Estrus and ovulation synchronization strategies in beef cattle

  • Ramanathan Kasimanickam Veterinary Clinical Sciences, Washington State University, Pullman, WA, USA
  • Quinlan Harting Veterinary Clinical Sciences, Washington State University, Pullman, WA, USA
  • Rachel Hanson Animal Health Clinic, Blackfoot, ID, USA
  • Randa Boler Veterinary Clinical Sciences, Washington State University, Pullman, WA, USA
Keywords: Beef cattle, estrus, ovulation, synchronization, artificial insemination

Abstract

Various technologies in bioveterinary medicine offer beef producers unique opportunities to improve overall herd genetics. Research and technology have greatly enhanced our understanding of cattle reproductive physiology, facilitating induction and synchronization of estrus and/or ovulation in replacement heifers and postpartum cows. These improvements assist beef producers to increase the use of artificial insemination (AI) and facilitate mass breeding at predetermined times. In addition to improving genetics, this helps to increase uniformity (genetics and body weight) at weaning. Pregnancy rates following implementation of these approaches are acceptable and generally comparable to breeding after detecting estrus. This review explains dynamics of synchronization, treatment regimens for various protocols, and factors that need to be considered while implementing protocols to achieve greater success.

Downloads

Download data is not yet available.

References


1.
NAHMS. Part III: reference of 1997 Beef Cow-Calf Production Management and Disease Control. 1998. p. 9-11. Available from: https://www.aphis.usda.gov/animal_health/nahms/beefcowcalf/downloads/beef97/Beef97_dr_PartIII.pdf [cited 22 September 2023].

2.
NAHMS. Part II: Reference of Beef Cow-Calf Management Practices in the United States, 2007–08. 2008. p. 5-31. Available from: https://www.aphis.usda.gov/animal_health/nahms/beefcowcalf/downloads/beef0708/Beef0708_dr_PartII_1.pdf [cited 22 September 2023].

3.
Johnson SK Fogleman SL, Jones R: Comparison of breeding system costs for estrus-synchronization protocols plus artificial insemination versus natural service. Kansas Agric Exp Station Res Rep 2003;0:105-116. doi: 10.4148/2378-5977.1661

4.
Lamb GC: Impacts of estrous synchronization on cowherd performance. Range Beef Cow Symposium. 2015. p. 342. Available from: http://digitalcommons.unl.edu/rangebeefcowsymp/342 [cited 22 September 2023].

5.
Hall JB: Capturing the Value of Artificial Insemination in Commercial Herds. Proceedings, The Range Beef Cow Symposium XXVI. Mitchell, NE, USA 2019. p 23-30. Available from: https://beef.unl.edu/documents/RBC-Symposium/2019/RBCS-2019-03-Capturing-the-Value-of-Artificial-Insemination-in-Commercial-Herds.pdf [cited 22 September 2023].

6.
Rodgers JC, Bird SL, Larson JE, et al: An economic evaluation of estrous synchronization and timed artificial insemination in suckled beef cows. J Anim Sci 2012;90:4055-4062. doi: 10.2527/jas.2011-4836

7.
Lauderdale JW: 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 2009;87:801-812. doi: 10.2527/jas.2008-1407

8.
Cooper MJ: Control of oestrous cycles of heifers with a synthetic prostaglandin analogue. Vet Rec 1974;95:200-203. doi: 10.1136/vr.95.10.200

9.
Macmillan KL, Day AM: Prostaglandin F(2alpha) – a fertility drug in dairy cattle? Theriogenology 1982;18:245-253. doi: 10.1016/0093-691x(82)90001-2

10.
Rabiee AR, Lean IJ, Stevenson MA: Efficacy of Ovsynch program on reproductive performance in dairy cattle: a meta-analysis. J Dairy Sci 2005;88:2754-2770. doi: 10.3168/jds.S0022-0302(05)72955-6

11.
Trimberger GW, Davis HP: Breeding efficiency in dairy cattle bred at various stages of estrus by artificial insemination. J Dairy Sci 1943;26:757-759.

