Follicular populations and luteal function in dairy heifers treated with a controlled internal drug release insert for 14 days as a method to synchronize the estrous cycle before prostaglandin F2α treatment and artificial insemination

Pregnancy-associated glycoproteins (PAGs) and progesterone concentrations were assessed in Holstein heifers 28 days post-insemination, following estrus synchronization with either a double prostaglandin (PG) injection or the ovsynch protocol. Animals between 15 and 20 months of age, with a 3-3.5 BCS, were randomly assigned to three groups: Heifers in the control group (n = 70) were monitored for estrus behaviour for 21 days and inseminated when detected in standing heat; Estrus of heifers in the Ovsynch group (n = 70)) was synchronized following the Ovsynch protocol, and timed artificial insemination was performed 16 h after the completion of treatment; Animals in the PG group (n = 70) received two prostaglandin-F2α injections 11 days apart, were monitored for estrus behaviour for 2-5 days following the last injection, and inseminated when in heat. Serum PAGs and progesterone concentrations were measured in pregnant heifers (control group n = 25; ovsynch group n = 22; PG group n = 21) on day 28 after artificial insemination (AI). Mean serum PAGs concentrations (OD: optical density) were similar between groups (control = 3.37 ± 0.148, Ovsynch = 3.21 ± 0.136, and PG = 3.34 ± 0.143; p > 0.05). However, serum progesterone concentrations were found to be lower in the ovsynch group (4.70 ± 0.17 ng/mL) when compared to the PG (5.34 ± 0.13 ng/mL) or the control (5.37 ± 0.08 ng/mL) groups (p < 0.001). There was no correlation between serum PAGs and progesterone levels at day 28 post-insemination, or between early pregnancy PAGs concentrations and fetal death rates. Further research, including multiple sampling time points throughout gestation, after estrus synchronization protocols is warranted, to determine if there are associated temporal changes in PAGs and progesterone profiles that could impact reproductive parameters in dairy heifers.

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519 Late-Breaking: Evaluation of the 7 & 7 Synch and Bee Synch II protocols for control of the estrous cycle among cows of varying percentage Bos indicus influence

Journal of Animal Science ◽

10.1093/jas/skab235.284 ◽

2021 ◽

Vol 99 (Supplement_3) ◽

pp. 154-155

Author(s):

Carson M Andersen ◽

Matthew P Holton ◽

Pedro L Fontes ◽

Jordan M Thomas ◽

Lucas Goncalves ◽

...

Keyword(s):

Estrous Cycle ◽

Artificial Insemination ◽

Color Doppler ◽

Ovarian Follicle ◽

Bos Indicus ◽

Prostaglandin F2α ◽

Blood Perfusion ◽

Fixed Time ◽

Gonadotropin Releasing Hormone ◽

Corpora Lutea

Abstract The 7 & 7 Synch and Bee Synch II protocols for control of the estrous cycle were compared among cows with varying percentages of Bos indicus influence. Angus (n = 48), ⅛ - ¼ Brahman-influenced (n = 90), Brangus (n = 11), and ½ Brahman-influenced (n = 56) cows were blocked based on breed, age, and days postpartum and randomly assigned to treatment. Cows treated with 7 & 7 Synch (n = 104) received prostaglandin F2α (PG; 25 mg dinoprost tromethamine) and insertion of an intravaginal progesterone-releasing insert (CIDR; 1.38g progesterone) on Day -17, gonadotropin-releasing hormone (GnRH; 100 μg gonadorelin) on Day -10, and PG coincident with CIDR removal on Day -3. Cows treated with Bee Synch II (n = 101) received PG coincident with CIDR insertion on Day -8 and PG coincident with CIDR removal on Day -3. Fixed-time artificial insemination was performed on Day 0 at 66 h. Ovarian ultrasound was performed on Day -3 to assess presence of corpora lutea (CL) and diameter of the largest ovarian follicle (LFD), and color Doppler was used on Day 7 to assess CL blood perfusion. A greater proportion of 7 & 7 Synch cows (P < 0.0001) had CL on Day -3 (83%; 86/104) compared with Bee Synch II cows (48%; 48/101). On Day -3, LFD did not differ among Bos indicus-influenced cows treated with Bee Synch II (12.5±0.3 mm), Bos indicus-influenced cows treated with 7 & 7 Synch (12.2±0.3 mm), or Angus cows treated with 7 & 7 Synch (12.1±0.6 mm); however, greater LFD was observed among Angus cows treated with Bee Synch II (15.4±0.8 mm). Brangus cows had greater periphery signal percentages (P = 0.02) when treated with 7 & 7 Synch compared with Bee Synch II. In conclusion, across cow of varying percentage Bos indicus influence, 7 & 7 Synch resulted in a greater proportion of cows with CL on Day -3.

