References

Alvarez, P., L.J. Spicer, C.C. Chase, M.E. Jr Payton and T.D. Hamilton et al., 2000. Ovarian and endocrine characteristics during an estrous cycle in Angus, Brahman and Senepol cows in a subtropical environment. J. Anim. Sci., 78: 1291-1302.
PubMed  |  

Ariff, O.M., 1992. State of the beef industry in the year 2020. Proceedings of the 15th Malaysian Society of Animal Production Annual Conference, May 26-27, 1992, Kuala Terengganu, Malaysia, pp: 1-7.

Barros, C.M., M.B.P. Moreira, R.A. Figueiredo, A.B. Teixeira and L.A. Trinca, 2000. Synchronization of ovulation in beef cows (Bos indicus) using GnRH, PGF2α and estradiol benzoate. Theriogenology, 53: 1121-1134.
CrossRef  |  Direct Link  |  

Crane, M.B., J. Bartoleme, P. Melendez, A. De Vies, C. Risco and L.F. Archbald, 2006. Comparison of synchronization of ovulation with timed insemination and exogenous progesterone as therapeutic strategies for ovarian cysts in lactating dairy cows. Theriogenology, 65: 1563-1574.
CrossRef  |  PubMed  |  

Dobson, H. and R.F. Smith, 2000. What is stress and how does it affect reproduction? Anim. Reprod. Sci., 61: 743-752.
PubMed  |  

Echternkamp, S.E. and R.M. Thallman, 2011. Factors affecting pregnancy rate to estrous synchronization and fixed-time artificial insemination in beef cattle. J. Anim. Sci., 89: 3060-3068.
PubMed  |  

Fortune, J.E. and S.M. Quirk, 2002. Regulation of steroidogenesis in bovine preovulatory follicles. J. Anim. Sci., 65: 638-647.

Ireland, J.J., P.B. Coulson and R.L. Murphree, 1979. Follicular development during four stages of the estrous cycle of beef cattle. J. Anim. Sci., 49: 1261-1269.
PubMed  |  

Larson, J.E., G.C. Lamb, J.S. Stevenson, S.K. Johnson and M.L. Day et al., 2006. Synchronization of estrus in suckled beef cows for detected estrus and artificial insemination and timed artificial insemination using gonadotropin-releasing hormone, prostaglandin F_2α and progesterone. J. Anim. Sci., 84: 332-342.
Direct Link  |  

Lauderdale, J.W., 2009. ASAS centennial paper: Contributions in the Journal of Animal Science to the development of protocols for breeding management of cattle through synchronization of estrus and ovulation. J. Anim. Sci., 87: 801-812.
CrossRef  |  PubMed  |  

Leitman, N.R., D.C. Busch, J.F. Bader, D.A. Mallery and D.J. Wilson et al., 2008. Comparison of protocols to synchronize estrus and ovulation in estrous-cycling and prepubertal beef heifers. J. Anim. Sci., 86: 1808-1818.
CrossRef  |  PubMed  |  

Lopez-Gatius, F., 2000. Site of semen deposition in cattle: A review. Theriogenology, 53: 1407-1414.
CrossRef  |  PubMed  |  

Monteiro, F.M., D.S. Meloa, M.M.G. Ferreira, L.M. Carvalho and E. Sartoreli e Sartoreli et al., 2009. LH surge in Nelore cows (Bos indicus), after induced estrus or after ovarian superestimulation. Anim. Reprod. Sci., 110: 128-138.
CrossRef  |  PubMed  |  

Pursley, J.R., M.O. Mee and M.C. Wiltbank, 1995. Synchronization of ovulation in dairy cows using PGF_2α and GnRH. Theriogenology, 44: 915-923.
CrossRef  |  Direct Link  |  

Randel, R.D., 1984. Seasonal effects on female reproductive functions in the bovine (Indian breeds). Theriogenol., 21: 170-185.
Direct Link  |  

Richard, M.W., J.C. Spitzer and M.B. Warner, 1986. Effects of varying levels of postpartum nutrition and body condition at calving on subsequent reproductive performance in beef cattle. J. Anim. Sci., 62: 300-306.
Direct Link  |  

Richardson, A.M., B.A. Henslet, T.J. Marple, S.K. Johnson and J.S. Stevenson, 2002. Characteristics of oestrus before and after the first insemination and fertility of heifers after synchronized oestrus with GnRH, PGF2α and progesterone. Characteristics of oestrus before and after the first insemination and fertility of heifers after synchronized oestrus with GnRH, PGF2α and progesterone. J. Anim. Sci., 80: 2792-2800.
Direct Link  |  

Saumande, J. and P. Humblot, 2005. The variability in the interval between estrus and ovulation in cattle and its determinants. Anim. Reprod. Sci., 85: 171-182.
PubMed  |  

Segerson, E.C., T.R. Hansen, D.W. Libby, R.D. Randel and W.R. Getz, 1984. 1984. Ovarian and uterine morphology and function in angus and brahman cows. J. Anim. Sci., 59: 1026-1046.
PubMed  |  

Williams, S.W., R.L. Stanko, M. Amstalden and G.L. Williams, 2002. Comparison of three approaches for synchronization of ovulation for timed artificial insemination in Bos indicus-influenced cattle managed on the Texas gulf coast. J. Anim. Sci., 80: 1173-1178.
PubMed  |  

Yoshioka, K., C. Suzuki, S. Arai, S. Iwamura and H. Hirose, 2001. Gonadotropin-releasing hormone in the third ventricular cerebrospinal fluid of the heifer during the estrous cycle. Biol. Reprod., 64: 563-570.
PubMed  |