Anticipation of estrus and ovulation in Nelore heifers with low antral follicle count




Antral follicles; Beef; Cattle; Ovulation.


This study aimed to establish the relationship between antral follicle count (AFC), the time of puberty, and ovarian response in Nelore heifers subjected to timed-AI (TAI) protocols. Prepubescent Nelore heifers (Bos indicus; n = 30) were examined by transrectal ultrasound and videos of the ovaries were recorded for later CFA (≥ 3 mm). After AFC, heifers were divided into 2 groups, low and high AFC and then further ultrasonic ovarian assessments were performed to determine the onset of puberty. Once puberty was established in all heifers, they were submitted to an FTAI protocol. There were no differences (P > 0.1) between groups on the time of puberty, ovulation rate, the proportion of heifers that expressed estrus, and on preovulatory follicle diameter. However, heifers with low AFC had a smaller ovarian area in the prepubertal period (4.36 ± 0.3 vs. 5.65 ± 0.2 cm2) and, in the FTAI, they had the moment of estrus (48 ± 0.0 vs. 58.5 ± 3.1 h) and earlier ovulation (60 ± 1.8 vs. 72.6 ± 4.7 h) compared to heifers with high AFC (P < 0.05). In addition, heifers in the low AFC group had a higher (P = 0.05) pregnancy per AI (76.9%, 10/13) than the high AFC group (29.4%, 5/17). In this study, heifers with low AFC had the moment of ovulation anticipated and greater pregnancy per AI compared to heifers with high AFC.


Bonato, D. V., Ferreira, E. B., Gomes, D. N. Bonato, F. G. C., Droher, R. G., Morotti, F., & Seneda, M. M. (2022). Follicular dynamics, luteal characteristics, and progesterone concentrations in synchronized lactating Holstein cows with high and low antral follicle counts. Theriogenology, 179, 223-229. 0093-691X

Broekmans, F. J., Ziegler, D., Howles, C. M., Gougeon, A., Trew, G., & Olivennes, F. (2010). The antral follicle count: practical recommendations for better standardization. Fertil Steril, 94(3), 1044-51.

Burns, D. S., Jimenez-Krassel. F., Ireland, J. L. H., Knight, P. G, & Ireland, J. J. (2005). Numbers of antral follicles during follicular waves in cattle: evidence for high variation among animals, very high repeatability in individuals, and an inverse association with serum follicle-stimulating hormone concentrations. Biol Reprod, 73(1), 54-62. 10.1095/biolreprod.104.036277.

Cunha, F., Cushman, R. A., Santa Cruz, R., De Nava. G., & Viñoles, C. (2020). Antral follicular count has limited impact in the selection of more fertile beef heifers. Livest Sci, 241:104230.

Evans, A. C. O., Mossa, F., Walsh, S. W., Scheetz, D., Jimenez-Krassel, F., Ireland, J. L. H., Smith, G. W., & Ireland, J. J (2012). Effects of maternal environment during gestation on ovarian folliculogenesis and consequences for fertility in bovine offspring. Reprod Domest Anim, 47(4), 31-37. 10.1111/j.1439-0531.2012.02052.x.

Funston, R. N., Martin, J. L., Larson, D. M, & Roberts, A. J. (2012). Physiology and endocrinology symposium: nutritional aspects of developing replacement heifers. J Anim Sci, 90(4):1166-71. https://doi: 10.2527/jas.2011-4569

Garcia, S. M., Morotti, F., Cavalieri, F. L. B., Lunardelli, P. A., Santos, A. O., Membrive, C. M. B., Castilho, C., Puelker, R. Z., Silva, J. O. F., Zangirolamo, A. F., & Seneda, M. M. (2020). Synchronization of stage of follicle development before OPU improves embryo production in cows with large antral follicle counts. Anim Reprod Sci, 221:106601.

Ireland, J. J., Ward, F., Jimenez-Krassel, F., Ireland, J. L. H., Smith, G. W, Lonergan, P., & Evans ACO. (2007). Follicle numbers are highly repeatable within individual animals but are inversely correlated with FSH concentrations and the proportion of good-quality embryos after ovarian stimulation in cattle. Hum Reprod, 22(6), 1687–1695.

