scholarly journals 299 Treatment with prostaglandin F2α and an intravaginal progesterone insert in advance of gonadotropin-releasing hormone enhances response to estrus synchronization in mature beef cows

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 138-139
Author(s):  
Rachael C Bonacker ◽  
Katy S Stoecklein ◽  
Jaclyn N Ketchum ◽  
Emma R Knickmeyer ◽  
James William C Locke ◽  
...  
Keyword(s):  
Ovarian Follicle ◽  
Prostaglandin F2α ◽  
Beef Cows ◽  
Gonadotropin Releasing Hormone ◽  
Control Treatment ◽  
Estrus Synchronization ◽  
Releasing Hormone ◽  
Representative Subset ◽  
Estrus Detection ◽  
Follicle Size

Abstract An experiment was designed to evaluate the effect of treatments in advance of gonadotropin-releasing hormone (GnRH; 100μg gonadorelin) administered at the start of estrus synchronization. We hypothesized that administration of prostaglandin F2α (PG; 500μg cloprostenol) followed by treatment with an intravaginal progesterone-releasing insert (CIDR; 1.38g progesterone) would result in increased follicle size at GnRH, thereby enhancing response to GnRH and overall response to estrus synchronization. Postpartum suckled beef cows (n = 183) in two locations were assigned to one of five treatments based on age, days postpartum, and body condition score. Treatments (Figure 1) were designed as a two-by-two factorial with a control (Treatment 1). Treatments 2–5 received a CIDR insert from Day -17 to Day -10, with (Treatments 2 and 3) or without (Treatments 4 and 5) administration of PG coincident with CIDR insertion on Day -17. Coincident with GnRH administration on Day -10, CIDR inserts were either removed (Treatments 2 and 4) or remained in place until Day -3 (Treatments 3 and 5). On Day -3, estrus detection aids were applied and a representative subset of cows in each treatment were fitted with estrus detection transmitters. Blood samples were collected on Days -27, -17, -10, -3, and 0 for determination of serum estradiol and/or progesterone concentrations via radioimmunoassay. For a representative subset of cows (n = 111), transrectal ovarian ultrasound was performed to assess ovarian follicle size and presence of corpora lutea on Days -17, -10, -3, and 0. Treatment with PG and CIDR in advance of GnRH resulted in improvements (P < 0.05) in several response variables, including follicle size on Day -17 and estrous response prior to AI. Results support the hypothesis that administration of PG and treatment with a CIDR for 7 d prior to GnRH improves likelihood of GnRH response and enhances response of mature cows to estrus synchronization.

PSXII-15 Evaluation of later timing of fixed-time artificial insemination for beef cows when using sex-sorted semen following the 7 & 7 Synch protocol

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 423-424
Author(s):  
Carson M Andersen ◽  
Emily G Smith ◽  
Genna M VanWye ◽  
Jordan M Thomas
Keyword(s):  
Artificial Insemination ◽  
Prostaglandin F2α ◽  
Fixed Time ◽  
Beef Cows ◽  
Gonadotropin Releasing Hormone ◽  
Power Of Test ◽  
Releasing Hormone ◽  
Estrus Detection ◽  
To Receive ◽  
Activation Status

Abstract An experiment was designed to evaluate later timing of fixed-time artificial insemination (FTAI) with sex-sorted semen among postpartum beef cows following the 7 & 7 Synch protocol, with the hypothesis that later timing would result in increased pregnancy rates (P/AI) among cows that expressed estrus prior to FTAI. Beef cows (n = 414) were blocked based on age and days postpartum (DPP) and randomly assigned to receive FTAI at 66 or 72 h after administration of prostaglandin F2α (PG). Estrus was synchronized using the 7 & 7 Synch protocol, which consists of administration of PG (500 μg cloprostenol) and insertion of an intravaginal progesterone-releasing insert (CIDR; 1.38 g progesterone) on Day 0, gonadotropin-releasing hormone (GnRH; 100 μg gonadorelin) on Day 7, and PG coincident with CIDR removal on Day 14. Estrus detection aids (EstrotectTM) were applied to all cows on Day 14, and activation status was recorded at fixed-time artificial insemination (FTAI) on Day 17. All cows that expressed estrus prior to FTAI received sex-sorted semen (4 × 106 cells per unit; SexedULTRA 4MTM). The proportion of cows expressing estrus prior to FTAI did not differ between treatments at this power of test [66 h: 71% (146/205); 72 h: 76% (158/209)]. Additionally, P/AI of estrous cows inseminated with sex-sorted semen did not differ between treatments [66 h: 44% (90/205); 72 h: 39% (82/209)]. In conclusion, later timing of FTAI following the 7 & 7 Synch protocol failed to improve P/AI of estrous cows inseminated with sex-sorted semen.

