New perspectives and evolution of ovulation synchronization protocols in bovine females
José Nélio de Sousa Sales; Laís Reis Carvalho; Luiz Manoel Sousa Simões; Lucas Araujo Lemos; Matheus Pedroso Vicente; Rafael Resende Rabelo Silva; Luísa Oliveira Orlandi; Pietro Sampaio Baruselli; José Camisão de Souza
Abstract
Keywords
References
Abreu LA, Cutaia L, Wallace SP, Resende TS, Carreira ALM, Cunha BS, Sousa AVG, Silva LA, Catussi BLC, Baruselli PS. 2023. Efficacy of eCG-like on preovulatory follicle diameter and pregnancy rate in Nelore cows submitted to FTAI. In: Proceedings of the 49th Annual Conference of International Embryo Technology Society; 2023 Jan 15-19; Lima. Champaign: IETS; 2023.
Alves RLOR, Silva MA, Consentini CEC, Silva LO, Folchini NP, Oliva AL, Prata AB, Gonçalves JRS, Wiltbank MC, Sartori R. Hormonal combinations aiming to improve reproductive outcomes of
Archbald LF, Tran T, Massey R, Klapstein E. Conception rates in dairy cows after timed-insemination and simultaneous treatment with gonadotrophin releasing hormone and/or prostaglandin F2 alpha. Theriogenology. 1992;37(3):723-31.
Barros CM, Moreira MBP, Figueiredo RA, Teixeira AB, Trinca LA. Synchronization of ovulation in beef cows (
Baruselli PS, Reis EL, Marques MO, Nasser LF, Bó GA. The use of hormonal treatments to improve reproductive performance of anestrous beef cattle in tropical climates. Anim Reprod Sci. 2004;82–83:479-86.
Baruselli PS, Ferreira RM, Colli MHA, Elliff FM, Sá MF Fo, Vieira L, Freitas BG. Timed artificial insemination: current challenges and recent advances in reproductive efficiency in beef and dairy herds in Brazil. Anim Reprod. 2017;14:558-71.
Baruselli PS, Ferreira RM, Sá MF Fo, Bó GA. Review: using artificial insemination v. natural service in beef herds. Animal. 2018a;12(s1):s45-52.
Baruselli PS, Sales JNS, Sala RV, Vieira LM, Sá MF Fo. History, evolution and perspectives of timed artificial insemination programs in Brazil. Anim Reprod. 2018b;9:139-52.
Baruselli PS, Abreu LÂ, Catussi BLC, Oliveira ACDS, Rebeis LM, Gricio EA, Albertini S, Sales JNS, Rodrigues CA. Use of new recombinant proteins for ovarian stimulation in ruminants. Anim Reprod. 2023;20(2):e20230092.
Baruselli PS. Após 2 anos de queda, mercado de IATF retoma crescimento [Internet]. São Paulo: FZMV-USP; 2025a. (Boletim Eletrônico do Departamento de Reprodução Animal) [cited 2025 Jul 22]. Available from: http://vra.fmvz.usp.br/boletim-eletronico-vra/
Baruselli PS, Abreu LA, Menchaca A, Bó GA. The future of beef production in South America. Theriogenology. 2025b;231:21-8.
Beal WE, Good GA. Synchronization of estrus in postpartum beef cows with melengestrol acetate and prostaglandin F2 alpha. J Anim Sci. 1986;63(2):343-7.
Bello NM, Steibel JP, Pursley JR. Optimizing ovulation to first GnRH improved outcomes to each hormonal injection of ovsynch in lactating dairy cows. J Dairy Sci. 2006;89(9):3413-24.
Bicalho RC, Cheong SH, Warnick LD, Guard CL. Evaluation of progesterone supplementation in a prostaglandin F2α-based presynchronization protocol before timed insemination. J Dairy Sci. 2007;90(3):1193-200.
Bo GA, Pierson RA, Mapletoft RJ. The effect of estradiol valerate on follicular dynamics and superovulatory response in cows with Syncro-Mate-B implants. Theriogenology. 1991;36(2):169-83.