12.
Trimberger GW: Conception rate in dairy cattle by insemination at various intervals before and after ovulation. J Dairy Sci 1944;27:659-660. doi: 10.3168/jds.S0022-0302(45)95220-9

13.
Dorsey BR, Kasimanickam R, Whittier WD, et al: Effect of time from estrus to AI on pregnancy rates in estrous synchronized beef heifers. Anim Reprod Sci 2011;127:1-6. doi: 10.1016/j.anireprosci.2011.07.014

14.
Kristula M, Bartholomew R, Galligan D, et al: Effects of a prostaglandin F2 alpha synchronization program in lactating dairy cattle. J Dairy Sci 1992;75:2713-2718. doi: 10.3168/jds.S0022-0302(92)78033-3

15.
Ferguson SD, Galligan DT: Reproductive programs in dairy herds. Proc Central Veterinary Conference 1993;1:161-178.

16.
Pankowski JW, Galton DM, Erb HN, et al: Use of prostaglandin F2a as a postpartum reproductive management tool for lactating dairy cows. J Dairy Sci 1995;78:1477. doi: 10.3168/jds.S0022-0302(95)76770-4

17.
Geary TW, Downing ER, Bruemmer JE, et al: Ovarian and estrous response of suckled beef cows to the Select Synch estrous synchronization protocol. Prof Anim Sci 2000;16:1-5. doi: 10.15232/S1080-7446(15)31653-3

18.
Patterson DJ, Kiracofe GH, Stevenson JS, et al: Control of the bovine estrous cycle with melengestrol acetate (MGA): A review. J Anim Sci 1989;67:1895-1906. doi: 10.2527/jas1989.6781895x

19.
Thomas JM, Locke JWC, Bishop BE, et al: Evaluation of the 14-d CIDR-PG and 9-d CIDR-PG protocols for synchronization of estrus in Bos indicus-influenced and Bos taurus beef heifers. Theriogenology 2017;92:190-6. doi: 10.1016/j.theriogenology.2017.01.020

20.
Twagiramungu H, Guilbault LA, Dufour JJ: Synchronization of ovarian follicular waves with a gonadotropin-releasing hormone agonist to increase the precision of estrus in cattle: a review. J Anim Sci 1995;73:3141-3151. doi: 10.2527/1995.73103141x

21.
Deutscher GH: Extending interval from seventeen to nineteen days in the melengestrol acetate-prostaglandin estrous synchronization program for heifers. Prof Anim Sci 2000;16:164-168. doi: 10.15232/S1080-7446(15)31687-9

22.
Tauck SA, Wilkinson JR, Olsen JR, et al: Comparison of controlled internal drug release device and melengestrol acetate as progestin sources in an estrous synchronization protocol for beef heifers. Theriogenology 2007;68:162-167. doi: 10.1016/j.theriogenology.2007.03.027

23.
Nash JM, Mallory DA, Ellersieck MR, et al: Comparison of long- versus short-term CIDR-based protocols to synchronize estrus prior to fixed-time AI in postpartum beef cows. Anim Reprod Sci 2012;132:11-16. doi: 10.1016/j.anireprosci.2012.03.013

24.
Kasimanickam R, Schroeder S, Hall JB, et al: Fertility after implementation of long- and short-term progesterone-based ovulation synchronization protocols for fixed-time artificial insemination in beef heifers. Theriogenology 2015;83:1226-1232. doi: 10.1016/j.theriogenology.2015.01.004

25.
Kojima FN, Salfen BE, Bader JF, et al: Development of an estrus synchronization protocol for beef cattle with short-term feeding of melengestrol acetate: 7-11 Synch. J Anim Sci 2000;78:2186-2191. doi: 10.2527/2000.7882186x

26.
Bremer VR, Damiana SM, Ireland FA, et al: Optimizing the interval from PGF to timed AI in the CO-Synch+CIDR and 7-11 Synch estrus synchronization protocols for postpartum beef cows. J Anim Sci 2004;82(Suppl. 2):106.

27.
Patterson DJ, Wood SL, Kojima FN, et al: Current and emerging methods to synchronize estrus with melengestrol acetate. In: 49th Annual Beef Cattle Short Course Proceedings “Biotechnologies of Reproductive Biology”. Gainesville, FL; Univesity of Florida: 2000. p. 45-66.

