RESUMO
Hormonal protocols based on progestogens and equine chorionic gonadotrophin (eCG) are efficient for estrus and ovulation synchronization in ewes. Although eCG is indispensable during seasonal anestrus, it may not be necessary during the breeding season. Thus, we tested the hypothesis that GnRH is effective in replacing eCG during the breeding season allowing satisfactory ovulation rate, luteal function and conception rates after timed artificial insemination (TAI). Ewes (n = 134) with a minimum body condition score of 2.5 (0-5 scale) were treated with intravaginal devices (IVD) containing 60 mg of medroxyprogesterone acetate (MPA) for seven days and received 0.26 mg of sodium cloprostenol at the time of IVD removal. In Exp. 1, at IVD removal, ewes (n = 29) were allocated to three groups: eCG (200 IU at IVD removal; n = 10); eCG+GnRH (200 IU eCG at IVD removal and 4 µg of buserelin 36 h later; n = 10); or GnRH (buserelin 36 h after IVD removal; n = 9). Blood samples were collected 2, 6 and 12 days after TAI moment (54 h after IVD removal), for progesterone (P4) analysis. In Exp 2, the ewes were allocated to eCG (n = 10) or GnRH (n = 10) groups, as above described, and ovulation moment was evaluated 54, 66 and 78 h after IVD removal. In Exp 3, TAI was performed in ewes from eCG (n = 45) and GnRH (n = 40) groups using 100 × 106 motile spermatozoa from a pool of semen collected from four rams. In Exp. 1, based on P4 levels, we confirmed that all the ewes ovulated (29/29) and there was no significant effect of group (P = 0.89) or group x day (P = 0.18) on P4 concentration, being observed a significant effect of day (P = 0.0001). In Exp. 2, the maximum DF diameter (P = 0.26) and ovulation moment (P = 0.69) did not differ between groups. In Exp. 3, pregnancy rate was significantly lower (P = 0.02) in GnRH (22.5 %; 9/40) compared to eCG (46.7 %; 21/45). The results indicate that, although ovulation and luteal function were not altered after eCG, eCG+GnRH or GnRH treatment, GnRH alone before TAI cannot be used to replace eCG treatment during the breeding season.
Assuntos
Gonadotropina Coriônica , Sincronização do Estro , Hormônio Liberador de Gonadotropina , Inseminação Artificial , Animais , Feminino , Inseminação Artificial/veterinária , Hormônio Liberador de Gonadotropina/farmacologia , Hormônio Liberador de Gonadotropina/administração & dosagem , Ovinos/fisiologia , Gonadotropina Coriônica/farmacologia , Gonadotropina Coriônica/administração & dosagem , Gravidez , Sincronização do Estro/métodos , Progesterona/sangue , Progesterona/farmacologia , Progesterona/administração & dosagem , Estações do Ano , Acetato de Medroxiprogesterona/administração & dosagem , Acetato de Medroxiprogesterona/farmacologia , Ovulação/efeitos dos fármacos , Ovulação/fisiologia , Gonadotropinas Equinas/farmacologia , Gonadotropinas Equinas/administração & dosagemRESUMO
The aim of the current study was to evaluate the effect of a novel recombinant eCG (reCG) on pregnancy rates to AI (P/AI) in suckled beef cows of different breeds that were synchronized with an estradiol/progesterone (P4)-based protocol for fixed-time AI (TAI). In experiment 1, 1244 Bos taurus suckled cows were used. On Day 0 all cows received an intravaginal P4 device (600 mg P4) and 2 mg of estradiol benzoate. On Day 7, devices were removed, and all cows received 0.150 mg of D-cloprostenol plus 1 mg of estradiol cypionate and were randomly divided to receive 140 IU or 105 IU of reCG or no reCG treatment (controls) at that time. Cows were tail painted for estrus detection and those in estrus by 48 h after P4 device removal were inseminated; whereas those not showing estrus were also inseminated and received GnRH at the same time. In experiment 2, 818 Bos taurus x Bos indicus crossbred suckled cows received the same FTAI protocol used in Experiment 1. Cows were randomly divided at the time of P4 device removal into 4 groups to receive 140 IU, 105 IU or 84 IU of reCG or no reCG treatment. In experiment 3, 345 Bos indicus suckled cows were submitted to the same FTAI protocol as those in previous experiments and were randomly divided into three groups to receive 140 IU or 105 IU of reCG, or 300 IU of serum derived eCG (PMSG). In Experiment 1, estrus rate and P/AI was greater (P < 0.05) in cows treated with reCG (79.9 and 53.5 %, 76.9 and 52.3 % for the 105 UI and 140 UI reCG groups, respectively) than those in the control group (69.9 and 44.4 %, respectively). In Experiment 2, cows treated with reCG tended (P < 0.1) to achieve a greater P/AI than control cows (38.6 %, 37.1 %, 36.2 % and 28.2 % for those receiving 84 IU, 105 IU,140 IU of reCG, and those in the control group); but when P/AI of all cows treated with reCG was contrasted to that of control cows, the difference was significant (P < 0.01). In Experiment 3, P/AI in cows treated with 84 IU of reCG (54 %) did not differ from that of cows treated with serum derived eCG (59 %) but both were greater (P < 0.05) than cows treated with 105 UI of reCG (41 %). In conclusion, treatment with reCG improved fertility in suckled Bos taurus and Bos taurus x Bos indicus beef cows. In suckled Bos indicus cows, although treatment with reCG and serum derived eCG were comparable, the higher dosage of reCG was detrimental to their P/AI.
