Este estudo teve como objetivo avaliar o efeito da presença de corpo lúteo (CL) no início do protocolo de inseminação artificial a tempo fixo (IATF), no diâmetro do folículo ovulatório (DFO), na expressão de estro e na taxa de prenhez usando cipionato de estradiol (CE) ou GnRH como indutor de ovulação em novilhas de corte. No dia 0, novilhas [n = 414; 317 ± 23 kg; 3,08 ± 0,21 escore de condição corporal (escala de 1 a 5) entre 22 e 24 meses de idade] receberam um dispositivo intravaginal contendo 1g de progesterona (P4) e foram administrados 2 mg de benzoato de estradiol, IM. No dia 8, o dispositivo foi removido e as novilhas receberam 500 μg de cloprostenol sódico IM e foram divididas em dois grupos: CE [n = 213; 0,5 mg de CE, IM, no dia 8] e GnRH [n = 201; 25 μg de Licerelina, IM, no dia da IATF] e a IATF foi realizada 50 h após a remoção do dispositivo. As novilhas tiveram a região sacral pintada para verificar a expressão do estro entre a remoção do dispositivo de P4 e a IATF. No dia 0, foram realizados exames ultrassonográficos para verificar a presença de CL (com CL = 213, sem CL = 202), no dia 10 para medir o DFO e no dia 11 para confirmar a ovulação. As novilhas foram classificadas em 3 grupos de acordo com o DFO: pequeno (≤ 9,5mm), médio (9,6-11,5mm) e grande (≥ 11,6mm) para avaliar seu efeito na expressão de estro e prenhez. A expressão de estro foi confirmada quando a tinta estava removida no dia 10. A expressão de estro foi maior (P <0,05) no grupo CE em comparação com o grupo GnRH. O DFO diferiu (P <0,05) de acordo com a presença de CL ( P < 0,05), mas foi semelhante entre os tratamentos. A taxa de ovulação não diferiu nos grupos CE e GnRH. As taxas de prenhez foram semelhantes (P> 0,05) entre os grupos CE e GnRH, no entanto, a taxa de prenhez foi maior nas novilhas que expressaram estro (P <0,05), do que naquelas que não expressaram. A presença de CL no início do protocolo de IATF esteve associada a maior taxa de prenhez (P <0,05) no grupo GnRH em relação ao grupo CE, mas não diferiu entre novilhas sem CL. A manifestação de estro para novilhas tratadas com GnRH aumenta de acordo com DFO. O grupo CE apresenta alta manifestação de estro independente do DFO. A taxa de prenhez é maior à medida que o DFO aumenta. Em conclusão, as novilhas com CL no início do protocolo de IATF possuem maior folículo ovulatório, e quando tratadas com GnRH como indutor de ovulação atingem maiores taxas de prenhez. O tamanho do folículo ovulatório foi associado com o comportamento de estro e as taxas de prenhez nos tratamentos de CE e GnRH. / The aim of this study was to evaluate the effect of presence of corpus luteum (CL) at the onset of timed AI (TAI) protocol in ovulatory follicle diameter (OFD), estrus expression and pregnancy rate using estradiol cypionate (EC) or GnRH as ovulation inductor in beef heifers. On day 0, heifers [n=414; 317±23 kg; 3.08±0.21 body condition score (1 to 5 scale) and 22-24 months of age] received a 1g progesterone (P4) intravaginal device and 2 mg of estradiol benzoate, IM,. On day 8, device was removed, heifers received 500 μg of sodium cloprostenol, IM, and were divided in two groups: EC [n=213; 0.5mg EC, IM, on day 8] and GnRH [n=201; 25 μg of Licerelin, IM, at TAI] TAI was performed 50 h after device removal. The heifers had the base of the tail painted to verify estrus expression between P4 device removal and IATF. On day 0, ultrasound examinations were performed to verify the presence of CL (with CL = 213, without CL = 202).On day 10 to measure OFD and on day 11 to confirm ovulation. Heifers were classified into three groups according to OFD: small (≤ 9.5 mm), medium (9.6-11.5 mm) and large (≥ 11.6 mm) to evaluate their effect on estrus expression and pregnancy rate. Estrus expression was confirmed when ink marking was removed on day 10. Estrus expression was higher (P <0.05) in the EC group compared to GnRH group. The OFD differed (P <0.05) according to the presence of CL (P <0.05), but was similar between the treatments. The ovulation rate did not differ in CE and GnRH groups. Pregnancy rates were similar (P> 0.05) between the EC and GnRH groups, however, the pregnancy rate was higher in heifers who expressed estrus (P <0.05) than in those who did not express it. The presence of CL at the beginning of the IATF protocol was associated with a higher pregnancy rate (P <0.05) in the GnRH group in relation to the EC group, but did not differ between heifers without CL. The estrus manifestation for heifers treated with GnRH increases as the DFO increases, while the EC heifers has a high estrus manifestation independent of the DFO. The pregnancy rate also increases as DFO increases. In conclusion, heifers with CL at the beginning of the IATF protocol have increased ovulatory follicle size, and when treated with GnRH, as an ovulation inducer, attained higher pregnancy rates. The size of the ovulatory follicle was associated with higher estrus behavior and higher pregnancy rates in the EC and GnRH treatments.