28.
Wood SL, Lucy MC, Smith MF, et al: Improved synchrony of estrus and ovulation with addition of GnRH to a melengestrol acetate-prostaglandin F2α estrus synchronization treatment in beef heifers. J Anim Sci 2001;79:2210. doi: 10.2527/2001.7982210x

29.
Funston RN, Ansotegui RP, Lipsey RJ, et al: Synchronization of estrus in beef heifers using either melengesterol acetate (MGA)/prostaglandin or MGA/Select Synch. Theriogenology 2002;57:1485-1491. doi: 10.1016/s0093-691x(02)00654-4

30.
Bader JF, Kojima FN, Schafer DJ, et al: A comparison of progestin-based protocols to synchronize ovulation and facilitate fixed-time artificial insemination in postpartum beef cows. J Anim Sci 2005;83:136-143. doi: 10.2527/2005.831136x
31. Barnes M, Kasimanickam R, Kasimanickam V: Effect of subclinical endometritis and flunixin meglumine administration on pregnancy in embryo recipient beef cows. Theriogenology 2023;201:76-82. doi: 10.1016/j.theriogenology.2023.02.020
32. Kasimanickam R, Kasimanickam V, Ratzburg K: Pregnancy and offspring sex ratio following insemination with SexedULTRA and conventional semen in cows in a commercial beef operation. Reprod Domest Anim 2021;56:1435-1445. doi: 10.1111/rda.14008

33.
Kasimanickam R, Kasimanickam V, Kappes A: Timed artificial insemination strategies with or without short-term natural service and pregnancy success in beef heifers. Theriogenology 2021;166:97-103. doi: 10.1016/j.theriogenology.2021.02.023

34.
Kasimanickam R, Kasimanickam V, Kastelic J, et al: Effects of twice daily compared with split-time estrous detection on pregnancy percentage in recipient beef cows. Anim Reprod Sci 2020;219:106526. doi: 10.1016/j.anireprosci.2020.106526

35.
Kasimanickam R, Jorgensen-Muga K, Beumeler J, et al: Estrous response and pregnancy percentages following use of a progesterone-based, split-time estrous synchronization treatment regimens in beef heifers. Anim Reprod Sci 2020;221:106544. doi: 10.1016/j.anireprosci.2020.106544
36. Kasimanickam RK, Hall JB, Estill CT, et al: Flunixin meglumine improves pregnancy rate in embryo recipient beef cows with an excitable temperament. Theriogenology 2018;107:70-77. doi: 10.1016/j.theriogenology.2017.10.043
37. Kasimanickam RK, Whittier WD, Hall JB, et al: Estrous synchronization strategies to optimize beef heifer reproductive performance after reproductive tract scoring. Theriogenology 2016;86:831-838. doi: 10.1016/j.theriogenology.2016.03.004

38.
Wilson DJ, Mallory DA, Busch DC, et al: Comparison of short-term progestin-based protocols to synchronize estrus and ovulation in postpartum beef cows. J Anim Sci 2010;88:2045-2054. doi: 10.2527/jas.2009-2627
39. Larson JE, Lamb GC, Stevenson JS, et al: Synchronization of estrus in suckled beef cows for detected estrus and artificial insemination and timed artificial insemination using gonadotropin-releasing hormone, prostaglandin F2alpha, and progesterone. J Anim Sci 2006;84:332-342. doi: 10.2527/2006.842332x
40. Stevenson JS, Thompson KE, Forbes WL, et al: Synchronizing estrus and(or) ovulation in beef cows after combinations of GnRH, norgestomet, and prostaglandin F2alpha with or without timed insemination. J Anim Sci 2000;78:1747-1758. doi: 10.2527/2000.7871747x

41.
Bó GA, Adams GP, Pierson RA, et al: Exogenous control of follicular wave emergence in cattle. Theriogenology 1995;43:31-40. doi: 10.1016/0093-691X(94)00010-R

42.
Bó GA, Adams GP, Nasser LF, et al: Effect of estradiol valerate on ovarian follicle, emergence of follicular wave and circulating gonadotropins in heifers. Theriogenology 1993;40:225-239. doi: 10.1016/0093-691X(93)90261-3

43.
Thundathil J, Kastelic JP, Mapletoft RJ: The effect of estradiol cypionate (ECP) on ovarian follicular development and ovulation in dairy cattle. Can J Vet Res 1997;61:314-316.

