9±5.3%, respectively; P = 0.0687). AI pregnancy rates were greater in cows with >1 ng/mL P4 compared to cows with < 1 ng/mL P4 at the start of FTAI (77.7±7 vs. 55.7±6.2%, respectively; P = 0.0204). Furthermore, AI pregnancy rates were decreased by inseminator C (26.1±7.4) compared to the other inseminators this breeding season (A-54.4±7.9; B- 62.3±5.3; D-57.8±7.2; and E -51.1±5.2; P = 0.0026). Based on these data, incorporating a pre-synchronization program to ensure the presence of a CL at the start of a FTAI protocol may improve pregnancy success in postpartum beef cows.

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

scholarly journals 218 Effect of GnRH injection at -72 h in MGA-PG estrus synchronization protocol

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 122-122
Author(s):  
McKay Erickson ◽  
Rick N Funston
Keyword(s):  
Pregnancy Rate ◽  
Prostaglandin F2α ◽  
Fixed Time ◽  
Pregnancy Rates ◽  
Estrus Synchronization ◽  
Estrus Detection ◽  
To Receive ◽  
Observation Period ◽  
Synchronization Protocol

Abstract Beef heifers (n = 1524) from two operations in central Nebraska were randomly assigned to one of two treatments [0 or 5 μg GnRH at prostaglandin F2α (PGF) administration 72 hrs before insemination]. Both locations utilized MGA-PG fixed-time AI (TAI) estrus synchronization protocol. The first location (L1, n = 1076, 382 ± 3 kg) processed heifers 72 hours prior to insemination and every third heifer was assigned to receive an injection of GnRH (5 ug) (TRT) and an injection of PGF. The remaining heifers received PGF and 0 μg GnRH. At insemination all heifers received 100 ug GnRH. Heifers were then observed for estrus behavior from 10–21 days post TAI and re-inseminated if estrus was detected. Heifers pregnant from the second breeding were added to final pregnancy rate. The second location (L2) utilized estrus detection patches and performed only TAI (n = 448, 363 ± 7 kg) following MGA-PG synchronization protocol outlined above without the estrus observation period. Treatment did not significantly (P > 0.20) improve TAI pregnancy rates [L1 TAI 56.3% (TRT) vs 57.3%; L1 AI Total 78.3% (TRT) vs 73.9%; L2 TAI 58.5% (TRT) vs 52.5%] among the two herds. The administration of 5 μg GnRH at PGF tended to increase (P = 0.12, 74% vs 63%) pregnancy rates for those inseminated during the follow up heat detection period at L1. The treatment did not (P > 0.20) improve pregnancy for the time-AI heifers. In addition, TAI pregnancy rates were similar (P > 0.20) at L2. There were greater (P < 0.20) effect of pen on pregnancy rate.

Estrous synchronization and fertility of cross-bred dairy cows using prostaglandin F2α and gonadotropin releasing hormone

2021 ◽  
pp. 171-175
Author(s):  
Abubakr O. Ismail ◽  
◽  
Erneo B. Ochi ◽  
Ambrose S. Jubara ◽  
Bakri Ahmed A/Rahim ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Artificial Insemination ◽  
Prostaglandin F2α ◽  
Fixed Time ◽  
Gonadotropin Releasing Hormone ◽  
Pregnancy Rates ◽  
Releasing Hormone ◽  
Treatment Groups ◽  
Estrous Synchronization ◽  
Descriptive Statistical Analysis

A comparative hormonal study of prostaglandin, gonadotropin releasing hormone and their combination was conducted on 30 randomly selected cross-bred dairy cows of SEMEX project for artificial insemination in Hillat Kuku, Khartoum North, Sudan. The study attempts to determine the response of the animals to hormonal induction and synchronization of estrous as well as fertility following fixed time artificial insemination. Three treatment groups of 10 cows each were undertaken. Groups 1, 2 and 3 involved administration of prostaglandin F2α (PGF2α), gonadotropin releasing hormone (GnRH) and a combination of PGF2α + GnRH, respectively. Descriptive statistical analysis was performed. The results revealed that all the three protocols induced and synchronized estrous were almost synchronous in all the treated groups. However, protocol 3 revealed a significantly (p<0.05) better result of 70% pregnancy rate compared to other two protocols that equally provided 50% pregnancy rates. The study resolves that protocol 3 be highly recommended to change the mindset of farmers about the spread of reproductive technology in Sudan. Protocols 1 and 2 provided acceptable pregnancy rates that can be enhanced with the improvement of management.

