TY  - JOUR
T1  - The Effect of Ovarian Laterality on Various Reproductive Parameters in Arabian Mares
AU  - Çil, Beste
AU  - Şahin, Mustafa Oğuzhan
AU  - Sayım, Ali Alparslan
PY  - 2025
DA  - March
Y2  - 2025
DO  - 10.47748/tjvr.1636757
JF  - Turkish Journal of Veterinary Research
JO  - TJVR
PB  - Ebubekir CEYLAN
WT  - DergiPark
SN  - 2602-3695
SP  - 57
EP  - 64
VL  - 9
IS  - 1
LA  - en
AB  - Objective: The present study aimed to investigate the effect of ovarian laterality on pregnancy outcomes and foal sex, and to explore the role of age and parity in determining the ovulation side in Arabian mares. Materials and Methods: Objective: The present study aimed to investigate the effect of ovarian laterality on pregnancy outcomes and foal sex, and to explore the role of age and parity in determining the ovulation side in Arabian mares. Material-Methods: Data were collected from 358 mares over a five-year period, during which 885 estrus cycles were monitored. The side of ovulation was determined using ultrasonography, and pregnancy was confirmed on days 14, 28, and 45 post ovulation. The mares were categorized into four age groups as 3-8, 9-13, 14-17, and ≥ 18 years.Results: The laterality of ovulation was evenly distributed between the right (49.3%) and left (50.7%) ovaries, with no significant difference in pregnancy outcomes between the two sides. The majority of pregnancies resulted from the first ovulation (51.9%), and pregnancy outcomes did not differ significantly among the ovulatory sequences. Likewise, no significant relationship was found between the ovulation side and foal sex. The distribution of ovulation sides was similar across the age groups; however, pregnancy rates declined with age. A significant relationship was observed between the age group and the ovulation side that resulted in pregnancy (p
KW  - Age
KW  - Equine
KW  - Foal sex
KW  - Ovulation Side
KW  - Pregnancy
CR  - Allen WR, Brown L, Wright M, Wilsher S. Reproductive efficiency of Flatrace and National Hunt thoroughbred mares and stallions in England. Equine Vet J. 2007; 39:438-445.
CR  - Bain AM, Howey WP. Ovulation and transuterine migration of the conceptus in Thoroughbred mares. J Reprod Fertil. 1975; 23(Suppl):541-544.
CR  - Baird DD, Birney EC. Bilateral distribution of implantation sites in small mammals of 22 North American species. J Reprod Fertil. 1985; 75:381-392.
CR  - Balasch J, Ballescá JL, Pimentel C, Creus M, Fábregues F, Vanrell JA. Infertility: Late low-dose pure follicle stimulating hormone for ovarian stimulation in intrauterine insemination cycles. Hum Reprod. 1994; 9(10):1863-1866.
CR  - Bosh KA, Powell D, Shelton B, Zent W. Reproductive performance measures among thoroughbred mares in central Kentucky, during the 2004 mating season. Equine Vet J. 2009; 41:883-888.
CR  - Butterfield RM, Mathews RG. Ovulation and the movement of the conceptus in the first 35 days of pregnancy in thoroughbred mares. J Reprod Fertil. 1979; 27:447-452.
CR  - Cameron EZ, Linklater WL, Stafford KJ, Veltman CJ. Birth sex ratios relate to mare condition at conception in Kaimanawa horses. Behav Ecol. 1999; 10(5):472-475.
CR  - Cameron EZ, Linklater WL. Extreme sex ratio variation in relation to change in condition around conception. Biol Lett. 2007; 3(4):395-397.
CR  - Chow WSO, Chow PH. Asymmetry in the ovary and uterus of the golden hamster (Mesocricetus auratus). J Reprod Fertil. 1987; 80:21-24.
CR  - Clark MM, Ham M, Galef BG Jr. Differences in the sex ratios of offspring originating in the right and left ovaries of Mongolian gerbils (Meriones unguiculatus). J Reprod Fertil. 1994; 101:393-396.
CR  - Cushman RA, Allan MF, Snowder GD, Thallman RM, Echternkamp SE. Evaluation of ovulation rate and ovarian phenotype in pubertal heifers from a cattle population selected for increased ovulation rate. J Anim Sci. 2005; 83(8):1839-1844.
CR  - Delehanty DJ, O'Hearn PP. Behavioral and morphological asymmetries in chukar Alectoris chukar copulation. J Avian Biol. 2005; 36(4):276-279.