Assuntos
Inseminação Artificial , Animais , Bovinos , Feminino , Inseminação Artificial/veterinária , Inseminação Artificial/métodos , Gravidez , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/administração & dosagem , Gonadotropina Coriônica/farmacologia , Gonadotropina Coriônica/administração & dosagem , Sincronização do Estro/métodos , Progesterona/farmacologia , Progesterona/administração & dosagem , Gonadotropinas Equinas/farmacologia , Gonadotropinas Equinas/administração & dosagem , Taxa de GravidezRESUMO
This study aimed to evaluate the effects of different doses of equine chorionic gonadotropin (eCG; 200 and 300 IU) administered at the end of a fixed-time artificial insemination (FTAI) treatment protocol on ovulation, pregnancy, and twin rates in Bos taurus beef heifers. In addition, pregnancy losses in heifers with singleton and twin pregnancies were determined. A total of 2382 Angus heifers treated with a 6-day estradiol/progesterone-based protocol for FTAI (J-Synch protocol) were randomly allocated to two experimental groups to receive 200 or 300 IU of eCG administered intramuscularly at the time of intravaginal progesterone device removal; FTAI was performed from 60 to 72 h after device removal. The pregnancy rate did not differ (P = 0.89) between the 200 and 300 IU eCG groups. The number of corpus luteum induced by both eCG doses was determined by ultrasonographic examination 14 days after insemination and those treated with 300 IU of eCG had a greater double ovulation rate (P < 0.05). In addition, 300 IU eCG treated heifers had a higher twinning rate on day 30 of gestation (P < 0.05) and parturition (P < 0.05). Pregnancy losses from 30 days of gestation to calving did not differ between heifers treated with 200 and 300 IU of eCG (P = 0.70). However, regardless of the experimental group, heifers bearing twins had greater pregnancy losses than heifers with singletons (P < 0.05). In conclusion, reducing the dose of eCG from 300 to 200 IU under FTAI treatment protocol decreases double ovulation and twinning rates, maintaining a similar pregnancy rate in heifers. Nulliparous cows carrying two fetuses suffer greater pregnancy losses than cows with singletons.
Assuntos
Gonadotropinas Equinas , Inseminação Artificial , Ovulação , Animais , Feminino , Gravidez , Bovinos/fisiologia , Inseminação Artificial/veterinária , Ovulação/efeitos dos fármacos , Gonadotropinas Equinas/farmacologia , Gonadotropinas Equinas/administração & dosagem , Gonadotropina Coriônica/farmacologia , Gonadotropina Coriônica/administração & dosagem , Aborto Animal , Gravidez de Gêmeos , Progesterona/administração & dosagem , Progesterona/farmacologia , Taxa de GravidezRESUMO
Background: Lacaune is an important sheep breed and shows reproductive seasonality which affects dairy product supply. The most common hormonal protocols are based on progesterone-releasing devices in order to reach reproductive activity. Due to international consumer demand for natural, green, and clean methods, such issues encourage the minimal or absent use of synthetic hormones in livestock. In this sense, the present study tested the efficiency of induction and estrus synchronization protocols in lacaune ewes, considering: application interval of synthetic prostaglandin at the breeding season; length of synthetic progesterone exposure; and eCG dose at the outbreeding season. Materials, Methods & Results: In study 1: 52 ewes were submitted to estrus synchronization protocol using two doses of d-cloprostenol 7 or 9 days apart. In study 2: 47 ewes were submitted to estrus induction protocol using an intravaginal device containing 60 mg of medroxyprogesterone acetate maintained for 6, 9, or 12 days. In study 3: 46 ewes were submitted to synchronized estrus induction protocol using intravaginal progesterone device for six days. On the fifth day, d-cloprostenol and 300 IU or 400 IU of eCG were administered. For all studies, signs of estrus beginning/ending were recorded and natural mating was performed. After 30 days, transrectal ultrasound was performed for pregnancy diagnosis. In study 1, groups presented similar rate of estrus behavior (78.8%) and pregnancy (average 75.6%). Meanwhile, compared to G9days (37.8 ± 7.2 h), interval between the second dose of prostaglandin and beginning of estrus was smaller in G7days (31.5 ± 7.8 h). No difference was found among variables studied in study 2 (P > 0.05), nevertheless the SD for the estrus duration was shorter (P < 0.05) in G6days and G12 days when compared with the G9days . Equally, the SD...
Assuntos
Feminino , Animais , Gonadotropinas Equinas/administração & dosagem , Ovinos/fisiologia , Progesterona/administração & dosagem , Prostaglandinas Sintéticas/administração & dosagem , Sincronização do Estro/métodos , Endogamia , Técnicas de Reprodução Assistida/veterináriaRESUMO
This study evaluated the efficiency application of low dose of equine chorionic gonadotropin (eCG) using Hou Hai acupoint for fixed-term artificial insemination (FTAI) in beef cows. Seventy cows received intravaginal devices with progesterone, and 3 mg of estradiol benzoate on day zero (D0) of FTAI. On D9, the devices were removed, and 150 μg of prostaglandin F2α was applied; the animals were then randomly distributed to three treatment groups: T1 (n = 23), 300 IU of eCG intramuscularly (IM); T2 (n = 23), 90 IU of eCG at acupoint Hou Hai; and T3 (n = 25), 90 IU of eCG at false acupoint IM. On D10, the animals received 1 mg of gonadotropin-releasing hormone IM, and FTAI was performed, 52 h after the devices were removed. The quantitative variables with normal distribution were assessed using analysis of variance at 5% probability. For variables that did not show normal distribution, Kruskal-Wallis test at 5% probability was used. No significant difference was noted among the groups (P > 0.05) for the interval between device withdrawal at ovulation (58.2 ± 12.2 h), diameter of the largest follicle on D9 (9.9 ± 2.2 mm), diameters of the ovulatory follicle (12.2 ± 3.0 mm) and the second largest follicle (6.7 ± 2.1 mm), follicular growth rate (0.8 ± 0.3 mm/d), ovulation rate (82%), corpus luteum size (2.32 ± 0.35 cm2), and pregnancy rate (58.67%). The protocol cost per animal was US$ 10.67 (T1) and US$ 8.50 (T2 and T3). The use of 90 IU of eCG applied at Hou Hai acupoint or at false acupoint caused satisfactory synchronization of estrus in beef cows. In addition, this procedure was cost-effective.(AU)
