1
|
Tanner JC, Barrell GK. Reproductive performance of a cohort of Standardbred mares under a commercial breeding system. Equine Vet J 2024; 56:776-785. [PMID: 37559421 DOI: 10.1111/evj.13989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 07/27/2023] [Indexed: 08/11/2023]
Abstract
BACKGROUND Despite being a large commercial breeding industry, there is little published data on the reproductive success of Standardbred mares. OBJECTIVES To quantify the reproductive performance of Standardbred mares under artificial breeding systems in a commercial setting and determine the incidence of early embryonic and other pre-partum losses. STUDY DESIGN Retrospective cohort study. METHODS Data from four commercial farms were collected across four breeding years, and all mares were bred via artificial insemination. A total of 3995 mares contributed 7229 mare years. First-cycle pregnancy rate (FCPR) and end of season pregnancy rate (SPR) were analysed in mixed-effects logistic regression models. Time-to-conception interval was analysed in a Cox regression model. RESULTS The mean FCPR was 61.4% (confidence interval [CI] 60.3%-62.6%), the mean end of SPR was 84.7% (CI 83.8-85.5%), the mean live foal rate (FR) was 73.1% (CI 72.1%-74.2%). Mares located on-farm were more probable to be pregnant in terms of both FCPR (odds ratio [OR] 1.168, CI 1.018-1.340, p = 0.026) and SPR (OR 2.026, CI 1.673-2.454, p < 0.001), mares inseminated with thawed-frozen semen were less probable to be pregnant in terms of FCPR (OR 0.598, CI 0.457-0.783, p < 0.001) and SPR (OR 0.479, CI 0.354-0.647, p < 0.001) compared with insemination with fresh-extended semen. Older mares (14 years and older) were less probable to be pregnant in terms of FCPR (OR 0.795, CI 0.688-0.919, p = 0.002) and SPR (0.435, CI 0.352-0.538, p < 0.001) compared with young mares (3- to 8-year old). MAIN LIMITATIONS Retrospective data relied on accurate record keeping of stud farms and no mare-treatment or ovulation induction records were available. Live FRs relied mostly on annual foaling returns so fetal/foal deaths may be underrepresented. CONCLUSION This study provides substantial baseline data on reproductive performance for Standardbred mares managed under a commercial artificial breeding system.
Collapse
Affiliation(s)
- Jasmine C Tanner
- Department of Agricultural Sciences, Faculty of Agriculture and Life Sciences, Lincoln University, Christchurch, New Zealand
| | - Graham K Barrell
- Department of Agricultural Sciences, Faculty of Agriculture and Life Sciences, Lincoln University, Christchurch, New Zealand
| |
Collapse
|
2
|
Köhne M, Hegger A, Tönissen A, Hofbauer L, Görgens A, Sieme H. Success of different therapies for bacterial endometritis in stud farm practice. J Equine Vet Sci 2024; 133:105009. [PMID: 38262523 DOI: 10.1016/j.jevs.2024.105009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/08/2023] [Accepted: 01/15/2024] [Indexed: 01/25/2024]
Abstract
Bacterial endometritis is a major problem in equine reproduction usually treated with antibiotics, however reports of success rates are scarce. This study collected data from mares diagnosed with intrauterine bacterial growth and compared the outcome of different therapies for bacterial endometritis in German stud farm practice. Data on mares with positive uterine culture results were collected retrospectively in veterinary practices (n = 5; 2018-2022). Information relating to 30 factors (mare, diagnostics, therapy, pregnancy rate) of bacterial endometritis cases (n = 772) were recorded and analyzed. Possible effects on treatment success (positive pregnancy result in the first cycle after treatment) were tested by binomial logistic regression. In most cases β-hemolytic streptococci were detected (n = 707). Treatments for the endometritis included trimethoprim-sulfonamides (n = 409), procaine-penicillin (n = 227), marbofloxacin (n = 53) or no antibiotics (n = 59) and most antibiotics were administered systemically (n = 711) rather than locally (n = 23). Uterine lavage was reported in 49 % of mares. Uterotonic drugs were administered in 42.2 % of mares. Breeding programs included artificial insemination (AI) with chilled semen (n = 667), AI with frozen semen (n = 169), transfer of fresh (n = 112) or cryopreserved (n = 27) embryos and natural cover (n = 27). In the first cycle after treatment, the pregnancy rate was 47 % and it rose to 69 % by end of the season. Treatment success was affected by duration of antibiotic treatment, veterinary practice, and presence of clinical signs. In conclusion, reported treatment practices in German stud farm practice resulted in acceptable pregnancy results and the multiple binomial logistic regression approach identified factors affecting the pregnancy outcome in this dataset.