CR  - Dominko T, First NL. Relationship between the maturational state of oocytes at the time of insemination and sex ratio of subsequent early bovine embryos. Theriogenology. 1997; 47:1041-1050.
CR  - Endo A, Goto T, Sakai N. Distribution by sex of mouse fetuses in the intrauterine position. Gamete Res. 1987; 16(1):79-82.
CR  - Flores JG, Bueno VLC, Bastos HBDA, Rechsteiner SMDEF. Foal sex in Thoroughbred horses: related factors. Anim Reprod. 2024; 21(3):e20230073.
CR  - Fritzsche P, Riek M, Gattermann R. Effects of social stress on behavior and corpus luteum in female golden hamsters (Mesocricetus auratus). Physiol Behav. 2000; 68(5):625-630.
CR  - Fukuda M, Fukuda K, Andersen CY, Byskov AG. Ovary and Ovulation: contralateral selection of dominant follicle favours pre-embryo development. Hum Reprod. 1996; 11(9):1958-1962.
CR  - Fukuda M, Fukuda K, Andersen CY, Byskov AG. Ovulation jumping from the left to the right ovary in two successive cycles may increase the chances of pregnancy during intrauterine insemination and/or in vitro fertilization natural cycles. Fertil Steril. 2006; 85(2):514-517.
CR  - Fukuda M, Fukuda K, Andersen CY, Byskov AG. Right-sided ovulation favours pregnancy more than left-sided ovulation. Hum Reprod. 2000; 15(9):1921-1926.
CR  - Gharagozlou F, Akbarinejad V, Youssefi R, Rezagholizadeh A. Effect of sire-associated factors on secondary sex ratio of offspring in equine. J. Equine Vet. Sci. 2014; 34(7):926-929.
CR  - Gharagozlou F, Vojgani M, Akbarinejad V, et al. Parallel distribution of sexes within left and right uterine horns in Holstein dairy cows: evidence that the effect of side of pregnancy on sex ratio could be breed-specific in cattle. Anim Reprod Sci. 2013; 142(3-4):101-105.
CR  - Ginther OJ. Effect of reproductive status on twinning and on side of ovulation and embryo attachment in mares. Theriogenology. 1983; 20:383-395.
CR  - Giraldo AM, Hylan D, Bondioli KR, Godke RA. Distribution of sexes within the left and right uterine horns of cattle. Theriogenology. 2010; 73(4):496-450.
CR  - Grant VJ, Chamley LW. Sex-sorted sperm and fertility: an alternative view. Biol Reprod. 2007; 76:184-188.
Grant VJ, Irwin RJ, Standley NT, Shelling AN, Chamley LW. Sex of bovine embryos may be related to mothers’ preovulatory follicular testosterone. Biol Reprod. 2008; 78:812-815.
CR  - Grant VJ, Irwin RJ. Follicular fluid steroid levels and subsequent sex of bovine embryos. J Exp Zool A Comp Exp Biol. 2005; 303:1120-1125.
CR  - Grizelj J, Vince S, Samardžija M, et al. Use of ultrasonography to detect ovarian response in goats submitted to multiple ovulation and embryo transfer program. Vet Arhiv. 2013; 83(2):125-134.
CR  - Gutiérrez-Adán A, Granados J, Garde JJ, Perez-Guzman M, Pintado B, De La Fuente J. Relationship between sex ratio and time of insemination according to both time of ovulation and maturational state of oocyte. Zygote. 1999; 7(1):37-43.
CR  - Hall S, Jarrin-Yepez P, Schneider L, et al. Influence of period between breeding and ovulation on foal sex ratio. Clin Theriogenol. 2022; 14(1):18-31.
CR  - Hylan D, Giraldo AM, Carter JA, Gentry Jr GT, Bondioli KR, Godke RA. Sex ratio of bovine embryos and calves originating from the left and right ovaries. Biol Reprod. 2009; 81(5):933-938.
CR  - Karamishabankareh H, Hajarian H, Shahsavari M, Moradinejad R. In vivo and in vitro study of the function of the left and right bovine ovaries. Theriogenology. 2015; 84(5):724-731.
CR  - Kuhl J, Stock KF, Wulf M, Aurich C. Maternal lineage of warmblood mares contributes to variation of gestation length and bias of foal sex ratio. PLoS One. 2015; 10(10):e0139358.