44.
Martínez MF, Kastelic JP, Colazo MG, et al: Effects of estradiol on gonadotrophin release, estrus and ovulation in CIDR-treated beef cattle. Domest Anim Endocrinol 2007;33:77-90. doi: 10.1016/j.domaniend.2006.04.009

45.
Adams GP, Jaiswal R, Singh J, et al: Progress in understanding ovarian follicular dynamics in cattle. Theriogenology 2008;69:72-80. doi: 10.1016/j.theriogenology.2007.09.026

46.
Pursley JR, Stevenson JS, Minton JE: Ovarian follicular waves in dairy cows after administration of gonadotropin-releasing hormone at estrus. J Dairy Sci 1993;76:2548-2560. doi: 10.3168/jds.S0022-0302(93)77590-6

47.
Kasimanickam RK, Kasimanickam VR, Oldham J, et al: Cyclicity, estrus expression and pregnancy rates in beef heifers with different reproductive tract scores following progesterone supplementation. Theriogenology 2020;145:39-47. doi: 10.1016/j.theriogenology.2020.01.028
48. Bridges A: Timed-artificial insemination in beef cows: what are the options? Purdue University Cooperative Extension Service, West Lafayette, IN, USA. 2008; AS-575-W. Available from: https://www.extension.purdue.edu/extmedia/as/as_575_w.pdf [cited 15 October 2023].

49.
Bridges GA, Helser LA, Gru DE, et al: Decreasing the interval between GnRH and PGF2α from 7 to 5 days and lengthening proestrus increased timed-AI pregnancy rates in beef cows. Theriogenology 2008;69:843-851. doi: 10.1016/j.theriogenology.2007.12.011

50.
Bridges GA, Lake SL, Kruse SG, et al: Comparison of three CIDR-based fixed-time AI protocols in beef heifers. J Anim Sci 2014;92:3127-3133. 94. doi: 10.2527/jas.2013-7404

51.
Valdez KE, Cuneo SP, Turzillo AM: Regulation of apoptosis in the atresia of dominant bovine follicles of the first follicular wave following ovulation. Reproduction 2005;130:71-81. doi: 10.1530/rep.1.00430

52.
Peterson C, Alkar A, Smith S, et al: Effects of one versus two doses of prostaglandin F2alpha on AI pregnancy rates in a 5-day, progesterone-based, CO-Synch protocol in crossbred beef heifers. Theriogenology 2011;75:1536-1542. doi: 10.1016/j.theriogenology.2010.12.017

53.
Whittier WD, Currin JF, Schramm H, et al: Fertility in Angus cross beef cows following 5-day CO-Synch + CIDR or 7-day CO-Synch + CIDR estrus synchronization and timed artificial insemination. Theriogenology 2013;80:963-969. doi: 10.1016/j.theriogenology.2013.07.019

54.
Ahmadzadeh A, Gunn D, Hall JB, et al: Evaluation of treatment with a 5-day versus 7-day controlled internal drug-release insert on reproductive outcomes of beef heifers using a modified timed-artificial insemination protocol. Prof Anim Sci 2015;31:270-277. doi: 10.15232/pas.2014-01378

55.
Stevenson JS, Hill SL, Grieger DM, et al: Two split-time artificial insemination programs in suckled beef cows. J Anim Sci 2017;95:5105-111. doi: 10.2527/jas2017.1805

56.
Navanukraw C, Redmer DA, Reynolds LP, et al: A modified presynchronization protocol improves fertility to timed artificial insemination in lactating dairy cows. J Dairy Sci 2004;87:1551-1557. doi: 10.3168/jds.S0022-0302(04)73307-X

57.
Macmillan KL, Thatcher WW: Effects of an agonist of gonadotropin-releasing hormone on ovarian follicles in cattle. Biol Reprod 1991;45:883-889. doi: 10.1095/biolreprod45.6.883