Avaliou-se a eficiência da aplicação de subdose gonadotrofina coriônica equina (eCG) utulizando como via de administração o acuponto Hou Hai em protocolos de inseminação artificial em tempo fixo (IATF) para vacas de corte. Setenta vacas receberam no dia zero (D0) do protocolo dispositivos intravaginais com progesterona, e 3mg de benzoato de estradiol. No D9 foram retirados os dispositivos, aplicado 150µg de prostaglandina F2α e distribuídos os animais aleatoriamente em três tratamentos: T1 (n=23) - 300UI de eCG por via intra muscular (IM); T2 (n=23) - 90UI de eCG no acuponto Hou Hai e T3 (n=25) - 90UI de eCG em falso acuponto, IM. No D10 os animais receberam 1mg de GnRH por via IM e foi realizada a IATF, 52 horas após a retirada dos dispositivos. Para as variáveis quantitativas com distribuição normal foi utilizada ANOVA, a 5% de probabilidade. Para as variáveis que não apresentaram distribuição normal, utilizou-se o teste de Kruskal-Wallis, a 5% de probabilidade. Não houve diferença (P >0,05) para o intervalo entre a retirada do dispositivo à ovulação (58,2 ± 12,2h), diâmetro do maior folículo no D9 (9,9 ± 2,2mm), diâmetros do folículo ovulatório (12,2 ± 3,0mm) e do segundo maior folículo (6,7 ± 2,1mm), taxa de crescimento folicular (0,8 ± 0,3mm/d), taxa de ovulação (82%), área de corpo lúteo (2,32 ± 0,35 cm2) e taxa de prenhez (58,67%). O custo do protocolo por animal foi de US$ 10,67 (T1) e US$ 8,50 (T2 e T3). Sugere-se que a utilização de 90UI de eCG aplicada no acuponto Hou Hai ou em falso acuponto foram satisfatórios na sincronização de estro de vacas de corte. Além disso, possibilita a redução do custo do protocolo.(AU)
Assuntos
Animais , Feminino , Bovinos , Gonadotropina Coriônica/administração & dosagem , Gonadotropinas Equinas/administração & dosagem , Inseminação Artificial/veterinária , Sincronização do EstroRESUMO
This study evaluated the efficiency application of low dose of equine chorionic gonadotropin (eCG) using Hou Hai acupoint for fixed-term artificial insemination (FTAI) in beef cows. Seventy cows received intravaginal devices with progesterone, and 3 mg of estradiol benzoate on day zero (D0) of FTAI. On D9, the devices were removed, and 150 μg of prostaglandin F2α was applied; the animals were then randomly distributed to three treatment groups: T1 (n = 23), 300 IU of eCG intramuscularly (IM); T2 (n = 23), 90 IU of eCG at acupoint Hou Hai; and T3 (n = 25), 90 IU of eCG at false acupoint IM. On D10, the animals received 1 mg of gonadotropin-releasing hormone IM, and FTAI was performed, 52 h after the devices were removed. The quantitative variables with normal distribution were assessed using analysis of variance at 5% probability. For variables that did not show normal distribution, Kruskal-Wallis test at 5% probability was used. No significant difference was noted among the groups (P > 0.05) for the interval between device withdrawal at ovulation (58.2 ± 12.2 h), diameter of the largest follicle on D9 (9.9 ± 2.2 mm), diameters of the ovulatory follicle (12.2 ± 3.0 mm) and the second largest follicle (6.7 ± 2.1 mm), follicular growth rate (0.8 ± 0.3 mm/d), ovulation rate (82%), corpus luteum size (2.32 ± 0.35 cm2), and pregnancy rate (58.67%). The protocol cost per animal was US$ 10.67 (T1) and US$ 8.50 (T2 and T3). The use of 90 IU of eCG applied at Hou Hai acupoint or at false acupoint caused satisfactory synchronization of estrus in beef cows. In addition, this procedure was cost-effective.
Avaliou-se a eficiência da aplicação de subdose gonadotrofina coriônica equina (eCG) utulizando como via de administração o acuponto Hou Hai em protocolos de inseminação artificial em tempo fixo (IATF) para vacas de corte. Setenta vacas receberam no dia zero (D0) do protocolo dispositivos intravaginais com progesterona, e 3mg de benzoato de estradiol. No D9 foram retirados os dispositivos, aplicado 150µg de prostaglandina F2α e distribuídos os animais aleatoriamente em três tratamentos: T1 (n=23) - 300UI de eCG por via intra muscular (IM); T2 (n=23) - 90UI de eCG no acuponto Hou Hai e T3 (n=25) - 90UI de eCG em falso acuponto, IM. No D10 os animais receberam 1mg de GnRH por via IM e foi realizada a IATF, 52 horas após a retirada dos dispositivos. Para as variáveis quantitativas com distribuição normal foi utilizada ANOVA, a 5% de probabilidade. Para as variáveis que não apresentaram distribuição normal, utilizou-se o teste de Kruskal-Wallis, a 5% de probabilidade. Não houve diferença (P >0,05) para o intervalo entre a retirada do dispositivo à ovulação (58,2 ± 12,2h), diâmetro do maior folículo no D9 (9,9 ± 2,2mm), diâmetros do folículo ovulatório (12,2 ± 3,0mm) e do segundo maior folículo (6,7 ± 2,1mm), taxa de crescimento folicular (0,8 ± 0,3mm/d), taxa de ovulação (82%), área de corpo lúteo (2,32 ± 0,35 cm2) e taxa de prenhez (58,67%). O custo do protocolo por animal foi de US$ 10,67 (T1) e US$ 8,50 (T2 e T3). Sugere-se que a utilização de 90UI de eCG aplicada no acuponto Hou Hai ou em falso acuponto foram satisfatórios na sincronização de estro de vacas de corte. Além disso, possibilita a redução do custo do protocolo.