7 INFLUENCE OF ESTRUS EXPRESSION AND TREATMENT WITH GnRH ON PREGNANCY RATES IN BEEF CATTLE SYNCHRONIZED WITH PROGESTERONE DEVICES AND ESTRADIOL AND INSEMINATED AT A FIXED-TIME

2017 ◽  
Vol 29 (1) ◽  
pp. 111 ◽  
Author(s):  
G. A. Bó ◽  
A. Cedeño ◽  
A. Tribulo ◽  
S. Andrada ◽  
R. Tribulo ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Beef Cattle ◽  
Body Condition Score ◽  
Fixed Time ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Device Removal ◽  
Oestradiol Benzoate ◽  
Condition Score ◽  
To Receive

We have previously shown that expression of oestrus significantly influences the time of ovulation and pregnancy rates to timed-AI (P/TAI) in beef cattle synchronized with progesterone devices and oestradiol (Bó et al. 2016 Theriogenology 86, 388–396). Furthermore, delaying TAI from 48 h to 54–58 h after device removal improved P/TAI of those animals not showing oestrus by 48 h. The objective of the present study was to determine whether the administration of GnRH to those animals not showing oestrus by 48 h after device removal had an impact on P/TAI. Non-lactating and suckled beef cows and heifers (Bonsmara, Brangus, and Braford; n = 868), with a corpus luteum (CL) or a follicle ≥8 mm in diameter detected by ultrasonography (Mindray DP 30 Vet, 7.5 MHz, China) and body condition score 2 to 4 (1 to 5 scale) were synchronized in 3 replicates. On Day 0, animals received a progesterone device (DIB 0.5 g, Zoetis, Argentina) and 2 mg of oestradiol benzoate (Von Franken, Argentina). On Day 8, DIB were removed and cows received 0.150 mg of D+cloprostenol (Río de Janeiro, Argentina) plus 0.5 mg oestradiol cypionate (Cipiosyn, Zoetis). In addition, all cows were tail-painted on the sacrococcygeal area (CeloTest, Biotay, Argentina) at DIB removal and were observed to determine the expression of oestrus, according to the percentage of paint loss (PL) 48 h later. The animals that showed oestrus (PL > 30%) were recorded and TAI at that time while those with PL ≤ 30% (not in oestrus) were randomly allocated to receive 100 μg of gonadorelin (GnRH; Gonasyn, Zoetis) or no treatment and TAI between 54 to 58 h after DIB removal. Pregnancy was diagnosed by ultrasonography at 45 days after TAI, and data were analysed by logistic regression. There were no significant differences among replicates, inseminators, semen source or animal class (dry cows, suckled cows or heifers; P > 0.11). However, animals showing oestrus by 48 h after DIB removal had higher P/TAI (371/666; 55.7; P < 0.04) than those that did not show oestrus (96/202; 47.5%). Within animals not showing oestrus at 48 h, those that were in oestrus by the TAI at 54 to 58 h had higher P/TAI (71/124, 57.3%; P < 0.01) than those that did not show oestrus within that period (27/78; 34.6%). In addition, P/TAI was higher (P < 0.01) in animals that received GnRH (66/113; 58.4%) than in those that did not receive GnRH (30/89; 33.7%). In conclusion, the expression of oestrus significantly affected P/TAI in beef cattle synchronized with progesterone devices and oestradiol. Furthermore, treatment of animals not showing oestrus by 48 h after DIB removal with GnRH resulted in improved P/TAI performed 6 to 10 h later.

scholarly journals 166 EFFECT OF TREATMENT WITH hCG OR GnRH AT THE TIME OF EMBRYO TRANSFER ON PREGNANCY RATES IN COWS SYNCHRONIZED WITH PROGESTERONE VAGINAL DEVICES, ESTRADIOL BENZOATE, AND eCG

2005 ◽  
Vol 17 (2) ◽  
pp. 234 ◽  
Author(s):  
R. Tribulo ◽  
E. Balla ◽  
L. Cutaia ◽  
G.A. Bo ◽  
P.S. Baruselli ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Bos Taurus ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Beef Cows ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Condition Score ◽  
Pregnancy Status ◽  
To Receive

