Jeferson Ferreira da Fonseca

Effects of GnRH administration on ovulation and fertility in ewes subjected to estrous synchronization

The objective of this study was to verify the effects of GnRH on ovulation and pregnancy of ewes subjected to a short-term synchronization of estrus. Santa Ines and crossbred Santa Ines/Dorper ewes received 60 mg MAP sponges during 6 days plus 300 IU eCG and 30 μg d-cloprostenol 24 h prior to sponge withdrawal (SW). Ewes were assigned to receive 0.9% NaCl solution (T control ; n = 32) or 25 μg GnRH (licerelin, T GnRH ; n = 34) 24 hours after SW. Each group was assigned to intrauterine insemination by laparoscopy (n = 25) or to natural mating (n = 41). Artificial insemination was performed with a single dose of fresh semen. For controlled mating, females were exposed to males 12, 24, 36 and 48 hours after SW. Ten females per treatment were subjected to transrectal ultrasound examination at 12-hour intervals (SW to 60 hours after). Estrous response (100.0% vs 95.2%), interval from SW to estrus (32.9±7.4 vs 29.8±6.9 hours), estrous length (37.4±9.0 vs 31.5±10.4 hours), pregnancy rates (57.0% vs 41.0%), ovulation rate (100.0% vs 90.0%), number of ovulations/ewe (1.1±0.3 vs 1.2±0.4), maximum follicular diameter (6.4±0.7 vs 6.1±0.6 mm), interval from SW to ovulation (59.1±3.5 vs 58.4±3.5 hours) did not differ between T control and T GnRH , respectively. Administration of GnRH 24 hours after SW does not improve ovulation or pregnancy rate in estrous synchronization in ewes.

Correlations between ovarian follicular blood flow and superovulatory responses in ewes.

The primary goal of this study was to employ ultrasonography to examine the ovaries of ewes undergoing superovulatory treatment for correlations between antral follicular blood flow and ovarian responses/embryo yields. Five Santa Inês ewes were subjected to a short- (Days 0-6, Group 1) and five to a long-term progesterone-based protocol (Days 0-12, Group 2) to synchronize estrus and ovulations after the superovulatory treatment. Porcine FSH (pFSH, 200mg) was administered in 8 decreasing doses over 4 days, starting on Days 4 and 10 in Groups 1 and 2, respectively. After CIDR removal, all ewes were bred by a ram and embryos were recovered surgically 7 days later. Transrectal ovarian ultrasonography was performed the day before and on all 4 days of the superovulatory treatment. Both an arbitrary-scale [(0) non-detectable; (1) small; (2) moderate; (3) intense blood flow] and quantitative analysis of the blood flow area were used to assess the follicular blood flow in color Doppler images. There were no significant correlations between the arbitrary blood flow scores and superovulatory responses in the ewes of the present study. However, there was a positive correlation between the quantitative estimates of follicular blood flow on the final day of the superovulatory treatment, and the number (DA: r=0.68, P<0.05; DA/TA×100%: r=0.85, P<0.05) and percentage (DA: r=0.65, P<0.05; DA/TA×100%: r=0.91, P<0.001) of unfertilized eggs (DA: Doppler area, TA: total area of the largest ovarian cross section). This experiment presents a commercially practical tool for predicting superovulatory outcomes in ewes and evidence for the existence of follicular blood flow threshold that may impinge negatively on oocyte quality when surpassed during hormonal ovarian superstimulation.

Progestin-impregnated intravaginal sponges for estrus induction and synchronization influences on goats vaginal flora and antimicrobial susceptibility