Assuntos
Feminino , Animais , Bovinos , Gonadotropina Coriônica/administração & dosagem , Gonadotropinas Equinas/administração & dosagem , Inseminação Artificial/veterinária , Sincronização do EstroRESUMO
Avaliaram-se diferentes momentos de aplicação da gonadotrofina coriônica equina (eCG) em protocolos de inseminação artificial em tempo fixo (IATF) para vacas de leite. Foram utilizadas 76 fêmeas, as quais receberam, no dia zero (D0) do protocolo, dispositivos intravaginais de progesterona, sendo esses retirados no D9, e os animais foram, então, distribuídos aleatoriamente em três tratamentos: T1 - aplicação de eCG no momento da retirada dos dispositivos; T2 e T3 - aplicação de eCG 48h e 24h antes da retirada dos dispositivos, respectivamente. No D10 os animais receberam 1mg de GnRH, e a IATF foi realizada 52 horas após a retirada do implante. Não houve diferença (P>0,05) para intervalo entre a retirada do implante à ovulação (72,56±3,92h), o diâmetro do maior folículo no D9 (10,88±1,49mm), o diâmetro do folículo ovulatório (15,15±1,16mm) e do segundo maior folículo (7,49±0,52mm), a taxa de crescimento folicular (1,38±0,04mm/dia), a taxa de ovulação (96,67%), o intervalo entre diâmetro final e inicial do folículo dominante (73,49±3,84h), a área de corpo lúteo (2,27±0,43cm²), a porcentagem de CL no ovário direito (53,00%) e no esquerdo (26,33%) e a taxa de gestação (33,33%). O momento da aplicação da eCG não influenciou na eficiência do protocolo. Recomenda-se a utilização da eCG no momento da retirada do implante por otimização do manejo.(AU)
Different times of application of equine chorionic gonadotropin (eCG) in Fixed-Time Artificial Insemination (FTAI) protocols for dairy cows were evaluated. A total of 76 females were used, which received intravaginal progesterone devices on day zero (D0) of the protocol, which were withdrawn on D9, and the animals were then randomly distributed in three treatments: T1- application of eCG at the time of device withdrawal; T2 and T3 - application of eCG 48h and 24h before withdrawal of the devices, respectively. On D10 the animals received 1mg of GnRH and the FTAI was carried out 52 hours after the removal of the implant. There was no difference (P>0.05) for interval from implant removal to ovulation (72.56±3.92h), diameter of the largest follicle of D9 (10.88±1.49mm), diameters of ovulatory follicle (15.15±1.16mm) and of the second largest follicle (7.49±0.52mm), follicle growth rate (1.38±0.04mm/day), ovulation rate (96.67%), interval between final diameter and initial diameter of dominant follicle (73.49±3.84h), corpus luteum area (2.27±0.43cm²), percentage of CL in right ovary (53.00%) and in left ovary (26.33%) and pregnancy rate (33.33%). The time of the application of eCG did not influence the efficiency of the protocol. We recommend the use of eCG at the time of the removal of the implant for management optimization.(AU)
Assuntos
Animais , Feminino , Bovinos , Ovulação , Inseminação Artificial/veterinária , Gonadotropinas Equinas/administração & dosagemRESUMO
Avaliaram-se diferentes momentos de aplicação da gonadotrofina coriônica equina (eCG) em protocolos de inseminação artificial em tempo fixo (IATF) para vacas de leite. Foram utilizadas 76 fêmeas, as quais receberam, no dia zero (D0) do protocolo, dispositivos intravaginais de progesterona, sendo esses retirados no D9, e os animais foram, então, distribuídos aleatoriamente em três tratamentos: T1 - aplicação de eCG no momento da retirada dos dispositivos; T2 e T3 - aplicação de eCG 48h e 24h antes da retirada dos dispositivos, respectivamente. No D10 os animais receberam 1mg de GnRH, e a IATF foi realizada 52 horas após a retirada do implante. Não houve diferença (P>0,05) para intervalo entre a retirada do implante à ovulação (72,56±3,92h), o diâmetro do maior folículo no D9 (10,88±1,49mm), o diâmetro do folículo ovulatório (15,15±1,16mm) e do segundo maior folículo (7,49±0,52mm), a taxa de crescimento folicular (1,38±0,04mm/dia), a taxa de ovulação (96,67%), o intervalo entre diâmetro final e inicial do folículo dominante (73,49±3,84h), a área de corpo lúteo (2,27±0,43cm²), a porcentagem de CL no ovário direito (53,00%) e no esquerdo (26,33%) e a taxa de gestação (33,33%). O momento da aplicação da eCG não influenciou na eficiência do protocolo. Recomenda-se a utilização da eCG no momento da retirada do implante por otimização do manejo.(AU)
Different times of application of equine chorionic gonadotropin (eCG) in Fixed-Time Artificial Insemination (FTAI) protocols for dairy cows were evaluated. A total of 76 females were used, which received intravaginal progesterone devices on day zero (D0) of the protocol, which were withdrawn on D9, and the animals were then randomly distributed in three treatments: T1- application of eCG at the time of device withdrawal; T2 and T3 - application of eCG 48h and 24h before withdrawal of the devices, respectively. On D10 the animals received 1mg of GnRH and the FTAI was carried out 52 hours after the removal of the implant. There was no difference (P>0.05) for interval from implant removal to ovulation (72.56±3.92h), diameter of the largest follicle of D9 (10.88±1.49mm), diameters of ovulatory follicle (15.15±1.16mm) and of the second largest follicle (7.49±0.52mm), follicle growth rate (1.38±0.04mm/day), ovulation rate (96.67%), interval between final diameter and initial diameter of dominant follicle (73.49±3.84h), corpus luteum area (2.27±0.43cm²), percentage of CL in right ovary (53.00%) and in left ovary (26.33%) and pregnancy rate (33.33%). The time of the application of eCG did not influence the efficiency of the protocol. We recommend the use of eCG at the time of the removal of the implant for management optimization.(AU)
Assuntos
Animais , Feminino , Bovinos , Ovulação , Inseminação Artificial/veterinária , Gonadotropinas Equinas/administração & dosagemRESUMO
Avaliou-se a eficiência da administração de subdoses de eCG nos acupontos Bai Hui e Hou Hai em protocolos de sincronização de estro em cabras. Na primeira etapa, 57 cabras foram distribuídas aleatoriamente em quatro tratamentos: T1- 300UI de eCG intramuscular (IM); T2- 60UI de eCG no acuponto Hou Hai; T3- 60UI de eCG no acuponto Bai Hui e T4- 60UI de eCG IM; e na segunda etapa, 28 cabras foram distribuídas aleatoriamente em três tratamentos: T1- 300UI de eCG IM; T2- 30UI de eCG no acuponto Bai Hui e T3- 30UI de eCG IM. Ao final do tratamento hormonal, as cabras foram monitoradas para detecção do estro, realização das coberturas e avaliação do comportamento reprodutivo. Os dados foram submetidos à análise de normalidade, seguida dos testes estatísticos adequados para cada variável. Na primeira etapa experimental, obteve-se maior duração de estro nas cabras do T1 (P=0,009). Na segunda etapa experimental, obteve-se maior número de animais em estros no T1 (P=0,03). As demais variáveis para ambas as etapas não sofreram influência dos tratamentos (P>0,05), demonstrando que a administração de subdoses de eCG nos acupontos Bai Hui e Hou Hai foi eficiente para sincronizar o estro.(AU)