Collapse
Affiliation(s)
- Martin Köhne
- Unit for Reproductive Medicine - Clinic for Horses, University of Veterinary Medicine, Foundation, 30559 Hannover, Germany.
| | - Anna Hegger
- Clinic for Horses Mühlen, 49349 Steinfeld (Oldenburg), Germany, Germany
| | - Anna Tönissen
- Unit for Reproductive Medicine - Clinic for Horses, University of Veterinary Medicine, Foundation, 30559 Hannover, Germany
| | - Lisa Hofbauer
- Clinic for Horses Mühlen, 49349 Steinfeld (Oldenburg), Germany, Germany
| | - Alexandra Görgens
- Clinic for Horses Mühlen, 49349 Steinfeld (Oldenburg), Germany, Germany
| | - Harald Sieme
- Unit for Reproductive Medicine - Clinic for Horses, University of Veterinary Medicine, Foundation, 30559 Hannover, Germany
| |
Collapse
|
3
|
BIANCHI CP, BRUNO S, VIDELA DORNA I, RODRÍGUEZ E, ABA MA. Effect of short-term artificial light and transvaginal progesterone device on first ovulation in late transitional mares. J Equine Sci 2022; 33:1-6. [PMID: 35510073 PMCID: PMC9018460 DOI: 10.1294/jes.33.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 02/08/2022] [Indexed: 11/07/2022] Open
Abstract
In study I, plasma progesterone concentrations were evaluated in anoestrous mares that
received an intravaginal progesterone release device (IPRD) for 10 days. Mares were
divided into 3 groups based on the dosage of progesterone (0 g, n=3; 1.38 g, n=5; and 1.9
g, n=5). No statistical differences were found in plasma progesterone concentrations
between the two doses tested. In study II, the effects of a protocol based on a short
program of artificial light combined with an IPRD containing 1.38 g of progesterone on
oestrous behaviour and onset of ovulation were evaluated. IPRDs were inserted into 31 late
transitional mares (10 days of treatment). The mares were divided into a control group
(n=9, IPRD with 0 g of progesterone) and two treatment groups (T1, n=10, IPRD with 0 g of
progesterone and artificial light; T2, n=12, IPRD with 1.38 g of progesterone and
artificial light). The percentages of mares in heat within the first 14 days after
treatment were 100%, 70%, and 100% in the control, T1, and T2 groups, respectively
(P=0.097), and their ovulation rates were 44%, 60%, and 100%, respectively (P≤0.01). In
conclusion, a protocol based on artificial light and an IPRD containing 1.38 g of
progesterone for 10 days could be considered to advance the first ovulation of the year in
late transitional mares, as it ensures a higher rate of ovulation within the first 14 days
after treatment.