Bo GA, Adams GP, Pierson RA, Tribulo HE, Caccia M, Mapletoft RJ. Follicular wave dynamics after estradiol-17β treatment of heifers with or without a progestogen implant. Theriogenology. 1994;41(8):1555-69.
Bó GA, Caccia M, Martinez M, Mapletoft RJ. Follicular wave emergence after treatment with estradiol benzoate and CIDR-B vaginal devices in beef cattle. In: Proceedings of the 13th International Congress on Animal Reproduction; 1996 Jun 30-Jul 4; Sydney. Sydney: VGLS; 1996.
Bó GA, Baruselli PS, Moreno D, Cutaia L, Caccia M, Tríbulo R, Tríbulo H, Mapletoft RJ. The control of follicular wave development for self-appointed embryo transfer programs in cattle. Theriogenology. 2002;57(1):53-72.
Bó GA, Baruselli PS, Martínez MF. Pattern and manipulation of follicular development in
Borchardt S, Pohl A, Carvalho PD, Fricke PM, Heuwieser W. Short communication: Effect of adding a second prostaglandin F2α injection during the Ovsynch protocol on luteal regression and fertility in lactating dairy cows: A meta-analysis. J Dairy Sci. 2018;101(9):8566-71.
Bridges PJ, Lewis PE, Wagner WR, Inskeep EK. Follicular growth, estrus and pregnancy after fixed-time insemination in beef cows treated with intravaginal progesterone inserts and estradiol benzoate. Theriogenology. 1999;52(4):573-83.
Bryan MA, Bó GA, Heuer C, Emslie FR. Use of equine chorionic gonadotrophin in synchronised AI of seasonal-breeding, pasture-based, anoestrous dairy cattle. Reprod Fertil Dev. 2010;22(1):126-31.
Bryan MA, Bó G, Mapletoft RJ, Emslie FR. The use of equine chorionic gonadotropin in the treatment of anestrous dairy cows in gonadotropin-releasing hormone/progesterone protocols of 6 or 7 days. J Dairy Sci. 2013;96(1):122-31.
Carneiro TO, Neri HDH, Batista EOS, Valenza A, Souza AH. Improved conception results following GnRH treat-ment on day 2 of progesterone and estradiol-based synchronization protocols in high producing dairy cows. Anim Reprod. 2017;14:709.
Carvalho LR, Simões LMS, Lemos LA, Vicente MP, Souza SV, Gonçales WA Jr, Guerreiro BM, Freitas BG, Souza JC, Sales JNS. Use of injectable progesterone to replace the intravaginal progesterone device on the ovulation synchronization protocol reduces the pregnancy rate in
Carvalho LR, Lemos LA, Teixeira L, Vicente MP, Simões LMS. Reducing the period of permanence of the intravaginal progesterone device decreases the conception rate of suckled
Cattaneo L, Prieto C, Ojeda D, Pereira A, Frutos J, Bó GA. The use of a recombinant equine chorionic gonadotropin (reCG) in fixed-time AI programs in beef cattle. Theriogenology. 2024;227:77-83.
Chebel RC, Santos JEP, Cerri RLA, Rutigliano HM, Bruno RGS. Reproduction in dairy cows following progesterone insert presynchronization and resynchronization protocols. J Dairy Sci. 2006;89(11):4205-19.
Christian RE, Casida LE. The effects of progesterone in altering the estrus cycle of the cow. J Anim Sci. 1948;7:540.
Colazo MG, Kastelic JP, Mapletoft RJ. Effects of estradiol cypionate (ECP) on ovarian follicular dynamics, synchrony of ovulation, and fertility in CIDR-based, fixed-time AI programs in beef heifers. Theriogenology. 2003;60(5):855-65.
Consentini CEC, Wiltbank MC, Sartori R. Factors that optimize reproductive efficiency in dairy herds with an emphasis on timed artificial insemination programs. Animals. 2021;11(2):301.
