Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-09-12T18:07:34Z No. of bitstreams: 1 2011 - Paula Cardoso de Almeida Silva.pdf: 463902 bytes, checksum: 375c57bac0b880fd3baf2320ee7abb93 (MD5) / Made available in DSpace on 2016-09-12T18:07:34Z (GMT). No. of bitstreams: 1 2011 - Paula Cardoso de Almeida Silva.pdf: 463902 bytes, checksum: 375c57bac0b880fd3baf2320ee7abb93 (MD5) Previous issue date: 2012-01-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Embryo transfer (ET) is one of the most prominent techniques in the expansion of horse breeding, enabling the production of more products of a single mare per year, thus increasing the number of animals with high genetic value. The hormonal control of ovulation can be used as a tool to optimize the reproductive parameters and reduce the costs in an ET program. This study compared the effectiveness of lower doses than those traditionally used of Deslorelin and hCG, evaluating the time between ovulation and induction, the recovery rates and embryo attachment. The study was conducted at the Department of Animal Reproduction and Evaluation of UFRRJ. We conducted follow-up of 85 estrous cycles of Breton Postier and Mangalarga Marchador mares, when the mares presenting an ovarian follicle ? 35 mm, they were divided randomly into one of three treatments: G1 (n = 32) - treatment with 1000 IU (1.0 ml iv) of hCG (Chorulon ? - Intervet Schering-Plough Animal Health), G2 (n = 28) - treatment with 0.75 mg (0.75 ml iv) Deslorelin (Botupharma) and G3 (n = 28) - Treatment with 1.0 ml saline iv. Twenty four hours after application, ultrasound evaluation of ovarian was held every six hours up to ovulation. The donors were inseminated the day after induction and embryo collection took place in nine days after ovulation. The recovered embryos were immediately transferred to recipients previously synchronized, these pregnancy diagnosis was performed at 15 and 30 days old embryo. Data regarding the time between ovulation and induction and characteristics of follicular development were analyzed using analysis of variance (ANOVA), and the averages of these data were analyzed when needed by the Tukey test. The data regarding the percentage of mares ovulated in different periods, were analyzed using the Qui-quadrado (?2) 5%. In the case of embryo recovery rate, the data were analyzed using the Fisher exact test, however in relation to pregnancy rate was not possible to perform statistical analysis due to low sample size. The percentage of ovulation in up to 36 hours for G1, G2 and G3 were 34.4%, 13.3% and 8.7%, between 36 and 42 hours were 62.5%, 56.7% and 8.7%, from 42 to 48 hours were 0%, 20% and 13%, more than 48 hours were 3.1%, 10% and 69.6% respectively. Having thus a significant difference between treated and control groups (p <0.05). The embryo recovery rate was 75% (6/8) in G1 and G2, and 44.4% (4/9) in group G3, there was no significant difference between groups (p> 0.05). The rate of pregnancy at fifteen days old embryo was 69.2% (9/13). Thus the lower doses commonly used with inducing agents in question, were effective in promoting ovulation within 48 hours, but the use of these didn't result in significant improvement in the rates of embryo recovery. / A transfer?ncia de embri?es (TE) ? uma das t?cnicas de maior destaque na expans?o da equideocultura, possibilitando a produ??o de maior n?mero de produtos de uma mesma ?gua por ano, aumentando assim o n?mero de animais com alto valor gen?tico. O controle hormonal do momento da ovula??o pode ser usado como uma ferramenta para otimizar os par?metros reprodutivos e reduzir os custos em um programa de TE. O presente estudo comparou a efici?ncia de doses mais baixas do que as tradicionalmente utilizadas de hCG e Deslorelina avaliando o tempo entre a indu??o e a ovula??o, as taxas de recupera??o e fixa??o embrion?ria. O estudo foi desenvolvido no Departamento de Reprodu??o e Avalia??o Animal da UFRRJ. Foi realizado o acompanhamento de 85 ciclos estrais de ?guas da ra?a Bret?o Postier e Mangalarga Marchador, onde as ?guas ao apresentarem um fol?culo ovariano ? 