scholarly journals Estrus Synchronization Using Prostaglandin F2α (PGF2α) and Combination of PGF2α and Gonadotropin-Releasing Hormone In Ongole Crossbred

2020 ◽  
Vol 151 ◽  
pp. 01009
Author(s):  
Pudji Astuti ◽  
Claude M. Airin ◽  
Slamet Widiyanto ◽  
Sarmin Sarmin ◽  
Amelia Hana ◽  
...  
Keyword(s):  
Statistical Methods ◽  
Artificial Insemination ◽  
Luteal Phase ◽  
Prostaglandin F2α ◽  
Gonadotropin Releasing Hormone ◽  
Estrus Synchronization ◽  
Significant Difference ◽  
Estrus Detection ◽  
Female Cattle ◽  
Estrus Phase

The response of estrus can be enhanced by providing PGF2α and a combination of PGF2αGnRH so that the time of mating using Artificial Insemination (AI) can be held precisely. This study aims to compare the response of estrus synchronization using PGF2α compare to PGF2α-GnRH. Twenty female cattle Ongole Crossbreds, 4-6 years, BCS average of 3-4 were used in this research. Cattle were selected based on their luteal phase at the days of 7 to 18 by rectal examination. Then, all of the cattle were injected by cloprostenol® with a dose of 500 ug intrauterine. Ten of the animals were injected by 2.5 mL of Fertagyl® intramuscularly after 48 hours then continued observing and response estrus detection. The onset of estrus using PGF2α was detected on 75.94 ± 0.78, while 41.57 ± 28.40 hours for PGF2α-GnRH Using statistical, there was a significant difference (P<0.05). Duration of estrus phase using PGF2α was 24.65 ± 0.49 whereas PGF2α-GnRH was 10.88 ± 7.45 hours. Using statistical methods, there was a significant difference (P <0.05). It could be concluded that the use of PGF2α was more effective for the duration and intensity of estrus, and a combination of PGF2α -GnRH is more effective for stimulating estrus.

scholarly journals PSXIII-14 The impact of estrus intensity on variables associated with fertility in Bos taurus-influenced beef cows

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 362-363
Author(s):  
Reinaldo F Cooke ◽  
Nicola Oosthuizen ◽  
Kelsey Schubach ◽  
Alice Brandão ◽  
Ramiro Oliveira Filho ◽  
...  
Keyword(s):  
Physical Activity ◽  
Bos Taurus ◽  
Fixed Time ◽  
Beef Cows ◽  
Estrus Synchronization ◽  
Estrus Detection ◽  
Follicle Size ◽  
The Impact ◽  
Ovarian Dynamics ◽  
Synchronization Protocol

Abstract To evaluate the impact of estrus expression and intensity on parameters associated with reproductive performance, 219 lactating, multiparous Bos taurus-influenced beef cows were enrolled in this study. Cows were exposed to an estrus synchronization protocol, where they received a 100-µg injection of GnRH and a CIDR insert on d -10, a 25-mg injection of PGF2a at CIDR removal on d -3, and an injection of GnRH 60–66 h following CIDR removal at fixed-time AI (TAI; d 0). Cows were fitted with a pedometer behind their right shoulder on d -10, and an estrus detection patch was applied to their tail-head on d -3. Estrus expression was defined as removal of &gt; 50% of the rub-off coating from the patch on d 0. Net physical activity during estrus was calculated by subtracting daily activity during the non-estrus period (d -10 to -3) from activity during the expected estrus period (d -3 to 0). Cows were classified into 3 groups: cows that did not express estrus (NOESTR; n = 119), cows that expressed estrus with net physical activity greater than the median (HIESTR; n = 50), and the remaining cows (LWESTR; n = 50). Ultrasonography was performed on d -3, 0, and 7 to determine the presence and size of ovarian structures. Pregnancy diagnosis was performed 29 d after TAI. Net physical activity was greater in HIESTR compared to both LWESTR and NOESTR (P &lt; 0.01). Dominant follicle size was greater in HIESTR compared to both LWESTR and NOESTR (P &lt; 0.01). Furthermore, HIESTR had greater corpus luteum volume on d 7 than LWESTR and NOESTR (P &lt; 0.01). Pregnancy rates to AI (PR/AI) were greater in HIESTR and LWESTR compared to NOESTR (P &lt; 0.01). In conclusion, cows that expressed estrus at a greater intensity had improved ovarian dynamics. Additionally, cows that exhibited estrus had greater PR/AI compared to non-estrual cows.