A inseminação artificial em tempo fixo (IATF), juntamente com a inseminação artificial pós-cervical (IAPC), permite uma redução expressiva da mão de obra e uma melhor utilização dos machos geneticamente superiores. O objetivo deste estudo foi avaliar a eficiência do eCG associado agonista de GnRH (buserelina) ou apenas buserelina para indução e sincronização da ovulação em porcas desmamadas e submetidos a apenas uma IATF. Um total de 495 femeas suínas desmamadas foram utilizadas, cuja detecção de estro foi realizada uma vez ao dia (07:30). As fêmeas foram divididas em três tratamentos: Controle (n = 165) - a primeira IA foi realizada no início do estro (0 h) e repetida a cada 24 h, posteriormente, durante o estro; Tratamento 2: eCG + GnRH (n = 165) – femeas receberam uma injeção intramuscular de 600 UI de eCG após o desmame, e uma injeção intramuscular de buserelina (10 μg) 86-89 h após a administração de eCG; Tratamento 3: GnRH - fêmeas receberam uma injeção intramuscular de buserelina (10 μg) 86-89 h após o desmame. Nos três grupos era realizada a exposição ao macho no dia seguinte ao desmame uma vez ao dia, e aquelas fêmeas que demostrassem estro eram retiradas dos protocolos de IATF. Os grupos tratados receberam uma única IA, 118-120 h após o desmame (30-33 h após a buserelina). A IAPC contou com doses homospérmicas (1,5 x 109 células de espermáticas/50 ml) que foram utilizadas nas femeas em todos os três tratamentos. Não houve diferenças entre os tratamentos quanto ao número de femeas em estro até o terceiro dia (P>0,05). O intervalo entre o desmame e a ovulação foi significativamente maior (P< 0,05) no grupo controle (141,5 ± 1,58 h) comparativamente aos tratamentos eCG+GnRH (133,3 ± 1,60 h) e GnRH (135,9 ± 1,57 h). As femeas do tratamento eCG+GnRH ovularam em média antes (P<0,05) em relação ao grupo GnRH (44,5 ± 1,74 vs 48,2 ± 1,73 h). A taxa de parto foi superior (P<0,05) no grupo de controle, comparativamente aos tratamentos eCG + GnRH e GnRH, mas não houve diferença (P>0,05) em leitões nascidos totais entre os tratamentos. O uso do GnRH, com ou sem a administração prévia de eCG, antecipa a ovulação nas fêmeas suínas desmamadas. Nas fêmeas tratadas com eCG+GnRH ou GnRH, há em maior percentual de fêmeas inseminadas fora do momento ideal, em relação à ovulação, o que pode prejudicar o desempenho reprodutivo, sendo necessários ajustes no momento de aplicação dos hormônios ou no momento da inseminação para estudos subsequentes. / Fixed-time artificial insemination (FTAI) together with post-cervical artificial insemination (PCAI), allows an expressive reduction in labor requirements and a wider use of higher indexing boars. The aim of this study was to evaluate the efficiency of eCG agonist of GnRH (buserelin) or just buserelin for induction and synchronization of ovulation in weaned sows and submitted to FTAI .A total of 495 weaned sows whose estrus detection was performed once daily (07:30 A.M), starting a day after weaning. The sows were allocated into three treatment groups: Control (n=165) – the first AI was performed at estrus onset (0 h) and repeated every 24 h thereafter during estrus; Treatment 2: eCG + GnRH (n=165) – sows received an intramuscular injection of 600 UI eCG after weaning, and an intramuscular injection of buserelin (10 μg) 86-89 h after eCG administration; Treatment 3: GnRH - sows received an intramuscular injection of buserelina (10 μg) 86-89 h after weaning. . In the three groups it was performed boar exposure in the following day to weaning once a day, and those sows that demonstrated oestrus were removed from FTAI protocols. Treated groups received a single AI, 118-120 h after weaning (30-33 h after buserelin). PCAI with homospermic doses (1.5 x 109 total of sperm cells/50 ml) were respectively performed in sows in all treatment group. There were no differences (P> 0,05) in number of sows that showed oestrus until the third day between treatments. The interval between weaning and ovulation was significantly higher (P< 0,05) in the control group (141,5 ± 1,58 h) comparatively the treatments eCG+GnRH (133,3 ± 1,60 h) and GnRH (135,9 ± 1,57 h). Sows of treatment eCG+GnRH ovulated earlier (P< 0,05) comparing to the GnRH group (44,5 ± 1,74 vs 48,2 ± 1,73 h). Higher (P<0,05) farrowing rate in control group comparatively to treatments eCG+GnRH e GnRH was observed, but there were no differences (P> 0,05) in total piglets born between treatments. Use of GnRH, with or without previous administration of eCG anticipates ovulation in sows weaned, in the sows treated with eCG + GnRH or GnRH, there is a greater percentage of females inseminated outside the ideal time, with respect to ovulation, it can harm the reproductive performance, with necessary adjustments at the time of application hormones or at the time of insemination for subsequent studies.