The objective was to characterize vaginal bacteria, their antimicrobial sensitivity, and the incidence of vaginitis, in goats before and after insertion of intravaginal sponges containing progesterone. Sponges were inserted in 37 Saanen goats and removed after 6, 9 or 12d (G6, G9 and G12). At sponge removal, all goats had clinical signs of vaginitis. Sampling was conducted just before sponge insertion and at 0, 24, 48, and 72 h after sponge removal. Vaginal secretions were subjected to standard bacteriological procedures, including isolation of bacteria, subculture, and determination of sensitivity to antimicrobials (gentamicin, cefalotin, tetracycline, ciprofloxacin, trimethoprim-sulfamethoxazole, amoxicillin and clavulanic acid, penicillin G and cefoxitin). Ciprofloxacin, gentamicin, tetracycline and trimethoprim-sulfamethoxazole were the most effective for coliforms (100% sensitivity), whereas ciprofloxacin, gentamicin and tetracycline were the most effective for cocci (100, 98.6 and 97.2% sensitivity, respectively). In contrast, the least effective antimicrobials were cefalotin for the coliforms, and penicillin for the cocci (37.5 and 64.4% sensitivity, respectively), regardless of duration of implant presence and interval from implant removal to sampling. In conclusion, insertion of intravaginal progestin-impregnated sponges induced clinical vaginitis in goats. Members of Staphylococcus genus were the most frequently recovered species of the vaginal samples cultured, and all isolates were resistant to several antimicrobials.

Nonsurgical embryo recovery and transfer in sheep and goats

The embryo transfer techniques used in small ruminants worldwide are based in surgical procedures. These actions are performed under general anesthesia which needs a combination of animal fasting and drugs for secure animal handling and surgery manipulations. Therefore, it involves risks to animal health and life. The major limiting sequels are adhesions formed by the abdominal surgery, in the ovaries, uterus, or between them. These occurrences can both compromise uterus accessing and oocyte capture and are responsible for decreasing success and limiting successive embryo collections. In contrast, nonsurgical embryo procedures can be performed in a relatively simplified way. Nonsurgical embryo recovery does not need animal prolonged starvation, drug retention is minimized, and donors can stay in a standing position. After the end of embryo recovery, donors are promptly restored to their routine housing and feeding. Furthermore, this technique does not need incisions and, therefore, can be used repetitively in superovulated or nonsuperovulated goats and sheep for embryo recovery-a similar procedure done in cattle. In Brazil, promising results are reported using nonsurgical embryo transfer in recipient goats, and studies are currently evaluating similar procedures in sheep. Therefore, this review aimed to present the current panorama of nonsurgical embryo transfer in sheep and goats.

Use of complementary tests to evaluate the freezing ability of semen from goats under artificial photoperiod exposure

O congelamento do semen de bodes das racas Alpina e Saanen submetidos ao manejo de fotoperiodo artificial foi avaliado por meio dos testes de termorresistencia (TTR), hiposmotico (HOST) e de integridade do acrossoma. Foram utilizados oito machos caprinos (quatro da raca Alpina e quatro da raca Saanen) de duas idades diferentes (jovens e adultos). A qualidade do semen durante as etapas do congelamento foi superior em bodes jovens de ambas as racas. Avaliada pelo TTR, a motilidade do semen fresco apresentou longevidade pos-descongelamento. Os resultados de motilidade espermatica, obtidos imediatamente apos o descongelamento, tiveram reflexos positivos sobre o TTR, indicando que os semens que apresentaram maior motilidade pos-coleta (86,2% vs 79,3%) e pos-descongelamento (37,7% vs 32,0%) tiveram maior longevidade seminal. Os resultados do HOST, tanto para o semen fresco quanto para o congelado, nao diferiram entre racas e idades. Houve reducao na porcentagem de espermatozoides integros apos o congelamento e descongelamento do semen dos animais da raca Alpina e dos adultos Saanen. Houve reducao superior a 14% nos valores do HOST para o semen congelado em relacao aos valores observados para o semen fresco (38,0 vs 52,0%, respectivamente). A motilidade espermatica progressiva mostrou maior sensibilidade a criopreservacao que a integridade da membrana espermatica, indicando que a motilidade espermatica e mais afetada pelo processo de congelamento que a membrana plasmatica. A integridade do acrossoma nao foi influenciada pelo descongelamento. Os indices de danos acrossomais (edema, desprendimento parcial e ate perda total de acrossoma) mostraram-se dentro do padrao aceitavel (44,5%), tanto no pos-descongelamento como apos o termino do TTR.