The efficiency of administration of subdoses of eCG in the Bai Hui and Hou Hai acupoints in oestrus synchronization protocols in goats was evaluated. In the first stage, 57 goats were randomly assigned to four treatments: T1- 300UI of intramuscular eCG (IM); T2- 60UI of eCG in acupoint Hou Hai; T3- 60UI of eCG in the Bai Hui acupoint and T4- 60UI of eCG IM; and in the second stage, 28 goats were randomly assigned to three treatments: T1-300UI of eCG IM; T2-30UI of eCG in the Bai Hui acupoint and T3- 30UI of eCG IM. At the end of the hormonal treatment the goats were monitored for estrus detection, and evaluation of reproductive behavior. The data were submitted to normality analysis, followed by appropriate statistical tests for each variable. In the first experimental stage, a longer duration of estrus in the T1 goats (P= 0.009) was obtained. In the second experimental stage, a greater number of animals were obtained in estrus at T1 (P= 0.03). The other variables for both experiments were not influenced by the treatments (P> 0.05), demonstrating that administration of eCG subdoses in the Bai Hui and Hou Hai acupoints was efficient to synchronize the estrus.(AU)
Assuntos
Animais , Feminino , Cabras , Terapia por Acupuntura/veterinária , Sincronização do Estro/métodos , Gonadotropinas Equinas/administração & dosagem , Ciclo EstralRESUMO
Avaliou-se a eficiência da administração de subdoses de eCG nos acupontos Bai Hui e Hou Hai em protocolos de sincronização de estro em cabras. Na primeira etapa, 57 cabras foram distribuídas aleatoriamente em quatro tratamentos: T1- 300UI de eCG intramuscular (IM); T2- 60UI de eCG no acuponto Hou Hai; T3- 60UI de eCG no acuponto Bai Hui e T4- 60UI de eCG IM; e na segunda etapa, 28 cabras foram distribuídas aleatoriamente em três tratamentos: T1- 300UI de eCG IM; T2- 30UI de eCG no acuponto Bai Hui e T3- 30UI de eCG IM. Ao final do tratamento hormonal, as cabras foram monitoradas para detecção do estro, realização das coberturas e avaliação do comportamento reprodutivo. Os dados foram submetidos à análise de normalidade, seguida dos testes estatísticos adequados para cada variável. Na primeira etapa experimental, obteve-se maior duração de estro nas cabras do T1 (P=0,009). Na segunda etapa experimental, obteve-se maior número de animais em estros no T1 (P=0,03). As demais variáveis para ambas as etapas não sofreram influência dos tratamentos (P>0,05), demonstrando que a administração de subdoses de eCG nos acupontos Bai Hui e Hou Hai foi eficiente para sincronizar o estro.(AU)
The efficiency of administration of subdoses of eCG in the Bai Hui and Hou Hai acupoints in oestrus synchronization protocols in goats was evaluated. In the first stage, 57 goats were randomly assigned to four treatments: T1- 300UI of intramuscular eCG (IM); T2- 60UI of eCG in acupoint Hou Hai; T3- 60UI of eCG in the Bai Hui acupoint and T4- 60UI of eCG IM; and in the second stage, 28 goats were randomly assigned to three treatments: T1-300UI of eCG IM; T2-30UI of eCG in the Bai Hui acupoint and T3- 30UI of eCG IM. At the end of the hormonal treatment the goats were monitored for estrus detection, and evaluation of reproductive behavior. The data were submitted to normality analysis, followed by appropriate statistical tests for each variable. In the first experimental stage, a longer duration of estrus in the T1 goats (P= 0.009) was obtained. In the second experimental stage, a greater number of animals were obtained in estrus at T1 (P= 0.03). The other variables for both experiments were not influenced by the treatments (P> 0.05), demonstrating that administration of eCG subdoses in the Bai Hui and Hou Hai acupoints was efficient to synchronize the estrus.(AU)
Assuntos
Animais , Feminino , Cabras , Terapia por Acupuntura/veterinária , Sincronização do Estro/métodos , Gonadotropinas Equinas/administração & dosagem , Ciclo EstralRESUMO
In most goat breeds, testosterone serum concentration and semen quality decrease during the nonbreeding season. However, bucks reproductive activity may be stimulated with the administration of equine chorionic gonadotropin (eCG). Therefore, the aim of this study was to determine whether the repeated administration of eCG stimulates the reproductive status of bucks during the nonbreeding season. The study was performed with 19 bucks that were assigned to a group that was treated with eCG (GeCG) and an untreated control group (GCon). The GeCG bucks received an initial dose of 800 IU of eCG (Day 0), followed by four doses of 500 IU administered every 5 days beginning on Day 5. Serum testosterone and anti-eCG antibody concentrations, testicular and seminal traits were determined until Day 60. Testosterone concentration (from Day 3 to 21: p < 0.0001), anti-eCG titre (from Day 12 to 44: p ≤ 0.01), percentage of motile spermatozoa (Day 6: p = 0.006 and 14: p = 0.001) and of spermatozoa with progressive motility (Day 6: p = 0.01 and 14: p = 0.002) and the percentage of spermatozoa with functional membrane (Day 6: p = 0.02 and 22: p = 0.008) were higher in GeCG than in GCon bucks. Also in frozen-thawed samples, the percentage of motile spermatozoa tended to be higher in GeCG than that of GCon bucks (p = 0.07). In conclusion, the administration of eCG during the nonbreeding season stimulated the secretion of testosterone and improved fresh and possibly frozen-thawed semen quality. However, it also resulted in an increase in anti-eCG antibody titre.
Assuntos
Cabras/fisiologia , Gonadotropinas Equinas/administração & dosagem , Análise do Sêmen/veterinária , Espermatozoides/efeitos dos fármacos , Testosterona/sangue , Animais , Criopreservação/veterinária , Masculino , Estações do Ano , Preservação do Sêmen/veterináriaRESUMO
Two experiments were conducted with the aim of determining the effect of equine chorionic gonadotropin (eCG) administration on day 14 after insemination on ovarian response and pregnancy establishment in postpartum anestrous beef cows. In both experiments, cows were subjected to a progesterone- and estradiol-based treatment for fixed-time artificial insemination (FTAI) and were randomly allocated into 4 groups to receive or not receive eCG (400 IU) at the time of device removal and/or at 14 d after FTAI. In experiment 1, from day 14 to 22, daily ultrasonographic determinations were performed to monitor ovarian dynamics, and blood was collected to determine hormone concentrations in 60 cows. In experiment 2, confirmation of pregnancy was performed at 30 and 60 d after FTAI in 1,060 anestrous cows assigned to the same experimental design. Cows that received eCG on day 14 after FTAI showed increases in corpus luteum area (P < 0.01), follicle diameter (P < 0.05), serum progesterone concentrations (P < 0.01), and estradiol-17ß concentrations (P < 0.01), compared with cows that did not receive eCG on day 14. Pregnancy rate on day 30 was greater in those cows that received both eCG treatments (ie, at device removal and 14 d after insemination) than in those that did not receive eCG treatment (P < 0.05). In conclusion, eCG administered on day 14 after FTAI increases serum progesterone concentrations during the critical period of pregnancy in anestrous cows, and this second eCG treatment seems to have a positive effect on achieving pregnancy.