Investigou-se o desempenho reprodutivo de novilhas e vacas de corte submetidas a protocolos de sincronização de estros para a inseminação artificial e a associação entre marcadores moleculares e desempenho reprodutivo. Exp.1 avaliou-se a antecipação da aplicação da PGF2a em programa de IATF com implante de progesterona em 306 vacas Angus, com cria ao pé. A antecipação da aplicação da PGF2a afetou a taxa de concepção à IATF e prenhez final (P<0,05), respectivamente de 60,9% e 89,1% quando comparados a PGF2a na retirada do dispositivo, respectivamente de 49,3% e 76,7%. Exp.2 avaliaram-se os efeitos do GnRH e da manifestação de estro sobre o desempenho reprodutivo em 197 vacas Angus submetidas à IATF. A manifestação de estro antes da IATF influenciou a taxa de prenhez à IATF (TxPIATF) e prenhez final, respectivamente de 46,6%, 78,6% (C/estro) e 33,0%, 60,6% (S/estro) (P<0,05). O GnRH no momento da IATF resultou em menor taxa de prenhez à IATF, 32,3%, comparado a ausência de GnRH 48,0% (P<0,05), mas não afetou a prenhez final, respectivamente de 69,7% e 70,4%. Houve interação entre estro e GnRH. Vacas C/estro-C/GnRH tiveram 31,4% de prenhez à IATF contra vacas C/estro- S/GnRH com 61,5% (P<0,05). Nas vacas sem estro, o GnRH não apresentou efeito (P>0,05) na TxPIATF (32,6% e 33,3%). O escore de condição corporal (ECC) afetou a taxa de manifestação de estro e a TxPIATF, com superioridade (P<0,05) para vacas > de 3,0. Exp.3 compararam-se os efeitos de diferentes protocolos para a IATF com o acasalamento por touros (Controle) sobre o desempenho reprodutivo de 249 vacas Angus. Formou-se 5 grupos: Controle; Crestar 2º uso; OvSynch; Primer 1ºuso e Primer 2ºuso. A IATF dos animais foi realizada 27 dias e 38 dias após o inicio da estação do grupo controle. Sete dias após a IATF iniciou o repasse com touros. A estação de acasalamento (EA) foi de 91 dias para o grupo controle e 64 e 53 dias para os grupos IATF. A taxa de prenhez ao final da EA não se diferenciou entre os grupos 83,9%. As perdas reprodutivas entre o diagnóstico de gestação e o nascimento foram de 10,5%, sem diferenças entre grupos. O ECC de fêmeas que emprenharam no grupo controle foi diferente do ECC de fêmeas vazias, mas não se diferenciou nos animais da IATF. Exp.4 avaliaram-se protocolos de inseminação sobre o índice reprodutivo em 249 novilhas Britânicas e cruzas, acasaladas aos 14 e 27 meses. Novilhas de 14 e 27 meses foram submetidas aos tratamentos Crestar ou inseminação artificial (IA) por 7 dias, seguida por mais 5 dias após PGF2a (grupo PGF2a) Novilhas de 27 meses também foram submetidas ao OvSynch. Foram avaliados o peso vivo, ECC, escore de trato reprodutivo (ETR) ao início da estação reprodutiva. Os tratamentos OvSynch e Crestar tiveram 100% dos animais inseminados (IATF), enquanto os grupos IA com PGF2a aos 14 e 27 meses tiveram, respectivamente 21,9% e 43,5%. Não houve diferença nas taxas de concepção entre tratamentos e idades (P>0,05), com valores respectivos de 46,5%, 56,3%, 64,7% para Crestar, OvSynch, PGF2a e de 44,4% e 57,1%, para 14 e 27 meses. A taxa de prenhez à IA(TF) foi de 46,5%, 56,3%, 23,4% para Crestar, OvSynch, PGF2a, com superioridade (P<0,05) a favor do Crestar e OvSynch. A taxa de prenhez à IA(TF) foi de 18,6% e 41,3% (P<0,01) para idades 14 e 27 meses. A taxa de prenhez final, após o repasse com touros, foi superior a 90% em todos os grupos (P<0,05). O ETR influenciou a taxa de prenhez após a inseminação. Exp.5 e 6 buscou-se uma associação entre a resposta reprodutiva e marcadores moleculares ligados aos genes do receptor para IGF-1, LH , Leptina, receptores do FSH e LH. Foram utilizados dados de 249 novilhas (Exp4.) e 249 vacas (Exp.3). Nas novilhas a prenhez à inseminação e a prenhez final foram de 41,0% e 91,6%. Nas novilhas não foram encontradas associações entre marcadores e reprodução. No rebanho das vacas a taxa de natalidade no ano subseqüente foi de 75,5%, sem diferenças entre tratamentos, idade e escore ovariano. O ECC influenciou a taxa de natalidade, respectivamente de 55,6%, 75,8% e 82,4% (P<0,05) para os animais com ECC menor que 2,5; 2,5 a 2,9; maior ou igual a 3,0 ao do inicio EA. Vacas homozigóticas no marcador AFZ-1 apresentaram 84,4% de natalidade em comparação as heterozigóticas com 71,5% (P<0,05). A presença do alelo*161 nomarcador HEL5 resultou em 33,3% de natalidade, contra 76,5% em vacas sem esse alelo (P<0,05). Os experimentos evidenciaram que a antecipação da aplicação da PGF2a resultou em aumento da taxa de prenhez à IATF. O ECC mostrou-se como importante preditor do desempenho reprodutivo em vacas de corte. O uso do GnRH concomitante à IATF em vacas com manifestação de estro induzido com benzoato resultou em menor resposta reprodutiva à IATF. A IATF proporcionou aumento nas taxas de inseminação em novilhas, especialmente nas submetidas ao acasalamento 14 meses. O escore de trato reprodutivo ao início da estação de acasalamento influenciou a precocidade de concepção das novilhas. O atraso da realização da IATF após o início da EA não afetou a taxa de prenhez final de vacas de cria quando comparado ao acasalamento por touros. Marcadores moleculares apresentaram associação com o desempenho reprodutivo de bovinos. / Were investigated the reproductive performance of beef heifers and cows submitted to different estrus synchronization protocols for artificial insemination and the association between molecular markers and reproductive performance. Trial.1 The anticipation of the application of PGF2a in TAI program with implantation of progesterone in 306 nursing Angus cows was evaluated. Anticipating the application of PGF2a affected (P <0.05) conception rate to TAI and final pregnancy, respectively 60.9% and 89.1% when compared to PGF2a in the removal of the device, respectively 49.3% and 76.7%. Trial.2 The effects of GnRH and oestrus on reproductive performance in 197 Angus cows subjected to TAI It were evaluated. The expression of oestrus before TAI influenced the pregnancy rate to TAI (TxPTAI) and final pregnancy (P<0.05), respectively 46.6%, 78.6% (oestrus) and 33.0%, 60.6% (No/oestrus). GnRH at the time of TAI resulted in lower pregnancy rate to TAI (32.3%) compared to the absence of GnRH (48.0%) (P<0.05) but did not affect the final pregnancy, respectively 69, 7% and 70.4%. There was interaction between GnRH and oestrus. Cows with oestrus and GnRH