Animal Reproduction (AR)
Animal Reproduction (AR)

The ovarian and uterine responses of Baixadeiro mares to prostaglandin synchronization during the dry and rainy seasons

Luciana Cordeiro Rosa; Eliane Cristina Silva Dias; Renatta Silva Melo; Carla Janaína Rebouças Marques do Rosário; Felipe Lucas Correa Pereira; Luiz Bruno Oliveira Chung; Adriana Raquel de Almeida da Anunciação; Felipe de Jesus Moraes Junior; Fernando Andrade Souza; Ricardo de Macêdo Chaves

Downloads: 1
Views: 136


This study aimed to evaluate the effect of synchronization with prostaglandin F2α in Baixadeiro mares during the rainy and dry seasons. Fourteen mares were synchronized by administering two doses of 1 mL prostaglandin PGF 2α and monitored by rectal palpation and ultrasound for the assessment of follicular development and uterine echotexture. Of this total, nine mares allowed the collection of blood, in which the blood was collected by venipuncture of the jugular vein to determine progesterone (P4) by ELISA. Mares showed no differences (P > 0.05) in weight, body score condition (BSC), tone, uterine edema, frequency of ovulation, synchronization interval, estrus, and the total number of follicles between periods. However, there was a difference in large increased follicle diameter (P < 0.05) during the dry season. The average concentrations of P4 in mares differed (P < 0.05) between the pre- and post-ovulatory phases for both seasons and after ovulation, with higher concentrations in the rainy season. Furthermore, statistical differences in daily light (P < 0.05) were observed between the dry and rainy periods. Thus, we conclude that mares from the genetic grouping Baixadeiro showed no reproductive seasonality, though there was a difference in luminosity between the rainy and dry seasons. The treatment with two doses of PGF 2α was effective in synchronizing the mares, promoting the return of estrus in the dry and rainy periods. The mares remaining cyclically active throughout the year provided there were appropriate forage availability and quality levels to allow for normal values of body weight and condition.


estrus, follicular development, Baixadeiro mares


Abo-El maaty AM, El-Shahat KH. Hormonal and biochemical serum assay in relation to the estrous cycle and follicular growth in Arabian mare. As Pac J of Reprod, 2012;1(2):105-110.

Almeida HB, Viana WG, Arruda RP, Oliveira CA. Sincronização de estro e dinâmica folicular de éguas Crioulas submetidas a tratamentos com norgestomet, acetato de melengestrol e altrenogest. Braz J Vet Res Anim Sci. 2001;38(6):267-72.

Alonso MA, Silva LA, Affonso FJ, Lemes KM, Celeghini ECC, Lançoni R, Carvalho HF, Arruda RP. Effect of hCG application at different moments of the estrous cycle on corpus luteum and uterine vascularization and serum progesterone concentration in mares. Anim Reprod. 2019;16(2):317-27. PMid:33224293.

Arruda RPD, Visintin JA, Fleury JJ, Garcia AR, Madureira EH, Celeghini ECC, Neves Neto JR. Existem relações entre tamanho e morfoecogenicidade do corpo lúteo detectados pelo ultrassom e os teores de progesterona plasmática em receptoras de embriões equinos? Braz J Vet Res Anim Sci. 2001;38(5):233-9.

Barros BS, Hunka MM, Souza AL, Silva JFL, Coelho CS, Manso HECC, Manso Filho HC. Vitamin D concentrations and biological biomarkers of lactating mares and foals in the dry season. Pferdeheilkunde. 2019;35(4):344-9.

Bender ESC, Sampaio BFB, Nogueira BG, Costa-e-Silva EV, Zúccari CESN. Condição corporal e atividade reprodutiva de éguas. Arch Zootec. 2014;63(241):55-67.

Blanchard TL, Varner DD, Schumacher J. Reproductive Physiology of the Nonpregnant Mare. In: Fathman EM, Merchant T, editors. Manual of equine reproduction. St Louis, Missouri: Mosby; 2003. p.9-15.

Boeta M, Porras A, Zarco LA, Aguirre-Hernández R. Ovarian activity of the mare during winter and spring at a latitude of 19° 21′ north. J Equine Vet Sci. 2006;26(2):55-8.

Carnevale EM, Hermenet MJ, Ginther OJ. Age and pasture effects on vernal transition in mares. Theriogenology. 1997;47(5):1009-18. PMid:16728051.

Carranza J, Yoong WA, Mateos C, Caño Vergara B, Gómez CL, Macías V. Reproductive phenology of Creole horses in Ecuador in the absence of photoperiod variation: the effects of forage availability and flooding affecting body condition of mares. Anim Sci J. 2017;88(12):2063-70. PMid:28748628.