Ireland, J. L. H., Scheetz, D., Jimenez-Krassel, F., Themmen, A. P. N., Ward, F., Lonergan, P., Smith, G. W., Perez, G. I., Evans, A. C. O., & Ireland, J. J. (2008). Antral follicle count reliably predicts number of morphologically healthy oocytes and follicles in ovaries of young adult cattle. Biol Reprod, 79(6):1219-25.

Ireland, J. J., Smith, G. W., Scheetz, D., Jimenez-Krassel, F., Folger, J. K., Ireland, J. L. H., Mossa, F., Lonergan, P., & Evans, A. C. O. (2011). Does size matter in females? An overview of the impact of the high variation in the ovarian reserve on ovarian function and fertility, utility of anti-Müllerian hormone as a diagnostic marker for fertility and causes of variation in the ovarian reserve in cattle. Reprod Fertil Dev, 23(1):1-14.

Jimenez-Krassel, F., Folger, J. K., Ireland, J. L. H., Smith, G. W., Hou, X., Davis, J. S., Lonergan, P., Evans, A. C. O., & Ireland, J. J. (2009). Evidence That High Variation in Ovarian Reserves of Healthy Young Adults Has a Negative Impact on the Corpus Luteum and Endometrium During Estrous Cycles in Cattle. Biol Reprod, 80(6):1272-81. 10.1095/biolreprod.108.075093

Jimenez-Krassel, F., Scheetz, D. M., Neuder, L. M., Ireland, J. L. H., Pursley, J. R., Smith, G. W., & Ireland, J. J. (2015). Concentration of anti-Mullerian hormone in dairy heifers is positively associated with productive herd life. J Dairy Sci, 98(05), 3036–45. https ://

Jimenez-Krassel, F., Scheetz, D. M., Neuder, L. M., Pursley, J. R., & Ireland, J. J. (2017). A single ultrasound determination of ≥ 25 follicles ≥ 3 mm in diameter in dairy heifers is predictive of a reduced productive herd life. J Dairy Sci, 100(6), 5019–27. https ://

Lima, M. A., Morotti, F., Bayeux, B. M., De Rezende, R. G., Botigelli, R. C., De Bem, T. H. C., Fontes, P. K., Nogueira, M. F. G., Meirelles, F. V., Baruselli, O. S., Da Silveira, J. C., Perecin, F., & Seneda, M. M. (2020). Ovarian follicular dynamics, progesterone concentrations, pregnancy rates and transcriptional patterns in Bos indicus females with a high or low antral follicle count. Sci Rep-UK, 10(1), 1–13.

Martinez, M. F., Kastelic, J. P., Bó, G.A., Caccia, M., & Mapletoft, R. J. (2005). Effects of oestradiol and some of its esters on gonadotrophin release and ovarian follicular dynamics in CIDR-treated beef cattle. Animal Reproduction Science, 86(1-2), 37-52.

Melo Filho, G. A., & Queiroz, H. P. (2011). Gado de corte: o produtor pergunta, a Embrapa responde. 2 ed. Brasília, DF:Embrapa Informação Tecnológica. 261 p.

Moraes, F. L. Z., Morotti, F., Costa, C. B., Lunardelli, P. A., & Seneda, M. M. (2019). Relationships between antral follicle count, body condition, and pregnancy rates afer timed-AI in Bos indicu cattle. Theriogenology, 136(15), 10–14.

Morotti, F., Barreiros, T. R. R., Machado, F. Z., Gonzalez, S. M., Marinho, L. S. R., & Seneda, M. M. (2015). Is the number of antral follicles an interesting selection criterium for fertility in cattle? Anim Reprod, 12(3), 479-86.

Morotti, F., Santos, G. M. G., Júnior, C. K., Silva-Santos, K. C., Roso, V. M., & Seneda, M. M. (2017). Correlation between phenotype, genotype and antral follicle population in beef heifers. Theriogenology, 91, 21–26.