Características da dinâmica folicular e regressão luteal de vacas das raças Gir e Nelore após tratamento com cloprostenol sódico

ABSTRACT - The follicular dynamics and luteal regression were studied in 12 Gir and seven Nelore cows, treated with analogprostaglandin F 2 α, between day 10 and 12 of the estrous cycle. The synchronization rate was higher than 92% for the two breeds, andthe ovulation of second dominant follicle occurred in 72.7% of Gir and all Nelore cows. Ovulatory follicle diameter for Nelore was lower(11.0 ± 0.9 mm) than Gir cows (13.0 ± 1.7 mm). The average intervals from treatment to estrus, treatment to ovulation time and fromthe beginning of the estrus to ovulation were 88.7 and 91.6h, 119 and 113h, 26.5 and 24.3h for Nelore and Gir cows, respectivel y.Key Words: bovine, corpus luteum, estrus synchronization, luteolitic, zebu 1 Parte da tese de Doutorado do primeiro autor, parcialmente financiada pela FAPEMIG. 2 Med.Vet. autonomo – DsC – Rua Cap. Neves , 408. CEP: 37.170-000 B. Esperanca – MG. Bolsista do CNPq. E.mail: amborges@hotmail. com 3 Professor do Departamento de Zootecnia da UFV – Av. PH Holfs, s/n

Short, medium or long-term hormonal treatments for induction of synchronized estrus and ovulation in Saanen goats during the nonbreeding season

The objective of this study was to compare the effect of hormonal treatment duration through the use of intravaginal sponges impregnated with 60 mg MAP for 6 (G6; n = 10), 9 (G9; n = 10) or 12 (G12; n = 10) days. All nulliparous (n = 15) and lactating (n = 15) Saanen goats received 37.5 µg d-cloprostenol and 200 IU eCG 24 hours before sponge removal during the nonbreeding season. After sponge removal, estrus was monitored twice a day (06h00 and 18h00) by the use of fertile bucks. Transrectal ovarian ultrasonography was performed after device removal until ovulation detection. All goats were bred by artificial insemination (AI) or natural breeding (NB). All females received 250 IU hCG 5 d after AI or NB. No difference was observed among groups G6, G9 and G12 for: estrous response (90.0, 100.0 and 100.0%, respectively); interval from sponge removal to estrus (26.7±5.6, 25.2±2.8 and 25.2±3.3 hours), duration of estrus (28.5±7.1; 21.6±3.0 and 25.2±6.1 hours); ovulation rate (80.0, 100.0 and 70.0%); number of ovulations (1.9±0.2, 1.5±0.2 and 1.4±0.2); and pregnancy rate (60.0, 80.0 and 50.0%). Interval from sponge removal to ovulation was shorter in animals from G6 (44.6±2.2 hours) than for animals from G9 (52.8±2.7 hours) and G12 (60.0±4.5 hours). All treatments were effective in the induction of synchronized estrus in Saanen goats during the nonbreeding season, but ovulation occurred earlier when goats received sponges for 6 days.

Does supplemental LH changes rate and time to ovulation and embryo yield in Santa Ines ewes treated for superovulation with FSH plus eCG

The objective was to evaluate if supplemental LH given at the end of FSH treatment would synchronize the time of ovulation and increase the ovulation rate and embryo yield in Santa Ines ewes. Twenty superovulatory (SOV) programs were accomplished in cross-over design (60d interval). On D0, a CIDR device was inserted, and the device was replaced with a new one 7 days later, when 37.5µg of d-cloprostenol was administered. On D12, we started the SOV treatment, administering 256mg of pFSH 8 times, 12h apart. On D14, the CIDR was removed, and 200IU of eCG and 37.5µg of d-cloprostenol were administered. On D15, the ewes were allocated into one of two groups, a Control group (n=10) that received no supplemental LH and a LH group (n=10) treated with 7.5mg of LH 24h after CIDR removal. Artificial inseminations (AI) were performed 42 and 48h after CIDR removal. The ovarian structures were evaluated by laparoscopy immediately before each AI and 5 days later (D21) when the embryos were collected. The LH ewes ovulated more frequently (P=0.05) before 42h than between 42 and 48h. Treatment with LH tended to increase the frequency of CL and to decrease the anovulatory follicles (P=0.08). The supplemental LH increased the frequency of ewes with a high SOV response (≥11 CL; P=0.05). In conclusion, supplemental LH increased the frequency of ewes with high SOV response and ovulating prior to 42h, however, there was no synchrony between ovulations. The supplemental LH also decreased the frequency of anovulatory follicles, although the ovulation rate and embryo yield were unaffected.