35 mm foram divididas de maneira aleat?ria em um dos tr?s tratamentos: G1 (n = 32) ? tratamento com 1000 UI (1,0 ml i.v.) de hCG (Chorulon? - Intervet Schering-Plough Animal Health), G2 (n = 30) ? tratamento com 0,75 mg (0,75ml i.v.) de Deslorelina (Botupharma) e G3 (n=23) ? tratamento com 1,0 ml i.v. de solu??o salina. Vinte quatro horas ap?s a aplica??o, a avalia??o ultrassonogr?fica dos ov?rios passou a ser realizada a cada seis horas at? a detec??o da ovula??o. As ?guas doadoras foram inseminadas no dia seguinte a indu??o e as coletas de embri?o aconteceram no dia 9 ap?s a ovula??o. Os embri?es recuperados foram imediatamente transferidos para receptoras previamente sincronizadas, sendo o diagn?stico de gesta??o realizado aos 15 e 30 dias de idade embrionaria. Os dados referentes ao tempo entre indu??o e ovula??o e caracter?sticas do desenvolvimento folicular, foram analisados pelo m?todo de An?lise de Vari?ncia (ANOVA), sendo as m?dias desses dados analisadas quando necess?rio pelo teste de Tukey. Os dados referentes ao percentual de ?guas ovuladas em diferentes per?odos, foram analisados atrav?s do Qui-quadrado (?2) 5%. Em se tratando da taxa de recupera??o embrion?ria, os dados foram analisados atrav?s do teste Exato de Fisher, j? em rela??o a taxa de gesta??o n?o foi poss?vel realizar an?lise estat?stica devido ao baixo n?mero amostral. Os percentuais de ovula??o em at? 36 horas nos grupos G1, G2 e G3, foram 34,4 %, 13,3% e 8,7%, entre 36 e 42 horas, 62,5%, 56,7% e 8,7%, entre 42 e 48 horas, 0%, 20% e 13%, acima de 48 horas 3,1%, 10% e 69,6%, respectivamente. Havendo dessa maneira diferen?a significativa entre os grupos tratados e o controle (p < 0,05). A taxa de recupera??o embrion?ria foi de 75% (6/8) nos grupos G1 e G2 e 44,4% (4/9) no grupo G3; n?o houve diferen?a significativa entre os grupos (p > 0,05). J? a taxa de gesta??o aos quinze dias de idade embrion?ria foi de 69,2% (9/13). Deste modo as doses inferiores ?s comumente utilizadas, dos agentes indutores em quest?o, foram eficientes em promover a ovula??o em at? 48 horas, mas o uso destes, n?o resultou em melhora significativa nos ?ndices de recupera??o embrion?ria

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-05-03T21:06:02Z No. of bitstreams: 1 2014 - Leandro Mendes Mascarenhas.pdf: 2602264 bytes, checksum: 2ecbf1ab9ebc2505d6ab0ed4cbcfc5d4 (MD5) / Made available in DSpace on 2018-05-03T21:06:02Z (GMT). No. of bitstreams: 1 2014 - Leandro Mendes Mascarenhas.pdf: 2602264 bytes, checksum: 2ecbf1ab9ebc2505d6ab0ed4cbcfc5d4 (MD5) Previous issue date: 2014-02-26 / In cows, the "critical time" of the estrous cycle determined by the physiological state that must be defined to maintain the corpus luteum (CL) and pregnancy or luteolysis and a new estrus occurs 15 to 19 days after ovulation. The mechanisms involved in premature luteolysis and regression of the CL are not yet understood complements. It is probable that the early CL regression is related to PGF2a release mediated by the endometrium lower concentrations of P4 receptors, higher concentrations of OT receptors, or both, in the endometrium. Thus, uterine receptors for P4 and OT may influence the secretion of PGF2a from the 10th day of the cycle, during which the CL is more sensitive to the luteolytic action of PGF2a. This study aimed to evaluate the effect of exogenous OT, postpartum crossbred cows on reproductive efficiency, with emphasis on the period of maternal recognition of pregnancy. The experiment was conducted in Bom Jesus do Itabapoana, Northwest Region Fluminense between September 2013 and January 2014. Twenty- four cows were entered into a TAI program (D0 - progestin releasing intravaginal device + estradiol benzoate (EB - 2 mg, im); D8 - intravaginal device removal and application of PGF2a (0.526 mg, im); D9 - BE (1 mg, im); D10 - IA). After ovulation, cows were divided randomly into two groups: GO (n=12): oxytocin (25 IU, iv, milking morning and afternoon), GC (n=12): without OT. Sonographic evaluations were performed on days 10, 15, 18, 28 and 42. The diameter of CL was calculated