Cuervo-Arango J, Martín-Peláez MS, Claes AN. A practical guide to estimate the age of the early CL by ultrasonography in mares examined for the first time to be used as recipients in a commercial embryo transfer program. Theriogenology. 2020;153(1):48-53. PMid:32417611.

Cuervo-Arango J, Mateu-Sánchez S, Aguilar JJ, Nielsen JM, Etcharren V, Vettorazzi ML, Newcombe JR. The effect of the interval from PGF treatment to ovulation on embryo recovery and pregnancy rate in the mare. Theriogenology. 2015;83(8):1272-8. PMid:25666044.

Faria DR, Gradela A. Hormonioterapia aplicada à ginecologia equina. Rev Bras Reprod Anim. 2010;34(2):114-122. Available from:

Ferreira-Dias G, Claudino F, Carvalho H, Agrícola R, Alpoim-Moreira J, Silva JR. Seasonal reproduction in the mare: possible role of plasma leptin, body weight and immune status. Domest Anim Endocrinol. 2005;29(1):203-13. PMid:15927774.

Gastal MO, Gastal EL, Spinelli V, Ginther OJ. Relationships between body condition and follicle development in mares. Anim Reprod. 2004 [cited 2015 Sept 17];1(1):115-21. Available from:

Gazolla AG, Serra OR, Lima FC. Pelagens do cavalo da raça baixadeira. In: 46ª Reunião Anual Sociedade Brasileira Zootecnia; 2009 jul 14-17, Maringá, PR, Brasil. Maringá: SBZ; 2009. p.1-3.

Ginther OJ, Beg MA, Bergfelt DR, Donadeu FX, Kot K. Follicle selection in monovular species. Biol Reprod. 2001;65(3):638-47. PMid:11514323.

Ginther OJ, Beg MA, Donadeu FX, Bergfelt DR. Mechanism of follicle deviation in monovular farm species. Anim Reprod Sci. 2003;78(3-4):239-57. PMid:12818647.

Ginther OJ, Gastal EL, Rodrigues BL, Gastal MO, Beg MA. Follicle diameters and hormones concentrations in the development of single versus double ovulation in mares. Theriogenology. 2008;69(5):583-90. PMid:18242675.

Ginther OJ, Santos VG. Natural rescue and resurgence of the equine corpus luteum. J. Eq Vet Scie. 2015;35(1):1-6.

Ginther OJ, Utt MD, Beg MA. Follicle deviation and diurnal variation in circulating hormone concentrations in mares. Anim Reprod Sci. 2007;100(1-2):197-203. PMid:17000062.

Ginther OJ. Folliculogenesis during the transitional period and early ovulatory season in mares. J Reprod Fertil. 1990;90(1):311-20. PMid:2231551.

Ginther OJ. Reproductive biology of the mare: basic and applied aspects. 2nd ed. Cross Plains: Equiservices Publishing; 1995. p. 10-20.

Griffin PG, Hermenet MJ, Ginther OJ. A transient increase in uterine tone during early diestrus in mares. Theriogenology. 1992;37(6):1185-90.

Haetinger C, Torres A, Brum C, Nogueira CEW. Uso comparativo de progesterona sintética-P4 e PGF2-α na sincronização de cio em éguas da raça crioula. In: XVII Congresso de Iniciação científica e X Encontro de Pós-Graduaçã; 2000 Nov 11-14; Pelotas, RS. Pelotas: Universidade Federal de Pelotas; 2008.

Hayes KEN, Ginther OJ. Role of progesterone and estrogen in development of uterine tone in mares. Theriogenology. 1986;25(4):581-90. PMid:16726149.

Hayes KEN, Pierson RA, Scraba ST, Ginther OJ. Effects of estrous cycle and season on ultrasonic uterine anatomy in mares. Theriogenology. 1985;24(4):465-77. PMid:16726101.

Henneke DR, Potter GD, Kreider JL, Yeates BF. Relationship between condition score, physical measurements and body fat percentage in mares. Equine Vet J. 1983;15(4):371-2. PMid:6641685.

Houston AI, Stephens PA, Boyd IL, Harding KC, McNamara JM. Capital or income breeding? A theoretical model of female reproductive strategies. Behavioral Ecology. 2007;1(8):241–250.

INMET - Instituto Nacional de Meteorologia [homepage on the Internet]. Brasília: Ministério da Agricultura, Pecuária e Abastecimento; 2015. [cited 2015 Sept 17]. Available from:

Irvine CHG. Prostaglandins. In: Mckinnon AO, Voss JL, editors. Equine reproduction. Philadelphia: Lea & Febiger. 1993. p. 319-324.

Klein SL, Nelson RJ. Influence of social factors on immune function and reproduction. Rev Reprod. 1999;4(3):168-78. PMid:10521154.