CR  - Lan KC, Huang FJ, Lin YC, Kung FT, Lan TH, Chang SY. Significantly superior response in the right ovary compared with the left ovary after stimulation with follicle-stimulating hormone in a pituitary down-regulation regimen. Fertil Steril. 2010; 93(7):2269-2274.
CR  - Martinez F, Kaabi M, Martinez-Pastor F, et al. Effect of the interval between estrus onset and artificial insemination on sex ratio and fertility in cattle: a field study. Theriogenology. 2004; 62:1264-1270.
CR  - Morel MD, O’Sullivan JAM. Ovulation rate and distribution in the thoroughbred mare, as determined by ultrasonic scanning: the effect of age. Anim Reprod Sci. 2001; 66(1-2):59-70.
CR  - Najjar A, Khaldi S, Hamrouni A, Ben Said S, Benaoun B, Ezzaouia M. Variation factors of the pregnancy rate of Arab pure breed mares inseminated by the deep intracornual method in post-ovulation. Adv Anim Vet Sci. 2018; 6(1):40-43.
CR  - Nath LC. Reproductive efficiency of Thoroughbred and Standardbred horses in northeast Victoria. Aust Vet J. 2010; 88:169-175.
CR  - Pearson OP. Reproduction of a South American rodent, the mountain viscacha (Lagostomus maximus). Am J Anat. 1949; 84:143-173.
CR  - Peng Z, Man Q, Meng L, Wang S, Cai H, Zhang C, Zhu G. A pitx2-htr1b pathway regulates the asymmetric development of female gonads in chickens. PNAS Nexus. 2023; 2(6):1-11.
CR  - Ratto MH, Urra F, Silva M. Laterality of ovulation and presence of the embryo do not affect uterine horn blood flow during the first month of gestation in llamas. Front Vet Sci. 2020; 7:598117.
CR  - Rezagholizadeh A, Gharagozlou F, Akbarinejad V, Youssefi R. Left-sided ovulation favors more male foals than right-sided ovulation in Thoroughbred mares. J Equine Vet Sci. 2015; 35(1):31-35.
CR  - Sanderson MW. Twin ovulation, conception and gestation in the thoroughbred mare. [Master. Thesis]. Aberystwyth, Wales, UK: University of Wales; 1982.
CR  - Santos MM, Maia LL, Nobre DM, et al. Sex ratio of equine offspring is affected by the ages of the mare and stallion. Theriogenology. 2015; 84(7):1238-1245.
CR  - Scarlet D, Malama E, Fischer S, Knutti B, Bollwein H. Relationship between clinical uterine findings, therapy, and fertility in the mare. Vet. Sci. 2023; 10(4):259.
CR  - Scoggin CF. Not just a number: Effect of age on fertility, pregnancy and offspring vigour in Thoroughbred brood-mares. Reprod Fertil Dev. 2015; 27(6):872-879.
CR  - Shabankareh HK, Habibizad J, Torki M. Corpus luteum function following single and double ovulation during estrous cycle in Sanjabi ewes. Anim Reprod Sci. 2009; 114(4):362-369.
CR  - Sumar J, Adams GP. Reproductive anatomy and life cycle of the male and female llama and alpaca. In: Younquist RS, Threlfall WR, eds. Current Therapy in Large Animal Theriogenology. St. Louis, MO: Saunders Elsevier; 2007. pp.855-865
CR  - Wan Z, Lu Y, Lei R, Yu X, Yang F, Tu C, Li Z. Gene expression profiling reveals potential players of left-right asymmetry in female chicken gonads. Int J Mol Sci. 2017; 18(6):1299.
CR  - Wehner GR, Wood C, Tague A, Barker D, Hubert H. Efficiency of the OVATEC unit for estrus detection and calf sex control in beef cows. Anim Reprod Sci. 1997; 46:27-34.
CR  - Wesson JA, Ginther OJ. Influence of season and age on reproductive activity in pony mares on the basis of a slaughterhouse survey. J Anim Sci. 1981; 52(1):119-129.
CR  - Wimsatt WA. Some comparative aspects of implantation. Biol Reprod. 1975; 12:1-40.
Younglai EV, Pan CC, Bhavnani BR. Asymmetric distribution of male and female foetuses in the pregnant rabbit uterus. Experientia. 1981; 37:690-691
UR  - https://doi.org/10.47748/tjvr.1636757
L1  - https://dergipark.org.tr/en/download/article-file/4595755
ER  -