as the average of the two major axes and volumes (vol) using the formula for volume of a sphere (V = 4/3p ? (D / 2) 3) where D is the average diameter (DM) of CL. On day 28 of pregnancy diagnosis, confirmed at 45 and 60 days was carried out. We observed an increase in GC DM CL between the 10th and 18th. In GO DM CL decreased among 10th and 15th and most cows expressed estrus before day 18 (9/12 - 75%), six (50%) with return to estrus between the 15th and 18th. The vol. CL was higher in cows GC at all times with a significant difference (p<0.05) compared to GO on the 15th. Cows in the CG had vol. CL higher at all times and had a higher pregnancy rate (41.7%) compared to GO (25 %). The rates of fertilization and maintenance of pregnancy until day 42 demonstrates the low reproductive efficiency in GO compared to the CG (p=0.0022). With successive inseminations at 90 days one seven cows were empty in CG (8.33%) and GO (58.3%), respectively. The pattern of development and regression of the CL confirms the involvement of OT in the reproductive activity of lactating cows. The low reproductive efficiency in GO is probably due to the action of OT, confirming the hypothesis that exogenous OT can inhibit the maternal recognition of pregnancy. / Em vacas, o ?per?odo cr?tico? do ciclo estral determinado pelo estado fisiol?gico em que deve ser definida a manuten??o do corpo l?teo (CL) e da prenhez ou a lute?lise e um novo estro ocorre 15 a 19 dias ap?s a ovula??o. Os mecanismos envolvidos com a lute?lise prematura e regress?o do CL ainda n?o est?o complemente compreendidos. ? prov?vel que a regress?o precoce do CL esteja relacionada ? libera??o de PGF2a pelo endom?trio mediada por concentra??es mais baixas de receptores de P4, maiores concentra??es de receptores de OT, ou ambos, no endom?trio. Assim, receptores uterinos para a P4 e OT podem influenciar a secre??o de PGF2a a partir do 10? dia do ciclo, per?odo em que o CL ? mais sens?vel ? a??o luteol?tica da PGF2a. Objetivou-se avaliar o efeito da OT ex?gena, no p?s-parto de vacas mesti?as sobre a efici?ncia reprodutiva, com ?nfase no per?odo do reconhecimento materno da gesta??o. O experimento foi conduzido em Bom Jesus do Itabapoana, Regi?o Noroeste Fluminense entre setembro de 2013 e janeiro de 2014. Vinte e quatro vacas foram inseridas em um programa de IATF (D0 - dispositivo intravaginal liberador de progest?geno + benzoato de estradiol (BE - 2 mg, i.m.); D8 - remo??o do dispositivo intravaginal e aplica??o de PGF2a (0,526 mg, i.m.); D9 - BE (1 mg, i.m.); D10 ? IA). Ap?s a ovula??o, as vacas foram distribu?das aleatoriamente em dois grupos: GO (n=12): 25 UI ocitocina, i.v., na ordenha da manh? e da tarde; GC (n=12): sem OT. Avalia??es ultrassonogr?ficas foram realizadas nos dias 10, 15, 18, 28 e 42. O di?metro do CL foi calculado pela m?dia dos maiores eixos e os volumes (vol.) por meio da f?rmula para volume de uma esfera (V= 4/3p x (D/2)3), em que D ? o di?metro m?dio (DM) do CL. No dia 28 foi realizado o diagn?stico da gesta??o, confirmada aos 45 e 60 dias. Observou-se no GC um aumento do DM do CL entre os dias 10 e 18. No GO o DM do CL diminuiu entre os dias 10 e 15 e a maioria das vacas manifestaram cio antes do dia 18 (9/12 ? 75%), sendo seis (50%) com retorno ao cio entre os dias 15 e 18. O vol. do CL foi maior nas vacas do GC em todos os momentos com diferen?a significativa (p<0,05) em rela??o ao GO no dia 15. As vacas do GC tiveram o vol. do CL maior em todos os momentos e obtiveram uma maior taxa de prenhez (41,7%) comparativamente ao GO (25%). As taxas de fecunda??o e manuten??o da gesta??o at? o 42o dias evidencia a baixa efici?ncia reprodutiva no GO em rela??o ao GC (p=0,0022). Com sucessivas insemina??es aos 90 dias uma e sete vacas estavam vazias no GC (8,33%) e GO (58,3%), respectivamente. O padr?o de desenvolvimento e regress?o do CL confirma o envolvimento da OT na atividade reprodutiva de vacas em lacta??o. A baixa efici?ncia reprodutiva no GO deve-se provavelmente ? a??o da OT, confirmando a hip?tese de que a OT ex?gena pode inibir o reconhecimento materno da gesta??o.