had 31.4% pregnancy for TAI cows against with oestrus without GnRH with 61.5% (P <0.05). In cows without oestrus, GnRH had no effect (P> 0.05) TxPTAI (32.6% and 33.3%). The body condition score (BCS) affected the rate of oestrus and TxPTAI, with higher (P <0.05) for cows > than 3.0. Trial.3 The effects of different protocols for TAI with mating by bulls (control) on the reproductive performance of 249 Angus cows were compared. It was formed five groups: Control; Crestar 2nd use; OvSynch; Primer new and Primer 2nd use. The TAI was performed 27 days and 38 days after the start breeding season in the control group. Seven days after TAI was realized the clean-up bulls. The mating season (MS) was 91 days for the control group and 64 and 53 days for TAI groups. Pregnancy rate at the end of MS did not differ between groups (83.9%). Reproductive failure between diagnosis of pregnancy and birth were 10.5%, without differences between groups. The BCS to pregnant cows in the control group differed from open cows, but it was not different in cows submitted to TAI. Trial.4 Different protocols to insemination on reproduction in 249 British and crossbred heifers, bred at 14 and 27 months were evaluated. Heifers to 14 and 27 months were treated Crestar or artificial insemination (AI) for 7 days, followed by more than 5 days after PGF2a (PGF2a group) Heifers 27 months were also submitted to OvSynch. We evaluated body weight, BCS, reproductive tract score (RTS) to the beginning of the breeding season. Treatments OvSynch and Crestar had 100% of the animals inseminated (TAI), while groups with PGF2a IA at 14 and 27 months were respectively 21.9% and 43.5%. There was no difference in conception rates between treatment and age (P>0.05), with respective values of 46.5%, 56.3%, 64.7% for Crestar, OvSynch, PGF2a, and 44.4% and 57.1% for 14 and 27 months. Pregnancy rate to AI (TAI) was 46.5%, 56.3%, 23.4% for Crestar, OvSynch, PGF2a, with higher (P <0.05) in favor of Crestar and OvSynch. Pregnancy rate to AI (TAI) was 18.6% and 41.3% (P <0.01) for ages 14 and 27 months. The final pregnancy rate after clean-up bulls was superior to 90% in all groups (P<0.05). The RTS influenced the pregnancy rate after insemination. Trial.5 and 6 we looking for an association between the reproductive response and molecular markers linked to genes for IGF-1 receptor, LH , Leptin, FSH and LH receptors. We used data from 249 heifers (Trial4.) and 249 cows (Trial.3). Pregnancy in heifers at insemination and final pregnancy were 41.0% and 91.6%. No associations were found between markers and reproduction in heifers. In the cow`s herd the birth rate in subsequent years was 75.5%, with no differences between treatments, age and ovarian score. The BCS has influenced the birth rate, respectively 55.6%, 75.8% and 82.4% (P <0.05) for animals with BCS less than 2.5, 2.5 to 2.9; greater than or equal to 3.0 to the beginning of the MS. Cows in homozygous marker AFZ-1 showed 84.4% of the birth rate compared with 71.5% (P <0.05) in heterozygous cows. The presence of allele*161 to HEL5 marker resulted in 33.3% of birth rate vs. 76.5% in cows without this allele (P<0.05). The experiments showed that the anticipation of the implementation of PGF2a resulted in increased pregnancy rate to TAI. BCS has proven to be an important predictor of reproductive performance in beef cows. The use of GnRH in cows with the oestrus induced with benzoate showed worse reproductive response to TAI. The TAI has provided increased rates of insemination in heifers, especially in heifers submitted to matting by 14 months. The reproductive tract score at the beginning of the breeding season influenced the speed of conception in heifers. The delay of the realization of TAI after the onset of MS did not affect the final pregnancy rate of beef cows when compared to breeding only by bulls. Molecular markers were associated with the reproductive performance of cattle.

Investigou-se o desempenho reprodutivo de novilhas e vacas de corte submetidas a protocolos de sincronização de estros para a inseminação artificial e a associação entre marcadores moleculares e desempenho reprodutivo. Exp.1 avaliou-se a antecipação da aplicação da PGF2a em programa de IATF com implante de progesterona em 306 vacas Angus, com cria ao pé. A antecipação da aplicação da PGF2a afetou a taxa de concepção à IATF e prenhez final (P<0,05), respectivamente de 60,9% e 89,1% quando comparados a PGF2a na retirada do dispositivo, respectivamente de 49,3% e 76,7%. Exp.2 avaliaram-se os efeitos do GnRH e da manifestação de estro sobre o desempenho reprodutivo em 197 vacas Angus submetidas à IATF. A manifestação de estro antes da IATF influenciou a taxa de prenhez à IATF (TxPIATF) e prenhez final, respectivamente de 46,6%, 78,6% (C/estro) e 33,0%, 60,6% (S/estro) (P<0,05). O GnRH no momento da IATF resultou em menor taxa de prenhez à IATF, 32,3%, comparado a ausência de GnRH 48,0% (P<0,05), mas não afetou a prenhez final, respectivamente de 69,7% e 70,4%. Houve interação entre estro e GnRH. Vacas C/estro-C/GnRH tiveram 31,4% de prenhez à IATF contra vacas C/estro- S/GnRH com 61,5% (P<0,05). Nas vacas sem estro, o GnRH não apresentou efeito (P>0,05) na TxPIATF (32,6% e 33,3%). O escore de condição corporal (ECC) afetou a taxa de manifestação de estro e a TxPIATF, com superioridade (P<0,05) para vacas > de 3,0. Exp.3 compararam-se os efeitos de diferentes protocolos para a IATF com o acasalamento por touros (Controle) sobre o desempenho reprodutivo de 249 vacas Angus. Formou-se 5 grupos: Controle; Crestar 2º uso; OvSynch; Primer 1ºuso e Primer 2ºuso. A IATF dos animais foi realizada 27 dias e 38 dias após o inicio da estação do grupo controle. Sete dias após a IATF iniciou o repasse com touros. A estação de acasalamento (EA) foi de 91 dias para o grupo controle e 64 e 53 dias para os grupos IATF. A taxa de prenhez ao final da EA não se diferenciou entre os grupos 83,9%. As perdas reprodutivas entre o diagnóstico de gestação e o nascimento foram de 10,5%, sem diferenças entre grupos. O ECC de fêmeas que emprenharam no grupo controle foi diferente do ECC de fêmeas vazias, mas não se diferenciou nos animais da IATF. Exp.4 avaliaram-se protocolos de inseminação sobre o índice reprodutivo em 249 novilhas Britânicas e cruzas, acasaladas aos 14 e 27 meses. Novilhas de 14 e 27 meses foram submetidas