Consentini CEC, Alves RLOR, Silva MA, Galindez JPA, Madureira G, Lima LG, Gonçalves JRS, Wiltbank MC, Sartori R. What are the factors associated with pregnancy loss after timed-artificial insemination in
Consentini CEC, Abadia T, Galindez JPA, Lopes ALM, Ferro PPC, Pazini YE, Faria NV, Machado F, Capella T, Santos TN, Duarte M, Ferreira PP, Matos LMF, Ferreira DR, Campos E, Prata A, Melo LF, Wiltbank MC, Sartori R. Fertility programs for lactating dairy cows: A novel presynch + timed artificial insemination program (Double E-Synch) produces similar ovarian dynamics, synchronization, and fertility as Double-Ovsynch. J Dairy Sci. 2025;108(4):4435-47.
Crepaldi GA, Freitas BG, Vieira LM, Sá MF Fo, Guerreiro BM, Baruselli PS. Reproductive efficiency of Nelore females submitted to three consecutive FTAI programs with 32 days of interval between inseminations. Anim Reprod. 2014;11:355.
Crowe MA, Diskin MG, Williams EJ. Parturition to resumption of ovarian cyclicity: comparative aspects of beef and dairy cows. Animal. 2014;8(Suppl. 1):40-53.
Day ML, Anderson LH. Current concepts on the control of puberty in cattle. J Anim Sci. 1998;76(Suppl. 3):1-15.
Diskin MG, Mackey DR, Roche JF, Sreenan JM. Effects of nutrition and metabolic status on circulating hormones and ovarian follicle development in cattle. Anim Reprod Sci. 2003;78(3-4):345-70.
Dutt RH, Casida LE. Alteration of the estrual cycle in sheep by use of progesterone and its effect upon subsequent ovulation and fertility. Endocrinology. 1948;43(4):208-17.
Edwards S. The effects of short term calf removal on pulsatile LH secretion in the postpartum beef cow. Theriogenology. 1985;23(5):777-85.
Funston RN, Musgrave JA, Meyer TL, Larson DM. Effect of calving distribution on beef cattle progeny performance. J Anim Sci. 2012;90(13):5118-21.
Galina CS, Orihuela A, Rubio I. Behavioural trends affecting oestrus detection in Zebu cattle. Anim Reprod Sci. 1996;42(1-4):465-70.
Giordano JO, Thomas MJ, Catucuamba G, Curler MD, Wijma R, Stangaferro ML, Masello M. Effect of extending the interval from Presynch to initiation of Ovsynch in a Presynch-Ovsynch protocol on fertility of timed artificial insemination services in lactating dairy cows. J Dairy Sci. 2016;99(1):746-57.
Gonçales WA Jr, Colli MA, Ruivo WA, Carvalho LR, Vicente MP, Lemos LA, Simões LMS, Motta IG, Freitas BG, Sales JNS. Exposure to injectable progesterone prior to protocol for the resynchronization of ovulation in the fertility of
Heersche G Jr, Kiracofe GH, DeBenedetti RC, Wen S, McKee RM. Synchronization of estrus in beef heifers with a norgestomet implant and prostaglandin F2alpha. Theriogenology. 1979;11(3):197-208.
Herlihy MM, Giordano JO, Souza AH, Ayres H, Ferreira RM, Keskin A, Nascimento AB, Guenther JN, Gaska JM, Kacuba SJ, Crowe MA, Butler ST, Wiltbank MC. Presynchronization with Double-Ovsynch improves fertility at first postpartum artificial insemination in lactating dairy cows. J Dairy Sci. 2012;95(12):7003-14.
Jolly PD, McDougall S, Fitzpatrick LA, Macmillan KL, Entwistle KW. Physiological effects of undernutrition on postpartum anoestrus in cows. J Reprod Fertil Suppl. 1995;49:477-92. PMid:7623336.
Lopez H, Satter LD, Wiltbank MC. Relationship between level of milk production and estrous behavior of lactating dairy cows. Anim Reprod Sci. 2004;81(3-4):209-23.
Macmillan KL, Thatcher WW. Effects of an agonist of gonadotropin-releasing hormone on ovarian follicles in cattle. Biol Reprod. 1991;45(6):883-9.
Macmillan KL, Peterson AJ. A new intravaginal progesterone releasing device for cattle (CIDR-B) for oestrous synchronisation, increasing pregnancy rates and the treatment of post-partum anoestrus. Anim Reprod Sci. 1993;33(1-4):1-25.
