Hormônio folículo estimulante (FSH-p) em protocolo de sincronização da ovulação de fêmeas de bovinos mestiças (Bos taurus indicus x Bos taurus taurus)

• Autor(a) principal: Oliveira, Fabrício Albani
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5673
• topic: Hormônio gonadotrófico; Biotecnologia; Gonadotrophic hormone; Biotechnology; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::REPRODUCAO ANIMAL

The aim was to evaluate the use of follicle stimulating hormone (FSH-p) in IATF protocols in the follicular dynamics and pregnancy rates in crossbred puberal heifers and in crossbred cyclic and anestrus cows. In the study with heifers, 138 animals were used in experiments with complete random design. In experiment I the dynamics were evaluated by the protocol: Tcontrol (n = 11 heifers) day 0, insertion of intravaginal progesterone device (Primer®) plus the application (IM) of 2 mg of estradiol benzoate (Estrogin®); day 8, withdrawal of the Primer® and application, IM, of 0.150 mg of PGF2&#945; (Prolise®); day 9, (IM) 1 mg of estradiol benzoate was applied; day 10, the IA was carried out between 48 and 54 hours after the removal of the Primer; TFSH (n = 11 heifers) similar to the Tcontrol, but on day 8, 15 mg of FSH-p (Folltropin®)was administered. The ultrasonography examinations were carried out on days 0, 8, and on the IATF day until the ovulation event determined by the absence of the dominant follicle. In experiment II the pregnancy rate in similar protocols was evaluated, differing in the number of animals: Tcontrol = 55 heifers and TFSH = 61 heifers. In the cow´s study, 220 females were used for the evaluation of the follicular dynamics and pregnancy rate in crossbred cyclic and anestrous cows distributed in two experiments similar to the study with heifers. In both experiments, a factorial 2x2 design was used (synchronization protocols of the ovulation and cyclicality of the cows). In experiment I the dynamics were evaluated for the protocols consisting of cyclical cows (Tcyclic, n=23), and in anestrous (Tanestrous, n=22) and two protocols similar to that of experiment I of the heifers: 1) Tcontrol - 22 cows; 2) TFSH - 23 cows. Nevertheless, the distribution established in the cows was: Tcyclic+Tcontrol (n=11 cows), Tanestrous+Tcontrol (n=11 cows), Tcyclic+TFSH (n=12 cows), Tanestrous+TFSH (n=11 cows). The ultrasonography examinations were carried out in a similar scheme to the experiment I of the heifers. In experiment II, the evaluation of the pregnancy rate of the cows was for treatments similar to experiment I, differing by the number of animals: Tcyclic+Tcontrol (n=28), Tanestrous+Tcontrol (n=55), Tcyclic+TFSH (n=29), Tanestrous+TFSH (n=63). All the data were analyzed by the SAS program version 9.0 (2002) to 5 % probability. In the study with heifers, no difference (P> 0.05) was detected for the follicular growth rate, being 1.21 and 1.93 mm / day for the heifers in the Tcontrol and TFSH, respectively. The diameter of the largest follicle was not affected (P>0,05) by the treatment on day 10, being 10.27 and 9.47 mm in the TFSH and Tcontrole females, respectively. The ovulation rate was not affected (P>0,05) by the FSH-p treatment in the ovulation synchronization protocol (81.82 %, P> 0.05). However, the TFSH heifers showed a pregnancy rate (50.82 %) superior (P <0.05) to that of the Tcontrol (30.91 %). In the study with cows, there was no effect (P> 0.05) from the synchronization protocols, the cyclicity of the cows and the interaction among these factors in the follicular growth rate (1.08±0.12 mm / day), and on the interval of the progesterone device removal and the IATF to the ovulation (57.26±0.78 and 9.26±0.78 hours, respectively). No interaction (P>0,05) among the evaluated effects (treatment, cyclicality, day of observation) and the diameter of the largest follicle (10.15 ±0.44 mm). There was no interaction (P> 0.05) from the main effects for the ovulation and pregnancy rates and not even an effect from the protocols. The ovulation and pregnancy rates were greater (P <0.05) for the cyclic cows (91.39 % and 54.39 %), compared to those in anestrous (63.64 % and 24.58 %). It is concluded that the administration of FSH-p in an ovulation synchronization protocol in heifers and crossbred cows did not show differences in the patterns evaluated for follicular dynamics, but provided an efficient increase in the pregnancy rate in heifers. The cyclic cows showed a satisfactory pregnancy rate independent of the FSH-p administration.