Assuntos
Bovinos/fisiologia , Corpo Lúteo/efeitos dos fármacos , Gonadotropinas Equinas/farmacologia , Prenhez , Animais , Corpo Lúteo/fisiologia , Sincronização do Estro/fisiologia , Feminino , Gonadotropinas Equinas/administração & dosagem , Inseminação Artificial/veterinária , Período Pós-Parto , Gravidez , Prenhez/efeitos dos fármacosRESUMO
The magnitude of ovulation rate (OR) after hormonal induction in sheep should be considered when prolific genotypes are used. We investigated for the first time the effect of the Vacaria allele and its combined effect with the Booroola prolificacy mutation on OR after hormonal treatment during breeding and anoestrous season. A hundred forty-nine Ile de France crossbred ewes, raised in natural pastures in South Brazil, were used to evaluate the OR after treatment with progestagen (MAP) followed or not by equine chorionic gonadotrophin (eCG) treatment (MAP + eCG). During the breeding season, 96% MAP-treated ewes ovulated in comparison to 97% of MAP + eCG-treated females. The double heterozygous carriers (BNVN) presented the higher OR, followed by the single Vacaria (NNVN) and Booroola (BNNN) heterozygous females and least the wild-type (NNNN) ewes. During anoestrus, 96% eCG-treated ewes ovulated, in contrast to 6% treated with MAP alone. The OR of the gonadotrophin-treated females was higher in BNVN and BNNN than NNVN and NNNN ewes. An additive effect in the OR of the two mutations was observed since OR in double heterozygous ewes was similar to the sum of the effects of the alleles of the single heterozygous carrier ewes.
Assuntos
Alelos , Gonadotropinas Equinas/farmacologia , Indução da Ovulação/veterinária , Ovulação/genética , Progestinas/farmacologia , Ovinos/genética , Animais , Feminino , Gonadotropinas Equinas/administração & dosagem , Heterozigoto , Mutação , Ovulação/efeitos dos fármacos , Progestinas/administração & dosagemRESUMO
The objective of this study was to evaluate the effect of two sources of commercial porcine pituitary-derived follicle-stimulating hormone (pFSH) and pFSH-porcine Luteinizing Hormone (pLH), including equine chorionic gonadotropin (eCG), in ovulatory and embryonic response in Pelibuey sheep. Twenty-four Pelibuey sheep were used and were assigned randomly to four treatments (n = 6): (T1; 200 mg pFSH-Folltropin® ); (T2; 200 mg pFSH + 300 UI eCG-Folligon® ); (T3; 250 UI pFSH/pLH-Pluset® ) and (T4; 250 UI pFSH/pLH + 300 UI eCG). The interval of hours from withdrawal of the device to the beginning of oestrus (BO) was lower (p < .05) in sheep treated with eCG (T2 = 8.0 ± 1.4 and T4 = 10.0 ± 2.8) than in those without eCG (T1 = 12.6 ± 0.6 and T3 = 20.6 ± 2.4). The ovulatory rate (OR) was higher (p < .05) in T1 = 15.5 ± 2.8 and T2 = 15.6 ± 1.4, compared to T3 = 8.1 ± 3.2 and T4 = 11.8 ± 2.8; a significant difference was not shown between them (T1 vs. T2 and T3 vs. T4) when including eCG. The number of non-fertilized oocytes (NFO) was lower (p Ë .05) in T1 = 0.8 ± 0.4 and T3 = 1.8 ± 1.8, compared to those that included eCG (T2 = 6.3 ± 2.4 and T4 = 2.1 ± 1.2). The number of transferable embryos (TE) was higher (p < .05) when FSH was applied (T1 = 5.8 ± 1.1), compared with (T2 = 2.6 ± 1.1, T3 = 2.3 ± 1.4 and T4 = 2.8 ± 1.5). The commercial treatments (pFSH or pFSH-pLH) in combination with eCG did not improve OR, NFO and TE. However, the exclusive pFSH (Folltropin) treatment presented a higher OR, lower number of NFO and higher number of TE.
Assuntos
Hormônio Foliculoestimulante/farmacologia , Gonadotropinas Equinas/farmacologia , Hormônio Luteinizante/farmacologia , Indução da Ovulação/veterinária , Carneiro Doméstico , Animais , Transferência Embrionária/veterinária , Estradiol/sangue , Feminino , Fertilização/efeitos dos fármacos , Hormônio Foliculoestimulante/administração & dosagem , Gonadotropinas Equinas/administração & dosagem , Hormônio Luteinizante/administração & dosagem , Masculino , Oócitos , Indução da Ovulação/métodos , Superovulação/efeitos dos fármacosRESUMO
The aim of the study was to evaluate the feasibility of pre-selection of high or low responder does prior to the superovulatory protocols. Twenty Saanen does received 800 IU of equine chorionic gonadotropin (eCG) at the end of long-term progestogen treatment. Fourteen days later, a second progestogen protocol associated with a multiple-dose follicle stimulation hormone (FSH) treatment (5 IU/kg of FSH, in six decreasing doses between days 4 to 6 of the protocol) was administered. Transrectal ultrasound was used to assess the follicular status at the beginning of superovulatory treatments, at the oestrous onset and on the seventh day of the oestrous cycle for counting corpora lutea (CL). A significant lower number of CL was obtained in eCG-treated in comparision with FSH-treated does (p < 0.05). A quartic regression was able to explain the relationship between the number of CL in response to both treatments (r(2) =0.50; p < 0.05). Seventy per cent (14 of 20) of does maintained the same ovulatory response (high or low) after treatments. The Kappa (κ = 0.40; p < 0.05) and Spearman (rs = 0.39; p = 0.08) coefficients were able to show a relationship between treatments. Regarding the follicular status, there is a significant relationship between the number of small follicles (r = 0.71; r(2) =0.47; p < 0.01) and total follicles (r = 0.60; p < 0.01) at eCG and first FSH dose with the number of CL. Moreover, it was found a negative relationship between the presence of large follicles and the number of CL in response to eCG treatment (r = -0.44; p < 0.05), but not from FSH (p > 0.05). In conclusion, the screening test with eCG has the potential to identify Saanen does that will better respond to the superovulatory protocol with FSH. In addition, it highlighted the importance of an ultrasound evaluation prior to the beginning of superovulatory treatments with FSH to characterize the follicular status and identify the potential donors of high ovulatory response in MOET programmes in goats.
