Effects of Long-Term Fluorogestone Acetate Treatment Combined with PMSG on Oestrus Synchronization and Fertility in Guirra Ewes
The first objective was to asses the fertility of Guirra sheep using a standard artificial insemination procedure. In a second step, arising from the first objective, were studies the residual levels of plasma progesterone after treatment with intra-vaginal sponges impregnated with fluorogestone acetate (FGA) and determine the effect upon estrus incidence, interval to estrus onset and pregnancy rate. Estrous synchronization was carried out with FGA sponges (30 mg) for 12 days plus 400 IU eCG administered i.m. at sponge withdrawal. Ewes were AI at 54±1 h using fresh semen deposited in the entrance of the cervix. Blood samples were collected at day 19 ewes after AI, for determination progesterone concentration (P4). Ewes with a concentration of more than 1 ng/ml P4 were considered to be pregnant. In a second experiment, 70 ewes were randomly divided into 2 groups (T1 and T2) and synchronized as previous, but ewes in the second group were synchronized 6 days later than T1. Twelve days after sponge withdrawal for T2, all ewes were divided into 7 lots. One ram was introduced to each lot. Ewes for the T1 were mated at next natural estrous cycle while T2 group ewes were mated at the synchronized estrous and the next natural estrous. During all period, the ewes and rams sexual behavior was recorded by video camera. The ewes were considered in estrous when they were directly observed to accept a ride from a ram (standing reflex). The fertility examined the AI was the 24.7%. Similar percentage of ewes exhibiting estrous were observed (for natural or synchronized) but onset of estrous during the natural estrous was much shorter. The conception rate was higher for T1 compared with T2 (P<0.05) and significant differences were obtained when type of estrous were compared (P<0.05). It was concluded that a detrimental effect of f FGA sponge used for estrous synchronization on fertility in Guirra breed sheep was observed.
Ewes, Estrous Synchronization, Fertility, Progesterone, FGA
Sanchez A, Sanchez M. Razas ovinas Españolas. Ministerio de agricultura, pesca y alimentación. Madrid: Publicaciones de extensión agraria, Ministerio de agricultuta, pesca y alimentación, 1986; 773-782.
FAO. The state of the world's animal genetic resources for food and agriculture. In: B. Rischkowsky and D. Pilling, Editors, Food And Agriculture Organization of the United Nations, Rome, Italy, 2007.
Cardellino RA. Introduction and overview to the special issue on animal genetic resources. Livestock Science 2009; 120:163-165.
Holt WV, Pickard AR. Role of reproductive technologies and genetic resource banks in animal conservation. Rev Reprod 1999; 4:143-50.
Shackell GH, Kyle B, Littlejohn RP. Factors influencing the success of a large scale artificial insemination programme in sheep. Proc New Zeal Soc Anim Prod 1990; 50:427-430.
Buckrell BC, Buschbeck C, Gartley CJ, Kroetsch T, McCutcheon W, Martin J. Further development of a transcervical technique for artificial insemination in sheep using previously frozen semen. Theriogenology 1994; 42:601-611.
Hill JR, Thompson JA, Perkins NR. Factors affecting pregnancy rates following laparoscopic insemination of 28447 Merino ewes under commercial conditions: a survey. Theriogenology 1998; 49:697-709.
Lucidi, P., B. Barboni and M. Mattioli, Ram-induced ovulation to improve artificial insemination efficiency with frozen semen in sheep. Theriogenology 2001; 55:1797-1805.
Paulenz H, Adnoy T, Fossen OH, Soderquist L, Berg KA. Effect of deposition site and sperm number on the fertility of sheep inseminated with liquid semen. Vet Rec 2002; 150:299-302.
Wildeus S. Current concepts in synchronization of estrus: sheep and goats. J Anim Sci 2000; 77:1-14.
Robinson TJ, Quinlivan TD, Baxter C. The relationship between dose of progestagen and method of preparation of intravaginal sponges on their effectiveness for the control of ovulation in the ewe. J Reprod Fertil 1968; 17:471-483.
Hawk HW, Conley HH. Sperm transport in ewes administered synthetic progestagen. J Anim Sci 1971; 33:255-256.
Killian DB, Kiesling DO, Warren Jr. JE. Lifespan of corpora lutea induced in estrous synchronized cycling and anestrous ewes. J Anim Sci 1985; 61:210-215.
Scaramuzzi RJ, Downing JA, Campbell BK, Cognie Y. Control of fertility and fecundity of sheep by means of hormonal manipulation-review. Aust J Biol Sci 1988;41:37-45
Viñoles C, Forsberg M, Banchero G, Rubianes E. Effect of long-term and short-term progestagen treatment on follicular development and pregnancy rate in cyclic ewes. Theriogenology 2001; 55:993-1004.
Diskin MG, Austin EJ, Roche JF. Exogenous hormonal manipulation of ovarian activity in cattle. Domest Anim Endocrinol 2002; 23:211-28.
Hamra AH, Massri YG, Marcek JM, Wheaton JE. Plasma progesterone levels in ewes treated with progesterone-controlled internal drug release dispensers, implants and sponges. Anim Reprod Sci 1986; 11:187-194.
Greyling JPC, Brink WCJ. Synchronization of oestrus in sheep: the use of controlled internal drug release (CIDR) dispensers. S Afr J Anim Reprod 1987; 17:128-132.
Wheaton JE, Carlon KM, Windels HF, Johnston LJ. CIDR: a new progesterone releasing intravaginal device for induction of oestrus and cyclic control in sheep and goats. Anim Reprod Sci 1993; 33:127-141.
Greyling JPC, Erasmus JA, Taylor GJ, van der Merwe S. Synchronization of estrous in sheep using progestagen and inseminating with chilled semen during the breeding season. Small Rumin Res 1997; 26:137-143.