Although several studies have investigated the relationship between circulating progesterone and pregnancy rates in cattle, the beneficial effect of treatments that increase progesterone concentrations, by insertion of a progesterone (P4) releasing device or induction of an accessory CL with hCG, GnRH, or LH treatment, has resulted in inconsistent effects on pregnancy rates in embryo recipients. An experiment was designed to evaluate the effect of hCG or GnRH treatment, given at the time of embryo transfer without estrus detection, on pregnancy rates in recipients treated with intrauterine P4-releasing devices, estradiol benzoate (EB), and eCG. The experiment was performed in two replicates; non-lactating Bos taurus × Bos indicus crossbred beef cows with a body condition score between 2.5 to 3.5 (1-to-5 scale) were used (replicate 1, n = 180; replicate 2, n = 140). All cows received 1 g of P4 via a P4-releasing device (DIB, Syntex, Argentina) and 2 mg EB i.m. (Syntex) on Day 0, and 400 IU of eCG i.m. (Novormon 5000, Syntex) plus 150 μg d(+)cloprostenol i.m. (Ciclase, Syntex) on Day 5. DIBs were removed on Day 8 and all cows received 1 mg EB i.m. on Day 9. Recipients were not observed for signs of estrus, and those >1 CL, or a single CL with an area >256 mm2, received 195 Grade 1 and 46 Grade 2 frozen/thawed “direct transfer” embryos on Day 17. At the time of embryo transfer, recipients were randomly allocated to 1 of 3 treatment groups to receive 1500 IU hCG (Ovusyn, Syntex), 50 μg Lecirelina (GnRH, Gonasyn, Syntex), or no treatment (control) at that time. Ovarian ultrasonography was performed on Day 0 to determine ovarian status (only cows with a CL or a follicle >10 mm and uterine tone were used), on Day 17 to measure CL area, and 40 days after embryo transfer to determine pregnancy status. Data were analyzed by logistic regression and the effects of replication, technician, treatment, and embryo quality were considered in the model. From the 320 recipients treated with a DIB plus EB and eCG, 241 (75.3%) were selected to receive an embryo. Nine (3.7%) and 1 (0.4%) of the selected recipients had 2 and 3 CL, respectively. Pregnancy rates did not differ between replicates (replicate 1: 80/140, 57.1%; and replicate 2: 57/101, 56.4%; P = 0.84), technicians (technician 1: 65/118, 55.1%; and technician 2: 72/123, 58.5%; P = 0.64), or treatments (hCG: 43/80, 53.8%; GnRH: 45/83, 54.2%; and control: 49/78, 62.8% P = 0.99). However, pregnancy rates were higher (P = 0.001) in recipients receiving Grade 1 embryos (121/195, 62.1%) than in those receiving Grade 2 embryos (16/46, 34.8%). GnRH or hCG treatment at the time of embryo transfer did not increase pregnancy rates in recipients synchronized with P4 releasing devices, EB, and eCG. Research was supported by Syntex S.A., Estancia El Mangrullo S.A., and Agencia Cordoba Ciencia S.E.

scholarly journals 107 Timing of progesterone exposure effects pregnancy rates following fixed time artificial insemination in postpartum beef cows

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 43-44
Author(s):  
Anna L Smith ◽  
Rebecca K Poole ◽  
Kyle Mayberry ◽  
McKayla A Newsome ◽  
Harrison B Dudley ◽  
...  
Keyword(s):  
Artificial Insemination ◽  
Statistical Significance ◽  
Fixed Time ◽  
Beef Cows ◽  
Reproductive Technologies ◽  
Pregnancy Rates ◽  
Estrous Synchronization ◽  
Pregnancy Status ◽  
Timed Artificial Insemination ◽  
The Impact

Abstract Advancements in reproductive technologies have improved pregnancy rates in postpartum cows; however, undesirable consequences leading to reduced fertility still occur. Thus, the objectives were to determine if presence of a corpus luteum (CL) at the start of estrous synchronization (AIM1) or if the length of proestrus (interval from progesterone removal to a GnRH-induced LH surge; AIM2) alters fixed timed artificial insemination (FTAI) pregnancy rates. Cycling postpartum cows (n = 285) at two locations were synchronized using the CO-Synch+CIDR® FTAI protocol. Ultrasonographic measurements of luteal area were recorded at CIDR insertion. To determine the impact of proestrus length, cows were randomly assigned to either undergo CIDR removal at the time of PGF2a injection (long proestrus, n = 145), or CIDR removal 24 hours post PGF2a injection (short proestrus, n = 140). Blood samples were collected at CIDR insertion and at insemination for progesterone (P4) analysis. Pregnancy status to FTAI was assessed using ultrasonographic diagnosis at 30 d post insemination. Data were analyzed using a MIXED procedure of SAS and examined for effects of length of proestrus, P4 concentration, luteal area, sire, location, and age. Statistical significance was determined at P0.05) pregnancy rates. Pregnancy rates were greater in cows with >1 ng/mL P4 compared to cows with 0.05). Cows > 4 y old had higher AI pregnancy rates compared to 2–3 y cows (70.2±7.4 vs. 51±5.8%, respectively; P > 0.05). Based on these data, incorporating a presynchronization program to ensure the presence of a functional CL at the start of a FTAI protocol may improve pregnancy success in postpartum beef cows.

Sign in / Sign up

Export Citation Format

Share Document