Assuntos
Cabras/fisiologia , Gonadotropinas Equinas/administração & dosagem , Doação de Oócitos/veterinária , Animais , Corpo Lúteo/anatomia & histologia , Corpo Lúteo/efeitos dos fármacos , Feminino , Hormônio Foliculoestimulante/administração & dosagem , Doação de Oócitos/métodos , Folículo Ovariano/diagnóstico por imagem , Folículo Ovariano/efeitos dos fármacos , Indução da Ovulação/métodos , Indução da Ovulação/veterinária , Progestinas/administração & dosagem , Superovulação/fisiologia , Ultrassonografia/veterináriaRESUMO
This study evaluated the effect of different doses of eCG (control, 300 or 400 IU) administered at progesterone (P4) device removal in suckled Bos taurus beef cows undergoing a timed artificial insemination (TAI) protocol. A total of 966 cows received a P4 insert and 2.0 mg intramuscular estradiol benzoate at the onset of the synchronization. After 9 days, P4 insert was removed, and 12.5 mg of dinoprost tromethamine and 1 mg of estradiol cypionate were administered, followed by TAI 48 hours later. Then, the cows received one of three treatments as follows: control (n = 323), 300 (n = 326), or 400 IU of eCG (n = 317). A subset (n = 435) of cows in anestrus had their ovaries evaluated using ultrasound at the time of P4 removal and at TAI. Data were analyzed by orthogonal contrasts (C): C1 (eCG effect) and C2 (eCG dose effect). Estrous occurrence (control = 53.7%, 300 IU = 70.6%, and 400 IU = 77.0%) and pregnancy per artificial insemination (control = 29.7%, 300 IU = 44.8%, and 400 IU = 47.6%) were improved by eCG treatment (C1; P = 0.0004 and P < 0.0001, respectively). Furthermore, the cows receiving eCG presented larger follicles at TAI (control = 13.5 ± 0.3 mm, 300 IU = 14.0 ± 0.2 mm, and 400 IU = 15.1 ± 0.3 mm; P < 0.0001; C1). However, there was no effect of eCG dose on any response variables studied (C2; P > 0.15). In conclusion, the eCG treatment administered at the time of P4 removal increased the occurrence of estrus, the larger follicles at TAI, and pregnancy per artificial insemination of suckled B taurus beef cows. Despite the greater occurrence of estrus in noncyclic cows receiving 400 IU of eCG, both eCG doses (300 and 400 IU) were equally efficient to improve pregnancy to artificial insemination.
Assuntos
Gonadotropina Coriônica/administração & dosagem , Sincronização do Estro , Gonadotropinas Equinas/administração & dosagem , Inseminação Artificial , Folículo Ovariano/efeitos dos fármacos , Taxa de Gravidez , Animais , Animais Lactentes , Bovinos , Relação Dose-Resposta a Droga , Sincronização do Estro/efeitos dos fármacos , Sincronização do Estro/métodos , Feminino , Inseminação Artificial/métodos , Inseminação Artificial/veterinária , Masculino , Oogênese/efeitos dos fármacos , Folículo Ovariano/fisiologia , Indução da Ovulação/métodos , Indução da Ovulação/veterinária , GravidezRESUMO
This study aimed to evaluate the morphological changes in microvascular density and corpus luteum (CL) vascularization in cows treated with eCG during stimulatory and superovulatory protocols. Sixteen cows were synchronized and divided into three groups: control (n = 6), stimulated (n = 4) and superovulated (n =6), one was submitted to estrous synchronization (ES) and received no eCG (control), and those that were submitted to ES and received eCG before or after follicular deviation (superovulation and stimulation of the dominant follicle, respectively). Ovulation was synchronized using a progesterone device-based protocol. After six days of ovulation, the cows were slaughtered and the ovaries and CL were collected. The CLs were processed and photomicrographs were taken under light microscopy to assess the vascular volume density (Vv) by stereology, and scanning electron microscopy (SEM) was used to perform ultrastructural analysis of the microvasculature. The Vv in stimulated and superovulated cows significantly increased (P ≤ 0.0001) when compared to control, indicating that the eCG is able to induce angiogenic activity in bovine CL. However, no significant differences were observed between stimulated and superovulated cows. The SEM demonstrated ratings indicative of angiogenesis, marked by several button-shaped projections in the capillaries, and the presence of more dilated capillaries in CL treated with eCG. These morphological findings are evidence of an angiogenic effect of the eCG treatment in CL of cows.
Assuntos
Capilares/anatomia & histologia , Gonadotropina Coriônica/administração & dosagem , Corpo Lúteo/anatomia & histologia , Corpo Lúteo/efeitos dos fármacos , Gonadotropinas Equinas/administração & dosagem , Neovascularização Fisiológica/efeitos dos fármacos , Anatomia Transversal , Animais , Bovinos , Feminino , Imageamento Tridimensional , MicroscopiaRESUMO
The aims of this study were to improve the cost-benefit ratio of the application of artificial insemination in fixed time (TAI) by the transcervical route in sheep, to test the dosage reduction and the use of the vulvar submucosa (VSM) route as an alternative for the application of equine chorionic gonadotropin (eCG) on the efficiency of the synchronization protocol and fertility to artificial insemination (AI) and to measure the level of cortisol in ewes as a result the application of this biotechnique. Blood samples were collected before AI, immediately after AI and seven days after AI. Six groups of twenty animals were used, and each group received doses of 200, 300 and 400 IU of eCG by the intramuscular route (IM) and VSM. Estrus was detected, and 48 hours later, the inseminations were performed by the transcervical route. Among the 120 treated ewes, 87.5% came in estrus. The percentage of the intrauterine deposition of semen was 88.3%. The pregnancy rate ranged from 20 to 70% between treatments, with an average of 46.66%. The VSM route was viable for the application of eCG in doses of 300 and 400 IU. The reduction in the eCG dose to 200 IU by the IM route reduces costs while maintaining the efficiency of estrus synchronization protocols and TAI with frozen semen in Santa Ines ewes. The average levels of cortisol were significant, at 1.15, 2.86 and 0.52 ?g/dL according to the three collections, being higher after the animal was off the easel at the end of AI. The procedures for performing the transcervical AI technique indicate that stress in the animals produces satisfactory fertility results and a low cost in multiparous ewes of the Santa Ines breed.(AU)