Collapse
Affiliation(s)
- Carolina Paula BIANCHI
- Laboratory of Endocrinology, Department of Physiopathology, Faculty of Veterinary Sciences, National University of the Center of Buenos Aires Province, Buenos Aires, Argentina
| | - Santiago BRUNO
- General Lavalle Haras, Argentine Army, Buenos Aires, Argentina
| | | | - Edgardo RODRÍGUEZ
- Biostatistics Area, Faculty of Veterinary Sciences, National University of the Center of Buenos Aires Province, Buenos Aires, Argentina
| | - Marcelo Alfredo ABA
- Laboratory of Endocrinology, Department of Physiopathology, Faculty of Veterinary Sciences, National University of the Center of Buenos Aires Province, Buenos Aires, Argentina
| |
Collapse
|
4
|
Segabinazzi LGTM, Andrade LRP, Alvarenga MA, Dell’Aqua JA, Canisso IF. Use of Intravaginal Progesterone-Releasing Device Results in Similar Pregnancy Rates and Losses to Long-Acting Progesterone to Synchronize Acyclic Embryo Recipient Mares. Vet Sci 2021; 8:vetsci8090190. [PMID: 34564584 PMCID: PMC8472191 DOI: 10.3390/vetsci8090190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/24/2021] [Accepted: 09/01/2021] [Indexed: 11/16/2022] Open
Abstract
The objectives of this study were: (1) to assess uterine features and serum progesterone concentrations of acyclic mares synchronized and resynchronized with intravaginal progesterone release device (IPRD), and (2) to compare pregnancy rates and losses of cyclic and acyclic embryo recipient mares treated with different synchronization protocols. In Experiment 1, mares (n = 12) received estradiol for 3 days (E2-3d), and then 24 h after the last injection, an IPRD was inserted and kept in place for 9 days. Three days after IPRD removal, mares were treated with E2-3d, and then a new IPRD was inserted and maintained for three days. Serum progesterone concentrations were assessed 2, 6, and 12 h after insertion and removal of IPRD, and then daily from the insertion of the first IPRD to one day after removal of the second IPRD. Experiment 2 was conducted with embryo recipient mares randomly assigned to four groups: (1) Cyclic: mares (n = 75) had ovulation confirmed after receiving a single dose of histrelin when a periovulatory follicle was first detected, (2) LAP4: acyclic mares (n = 92) were treated with E2-3d and then administered a single dose of LAP4 24 h after the last estradiol injection, (3) IPRD: acyclic mares (n = 130) were treated with E2-3d and an IPRD for 4-8 days, and (4) RE-IPRD: acyclic mares (n = 32) were synchronized as in the IPRD group but not used for embryo transfer (ET), then 8 to 15 days later, the mares were resynchronized with E2-3d and an IPRD for 4-8 days. In vivo-produced Day-8 embryos were collected and transferred 4-8 days after ovulation or progesterone treatments. Mares in IPRD and RE-IPRD groups had the intravaginal device removed immediately before ET, and then a new IPRD was inserted right after ET. Pregnancy diagnosis was performed at 5, 30, and 60 days after ET. Once pregnancy was confirmed, mares in the three acyclic groups received weekly injections of LAP4 (1.5 g) until 120 days of pregnancy. Mares in IPRD and RE-IPRD groups had the device removed three days after the first pregnancy diagnosis. In Experiment 1, progesterone concentrations increased rapidly starting 2 h after insertion of IPRD (p < 0.05); then, concentrations plateaued well above pregnancy maintenance until removal on days 9 and 3, respectively. Progesterone concentrations were reduced to baseline 24 h after IPRD removal (p < 0.05). For experiment 2, there was no difference in pregnancy rates across groups (65-74%) or pregnancy losses by 60 days of gestation (7-12%) (p > 0.05). In conclusion, the IPRD used herein resulted in a rapid increase and a sharp decline in progesterone concentrations upon its insertion and removal, respectively. Finally, our results demonstrated that IPRD could be a compatible alternative to LAP4 to synchronize and resynchronize acyclic embryo recipient mares.
Collapse
Affiliation(s)
- Lorenzo G. T. M. Segabinazzi
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University, UNESP, Botucatu 18618-681, Brazil; (L.G.T.M.S.); (L.R.P.A.J.); (M.A.A.); (J.A.D.J.)