aos tratamentos Crestar ou inseminação artificial (IA) por 7 dias, seguida por mais 5 dias após PGF2a (grupo PGF2a) Novilhas de 27 meses também foram submetidas ao OvSynch. Foram avaliados o peso vivo, ECC, escore de trato reprodutivo (ETR) ao início da estação reprodutiva. Os tratamentos OvSynch e Crestar tiveram 100% dos animais inseminados (IATF), enquanto os grupos IA com PGF2a aos 14 e 27 meses tiveram, respectivamente 21,9% e 43,5%. Não houve diferença nas taxas de concepção entre tratamentos e idades (P>0,05), com valores respectivos de 46,5%, 56,3%, 64,7% para Crestar, OvSynch, PGF2a e de 44,4% e 57,1%, para 14 e 27 meses. A taxa de prenhez à IA(TF) foi de 46,5%, 56,3%, 23,4% para Crestar, OvSynch, PGF2a, com superioridade (P<0,05) a favor do Crestar e OvSynch. A taxa de prenhez à IA(TF) foi de 18,6% e 41,3% (P<0,01) para idades 14 e 27 meses. A taxa de prenhez final, após o repasse com touros, foi superior a 90% em todos os grupos (P<0,05). O ETR influenciou a taxa de prenhez após a inseminação. Exp.5 e 6 buscou-se uma associação entre a resposta reprodutiva e marcadores moleculares ligados aos genes do receptor para IGF-1, LH , Leptina, receptores do FSH e LH. Foram utilizados dados de 249 novilhas (Exp4.) e 249 vacas (Exp.3). Nas novilhas a prenhez à inseminação e a prenhez final foram de 41,0% e 91,6%. Nas novilhas não foram encontradas associações entre marcadores e reprodução. No rebanho das vacas a taxa de natalidade no ano subseqüente foi de 75,5%, sem diferenças entre tratamentos, idade e escore ovariano. O ECC influenciou a taxa de natalidade, respectivamente de 55,6%, 75,8% e 82,4% (P<0,05) para os animais com ECC menor que 2,5; 2,5 a 2,9; maior ou igual a 3,0 ao do inicio EA. Vacas homozigóticas no marcador AFZ-1 apresentaram 84,4% de natalidade em comparação as heterozigóticas com 71,5% (P<0,05). A presença do alelo*161 nomarcador HEL5 resultou em 33,3% de natalidade, contra 76,5% em vacas sem esse alelo (P<0,05). Os experimentos evidenciaram que a antecipação da aplicação da PGF2a resultou em aumento da taxa de prenhez à IATF. O ECC mostrou-se como importante preditor do desempenho reprodutivo em vacas de corte. O uso do GnRH concomitante à IATF em vacas com manifestação de estro induzido com benzoato resultou em menor resposta reprodutiva à IATF. A IATF proporcionou aumento nas taxas de inseminação em novilhas, especialmente nas submetidas ao acasalamento 14 meses. O escore de trato reprodutivo ao início da estação de acasalamento influenciou a precocidade de concepção das novilhas. O atraso da realização da IATF após o início da EA não afetou a taxa de prenhez final de vacas de cria quando comparado ao acasalamento por touros. Marcadores moleculares apresentaram associação com o desempenho reprodutivo de bovinos. / Were investigated the reproductive performance of beef heifers and cows submitted to different estrus synchronization protocols for artificial insemination and the association between molecular markers and reproductive performance. Trial.1 The anticipation of the application of PGF2a in TAI program with implantation of progesterone in 306 nursing Angus cows was evaluated. Anticipating the application of PGF2a affected (P <0.05) conception rate to TAI and final pregnancy, respectively 60.9% and 89.1% when compared to PGF2a in the removal of the device, respectively 49.3% and 76.7%. Trial.2 The effects of GnRH and oestrus on reproductive performance in 197 Angus cows subjected to TAI It were evaluated. The expression of oestrus before TAI influenced the pregnancy rate to TAI (TxPTAI) and final pregnancy (P<0.05), respectively 46.6%, 78.6% (oestrus) and 33.0%, 60.6% (No/oestrus). GnRH at the time of TAI resulted in lower pregnancy rate to TAI (32.3%) compared to the absence of GnRH (48.0%) (P<0.05) but did not affect the final pregnancy, respectively 69, 7% and 70.4%. There was interaction between GnRH and oestrus. Cows with oestrus and GnRH had 31.4% pregnancy for TAI cows against with oestrus without GnRH with 61.5% (P <0.05). In cows without oestrus, GnRH had no effect (P> 0.05) TxPTAI (32.6% and 33.3%). The body condition score (BCS) affected the rate of oestrus and TxPTAI, with higher (P <0.05) for cows > than 3.0. Trial.3 The effects of different protocols for TAI with mating by bulls (control) on the reproductive performance of 249 Angus cows were compared. It was formed five groups: Control; Crestar 2nd use; OvSynch; Primer new and Primer 2nd use. The TAI was performed 27 days and 38 days after the start breeding season in the control group. Seven days after TAI was realized the clean-up bulls. The mating season (MS) was 91 days for the control group and 64 and 53 days for TAI groups. Pregnancy rate at the end of MS did not differ between groups (83.9%). Reproductive failure between diagnosis of pregnancy and birth were 10.5%, without differences between groups. The BCS to pregnant cows in the control group differed from open cows, but it was not different in cows submitted to TAI. Trial.4 Different protocols to insemination on reproduction in 249 British and crossbred heifers, bred at 14 and 27 months were evaluated. Heifers to 14 and 27 months were treated Crestar or artificial insemination (AI) for 7 days, followed by more than 5 days after PGF2a (PGF2a group) Heifers 27 months were also submitted to OvSynch. We evaluated body weight, BCS, reproductive tract score (RTS) to the beginning of the breeding season. Treatments OvSynch and Crestar had 100% of the animals inseminated (TAI), while groups with PGF2a IA at 14 and 27 months were respectively 21.9% and 43.5%. There was no difference in conception rates between treatment and age (P>0.05), with respective values of 46.5%, 56.3%, 64.7% for Crestar, OvSynch, PGF2a, and 44.4% and 57.1% for 14 and 27 months. Pregnancy rate to AI (TAI) was 46.5%, 56.3%, 23.4% for Crestar, OvSynch, PGF2a, with higher (P <0.05) in favor of Crestar and OvSynch. Pregnancy rate to AI (TAI) was 18.6% and 41.3% (P <0.01) for ages 14 and 27 months. The final pregnancy rate after clean-up bulls was superior to 90% in all groups (P<0.05). The RTS influenced the pregnancy rate after insemination. Trial.5 and 6 we looking for an association between the reproductive response and molecular markers linked to genes for IGF-1 receptor, LH , Leptin, FSH and LH receptors. We used data from 249 heifers (Trial4.) and 249 cows (Trial.3). Pregnancy in heifers at insemination and final pregnancy were 41.0% and 91.6%. No associations were found between markers and reproduction in heifers. In the cow`s herd the birth rate in subsequent years was 75.5%, with no differences between treatments, age and ovarian score. The BCS has influenced the birth rate, respectively 55.6%, 75.8% and 82.4% (P <0.05) for animals with BCS less than 2.5, 2.5 to 2.9; greater than or equal to 3.0 to the beginning of the MS. Cows in homozygous marker AFZ-1 showed 84.4% of the birth rate compared with 71.5% (P <0.05) in heterozygous cows. The presence of allele*161 to HEL5 marker resulted in 33.3% of birth rate vs. 76.5% in cows without this allele (P<0.05). The experiments showed that the anticipation of the implementation of PGF2a resulted in increased pregnancy rate to TAI. BCS has proven to be an important predictor of reproductive performance in beef cows. The use of GnRH in cows with the oestrus induced with benzoate showed worse reproductive response to TAI. The TAI has provided increased rates of insemination in heifers, especially in heifers submitted to matting by 14 months. The reproductive tract score at the beginning of the breeding season influenced the speed of conception in heifers. The delay of the realization of TAI after the onset of MS did not affect the final pregnancy rate of beef cows when compared to breeding only by bulls. Molecular markers were associated with the reproductive performance of cattle.

A inseminação artificial em tempo fixo (IATF), juntamente com a inseminação artificial pós-cervical (IAPC), permite uma redução expressiva da mão de obra e uma melhor utilização dos machos geneticamente superiores. O objetivo deste estudo foi avaliar a eficiência do eCG associado agonista de GnRH (buserelina) ou apenas buserelina para indução e sincronização da ovulação em porcas desmamadas e submetidos a apenas uma IATF. Um total de 495 femeas suínas desmamadas foram utilizadas, cuja detecção de estro foi realizada uma vez ao dia (07:30). As fêmeas foram divididas em três tratamentos: Controle (n = 165) - a primeira IA foi realizada no início do estro (0 h) e repetida a cada 24 h, posteriormente, durante o estro; Tratamento 2: eCG + GnRH (n = 165) – femeas receberam uma injeção intramuscular de 600 UI de eCG após o desmame, e uma injeção intramuscular de buserelina (10 μg) 86-89 h após a administração de eCG; Tratamento 3: GnRH - fêmeas receberam uma injeção intramuscular de buserelina (10 μg) 86-89 h após o desmame. Nos três grupos era realizada a exposição ao macho no dia seguinte ao desmame uma vez ao dia, e aquelas fêmeas que demostrassem estro eram retiradas dos protocolos de IATF. Os grupos tratados receberam uma única IA, 118-120 h após o desmame (30-33 h após a buserelina). A IAPC contou com doses homospérmicas (1,5 x 109 células de espermáticas/50 ml) que foram utilizadas nas femeas em todos os três tratamentos. Não houve diferenças entre os tratamentos quanto ao número de femeas em estro até o terceiro dia (P>0,05). O intervalo entre o desmame e a ovulação foi significativamente maior (P< 0,05) no grupo controle (141,5 ± 1,58 h) comparativamente aos tratamentos eCG+GnRH (133,3 ± 1,60 h) e GnRH (135,9 ± 1,57 h). As femeas do tratamento eCG+GnRH ovularam em média antes (P<0,05) em relação ao grupo GnRH (44,5 ± 1,74 vs 48,2 ± 1,73 h). A taxa de parto foi superior (P<0,05) no grupo de controle, comparativamente aos tratamentos eCG + GnRH e GnRH, mas não houve diferença (P>0,05) em leitões nascidos totais entre os tratamentos. O uso do GnRH, com ou sem a administração prévia de eCG, antecipa a ovulação nas fêmeas suínas desmamadas. Nas fêmeas tratadas com eCG+GnRH ou GnRH, há em maior percentual de fêmeas inseminadas fora do momento ideal, em relação à ovulação, o que pode prejudicar o desempenho reprodutivo, sendo necessários ajustes no momento de aplicação dos hormônios ou no momento da inseminação para estudos subsequentes. / Fixed-time artificial insemination (FTAI) together with post-cervical artificial insemination (PCAI), allows an expressive reduction in labor requirements and a wider use of higher indexing boars. The aim of this study was to evaluate the efficiency of eCG agonist of GnRH (buserelin) or just buserelin for induction and synchronization of ovulation in weaned sows and submitted to FTAI .A total of 495 weaned sows whose estrus detection was performed once daily (07:30 A.M), starting a day after weaning. The sows were allocated into three treatment groups: Control (n=165) – the first AI was performed at estrus onset (0 h) and repeated every 24 h thereafter during estrus; Treatment 2: eCG + GnRH (n=165) – sows received an intramuscular injection of 600 UI eCG after weaning, and an intramuscular injection of buserelin (10 μg) 86-89 h after eCG administration; Treatment 3: GnRH - sows received an intramuscular injection of buserelina (10 μg) 86-89 h after weaning. . In the three groups it was performed boar exposure in the following day to weaning once a day, and those sows that demonstrated oestrus were removed from FTAI protocols. Treated groups received a single AI, 118-120 h after weaning (30-33 h after buserelin). PCAI with homospermic doses (1.5 x 109 total of sperm cells/50 ml) were respectively performed in sows in all treatment group. There were no differences (P> 0,05) in number of sows that showed oestrus until the third day between treatments. The interval between weaning and ovulation was significantly higher (P< 0,05) in the control group (141,5 ± 1,58 h) comparatively the treatments eCG+GnRH (133,3 ± 1,60 h) and GnRH (135,9 ± 1,57 h). Sows of treatment eCG+GnRH ovulated earlier (P< 0,05) comparing to the GnRH group (44,5 ± 1,74 vs 48,2 ± 1,73 h). Higher (P<0,05) farrowing rate in control group comparatively to treatments eCG+GnRH e GnRH was observed, but there were no differences (P> 0,05) in total piglets born between treatments. Use of GnRH, with or without previous administration of eCG anticipates ovulation in sows weaned, in the sows treated with eCG + GnRH or GnRH, there is a greater percentage of females inseminated outside the ideal time, with respect to ovulation, it can harm the reproductive performance, with necessary adjustments at the time of application hormones or at the time of insemination for subsequent studies.