58.
Stevenson JS, Sauls JA, Mendonça LGD, et al: Dose frequency of prostaglandin F2a administration to dairy cows exposed to presynchronization and either 5- or 7-day Ovsynch program durations: ovulatory and luteolytic risks. J Dairy Sci 2018;101:9575-9590. doi: 10.3168/jds.2018-14653

59.
Knickmeyer ER, Thomas JM, Locke JWC, et al: Altering duration of the presynchronization period in a long-term progestin-based estrus synchronization protocol for timed artificial insemination of beef heifers. Theriogenology 2019;136:66-71. doi: 10.1016/j.theriogenology.2019.06.027

60.
Small JA, Colazo MG, Kastelic JP, et al: Effects of progesterone presynchronization and eCG on pregnancy rates to GnRH-based, timed-AI in beef cattle. Theriogenology 2009;71:698-706. doi: 10.1016/j.theriogenology.2008.09.045

61.
Monn RE, Mackey JC, Dudley HB, et al: Effect of a pre-synchronization protocol on beef heifer AI pregnancy rates. J Anim Sci 2016;95:56-57. doi: 10.2527/ssasas2017.0115

62.
Colazo MG, Mapletoft RJ: A review of current timed-AI (TAI) programs for beef and dairy cattle. Can Vet J 2014;55:772-780.

63.
Berardinelli JG, Dailey RA, Butcher RL, et al: Source of progesterone prior to puberty in beef heifers. J Anim Sci 1979;49:1276-1281. doi: 10.2527/jas1979.4951276x

64.
Moriel P, Lancaster P, Lamb GC, et al: Effects of post-weaning growth rate and puberty induction protocol on reproductive performance of Bos indicus influenced beef heifers. J Anim Sci 2017;95:3523-3531. doi: 10.2527/jas.2017.1666

65.
Bao B, Garverick HA: Expression of steroidogenic enzyme and Gonadotropin receptor genes in bovine follicles during ovarian follicular waves: a review. J Anim Sci 1998;76:1903-1921. doi: 10.2527/1998.7671903x

66.
Sartori R, Fricke PM, Ferreira JC, et al: Follicular deviation and acquisition of ovulatory capacity in bovine follicles. Biol Reprod 2001;65:1403-1409. doi: 10.1095/biolreprod65.5.1403

67.
Ratzburg K, Jorgensen-Muga K, Murugesan J, et al: Presynchronization with CIDR, with or without GnRH, prior to CO-Synch in beef heifers. Theriogenology 2020;146:80-87. doi: 10.1016/j.theriogenology.2020.02.005

68.
Bonacker RC, Stoecklein KS, Locke JWC, et al: Treatment with prostaglandin F2α and an intravaginal progesterone insert promotes follicular maturity in advance of gonadotropin-releasing hormone among postpartum beef cows. Theriogenology 2020;157:350-359. doi: 10.1016/j.theriogenology.2020.08.018

69.
Bonacker RC, Gray KR, Breiner CA, et al: Comparison of the 7 & 7 Synch protocol and the 7-day CO-Synch + CIDR protocol among recipient beef cows in an embryo transfer program. Theriogenology 2020;158:490-496. doi: 10.1016/j.theriogenology.2020.09.033

70.
Seidel GE Jr: Update on sexed semen technology in cattle. Animal 2014;8 Suppl 1:160-164. doi: 10.1017/S1751731114000202

71.
Maicas C, Hutchinson IA, Kenneally J, et al: Fertility of fresh and frozen sex-sorted semen in dairy cows and heifers in seasonal-calving pasture-based herds. J Dairy Sci 2019;102:10530-10542. doi: 10.3168/jds.2019-16740

72.
Seidel GE, Jr, Schenk JL, Herickhoff LA, et al: Insemination of heifers with sexed sperm. Theriogenology 1999;52:1407-1420. doi: 10.1016/s0093-691x(99)00226-5

73.
Nebel R: Time of insemination relative to onset of activity threshold of cow manager® is associated with pregnancy risk when using gender selected™ semen for Jersey cattle. Dairy Vet Sci J 2018;5:555653. doi: 10.19080/JDVS.2018.05.555653