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, 1008 W Hazelwood Drive, Urbana, IL 61802, USA
| | - Luiz R. P. Andrade
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University, UNESP, Botucatu 18618-681, Brazil; (L.G.T.M.S.); (L.R.P.A.J.); (M.A.A.); (J.A.D.J.)
| | - Marco A. Alvarenga
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University, UNESP, Botucatu 18618-681, Brazil; (L.G.T.M.S.); (L.R.P.A.J.); (M.A.A.); (J.A.D.J.)
| | - Jose A. Dell’Aqua
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University, UNESP, Botucatu 18618-681, Brazil; (L.G.T.M.S.); (L.R.P.A.J.); (M.A.A.); (J.A.D.J.)
| | - Igor F. Canisso
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, 1008 W Hazelwood Drive, Urbana, IL 61802, USA
- Correspondence:
| |
Collapse
|
5
|
Teixeira A, Riveros J, Diniz J, Fonseca A, Silva D, Leo A, Pereira I, Valle G, Monteiro G, Oliveira L. Intravaginal progesterone device (1.9g) and estradiol benzoate for follicular control in the mare during spring and summer. ARQ BRAS MED VET ZOO 2021. [DOI: 10.1590/1678-4162-12272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ABSTRACT The objective of this study was to evaluate follicular growth and ovulatory rates in mares treated with an intravaginal progesterone device (P4) during the 10-day period, associated with the use of estradiol benzoate (EB). The results were compared during the transition period (ET) in the spring and the breeding season in the summer (ER). The variables were submitted to ANOVA (Tukey's test), considering P<0.05. No ovulation occurred during the permanence of the P4 implant in both experimental periods. The ovulatory rate in the ER was 100% (n = 8) and in the ET 62.5% (n = 5; P = 0.0547). Significant differences were observed (<0.001), in both periods, comparing follicular growth rates during the permanence of P4 device (ER: 1.33 ± 0.89mm/d; ET: 1.00 ± 0.81mm/d) to the period without P4 (ER: 3.63 ± 1.33 mm/d; ET: 3.31 ± 1.66 mm/d). The present study demonstrated applicability and efficiency of a hormonal protocol using P4 intravaginal device and EB for follicular control in mares, both during ET and ER.
Collapse
Affiliation(s)
| | | | | | | | - D.F. Silva
- Universidade Federal de Minas Gerais, Brazil
| | - A.M.P. Leo
- Universidade Federal de Minas Gerais, Brazil
| | | | | | | | | |
Collapse
|
6
|
Macan RC, Camargo CE, Zielinski BL, Cardoso NGH, de Lara NSS, Bergstein-Galan TG, Weiss RR, Kozicki LE. Timed artificial insemination in crossbred mares: Reproductive efficiency and costs. Reprod Domest Anim 2021; 56:459-466. [PMID: 33368635 DOI: 10.1111/rda.13884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 12/22/2020] [Indexed: 11/29/2022]
Abstract
Timed artificial insemination (TAI) has boosted the use of conventional artificial insemination (CAI) by employing hormonal protocols to synchronize oestrus and ovulation. This study aimed to evaluate the efficiency of a hormonal protocol for TAI in mares, based on a combination of progesterone releasing intravaginal device (PRID), prostaglandin (PGF2α ) and human chorionic gonadotropin (hCG); and compare financial costs between CAI and TAI. Twenty-one mares were divided into two groups: CAI group (CAIG; n = 6 mares; 17 oestrous cycles) and TAI group (TAIG; n = 15 mares; 15 oestrous cycles). The CAIG was subjected to CAI, involving follicular dynamics and uterine oedema monitoring with ultrasound examinations (US), and administration of hCG (1,600 IU) when the dominant follicle (DF) diameter's ≥35 mm + uterine oedema + cervix opening. The AI was performed with fresh semen (500 × 106 cells), and embryo was recovered on day 8 (D8) after ovulation. In TAI, mares received 1.9 g PRID on D0. On D10, PRID was removed and 6.71 mg dinoprost tromethamine was administered. Ovulation was induced on D14 (1,600 IU of hCG) regardless of the DF diameter's, and AI was performed with fresh semen (500 × 106 cells). On D30 after AI, pregnancy was confirmed by US. The pregnancy rate was 80.0% in TAIG and 82.3% in CAIG (p > .05). The TAI protocol resulted in 65% reduction in professional transport costs, and 40% reduction in material costs. The TAI was as efficient as CAI, provided reduction in costs and handlings, and is recommended in mares.