Os objetivos deste trabalho foram melhorar a relação custo benefício da aplicação da técnica de inseminação artificial pela via transcervical em tempo fixo (IATF) em ovinos, testando a redução da dose e da utilização da via submucosa vulvar (SMV) como alternativa na aplicação da gonadotrofina coriônica equina (eCG) sobre a eficiência do protocolo de sincronização e fertilidade à inseminação artificial (IA), e mensurar o nível de cortisol nas ovelhas em conseqüência da aplicação desta biotécnica. As coletas de sangue foram realizadas antes da IA, após a IA e sete dias após IA. Foram utilizados seis grupos de vinte animais, onde cada grupo recebeu dosagens de 200, 300 e 400 UI de eCG pela via intramuscular (IM) e SMV. O estro foi detectado e 48 horas após feitas as inseminações pela via transcervical. Das 120 ovelhas tratadas, 87,5% manifestaram estro. O percentual de deposição intra-uterina de sêmen foi de 88,3%. A taxa de gestação variou de 20 a 70% entre os tratamentos, obtendo-se média de 46,66%. A via SMV foi viável para aplicação de eCG em doses de 300 e 400 UI. A dose de eCG para 200 UI pela via IM apresentou melhor custo/benefício mantendo a eficiência dos protocolos de sincronização de estro e IATF com sêmen congelado em ovelhas da raça Santa Inês. Os níveis médios de cortisol foram significativos com 1,15; 2,86 e 0,52 ?g/dL de acordo com os três momentos de coleta, sendo maior após a IA. Apesar dos procedimentos para realização da técnica de IA transcervical indicar estresse nos animais, apresenta resultados satisfatórios de fertilidade e baixo custo em ovelhas multíparas da raça Santa Inês.(AU)
Assuntos
Animais , Ovinos , Inseminação Artificial/veterinária , Gonadotropinas Equinas/administração & dosagem , Fertilidade/efeitos dos fármacosRESUMO
The aims of this study were to improve the cost-benefit ratio of the application of artificial insemination in fixed time (TAI) by the transcervical route in sheep, to test the dosage reduction and the use of the vulvar submucosa (VSM) route as an alternative for the application of equine chorionic gonadotropin (eCG) on the efficiency of the synchronization protocol and fertility to artificial insemination (AI) and to measure the level of cortisol in ewes as a result the application of this biotechnique. Blood samples were collected before AI, immediately after AI and seven days after AI. Six groups of twenty animals were used, and each group received doses of 200, 300 and 400 IU of eCG by the intramuscular route (IM) and VSM. Estrus was detected, and 48 hours later, the inseminations were performed by the transcervical route. Among the 120 treated ewes, 87.5% came in estrus. The percentage of the intrauterine deposition of semen was 88.3%. The pregnancy rate ranged from 20 to 70% between treatments, with an average of 46.66%. The VSM route was viable for the application of eCG in doses of 300 and 400 IU. The reduction in the eCG dose to 200 IU by the IM route reduces costs while maintaining the efficiency of estrus synchronization protocols and TAI with frozen semen in Santa Ines ewes. The average levels of cortisol were significant, at 1.15, 2.86 and 0.52 ?g/dL according to the three collections, being higher after the animal was off the easel at the end of AI. The procedures for performing the transcervical AI technique indicate that stress in the animals produces satisfactory fertility results and a low cost in multiparous ewes of the Santa Ines breed.
Os objetivos deste trabalho foram melhorar a relação custo benefício da aplicação da técnica de inseminação artificial pela via transcervical em tempo fixo (IATF) em ovinos, testando a redução da dose e da utilização da via submucosa vulvar (SMV) como alternativa na aplicação da gonadotrofina coriônica equina (eCG) sobre a eficiência do protocolo de sincronização e fertilidade à inseminação artificial (IA), e mensurar o nível de cortisol nas ovelhas em conseqüência da aplicação desta biotécnica. As coletas de sangue foram realizadas antes da IA, após a IA e sete dias após IA. Foram utilizados seis grupos de vinte animais, onde cada grupo recebeu dosagens de 200, 300 e 400 UI de eCG pela via intramuscular (IM) e SMV. O estro foi detectado e 48 horas após feitas as inseminações pela via transcervical. Das 120 ovelhas tratadas, 87,5% manifestaram estro. O percentual de deposição intra-uterina de sêmen foi de 88,3%. A taxa de gestação variou de 20 a 70% entre os tratamentos, obtendo-se média de 46,66%. A via SMV foi viável para aplicação de eCG em doses de 300 e 400 UI. A dose de eCG para 200 UI pela via IM apresentou melhor custo/benefício mantendo a eficiência dos protocolos de sincronização de estro e IATF com sêmen congelado em ovelhas da raça Santa Inês. Os níveis médios de cortisol foram significativos com 1,15; 2,86 e 0,52 ?g/dL de acordo com os três momentos de coleta, sendo maior após a IA. Apesar dos procedimentos para realização da técnica de IA transcervical indicar estresse nos animais, apresenta resultados satisfatórios de fertilidade e baixo custo em ovelhas multíparas da raça Santa Inês.
Assuntos
Animais , Fertilidade/efeitos dos fármacos , Gonadotropinas Equinas/administração & dosagem , Inseminação Artificial/veterinária , OvinosRESUMO
The objective of the experiment was to compare the use of a PGF2α analogue (Cloprostenol) IM, with an intravaginal progestagen sponge, flurogestone acetate (FGA), and equine chorionic gonadotropin (eCG) IM application protocol. A total of 30 cyclical hair ewes (54.07 ± 0.5 kg live weight, body condition score 3.5 ± 0.5, and age 3 ± 1 years) were used. For the control group ewes (n = 15), intravaginal sponges (IS) impregnated with 20 mg of FGA were inserted for 12 days with 500 IU of eCG IM at sponges withdrawal. For the PG group ewes (Treatment group n = 15), two injections of Cloprostenol (75 mcg) were given 12 days apart. The presence of estrus was detected using two rams with 8 h interval beginning at the end of the treatment. Progesterone concentrations in blood were measured by solid phase radioimmunoassay. A student's t test was performed to analyze the duration of estrus and the interval between the ends of the treatment and the onset of estrus (ET-OE) presentation. Progesterone levels were compared with two-way ANOVA, with treatment, and day of menstrual cycle as fixed factors. Treatment costs ratio was calculated by dividing the total costs of FGA IS application between total costs of Cloprostenol application. Significant differences (P < 0.05) were found in the (ET-OE) interval and estrus duration. For the control group, estrus was presented at 30 + 8.2 h; in treatment group, at 44 h after the last application, duration of estrus was 54.9 + 8.34 h, and 41 + 1.83 h for the control and treatment group, pregnancy rates were 53.3 and 60.0 %, respectively. Significant differences (P < 0.001) were found from days 9 to 13 on Progesterone levels in both treatments. Treatment costs of Cloprostenol protocol were 2.63 cheaper than FGA including disposable material, biological products, and labor. It was concluded that Cloprostenol could be an effective tool in estrus synchronization in hair sheep in tropical areas.