L’alpha-foetoprotéine (AFP) est la protéine majoritaire du sérum fœtal de mammifère. C’est une glycoprotéine produite et sécrétée par l’endoderme viscéral du sac vitellin, les hépatocytes fœtaux et dans une moindre mesure, par l’intestin fœtal. Son profil d’expression est onco-fœtal :la synthèse de cette protéine chute fortement après la naissance mais peut reprendre en cas de régénération hépatique ou en cas de tumeurs diverses. Cette protéine est capable de fixer les oestrogènes et jouerait un rôle dans la différenciation sexuelle du cerveau femelle.<p>\ / Doctorat en sciences, Spécialisation biologie moléculaire / info:eu-repo/semantics/nonPublished

European eel (Anguilla anguilla, L., 1758) is suffering a strong population decrease and at the same time it is a very appreciated species and by now it has not been possible closing its cycle life. In fact, this species does not mature in captivity unless hormonally induced. So all the production is up to the natural population. All these factors together make urgent achieving the closing of the productive cycle and for this aim it is important to understand the reproductive physiology and the reasons of this development blockage. The present thesis wants to be a new contribution to the knowledge of reproductive physiology in female European eel submitted at hormonal treatment. To achieve this goal, expression of genes not previously studied in this species (cyp19a1, ara, arb, gnrhr1a, gnrhr1b, gnrhr2, zpb and zpc) was analyzed in eels reared under a constant thermal regime, accordingly to the usual rearing conditions. Also, the effect of rearing temperature on gene expression and steroid profile (T, 11-KT and E2) was studied. In fact, eels migrate to Sargasso Sea to reproduce and during the travel experiment temperature changes, while traditionally they are reared at a constant high temperature which could affect vitellogenesis progression and final oocyte quality. For the study it was necessary cloning and characterizing some genes which have not still been sequenced in European eel. Gene expression was studied by qPCR after designing primer and optimizing the qPCR race. Steroid profiles were analyzed by immunoassays and the gonadal development stages were established by histology. The first result obtained at the end of the study were six new genes characterized in European eel. The analysis of gene expression allowed to understand the involvement of specific genes during vitellogenesis (arb, gnrhr1b and gnrhr2) in different brain regions. The temperature was conformed as a crucial environmental factor affecting vitellogenesis. On one hand, eels matured at lower starting temperatures showed better reproductive parameters which could have an influence in the final oocyte quality. On the other hand higher temperatures are necessary to achieve further vitellogenetic stages / Mazzeo, I. (2014). Effect of thermal regime on the expression of key reproductive genes during hormonally-induced vitellogenesis in female European eels [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48490 / TESIS

Das Ziel der vorliegenden Arbeit war es, die brunststimulierende Wirkung des synthetisch hergestellten Gonadorelin[5-His, 6-Asp, 7-Trp, 8-Lys] (International Nonproprietary Name: Peforelin), das in dem Präparat Maprelin® XP10 enthalten ist, bei abgesetzten pluriparen Sauen zu prüfen. Im ersten Versuchsabschnitt wurde die zweckmäßige Dosierung ermittelt. Im zweiten Versuchsabschnitt wurde die Wirkung von Maprelin® XP10 mit der einer eCG- und einer Placebobehandlung verglichen. Die Bedingungen waren für die Versuchstiere in beiden Versuchsabschnitten homogen (etwa vierter Wurf, Säugezeit vier Wochen, Brunstkontrolle zweimal täglich in Anwesenheit eines geschlechtsaktiven Ebers, zweimal täglich sonographische Ovaruntersuchung, duldungsorientierte Besamung einmal täglich). In der Dosisfindungsstudie, in die 88 Tiere einbezogen wurden, erwies sich die Dosierung von 150 µg Peforelin, 24 Stunden nach dem Absetzen appliziert, als zweckmäßig zur Brunststimulation. Andere getestete Varianten (100 µg 24 Stunden, 150 µg 0 Stunden, 150 µg 48 Stunden, 187,5 µg 24 Stunden, 255 µg 24 Stunden nach dem Absetzen) waren hierzu weniger geeignet. In der Untersuchung zur klinischen Wirksamkeit wurden die 313 einbezogenen Tiere in drei Gruppen aufgeteilt und erhielten 24 Stunden nach dem Absetzen pro Tier 150 µg Peforelin (Gruppe I), 800 IE eCG (Gruppe II) oder 2 ml physiologische NaCl-Lösung als Placebo (Gruppe III). Zur Befunderhebung an den Ovarien wurden die Tiere zweimal täglich sonographisch untersucht. Die Östrusrate nach der Peforelin-Behandlung war derjenigen nach eCG-Injektion gleichwertig (95,1 bzw. 96,3 %), beide waren der Placebobehandlung signifikant überlegen (80,6 %). In die weiteren Auswertungen wurden nur Tiere mit Brunstbeginn bis zum siebten Tag nach dem Absetzen einbezogen. Das Absetz-Östrus-Intervall betrug 100,5, 94,2 bzw. 104,1 Stunden in den Gruppen I, II