Collapse
Affiliation(s)
- Rodrigo Chaves Macan
- Post Graduate Program, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil
| | - Carlos Eduardo Camargo
- Post Graduate Program, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil
| | - Bruna Lampe Zielinski
- Post Graduate Program, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil
| | | | | | | | | | - Luiz Ernandes Kozicki
- Post Graduate Program, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil
| |
Collapse
|
7
|
Rigoleto Júnior WL, Dias de Camargo Neto W, de Paula Nogueira G, Ferrari TA, Bertan Membrive CM, Giometti IC, Castilho C. Serum Progesterone and Conception Rates in Acyclic Embryo Recipient Mares Using a Bovine Progesterone-Releasing Intravaginal Device. J Equine Vet Sci 2020; 97:103325. [PMID: 33478762 DOI: 10.1016/j.jevs.2020.103325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 10/15/2020] [Accepted: 11/13/2020] [Indexed: 10/22/2022]
Abstract
The objective of this study was to quantify serum progesterone levels, uterine features, and pregnancy rates in acyclic, embryo recipient mares using a bovine progesterone-releasing intravaginal device in a commercial embryo transfer (ET) program. The study included 73 recipient mares of unknown breed, aged 3-10 years, weighing 350-500 kg, and kept under an intensive management system on Tifton 85 (Cynodon spp.) pastures with water and mineral salt ad libitum. The horses were divided into two groups: a group with a progesterone-releasing intravaginal device (1 g progesterone, G-IVP4, n = 24) and a control group (G-iP4, n = 49) receiving an injection of 1,500 mg long-acting progesterone. Jugular blood was collected for the G-IVP4 group for subsequent progesterone measurement by radioimmunoassay on three occasions: Day 0 (D0), intravaginal device was placed; Day 5 (D5), day of the ET; and Day 9 (D9), day of pregnancy diagnosis. There was an increase (P < .0001) in serum progesterone levels on D5 and D9 compared with D0 (4.09 ± 0.81 and 6.45 ± 1.03 ng/mL vs. 0.71 ± 0.14 ng/mL). There were no differences among groups in the pregnancy rate (P > .05), with rates of 83.33% and 73.46% for G-IVP4 and G-iP4, respectively. In conclusion, the intravaginal route for absorption of 1 g of progesterone device increased the serum level of progesterone sufficiently to prepare the uterus of acyclic recipient mares for ET, and the conception rate was similar to the standard protocol using long-acting injectable progesterone.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Caliê Castilho
- University of Western São Paulo, (UNOESTE), Presidente Prudente, São Paulo, Brazil.