74.
Bombardelli GD, Soares HF, Chebel RC: Time of insemination relative to reaching activity threshold is associated with pregnancy risk when using sex-sorted semen for lactating Jersey cows. Theriogenology 2016;85:533-539. doi: 10.1016/j.theriogenology.2015.09.042

75.
Gosálvez J, Ramirez MA, López-Fernández C, et al: Sex-sorted bovine spermatozoa and DNA damage: II. Dynamic features. Theriogenology 2011;75:206-211. doi: 10.1016/j.theriogenology.2010.09.011

76.
Kasimanickam R, Nebel RL, Peeler ID, et al: Breed differences in competitive indices of Holstein and Jersey bulls and their association with sperm DNA fragmentation index and plasma membrane integrity. Theriogenology 2006;66:1307-1315. doi: 10.1016/j.theriogenology.2006.04.025

77.
Steele H, Makri D, Maalouf WE, et al: Bovine sperm sexing alters sperm morphokinetics and subsequent early embryonic development. Sci Rep 2020;10:6255. doi: 10.1038/s41598-020-63077-6

78.
Reese S, Pirez MC, Steele H, et al: The reproductive success of bovine sperm after sex-sorting: a meta-analysis. Sci Rep 2021;11:17366. doi: 10.1038/s41598-021-96834-2

79.
Cavalieri J, Rubio I, Kinder JE, et al: Synchronization of estrus and ovulation and associated endocrine changes in Bos indicus cows. Theriogenology 1997;47:801-814. doi: 10.1016/S0093-691X(97)00036-8

80.
Galina CS, Arthur GH: Review on cattle reproduction in the tropics. Part 4. Oestrus cycles. Anim Breed Abstracts 1990;58:697-707.

81.
Bó GA, Cutaia L, Peres LC, et al: Technologies for fixed-time artificial insemination and their influence on reproductive performance of Bos indicus cattle. Soc Reprod Fertil Suppl 2007;64:223-236. doi: 10.5661/rdr-vi-223

82.
Baruselli PS, Reis EL, Marques MO, et al: The use of hormonal treatments to improve reproductive performance of anestrous beef cattle in tropical climates. Anim Reprod Sci 2004;82-83:479-486. doi: 10.1016/j.anireprosci.2004.04.025

83.
Pinheiro VG, Souza AF, Pegorer MF, et al: Effects of temporary calf removal and eCG on pregnancy rates to timed-insemination in progesterone-treated postpartum Nellore cows. Theriogenology 2009;71:519-524. doi: 10.1016/j.theriogenology.2008.08.018

84.
Murphy BD, Martinuk SD: Equine chorionic gonadotropin. Endocr Rev 1991;12:27-44. doi: 10.1210/edrv-12-1-27

85.
Roche JF, Crowe MA, Boland MP: Postpartum anoestrus in dairy and beef cows. Anim Reprod Sci 1992;28:371-378. doi: 10.1016/0378-4320(92)90123-U

86.
McMillan 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;33:1-25. doi: 10.1016/0378-4320(93)90104-Y

87.
Sá Filho OG, Dias CC, Lamb GC, et al: Progesterone-based estrous synchronization protocols in non-suckled and suckled primiparous Bos indicus beef cows. Anim Reprod Sci 2010;119:9-16. doi: 10.1016/j.anireprosci.2009.12.011

88.
Harrington TE: Effect of Transportation Time on Pregnancy Rates of Synchronized Yearling Beef Heifers. Ph.D. Thesis, Colorado State University, Fort Collins, CO, USA, 1995.

89.
Merrill ML, Ansotegui RP, Burns PD, et al: Effects of flunixin meglumine and transportation on establishment of pregnancy in beef cows. J Anim Sci 2007;85:1547-1554. doi: 10.2527/jas.2006-587

90.
Salverson R: Effects of shipping and heat stress on embryonic mortality in cattle. South Dakota State University, Animal Science Department. South Dakota Board of Regents. 2020. Available from: https://extension.sdstate.edu/sites/default/files/2020-10/P-00189.pdf [cited 28 September 2023].