scholarly journals Evaluation of the 7 and 7 synch protocol for control of the estrous cycle among beef cows prior to fixed-time artificial insemination with sex-sorted or conventional semen

2021 ◽  
Author(s):  
◽  
Carson M. Andersen
Keyword(s):  
Artificial Insemination ◽  
Fixed Time ◽  
Beef Cows ◽  
Gonadotropin Releasing Hormone ◽  
Pregnancy Rates ◽  
Releasing Hormone ◽  
Prostaglandin F2 Alpha ◽  
Estrus Detection ◽  
To Receive ◽  
Activation Status

Experiment 1 was conducted to compare 7 and 7 Synch and the 7-day CO-Synch + controlled internal drug release (CIDR[copyright]) protocols prior to fixed-time artificial insemination (FTAI) of beef cows with conventional or sex-sorted semen. Cows (n = 1,538) were blocked based on age and days postpartum (DPP) and randomly assigned to protocol and semen type. Cows assigned to 7-day CO-Synch + CIDR (n = 769) received administration of gonadotropin-releasing hormone (GnRH) and insertion of an intravaginal progesterone-releasing insert (CIDR) on Day -10, and administration of prostaglandin F2[alpha] (PG) coincident with CIDR removal on Day -3. Cows assigned to 7 and 7 Synch (n = 769) received PG and insertion of CIDR on Day -17, GnRH on Day -10, and PG coincident with CIDR removal on Day -3. Estrus detection aids were applied to all cows. Cows received FTAI 66 h after CIDR removal with conventional (20 x 106 cells per unit) or sex-sorted (4 x 106 cells per unit) semen. Estrus expression was affected by protocol (P = 0.01) by protocol x DPP (P = 0.0004), with 7 and 7 Synch (82 percent; 629/769) resulting in a greater proportion of cows expressing estrus (82 percent [629/769] versus 64 percent [492/769]), especially among cows with greater DPP. Pregnancy rates to FTAI were reduced (P < 0.0001) when using sex-sorted semen but greater among cows treated with 7 and 7 Synch (conventional semen: 72 percent [280/389]; sex-sorted semen: 52 percent [199/380]) compared with 7-day CO-Synch + CIDR (conventional semen: 61 percent [233/383]; sex-sorted semen: 44 percent [171/386]). Experiment 2 was designed to evaluate later timing of fixed-time artificial insemination (FTAI) with sex-sorted semen among postpartum beef cows following the 7 and 7 Synch protocol, with the hypothesis that later timing would result in increased pregnancy rates (P/AI) among cows that expressed estrus prior to FTAI. Beef cows (n=414) were blocked based on age and days postpartum (DPP) and randomly assigned to receive FTAI at 66 or 72 h after administration of prostaglandin F2[alpha] (PG). Estrus was synchrized using the 7 and 7 Synch protocol, which consists of administration of PG (500 [mu]g cloprostenol) and insertion of an intravaginal progesterone-releasing insert (CIDR; 1.38 g progesterone) on Day 0, gonadotropin-releasing hormone (GnRH; 100 [mu]g gonadorelin) on Day 7, and PG coincident with CIDR removal on Day 14. Estrus detection aids (EstrotectTM) were applied to all cows on Day 14, and activation status was recorded at fixed-time artificial insemination (FTAI) on Day 17. All cows that expressed estrus prior to FTAI received sex-sorted semen (4 x 106 cells per unit; SexedULTRA 4MTM). The proportion of cows expressing estrus prior to FTAI did not differ between treatments at this power of test (66 h: 71 percent [146/205]; 72 h: 76 percent [158/209]). Additionally, P/AI of estrous cows inseminated with sex-sorted semen did not differ between treatments (66 h: 45 percent [68/146]; 72 h: 40 percent [63/158]). In conclusion, later timing of FTAI following the 7 and 7 Synch protocol failed to improve P/AI of estrous cows inseminated h sex-sorted semen.

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