| |
Collapse
|
8
|
Teixeira ACB, Valle GR, Riveros JAN, Diniz JHW, Wenceslau RR, Monteiro GA, Leme FDOP, Oliveira LZ. Effects of Equine Chorionic Gonadotropin on Ovulatory and Luteal Characteristics of Mares Submitted to an P4-Based Protocol of Ovulation Induction With hCG. J Equine Vet Sci 2020; 94:103233. [PMID: 33077076 DOI: 10.1016/j.jevs.2020.103233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/19/2020] [Accepted: 08/17/2020] [Indexed: 10/23/2022]
Abstract
The aim of this study was to evaluate the effect of equine chorionic gonadotropin (eCG) at the end of progesterone (P4) treatment on follicular and luteal characteristics during transition period (TP) and reproductive breeding season (RP). A total of 13 crossbred mares were distributed in two experimental groups in the spring and summer (n = 26). The animals received intravaginal P4 (1.9 g) releasing device from D0 to D10. On removal of P4 device, the mares received 400 IU of eCG (eCG group) or saline solution (control group). Human chorionic gonadotropin (hCG; 1.750 IU) was administered (DhCG) as soon as ovulatory follicle (OF) ≥35 mm was detected. Ovarian ultrasonography was performed from D0 until 15 days after ovulation. Blood samples were collected on D0, D5, D10, DhCG, 9 days after ovulation (CL9D), and 13 days after ovulation (CL13D). P4 and estradiol concentrations were assessed by chemiluminescence. Data were compared by Tukey test at P < .05. Ovulation rate was similar (P = .096) between seasons (RP = 100%; TP = 70%) but occurred earlier (P = .015) in RP (34.8 ± 10.1 hours) compared with TP (42.0 ± 10.4 hours). Interactions between season and treatment were observed for OF diameter (mm) (RP/control = 36.2 ± 1.8ab; RP/eCG = 32.9 ± 2.8 b; TP/control = 32.2 ± 1.2 b; TP/eCG = 37.2 ± 1.9a; P = .004) and for corpus luteum (CL) diameter (mm) on CL13D (RP/control = 25.4 ± 3.5a; RP/eCG = 22.5 ± 1.8ab; TP/control = 21.6 ± 4.9 b; TP/eCG = 27.4 ± 4.3a; P = .023), although no differences were observed for serum P4 on CL13D (RP/control = 6.0 ± 3.1 ng/mL; RP/eCG = 5.8 ± 0.9 ng/mL; TP/control = 3.6 ± 2.7 ng/mL; TP/eCG = 5.1 ± 2.3 ng/mL; P = .429) or for day of structural CL regression (RP/control = 12.8 ± 1.9; RP/eCG = 12.1 ± 1.1; TP/control = 11.0 ± 1.7; TP/eCG = 13.2 ± 2.0; P = .102). The application of eCG at the moment of P4 implant removal seemed to increase the capacity of luteal maintenance during spring TP. However, eCG treatment was worthless during the breeding season.
Collapse
Affiliation(s)
| | | | | | | | - Raphael Rocha Wenceslau
- Escola de Veterinária, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | | | | | | |
Collapse
|
9
|
Dos Reis WVA, de Braga D, Júnior MV, Gheller JM, de Deco-Souza T, da Costa E Silva EV, Sampaio BFB, Macedo GG. P4/E2-based protocol for synchronisation of ovulation of mares during the breeding and non-breeding season. Trop Anim Health Prod 2020; 52:2647-2651. [PMID: 32458354 DOI: 10.1007/s11250-020-02286-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 05/13/2020] [Indexed: 11/26/2022]
Abstract
Dispersed ovulation at the breeding (BS) and anestrus at non-breeding season (NBS) are major impediments to embryo transfer and insemination programmes. The present study aimed to evaluate a hormonal P4/E2-based synchronisation protocol in mares during both the BS and the NBS on ovarian/follicle behaviour. Mares underwent a hormone protocol to synchronise their ovulation during the BS (n = 8) and NBS (n = 10), starting (D0) with the insertion of an intravaginal device containing 1 g of P4 and 7 mg Estradiol Benzoate IM. (EB). On D9, the device was removed and injected with 0.25 mg of cloprostenol sodic IM and 2 mg of EB IM. Follicular behaviour was evaluated using a daily transrectal ultrasound (24/24 h) from D0 until ovulation. When the dominant follicle (DF) measured at least 35 mm, females were injected with 0.25 mg of gonadorelin acetate IM to induce ovulation. The DF on D0 were similar in animals between BS (18.9 ± 8.4 mm) and NBS (23.7 ± 9.2 mm; p = 0.2700). However, in the BS the DF was smaller (14.2 ± 4.7 mm) on D9 than during NBS (22.0 ± 7.1 mm; p = 0.0177). During the BS, the ovulatory follicle is smaller (p = 0.0042) than during NBS, measured at 33.5 ± 4.6 mm and 41.3 ± 2.8 mm, respectively. Ovulation time after P4 removal was similar during BS (173.1 ± 68.8 h) and NBS (192 ± 58.2 h; p = 0.3507). There was no difference towards an ovulation rate during BS (88%) and NBS (60%; p = 0.0978). There was no difference in spontaneous ovulation during BS (43%) and NBS (0%; p = 0.6085). This hormonal protocol would be an effective tool for inducing cyclicity/ovulation in mares during BS and NBS.