Lopes KRF, Lima GL, Bezerra LGP, Barreto-Junior RA, Oliveira MF, Silva AR. Characterization of the ovarian preantral follicle populations and its correlation with age and nutritional status in Brazilian Northeastern donkeys (Equus assinus). Anim Reprod Sci. 2017;187:193-202. PMid:29126831.

McKinnon AO, Voss JL. Equine reproduction. 5th ed. Philadelphia: Lea & Febiger, 1992. p. 52.

Morel MCGD, Newcombe JR, Hayward K. Factors affecting pre-ovulatory follicle diameter in the mare: the effect of mare age, season and presence of other ovulatory follicles (multiple ovulation). Theriogenology. 2010;74(7):1241-7. PMid:20615543.

Moura JCA. Diagnóstico por imagem na reprodução equina “controle do útero”. Ciênc Anim. 2012;22(1):161-70.

Nagy P, Guillaume D, Daels P. Seasonality in mares. Anim Reprod Sci. 2000;60-61:245-62. PMid:10844199.

Nagy P, Huszenicza G, Reiczigel J, Juhasz J, Kulcsar M, Abavary K, Guillaume D. Factors affecting plasma progesterone concentration and the retrospective determination of time of ovulation in cyclic mares. Theriogenology. 2004;61(2-3):203-14. PMid:14662122.

Nascimento JN. Caracterização do ciclo estral de éguas da raça Pantaneiro e Campeiro no Planalto Central [dissertation]. Brasília: Universidade de Brasília; 2014. Portuguese.

Ogutu JO, Owen-Smith N, Piepho HP, Dublin HT. How rainfall variation influences reproductive patterns of African savanna ungulates in an equatorial region where photoperiod variation is absent. PLoS One. 2015;10(8):e0133744. PMid:26295154.

Pierson RA, Ginther OJ. Follicular population dynamics during the estrous cycle of the mare. Anim Reprod Sci. 1987;14(3):219-31.

Pierson RA. Foliculogenesis and ovulation. In: Mckinnon AO, Voss JL, editors. Equine reproduction. Malvern: Lea & Febiger. 1993. p.161-171.

Ramírez G, Gutiérrez C, Ramos M. Dinámica folicular en yeguas paso fino colombiano medido por ultrasonografía en la Sabana de Bogotá. Ver Med Vet. 2010;19(19):21-35.

Rodrigues PG, Raymundo MC, Souza JC, Miranda CMG, Rezende ASC. Gordura corporal e eficiência reprodutiva em éguas doadoras de embrião Mangalarga Marchador. Cienc Agrotec. 2011;35(5):1002-8.

Romano MA, Mucciolo RG, Silva AEDF. Biologia reprodutiva de éguas: estudo do ciclo estral e momento da ovulação. Braz J Vet Res Anim Sci. 1998;35(1):23-8.

Samper JC, Pycock JF. The normal uterus in estrus. In: Rudolph P, Gower J, editors. Current therapy in equine reproduction, St Louis, Missouri: Saunders-Elsevier; 2007. p.32-35.

Samper JC. Induction of estrus and ovulation: why some mares respond and others do not. Theriogenology. 2008;70(3):445-7. PMid:18554709.

Santos SA. Recomendações sobre manejo nutricional para equinos criados em pastagens nativas no Pantanal. Corumbá: EMBRAPA-CPAP; 1997. P. 22-63.

Serra OR. Condições de manejo, preservação e caracterização fenotípica do grupamento genético equino “Baixadeiro” [dissertation]. São Luís: Universidade Estadual do Maranhão; 2004. Portuguese.

Stabenfeldt HG, Edqvist EL. Processos reprodutivos na fêmea. In: Swenson JM, Reece OW, editors. Fisiologia dos animais domésticos. 11th ed. Rio de Janeiro: Roca, 1996, p. 615

Valle GR, Silva Filho JM, Palhares MS. Características cíclicas e ovulatórias de éguas mestiças em Minas Gerais, Brasil. Arq Cien Vet Zool. 2005 [cited 2015 Sept 17];8(2):155-63. Available from:

Vivo R, Santisteban R, Tovar P, Castejon MF. Valores de progesterona en plasma de yeguas españolas y arabes durante el ciclo reproductor. Arch Zootec. 1986 [cited 2015 Sept 17];131:59-67. Available from:

Zúccari CESN, Nunes DB, Corrêa Filho RAC. Eficiência reprodutiva de éguas da raça Pantaneira durante as estações de monta 1995/2000. Arch Zootec. 2002[cited 2015 Sept 17];51:139-48. Available from:

Zúccari CESN. Eficiência reprodutiva e dinâmica folicular de acordo com a condição corporal de éguas da raça Campolina [dissertation]. Belo Horizonte: Universidade Federal de Minas Gerais; 1990. Portuguese.

Submitted date:

Accepted date:

61fc1ed8a95395414c401d32 animreprod Articles
Links & Downloads

Anim Reprod

Share this page
Page Sections