Sincronização de estro em cabras da raça Saanen com esponja intravaginal e CIDR-G®

Compararam-se dois protocolos de curta duracao, associados a aplicacao de cipionato de estradiol (CE) para sincronizacao de estro, utilizando-se 12 cabras da raca Saanen, oito multiparas (M) e quatro nuliparas (N), distribuidas em dois tratamentos (T). O T1 (n = 4M e 2N) correspondeu a insercao de esponja impregnada com 60mg de acetato de medroxiprogesterona e o T2 (n= 4M e 2N), a insercao de CIDR-G®. No dia zero (d=0), dia da insercao dos dispositivos intravaginais, foi aplicado nos animais dos dois tratamentos 1mg de CE. Os dispositivos intravaginais permaneceram por cinco dias quando se iniciou a deteccao de estro, realizada a cada seis horas. Exames ultra-sonograficos foram feitos diariamente, durante a permanencia do dispositivo, e a cada seis horas apos a deteccao do estro, ate 12 horas apos a ovulacao. Houve regressao folicular com a emergencia de uma nova onda no quinto dia da permanencia do dispositivo CIDR-G®. As taxas de manifestacao de estro e de gestacao foram de 5/6 e 1/5 para T1 e de 6/6 e 2/6 para T2, respectivamente. Os intervalos da retirada do dispositivo ao inicio do estro e da retirada do dispositivo ao fim do estro e a duracao do estro foram: 74,0±39,1 e 34,7±15,1 horas (P 0,05), para T1 e T2, respectivamente. Em T1 e T2, os intervalos do inicio do estro a ovulacao foram 50,6±22,6 e 47,3±15,3 horas (P>0,05), do final do estro a ovulacao, -12,6±9,1 e -8,0±4,5 horas (P>0,05) e da retirada do dispositivo a ovulacao, 124,6±34,1 e 82,0±12,4 horas (P 0,05), respectivamente, para T1 e T2. A utilizacao da esponja e do CIDR-G® associada ao CE foi efetiva em induzir o estro. A ausencia de luteolise completa no momento da retirada do dispositivo foi responsavel pela grande variacao nas caracteristicas estudadas. Recomenda-se que os dispositivos liberadores de progesterona e seus analogos sinteticos sejam deixados por, no minimo, sete dias, quando associados ao CE.

Luteal dynamics in goats: morphological and endocrine features

Objetivou-se neste estudo estabelecer as caracteristicas morfologicas e endocrinas da dinâmica luteal em cabras. Foram utilizadas femeas da raca Toggenburg que manifestaram estro natural em um intervalo de 48 horas. Apos o estro, foram realizadas avaliacoes ultrassonograficas diarias dos ovarios durante 21 dias, utilizando-se um aparelho portatil (5 MHz). Amostras de sangue foram coletadas para dosagem de progesterona (P4) no plasma. Os corpos luteos foram detectados pela primeira vez no D5 e aumentaram progressivamente de tamanho ate o D9 (1,26 ± 0,08 cm2), nao havendo variacao nos dias subsequentes. Nas femeas com uma ovulacao, a primeira visualizacao do corpo luteo foi mais precoce que naquelas com ovulacao multipla (4,54 ± 0,18 vs 5,74 ± 0,25 dias). No momento da primeira visualizacao, a area luteal foi menor nos animais com uma ovulacao. A concentracao plasmatica de P4 aumentou progressivamente ate o D9 e nao apresentou aumento significativo ate o momento da luteolise, caracterizada por uma acentuada queda da concentracao de P4, atingindo valores inferiores a 1 ng/mL em um intervalo de 24 horas. A area luteal diminuiu de forma lenta e gradual. Foi observada uma correlacao positiva significativa entre a area e a concentracao de P4 durante a lutegeonese e a luteolise (r = 0,63 e r = 0,50; respectivamente). No dia em que o corpo luteo atinge sua area maxima (D9), as femeas com mais de um corpo luteo, com maior area de tecido luteal, nao apresentaram concentracao de P4 superior a daquelas com uma ovulacao (5,92 ± 0,59 vs 7,04 ± 0,79 ng/mL). Esses resultados indicam que a dinâmica luteal em caprinos da raca Toggenburg segue padroes semelhantes aos observados em outras racas e em outras especies e que o crescimento de tecido luteal refletiu positivamente na funcionalidade do corpo luteo.