Collapse
Affiliation(s)
- Willian Vaniel Alves Dos Reis
- Animal Reproduction Laboratory, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Daniela de Braga
- Animal Reproduction Laboratory, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Mozarth Vieira Júnior
- Animal Reproduction Laboratory, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Janaina Menegazzo Gheller
- Animal Reproduction Laboratory, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Thyara de Deco-Souza
- Animal Reproduction Laboratory, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Eliane Viana da Costa E Silva
- Animal Reproduction Laboratory, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Breno Fernandes Barreto Sampaio
- Animal Reproduction Laboratory, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Gustavo Guerino Macedo
- Animal Reproduction Laboratory, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil.
| |
Collapse
|
10
|
Gee EK, Rogers CW, Bolwell CF. Commercial equine production in New Zealand. 1. Reproduction and breeding. ANIMAL PRODUCTION SCIENCE 2020. [DOI: 10.1071/an16728] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The Thoroughbred and Standardbred studbooks are the largest in New Zealand, where the production of horses is pasture based. Each racing studbook is closed, and both have well structured systems in place for recording breeding data. There are significant pressures on the Thoroughbred and Standardbred breeding industries with declining broodmare numbers, and increasingly large book sizes for popular stallions. The breeding season for Thoroughbreds is very short, with disparity between the official breeding season and the physiologic breeding season for mares. These issues are confounded by variable gestation lengths of mares, making it difficult for mares to maintain yearly foaling patterns. However, the reproductive efficiency of Thoroughbred mares is improving, mainly due to veterinary and stud management practices such as those to ensure that dry mares are cycling at the start of the breeding season, foaling mares are bred on foal heat, and that mares are kept in good body condition at breeding. There is also a bias towards breeding younger mares with high fertility in preference to older mares, unless they have desired genetics or successful offspring. Careful management of popular Thoroughbred stallions ensures that large books of mares can be covered by natural service. In contrast, Standardbred stallions are collected every-other-day using an artificial vagina, allowing the breeding of mares at distant locations by artificial insemination, using chilled or frozen semen. Breeding horses kept at pasture under New Zealand conditions requires excellent stud management and veterinary management to achieve good outcomes.