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Luteal function and estrous cycle characteristics in mares treated with subtherapeutic doses of prostaglandin F2α

Theriogenology ◽

10.1016/s0093-691x(02)00826-9 ◽

2002 ◽

Vol 58 (2-4) ◽

pp. 537-539 ◽

Cited By ~ 1

Keyword(s):

Estrous Cycle ◽

Prostaglandin F2α ◽

Luteal Function

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Effect of two prostaglandin F2α injections administered 24 hours apart on the pregnancy rate of Simmental cows subjected to the Ovsynch or Ovsynch + Controlled internal drug release (CIDR) protocols

Medycyna Weterynaryjna ◽

10.21521/mw.6451 ◽

2020 ◽

Vol 76 (10) ◽

pp. 6451-2020

Author(s):

MUSHAP KURU ◽

CIHAN KACAR ◽

HASAN ORAL ◽

SEMRA KAYA ◽

NEBI CETIN ◽

...

Keyword(s):

Drug Release ◽

Pregnancy Rate ◽

Artificial Insemination ◽

Pregnancy Loss ◽

Prostaglandin F2α ◽

Fixed Time ◽

Group 4 ◽

Group 3 ◽

Group 2 ◽

Group 1

The aim of the present study was to determine the effects of one or two doses of prostaglandin F2α (PGF) on the pregnancy rate (PR) in Simmental cows subjected to the Ovsynch or Ovsynch + Controlled internal drug release (CIDR) protocols. On d 0, 100 µg gonadorelin diacetate tetrahydrate (GnRH) was injected into cows in group 1 (n = 50) and group 2 (n = 40) and CIDR was intravaginally inserted. On d 7, 25 mg dinoprost tromethamine (PGF2α, PGF) was administered, and GnRH was injected 56 h later. Fixed-time artificial insemination (TAI) was performed 16 h after GnRH injection. In group 3 (n = 62) and group 4 (n = 63), PGF was administered 7 d following GnRH treatment, and GnRH was injected 56 h later. TAI was performed 16 h after GnRH injection. In groups 2 and 4, a second dose of PGF was injected 24 h after the first dose. Pregnancy was determined by transrectal ultrasonography on d 30 and 60 post-TAI. The pregnancy rate (PR) on d 30 post-TAI was significantly different among the groups: 46%, 55%, 29%, and 36.5%, in groups 1, 2, 3, and 4, respectively (P = 0.048). In addition, the PR was 36.3% and 43.7% in the single PGF and double PGF injection groups, respectively. There was no statistical difference in the PR on d 60 post-TAI (P > 0.05). Pregnancy loss was between 4.34% and 11.11% (P > 0.05). The highest PR in the primiparous cows was observed in group 3 (57.7%). The PR was not significantly different among multiparous cows (P > 0.05). In conclusion, two injections of PGF administered 24 h apart in Simmental cows may increase the PR in the Ovsynch or Ovsynch + CIDR protocols.

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Comparison of a 16- versus a 19-day interval between controlled internal drug release removal and prostaglandin F2α following a 14-day controlled internal drug releasetreatment and fixed-time artificial insemination in postpartum beef cows1

Journal of Animal Science ◽

10.2527/jas.2013-7045 ◽

2014 ◽

Vol 92 (4) ◽

pp. 1759-1767 ◽

Cited By ~ 2

Author(s):

N. T. Martin ◽

J. M. Thomas ◽

J. M. Nash ◽

D. A. Mallory ◽

M. R. Ellersieck ◽

...

Keyword(s):

Drug Release ◽

Artificial Insemination ◽

Prostaglandin F2α ◽

Fixed Time

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The use of fixed time artificial insemination programmes for the use of sexed semen in block calving dairy heifers

Livestock ◽

10.12968/live.2021.26.3.124 ◽

2021 ◽

Vol 26 (3) ◽

pp. 124-130

Author(s):

Mike Kerby ◽

Tom Clarke ◽

Tom Angel ◽

Kythé Mackenzie

Keyword(s):

Artificial Insemination ◽

Prostaglandin F2α ◽

Cost Benefit ◽

Fixed Time ◽

Reproductive Efficiency ◽

Costs And Benefits ◽

Dairy Heifers ◽

Conception Rates ◽

Sexed Semen

In seasonal block calving herds reproductive efficiency can have a significant impact on productivity and profitability. Within this it is key that the nulliparous heifers calve down promptly in the block, and if these heifers can have heifer calves it will expediate genetic gain. There is extensive research into the conception rates of differing protocols and the literature is reviewed to support the choice of protocol used in the subsequent case study. The case study uses a 6-day progesterone protocol with two injections of prostaglandin F2α and sexed semen; it demonstrated acceptable conception rates as well as the variability that can occur between different bulls' semen straws. Finally, the case study assesses the costs and benefits of the synchronisation programme and concludes a cost benefit of £88.55 per heifer.

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