Macmillan KL, Burke CR. Effects of oestrous cycle control on reproductive efficiency. Anim Reprod Sci. 1996;42(1-4):307-20.
Madureira G, Motta JCL, Drum JN, Consentini CEC, Prata AB, Monteiro PLJ Jr, Melo LF, Alvarenga AB, Wiltbank MC, Sartori R. Progesterone-based timed AI protocols for
Marques MO, Morotti F, Silva CB, Ribeiro M Jr, Silva RCP, Baruselli PS, Seneda MM. Influence of category-heifers, primiparous and multiparous lactating cows-in a large-scale resynchronization fixed-time artificial insemination program. J Vet Sci. 2015;16(3):367-71.
Melo LF, Monteiro PLJ Jr, Surjus RS, Drum JN, Wiltbank MC, Sartori R. Progesterone-based fixed-time artificial insemination protocols for dairy cows: gonadotropin-releasing hormone versus estradiol benzoate at initiation and estradiol cypionate versus estradiol benzoate at the end. J Dairy Sci. 2016;99(11):9227-37.
Monteiro PLJ, Consentini CEC, Andrade JPN, Beard AD, Garcia-Guerra A, Sartori R, Wiltbank MC. Research on timed AI in beef cattle: Past, present and future, a 27-year perspective. Theriogenology. 2023;211:161-71.
Montiel F, Ahuja C. Body condition and suckling as factors influencing the duration of postpartum anestrus in cattle: a review. Anim Reprod Sci. 2005;85(1-2):1-26.
Moreira F, de la Sota RL, Diaz T, Thatcher WW. Effect of day of the estrous cycle at the initiation of a timed artificial insemination protocol on reproductive responses in dairy heifers. J Anim Sci. 2000;78(6):1568-76.
Moreira F, Orlandi C, Risco CA, Mattos R, Lopes F, Thatcher WW. Effects of presynchronization and bovine somatotropin on pregnancy rates to a timed artificial insemination protocol in lactating dairy cows. J Dairy Sci. 2001;84(7):1646-59.
Murphy BD, Martinuk SD. Equine chorionic gonadotropin. Endocr Rev. 1991;12(1):27-44.
Nascimento AB, Souza AH, Keskin A, Sartori R, Wiltbank MC. Lack of complete regression of the Day 5 corpus luteum after one or two doses of PGF2α in nonlactating Holstein cows. Theriogenology. 2014;81(3):389-95.
Navanukraw C, Redmer DA, Reynolds LP, Kirsch JD, Grazul-Bilska AT, Fricke PM. A modified presynchronization protocol improves fertility to timed artificial insemination in lactating dairy cows. J Dairy Sci. 2004;87(5):1551-7.
Felisbino AR No, Souza DFC, Campos RA, Albertini S, Bastos MR, Freitas BG, Colli MHA, Elliff FM, Sales JNS, Baruselli PS. The effectiveness of low-dose of eCG in timed AI Nelore (
O’Rourke M, Diskin MG, Sreenan JM, Roche JF. The effect of dose and route of oestradiol benzoate administration on plasma concentrations of oestradiol and FSH in long-term ovariectomised heifers. Anim Reprod Sci. 2000;59(1-2):1-12.
Pancarci SM, Jordan ER, Risco CA, Schouten MJ, Lopes FL, Moreira F, Thatcher WW. Use of estradiol cypionate in a presynchronized timed artificial insemination program for lactating dairy cattle. J Dairy Sci. 2002;85(1):122-31.
Pereira MHC, Wiltbank MC, Barbosa LFSP, Costa WM Jr, Carvalho MAP, Vasconcelos JLM. Effect of adding a gonadotropin-releasing-hormone treatment at the beginning and a second prostaglandin F2α treatment at the end of an estradiol-based protocol for timed artificial insemination in lactating dairy cows during cool or hot seasons of the year. J Dairy Sci. 2015;98(2):947-59.