Collapse
|
11
|
Polasek TCM, Kozicki LE, Pedrosa VB, Weiss RR, Bertol MAF, Camargo CE, Talini R. Impact of a progesterone-releasing intravaginal device and inflammatory reaction on ovarian activity in embryo-recipient anestrus mares. Theriogenology 2017; 90:175-184. [DOI: 10.1016/j.theriogenology.2016.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 10/14/2016] [Accepted: 11/07/2016] [Indexed: 11/26/2022]
|
12
|
Wespi B, Sieme H, Wedekind C, Burger D. Exposure to stallion accelerates the onset of mares' cyclicity. Theriogenology 2014; 82:189-94. [DOI: 10.1016/j.theriogenology.2014.03.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 03/18/2014] [Accepted: 03/20/2014] [Indexed: 11/30/2022]
|
13
|
Preovulatory progestagen treatment in mares fails to delay ovulation. Vet J 2013; 197:324-8. [PMID: 23384437 DOI: 10.1016/j.tvjl.2012.12.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 12/10/2012] [Accepted: 12/21/2012] [Indexed: 11/20/2022]
Abstract
The major objective of this study was to determine whether short-term preovulatory progestagen treatment of mares could effectively delay ovulation. Secondary objectives were to determine the effect such supplementation had on signs of estrus, follicular growth, postovulatory luteal function and pregnancy rate. Thirteen cyclic mares of different breeds were used in this study during the natural breeding season. Once mares were confirmed in estrus with a follicle of 35 mm in diameter, they were assigned in random order to receive no treatment (control), placement of a progesterone-impregnated controlled intravaginal drug releasing device (CIDR) for 2 days, or oral altrenogest treatment (0.044 mg/kg/d) for 2 days. Transrectal ultrasonography and teasing with a vigorous stallion were performed daily. Mares were inseminated every 48 h after the end of experimental treatment (progestagen groups) or beginning when the follicular diameter was 35 mm (control group) with fresh extended semen of a single fertile stallion. Each mare was followed for 3-5 cycles, allowing each treatment to be applied one or two times. Neither CIDR nor altrenogest treatment delayed ovulation. Treatment had no effect on follicular growth rate or the size of the ovulatory follicle immediately preceding ovulation. Both forms of progestagen treatment effectively abolished estrous behavior within 24h. Estrous response to the stallion returned to the control level after cessation of treatment. Similarly, a reduction in endometrial edema was detected during progestagen treatment, which returned to normal after cessation of treatment. Altrenogest treatment tended to reduce the chance of pregnancy (P=0.09) compared to the control group. The use of progestagens to delay ovulation in mares lacks efficacy and may threaten successful establishment of pregnancy.
Collapse
|
14
|
Vizuete G, Diez E, Galisteo J, Agüera E, Aguilera-Tejero E, Perez-Marín CC. Comparison of different treatments for oestrous induction in seasonally anovulatory mares. Reprod Domest Anim 2012; 48:463-9. [PMID: 23137389 DOI: 10.1111/rda.12098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 09/12/2012] [Indexed: 11/28/2022]
Abstract
The aim of this study was to evaluate the effects of different treatments for induction and synchronization of oestrus and ovulation in seasonally anovulatory mares. Fifteen mares formed the control group (C), while 26 mares were randomly assigned to three treatment groups. Group T1 (n = 11) were treated with oral altrenogest (0.044 mg/kg; Regumate(®) ) during 11 days. Group T2 (n = 7) was intravaginally treated with 1.38 g of progesterone (CIDR(®) ) for 11 days. In group T3 (n = 8), mares were also treated with CIDR(®) , but only for 8 days. All mares received PGF2α 1 day after finishing the treatment. Sonographic evaluation of follicles, pre-ovulatory follicle size and ovulation time was recorded. Progesterone and leptin levels were analysed. Results show that pre-ovulatory follicles were developed after the treatment in 88.5% of mares. However, the pre-ovulatory follicle growth was dispersal, and sometimes it was detected when treatment was not finished. While in mares treated with intravaginal device, the follicle was soon detected (1.5 ± 1.2 days and 2.3 ± 2.0 days in T2 and T3 groups, respectively), in T1 group, the pre-ovulatory follicle was detected slightly later (3.9 ± 1.6 days). The interval from the end of treatment to ovulation did not show significant differences between groups (T1 = 13.1 ± 2.5 days; T2 = 11.0 ± 3.6 days; T3 = 13.8 ± 4.3 days). The pregnancy rate was 47.4%, similar to the rate observed in group C (46.7%; p > 0.05). Initial leptin concentrations were significantly higher in mares, which restart their ovarian activity after treatments, suggesting a role in the reproduction mechanisms in mares. It could be concluded that the used treatments may be effective for oestrous induction in mares during the late phase of the seasonally anovulatory period. Furthermore, they cannot synchronize oestrus, and then, it is necessary to know the reproductive status of mares when these treatments are used for oestrous synchronization.
Collapse
Affiliation(s)
- G Vizuete
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, University of Cordoba, Cordoba, Spain
| | | | | | | | | | | |
Collapse
|