Husein MQ, Bailey MT, Ababneh MM, Romano JE, Crabo BG, Wheaton JE. Effect of eCG on the pregnancy rate of ewes transcervically inseminated with frozen-thawed semen outside the breeding season. Theriogenology 1998;49:997-1007.
Simonetti L, Blanco MR, Gardón JC. Estrus synchronization in ewes treated with sponges impregnated with different doses of medroxyprogesterone acetate. Small Ruminant Research 2000; 38:243-247.
Gómez-Brunet A, Santiago-Moreno J, Montoro V, Garde J, Pons P, González-Bulnes A, López-Sebastián A. Reproductive performance and progesterone secretion in estrus-induced Manchega ewes treated with hCG at the time of AI. Small Ruminant Research 2007; 71:117-360 122.
Anel L, Kaabi M, Abroug B, Alvarez M, Anel E, Boixo JC, de la Fuente J, de Paz P. Factors influencing the success of vaginal and laparoscopic artificial insemination in churra ewes: a field assay. Theriogenology 2005; 63:1235-1247.
Deweese WP, Glimp HA, Dutt R.H. Comparison of medroxyprogesterone acetate orally and in vaginal sponges for synchronizing estrus in ewes. Journal of Animal Science 1970; 31:394-397.
Crosby TF, Boland MP, Gordon I. Effect of progestagen treatments on the incidence of oestrus and pregnancy rates in ewes. Animal Reproduction Science 1991; 24:109-118.
Freitas VJF, Baril G, Saumande J. Induction and synchronization of estrus in goats: the relative efficiency of one versus two fluorogestone acetate-impregnated vaginal sponges. Theriogenology 1996; 46:1251-1256.
Robinson TJ. Use of progestagen-impregnated sponges inserted intravaginally or subcunaneously for the control of the estrous cycle in the sheep. Nature 1965; 206:39-43.
Greyling JPC, Van der Nest M. Synchronization of estrous in goats: dose effect of progestagen. Small Rumin Res 2000; 36:201-207.
Letelier CA, Contreras-Solis I, García-Fernández RA, Ariznavarreta C, Tresguerres JA, Flores JM, Gonzalez-Bulnes A. Ovarian follicular dynamics and plasma steroid concentrations are not significantly different in ewes given intravaginal sponges containing either 20 or 40 mg of fluorogestone acetate. Theriogenology 2009; 71:676-82.
Goodman RL. Neuroendocrine control of the ovine estrous cycle. In: KNOBIL, E., NEILL, J.D. (Eds) : The physiology of reproduction. Raven, New York, 1994.
Fitzgerald J, Butler WR. Seasonal effects and hormonal patterns related to puberty in ewe lambs. Biol Reprod 1982; 27:853-863.
Beard AP, Hunter MG. Effects of exogenous oxytocin and progesterone on GnRH induced short luteal phases in anestrousewes. Journal of Reproduction and Fertility 396 1996; 106:55-61.
Gordon I. Hormonal control of reproduction in sheep. Proc. Br. Soc. Anim. Prod. 1975; 4:79-93.
Pearce DT, Robinson TJ. Plasma progesterone concentrations, ovarian and endocrinological responses and sperm transport in ewes with synchronized oestrus. Journal of Reproduction and Fertility. 1985; 75:49-62.
Viñoles C, Meikle A, Forsberg M, Rubianes E. The effect of subluteal levels of exogenous progesterone on follicular dynamics and endocrine patterns during the early luteal phase of the ewe. Theriogenology 1999; 51:1351-1361.
González-Bulnes A, Veiga-Lopeza A, Garcia P, Garcia-Garcia RM, Ariznavarreta C, Sanchez MA, Tresguerres JAF, Cocero MJ, Flores JM. Effects of progestagens and prostaglandin analogues on ovarian function and embryo viability in sheep. Theriogenology 2005; 63:2523-2534.
Salamon S, Maxwell WM. Storage of ram semen. Anim Reprod Sci 2000; 62:77-111.
Mobarak MS, McDonnell H, Gordon I. The use of progesterone impregnated sponges in intact cyclic ewes bred by natural and artificial insemination. In: Research Report 1982-1983, Faculty of General Agriculture, University College, Dublin, 1984;101-108.
Kojima FN, Stumpf TT, Cupp AS, Werth LA, Robertson MS, Wolfe NW. Exogenous progesterone and progestins as used in estrous synchrony do not mimic the corpus luteum in regulation in luteinizing hormone and 17b-estradiol in circulation of cows. Biol Reprod 1992; 47:1009-1017.
Johnson SK, Dailey RA, Inskeep EK, Lewis PE. Effect of peripheral concentrations of progesterone on follicular growth and fertility in ewes. Domest Anim Endocrinol 1996;13:69-79.
Leyva V, Buckrell BC, Walton JS. Regulation of follicular activity and ovulation in ewes by exogenous progestagen. Theriogenology 1998; 50:395-416.
Flynn JD, Duffy P, Boland MP, Evans ACO. Progestagen synchronisation in the absence of a corpus luteum results in the ovulation of a persistent follicle in cyclic ewe lambs. Anim. Reprod. Sci. 2000; 62:285-296.
Mihm M, Baguisi A, Boland MP, Roche JF. Association between the duration of dominance of the ovulatory follicle and pregnancy rate in beef heifers. J Reprod Fertil 1994; 102:123-30.
Barrett DM, Bartlewski PM, Batista-Arteaga M, Symington A, Rawlings NC. Ultrasound and endocrine evaluation of the ovarian response to a single dose of 500 IU of eCG following a 12-day treatment with progestogen-releasing intravaginal sponges in the breeding and nonbreeding seasons in ewes. Theriogenology 2004; 61:311-27.