bzw. III. In der Brunstdauer und dem Intervall vom Östrusbeginn bis zur Ovulation unterschieden sich die drei Gruppen nicht. Die durchschnittliche Follikelgröße war in allen drei Gruppen zum Zeitpunkt des Absetzens 4 mm und zum Zeitpunkt der ersten Duldung 6 mm. Die Ovulationen fanden sowohl nach eCG als auch nach Maprelin® XP10 zwischen dem Mittag des sechsten (13.00 h) und der Nacht des siebten Tages (1.00 h) nach dem Absetzen statt. Bei der sonographischen Trächtigkeitsuntersuchung in der vierten Woche post inseminationem waren 100,0, 99,0 bzw. 97,6 % in den Gruppen I, II bzw. III positiv. Die Trächtigkeitsrate betrug 96,9, 97,1 bzw. 91,6 % in den Gruppen I, II bzw. III. Die Abferkelrate ergab 92,2, 93,4 und 73,8 % in den Gruppen I, II und III. Das Abferkelergebnis war in allen drei Gruppen gleich (11,7, 12,0 bzw. 11,6 insgesamt geborene Ferkel in den Gruppen I, II bzw. III). Es wurde eine negative Korrelation zwischen der Dauer des Absetz-Östrus-Intervalls und der Brunstdauer bzw. dem Intervall vom Östrusbeginn bis zur Ovulation nachgewiesen. Darüber hinaus korrelierten die Brunstdauer und das Intervall Östrusbeginn bis Ovulation positiv miteinander. In allen drei Gruppen stand die Follikelgröße bei der ersten Duldung in positiver Korrelation mit der Länge des Absetz-Östrus-Intervalls. Nach längerer Säugezeit kamen die Sauen tendenziell und in der Gruppe I signifikant früher in die Brunst als nach kürzerer Laktation. Weitere überprüfte potentielle Einflussfaktoren hatten weder auf den Brunsteintritt noch auf die erzielten Wurfgrößen oder andere Parameter Auswirkungen. Mit der vorliegenden Untersuchung wurde erstmals die Wirksamkeit des synthetisch hergestellten Peforelin zur Brunststimulation bei abgesetzten pluriparen Sauen nachgewiesen. Inwieweit das Präparat für diese Indikation auch bei primiparen Sauen oder Jungsauen wirksam eingesetzt werden kann, bleibt weiteren klinischen Prüfungen vorbehalten.

Limited breeding success in captive breeding programs has necessitated the development of assisted reproductive technologies (ART) to preserve and increase genetic variation and population numbers of both captive and wild amphibian groups. ART has been shown to be successful in numerous anuran species, and current studies focus on the application of ART in ex-situ populations. The focus of this project is to show that linking in-situ and ex-situ amphibian populations through sperm cryopreservation, genome banking, and in-vitro fertilization is possible, with the goal of increasing gene diversity throughout groups in order to produce self-sustaining, wild populations in the future. Specific objectives include developing a sperm-cryopreservation methodology using sperm from the model species Anaxyrus fowleri, applying this protocol to the cryopreservation of spermatozoa from two other threatened anurans to determine protocol transmissibility, and linking in-situ and ex-situ populations of an endangered species using cryopreserved sperm form wild males to produce viable offspring.

Le récepteur hypophysaire de la GnRH (RGnRH) joue un rôle crucial dans le contrôle de la fonctionde reproduction. Dans le promoteur distal du Rgnrh, j’ai caractérisé un élément de réponsebifonctionnel répondant aux protéines LIM à homéodomaine ISL1/LHX3 et à GATA2. D’autre part,deux motifs TAAT situés dans la région plus proximale confèrent à ce gène la capacité de répondreaux facteurs Paired-like PROP1 et OTX2. Tous ces facteurs, exprimés précocement au cours del’ontogenèse hypophysaire, pourraient participer à l’émergence de l’expression du Rgnrh. Hors del’hypophyse, j’ai découvert que le Rgnrh est exprimé au cours du développement postnatal dansl’hippocampe de rat, où il module la plasticité synaptique. Par ailleurs, j’ai identifié deux nouveauxsites d’expression, la rétine et la glande pinéale. Ces résultats mettent en lumière l’importancefonctionnelle de ce récepteur et de son ligand et les rôles multiples qu’il ont acquis au cours del’évolution des Vertébrés. / In the pituitary, the GnRH receptor (GnRHR) plays a crucial role in the neuroendocrine control ofreproductive function. Within the distal region of the Gnrhr promoter, I have characterized abifunctional response element modulated by the LIM homeodomain proteins ISL1/LHX3 and byGATA2. Besides, in the proximal region of the promoter, two TAAT motifs conferred response toPaired-like factors PROP1 and OTX2. All these factors are expressed during pituitary ontogenesis andcould participate in the onset and regulation of Gnrhr expression. Outside of the pituitary, I havediscovered that the Gnrhr was expressed during postnatal development in the rat hippocampus, whereit modulated synaptic plasticity. Furthermore, I have identified two novel sites of Gnrhr expression, theretina and the pineal gland. Altogether, these data highlight the functional importance of this receptorand its ligand as well as the multiple roles they have acquired during vertebrate evolution.