Pinheiro OL, Barros CM, Figueiredo RA, Valle ER, Encarnação RO, Padovani CR. Estrous behavior and the estrus-to-ovulation interval in Nelore cattle (
Prata AB, Madureira G, Robl AJ, Ribeiro HS, Sagae M, Elias MCV, Pimenta C, Barrios J, Hartmman D, Schneider AA, Sandoval GAF, Wiltbank MC, Sartori R. Progesterone-based timed AI protocols for
Pugliesi G, Zago Bisinotto D, Clara A, Mattos D, Tanner JHLM, Claro I Jr, Sá OG Fo, Fonseca R, Peres G, Luiz J, Vasconcelos M. Splitting the eCG dose during synchronization of ovulation for TAI in suckled beef cows. Anim Reprod. 2022;19(2):e22054.
Pugliesi G, Feltrin IR, Mattos ACD, Silva AG, Morelli KG, Nishmura TK, Sales JN. S., Pugliesi G, Feltrin IR, Mattos ACD, Silva AG, Morelli KG, Nishmura TK, Sales JNS. Evolution over the last 40 years of the assisted reproductive technologies in cattle: the Brazilian perspective for embryo transfer and resynchronization programs (part II). Anim Reprod. 2024;21(3):e20240058.
Pursley JR, Mee MO, Wiltbank MC. Synchronization of ovulation in dairy cows using PGF2alpha and GnRH. Theriogenology. 1995;44(7):915-23.
Rebeis LM, Weiler SA, Silva LP, Garcia TAM, Baumgarten HA, Casamayouret FF, Viacava R, Masselli AD Fo, Mori FK, Baruselli PS. Effect of treatment with bST at the beginning of the protocol (D0) on FTAI and FTET. Anim Reprod. 2023;20:1.
Roche JF, Crowley JP. The fertility of heifers inseminated at predetermined intervals following treatment with MGA and HCG to control ovulation. J Reprod Fertil. 1973;35(2):211-6.
Rodrigues CA, Castro A No, Catussi BLC, Rebeis LM, Pinho P, Randi F, Baruselli PS. Superstimulation prior to the ovum pick-up with a single dose of recombinant FSH improves in vitro embryo production in Holstein heifers. Anim Sci. Proc. 2023;14(3):483-4.
Rodrigues MM Jr, Oliveira WAN, Maranho H Jr, Freitas BG, Simões LMS. Injectable progesterone prior to the fixed-time embryo transfer (FTET) protocol increases the conception and pregnancy rate in Nelore cows. Anim Reprod. 2024;21(3):1.
Sá MF Fo, Santos JEP, Ferreira RM, Sales JNS, Baruselli PS. Importance of estrus on pregnancy per insemination in suckled
Sá MF Fo, Penteado L, Reis EL, Reis TANPS, Galvão KN, Baruselli PS. Timed artificial insemination early in the breeding season improves the reproductive performance of suckled beef cows. Theriogenology. 2013;79(4):625-32.
Sá MF Fo, Marques MO, Girotto R, Santos FA, Sala RV, Barbuio JP, Baruselli PS. Resynchronization with unknown pregnancy status using progestin-based timed artificial insemination protocol in beef cattle. Theriogenology. 2014;81(2):284-90.
Sales JNS, Crepaldi GA, Girotto RW, Souza AH, Baruselli PS. Fixed-time AI protocols replacing eCG with a single dose of FSH were less effective in stimulating follicular growth, ovulation, and fertility in suckled-anestrus Nelore beef cows. Anim Reprod Sci. 2011;124(1-2):12-8.
Sales JNS, Carvalho JBP, Crepaldi GA, Cipriano RS, Jacomini JO, Maio JRG, Souza JC, Nogueira GP, Baruselli PS. Effects of two estradiol esters (benzoate and cypionate) on the induction of synchronized ovulations in
Sales JNS, Carvalho JBP, Crepaldi GA, Soares JG, Girotto RW, Maio JRG, Souza JC, Baruselli PS. Effect of circulating progesterone concentration during synchronization for fixed-time artificial insemination on ovulation and fertility in
Sales JNS, Bottino MP, Silva LACL, Girotto RW, Massoneto JPM, Souza JC, Baruselli PS. Effects of eCG are more pronounced in primiparous than multiparous
Sales JNS, Pugliesi G, Carvalho LR, Simões LMS, Lemos LA, Vicente MP, Silva RRR, Baruselli PS. Evolution over the last 40 years of the assisted reproduction technologies in cattle - the Brazilian perspective I - timed artificial insemination. Anim Reprod. 2024a;21(3):e20240034.