Morotti, F., Moretti, R., Dos Santos, G. M. G., Silva-Santos, K. C., Ramos, C. P. H., & Seneda, M. M. (2018). Ovarian follicular dynamics and conception rate in Bos indicus cows with different antral follicle counts subjected to timed artificial insemination. Anim Reprod Sci, 188, 170–177.

Morotti, F., Camargo, H. S., Silva, L. O. L., Lorenzetti, E., Zangirolamo, A. F., & Seneda, M. M. (2021). Contagem de folículos antrais: relação com a eficiência das biotécnicas e fertilidade. Revista Brasileira de Reprodução Animal, 45(4), 202-209.

Mossa, F., Walsh, S. W., Butler, S. T., Berry, D. P., Carter, F., Lonergan, P., Smith, G. W., Ireland, J. J., & Evans, A. C. O. (2012). Low numbers of ovarian follicles ≥3mm in diameter are associated with low fertility in dairy cows. J Dairy Sci, 95(5), 2355–2361.

Nogueira, G. P. (2004). Puberty in South American Bos indicus (Zebu) cattle. Anim Reprod Sci, 82–83, 361–72.

Oliveira Junior, J. S., Cardoso, C. J. T., Silva, W. A. L., Kischel, H., Souza, M. B., Andrade, E. R., Nogueira, E., Silva-Santos, K. C., Seneda, M. M., & Melo-Sterza FA (2015). Antral follicles population in heifers and cows of Nelore and Girolando breeds. Semina: Ciências Agrárias (Online), 36, 3741-49.

Santa Cruz, R., Cushman, R. A., & Viñoles, C. (2018). Antral follicular count is a tool that may allow the selection of more precocious Bradford heifers at weaning. Theriogenology, 119, 35–42.

Santos, G. M. G., Silva-Santos, K. C., Barreiros, T. R. R., Morotti, F., Sanches, B. V., Moraes, F. L. Z., Blasch, W., & Seneda, M. M. (2016). High numbers of antral follicles are positively associated with in vitro embryo production but not the conception rate for FTAI in Nelore cattle. Anim Reprod Sci, 165, 17-21.

Seneda, M. M., Morotti, F., Zangirolamo, A. F., Da Silva, N. C., Sanches, T. K., Blaschi, W., & Barreiros, T. R. R. (2019). Antral follicle population in prepubertal and pubertal heifers. Reprod Fert Develop, 31(1), 10–16.

Silva-Santos, K. C., Santos, G. M. G., Júnior, C. K., Morotti, F., Siloto, L. S., Marcantonio, T. N., Urbano, M. R., Oliveira, R. L., Lima, D. C. M., & Seneda, M. M. (2014). Antral follicle populations and embryo production - in vitro and in vivo - of Bos indicus-taurus donors from weaning to yearling ages. Reprod Domest Anim, 49(2), 228-232.

Singh, J., Dominguez, M., Jaiswal, R., & Adams, G. P. (2004). A simple ultrasound test to predict the superstimulatory response in cattle. Theriogenology, 62(1-2), 227–243.

U-krit, W., Wadsungnoen, S., Yama, P., Jitjumnong, J., Sangkate, M., Promsao, N., Montha, N., Sudwan, P., Mektrirat, R., Panatuk, J., (2022). Understanding the Ovarian Interrelationship with Low Antral Follicle Counts (AFC) in the In Vivo Bos indicus Cow Model: Unilateral and Bilateral Main AFC as Possible Biomarkers of Ovarian Response to Hormonal Synchronisation. Biology, 11, 523. 10.3390/biology11040523




How to Cite

OLIVEIRA JÚNIOR, J. S. de; SILVA, G. M. da; MOREIRA, E. M.; ANDRADE, J. S.; NUNES, V. R. R.; MOROTTI, F.; ANDRADE, E. R.; SENEDA, M. M.; PFEIFER, L. F. M. Anticipation of estrus and ovulation in Nelore heifers with low antral follicle count . Research, Society and Development, [S. l.], v. 11, n. 6, p. e1211628576, 2022. DOI: 10.33448/rsd-v11i6.28576. Disponível em: Acesso em: 13 jun. 2024.



Agrarian and Biological Sciences