91.
Geary TW: Effects of adrenocorticotropic hormone and flunixin meglumine on pregnancy retention in beef cows. J Anim Sci 2012;90:207-211. doi: 10.2527/jas.2010-3564

92.
Anderson KJ, Lefever DG, Brinks JS, et al: The use of reproductive tract scoring in beef heifers. Agri Sci Pract 1991;12:123-128.

93.
Gutierrez K, Kasimanickam R, Tibary A, et al: Effect of reproductive tract scoring on reproductive efficiency in beef heifers bred by timed insemination and natural service versus only natural service. Theriogenology 2014;81:918-924. doi: 10.1016/j.theriogenology.2014.01.008

94.
Matteri RL, Carroll JA, Dyer CJ: Neuroendocrine responses to stress. In: Moberg GP, Mench JA: editors. The Biology of Animal Stress. Wallingford; CABI: 2000. p. 43-76.

95.
Möstl E, Palme R: Hormones as indicators of stress. Domest Anim Endocrinol 2002;23:67-74. doi: 10.1016/s0739-7240(02)00146-7

96.
Sapolsky RM, Romero LM, Munck AU: How do glucocorticoids influence stress responses? Integrating permissive, suppressive, stimulatory, and preparative actions. Endocr Rev 2000;21:55-89. doi: 10.1210/edrv.21.1.0389

97.
Grandin T: Assessment of stress during handling and transport. J Anim Sci 1997;75:249-257. doi: 10.2527/1997.751249x

98.
Voisinet BD, Grandin T, Tatum JD, et al: Feedlot cattle with calm temperaments have higher average daily gains than cattle with excitable temperaments. J Anim Sci 1997;75:892-896. doi: 10.2527/1997.754892x

99.
Kasimanickam R, Schroeder S, Assay M, et al: Influence of temperament score and handling facility on stress, reproductive hormone concentrations, and fixed time AI pregnancy rates in beef heifers. Reprod Domest Anim 2014;49:775-782. doi: 10.1111/rda.12368

100.
Kasimanickam R, Asay M, Schroeder S, et al: Calm temperament improves reproductive performance of beef cows. Reprod Domest Anim 2014;49:1063-1067. doi: 10.1111/rda.12436

101.
Lake SL, Scholljegerdes EJ, Hallford DM, et al: Effects of body condition score at parturition and postpartum supplemental fat on metabolite and hormone concentrations of beef cows and their suckling calves J Anim Sci 2006;84:1038-1047. doi: 10.2527/2006.8441038x

102.
Short RE, Bellows RA, Staigmiller RB, et al: Physiological mechanisms controlling anestrus and infertility in postpartum beef cattle. J Anim Sci 1990;68:799-816. doi: 10.2527/1990.683799x

103.
Astessiano AL, Pérez-Clariget R, Quintans G, et al: Metabolic and endocrine profiles and hepatic gene expression in periparturient, grazing primiparous beef cows with different body reserves. Livest Sci 2014;170:63-71. doi: 10.1016/j.livsci.2014.10.008

104.
Kasimanickam R, Firth P, Asay M, et al: Impact of body condition change post-breeding on reproductive performance of beef cows. Clinical Theriogenology 2012;4:469-476.

105.
Kasimanickam R, Whittier WD, Currin JF, et al: Effect of body condition at initiation of synchronization on estrus expression, pregnancy rates to AI and breeding season in beef cows. Clinical Theriogenology 2011;3:29-41.

106.
Whitman RH. Weight changes, body condition and beef-cow reproduction. PhD thesis. Colorado State University, Fort Collins, CO, USA, 1975.

107.
Ciccioli NH, Wettemann RP, Spicer LJ, et al: Influence of body condition at calving and postpartum nutrition on endocrine function and reproductive performance of primiparous beef cows. J Anim Sci 2003;81:3107-3120. doi: 10.2527/2003.81123107x
Published
2025-02-14
How to Cite
Kasimanickam R., Harting Q., Hanson R., & Boler R. (2025). Estrus and ovulation synchronization strategies in beef cattle. Clinical Theriogenology, 17, 9-23. https://doi.org/10.58292/CT.v17.11650