Sales JNS, Vicente MP, Carvalho LR, Lemos LA, Souza Simões LM, Alcantara Colli MH, Gonçales WA Jr, Ayres H, Vieira LM, Mingoti RD, Barbuio JP. Is estradiol valerate an alternative to estradiol benzoate in promoting the synchronization of ovulation and timed artificial insemination in suckled
Sales AFF, Cappellozza BI, Vilela E, Claro I Jr, Sá OG Fo, Vasconcelos JLM. Effects of equine chorionic gonadotropin dosage and its splitting in different days on reproductive performance of Nellore cows synchronized for timed-artificial insemination. Theriogenology. 2024c;218:267-75.
Sangsritavong S, Combs DK, Sartori R, Armentano LE, Wiltbank MC. High feed intake increases liver blood flow and metabolism of progesterone and estradiol-17beta in dairy cattle. J Dairy Sci. 2002;85(11):2831-42.
Schmitt EJP, Drost M, Diaz T, Roomes C, Thatcher WW. Effect of a gonadotropin-releasing hormone agonist on follicle recruitment and pregnancy rate in cattle. J Anim Sci. 1996;74(1):154-61.
Silva LACL, Simões LMS, Bottino MP, Santos APC, Santos G, Martinez IYH, Souza JC, Baruselli PS, Sales JNS. Presynchronization by induction of a largest follicle using a progesterone device in GnRH-based-ovulation synchronization protocol in crossbred dairy cows. Theriogenology. 2018;119:233-7.
Silva LO, Valenza A, Alves RLOR, Silva MA, Silva TJB, Motta JCL, Drum JN, Madureira G, Souza AH, Sartori R. Progesterone release profile and follicular development in Holstein cows receiving intravaginal progesterone devices. Theriogenology. 2021;172:207-15.
Silva LO, Cavalcanti PR, Alves RLOR, Folchini NP, Teixeira NN, Monteiro PJL, Wiltbank MC, Sartori R. Effect of the follicular stage and circulating progesterone concentrations at the beginning of an estradiol/progesterone-based synchronization protocol on profile of gonadotropins and follicle dynamics in beef heifers. Theriogenology. 2025;241:117421.
Simões LMS, Orlandi RE, Massoneto JPM, Scandiuzzi LA Jr, Freitas BG, Bastos MR, Souza JC, Sales JNS. Exposure to progesterone previous to the protocol of ovulation synchronization increases the follicular diameter and the fertility of suckled
Simões LMS, Freitas BG, Guerreiro BM, Sales JNS. Progesterone (Injectable Sincrogest) pre-exposition to ovulation synchronization protocol tend to increase the conception rate at 30 days after TAI in high production Bos taurus dairy cows. Anim Reprod. 2022;19(2):e22054.
Simões LMS, Lima EA, Carvalho LR, Martínez MBP, Zanatta GM, Santos MFO, Machado AB, Dias MM, Guerreiro BM, Freitas BG, Bastos MR, Sales JNS. Exposure to progesterone before an ovulation synchronization protocol increases the follicular diameter and fertility of multiparous suckled Bos taurus cows. Theriogenology. 2024;218:239-43.
Souza AH, Ayres H, Ferreira RM, Wiltbank MC. A new presynchronization system (Double-Ovsynch) increases fertility at first postpartum timed AI in lactating dairy cows. Theriogenology. 2008;70(2):208-15.
Souza AH, Viechnieski S, Lima FA, Silva FF, Araújo R, Bó GA, Wiltbank MC, Baruselli PS. Effects of equine chorionic gonadotropin and type of ovulatory stimulus in a timed-AI protocol on reproductive responses in dairy cows. Theriogenology. 2009;72(1):10-21.
Spitzer JC, Burrell WC, LeFever DG, Whitman RW, Wiltbank JN. Synchronization of estrus in beef cattle: I. Utilization of a norgestomet implant and injection of estradiol valerate. Theriogenology. 1978;10(2-3):181-200.
Stevenson JS, Britt JH. Detection of estrus by three methods. J Dairy Sci. 1977;60(12):1994-8.
Thatcher WW, Macmillan KL, Hansen PJ, Drost M. Concepts for regulation of corpus luteum function by the conceptus and ovarian follicles to improve fertility. Theriogenology. 1989;31(1):149-64.
Trimberger GW, Hansel W. Conception rate and lovarian function following estrus control by progesterone injections in dairy cattle. J Anim Sci. 1955;14(1):224-32.
Tschopp JC, Macagno AJ, Mapletoft RJ, Menchaca A, Bó GA. Effect of the addition of GnRH and a second prostaglandin F2α treatment on pregnancy per artificial insemination in lactating dairy cows submitted to an estradiol/progesterone-based timed-AI protocol. Theriogenology. 2022;188:63-70.
Tschopp JC, Menchaca A, Mapletoft RJ, Bó GA. Treatment alternatives to induce follicular wave emergence for timed-AI in lactating dairy Cows. Theriogenology. 2024;226:343-9.
Twagiramungu H, Guilbault LA, Proulx J, Dufour JJ. Synchronization of estrus and fertility in beef cattle with two injections of buserelin and prostaglandin. Theriogenology. 1992;38(6):1131-44.
Ulberg LC, Christian RE, Casida LE. Ovarian response in heifers to progesterone injections. J Anim Sci. 1951;10(3):752-9.
Vasconcelos JLM, Silcox RW, Rosa GJM, Pursley JR, Wiltbank MC. Synchronization rate, size of the ovulatory follicle, and pregnancy rate after synchronization of ovulation beginning on different days of the estrous cycle in lactating dairy cows. Theriogenology. 1999;52(6):1067-78.
Villarraza CJ, Antuña S, Tardivo MB, Rodríguez MC, Mussio P, Cattaneo L, Fontana D, Díaz PU, Ortega HH, Tríbulo A, Macagno A, Bó GA, Ceaglio N, Prieto C. Development of a suitable manufacturing process for production of a bioactive recombinant equine chorionic gonadotropin (reCG) in CHO-K1 cells. Theriogenology. 2021;172:8-19.
Willett EL. The fertility of heifers following administration of progesterone to alter the estrual cycle. J Dairy Sci. 1950;33:381-2
Williams GL, Talavera F, Petersen BJ, Kirsch JD, Tilton JE. Coincident secretion of follicle-stimulating hormone and luteinizing hormone in early postpartum beef cows: effects of suckling and low-level increases of systemic progesterone. Biol Reprod. 1983;29(2):362-73.
Wiltbank JN, Zimmerman DR. Estrus synchronization and fertility in Hereford heifers subsequent to administration of progesterone and estradiol. J Anim Sci. 1962;21:660.
Wiltbank JN, Gonzalez-Padilla E. Synchronization and induction of estrus in heifers with a progestagen and estrogen. Ann Biol Anim Biochim Biophys. 1975;15(2):255-62.
Wiltbank MC, Baez GM, Cochrane F, Barletta RV, Trayford CR, Joseph RT. Effect of a second treatment with prostaglandin F2α during the Ovsynch protocol on luteolysis and pregnancy in dairy cows. J Dairy Sci. 2015;98(12):8644-54.
Wolfenson D, Thatcher WW, Savio JD, Badinga L, Lucy MC. The effect of a GnRH analogue on the dynamics of follicular development and synchronization of estrus in lactating cyclic dairy cows. Theriogenology. 1994;42(4):633-44.
Yavas Y, Walton JS. Postpartum acyclicity in suckled beef cows: a review. Theriogenology. 2000;54(1):25-55.
Yelich JV, Geisert RD, Schmitt RAM, Morgan GL, McCann JP. Persistence of the dominant follicle during melengestrol acetate administration and its regression by exogenous estrogen treatment in beef cattle. J Anim Sci. 1997;75(3):745-54.
Zimbelman RG, Lauderdale JW, Sokolowski JH, Schalk TG. Safety and pharmacologic evaluations of melengestrol acetate in cattle and other animals: a review. J Am Vet Med Assoc. 1970;157(11):1528-36.
Submitted date:
04/23/2025
Accepted date:
06/30/2025
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