Qualidade de oócitos e embriões de cabras alimentadas com uréia na dieta

• Autor(a) principal: Amorim, Lincoln da Silva
• Data de Publicação: 2008
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1715
• topic: Cabras; Embriões; Hormônios; Oócitos; Uréia; Goats; Embryo; Hormones; Oocyte; Urea; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL

The first experiment was designed to evaluate the effect of urea concentration in the diet of Toggenburg breed goats on the number, quality, developmental stage and follicular status prior to superovulation. Eighteen goats were randomly assigned to receive 0 (n=8) or 2.4% (n=10) of urea in the dry matter of the diet (UDM). After weekly adaptation to intermediary concentrations of urea in the diet (0, 1.0 and 2.0% UDM), goats were synchronized and superovulated and embryos flushed by transcervical technique between the seventh and eighth day after matting. The embryo colleted was grading by quality and developmental stage using the criteria determined by International Embryo Transfer Society (IETS). The ovary was scanned (examined) by transrectal ultrasonography before the first FSH administration to measure the diameter and to count the number of follicles included in each diameter category. The estrus length and the interval between the withdrawal of vaginal progesterone device to the onset of estrus was not influenced by urea treatment on diet (P>0.05). Eleven goats responded to superovulation. The number of structures and embryos were not different between the treatments (P>0.05). The number and percentage of viable embryos and the excellent/good ones were not affected by the addition of 2.4% of UDM. Embryos flushed from goats fed with urea showed an advanced developmental stage compared to the ones not fed urea (P<0.05). The follicular status before FSH administration showed a small number of follicules with diameter less than 5 mm in animals fed with urea (P<0.05). In the second experiment, ten Saanen breed goats were distributed randomly and feed with 0 (n=5) and 2.4% (n=5) of UDM in accord to evaluate the effect of urea in the diet on the blood glucose and urea metabolic profile and hormones (oestradiol, progesterone and testosterone) and glucose and urea metabolic profile in the follicular fluid. Laparotomy was performed to aspirate the big follicules in each ovary and jugular blood was punctured on day of aspirations. The follicular oestradiol concentrations declined in the animals fed with urea and testosterone concentrations increased, when compared to the animals not fed urea (P<0.05). Follicular fluid progesterone concentrations did not differ among animals fed with the different diets tested (P>0.05), nevertheless the mean absolute number was greater in the 2.4% of urea treatment. Estradiol/progesterone rate was lower in the follicular fluid from animals fed with 2.4% UDM (P>0.05). In the third experiment, the stimulatory response, the oocyte quality and the morphology were determined from ten Saanen breed goats randomly distributed in to two treatments (0 and 2.4% of urea UDM) and were submitted to laparotomy in order to evaluate the ovarian response after hormonal stimuli and the quality of recovered oocytes. The ovarian response was not affect by urea level (P>0.05). Diets with 2.4% of urea increased the recovery rate of denude oocytes, partially denuded and or degenerated in relation to the animals not fed urea (P<0.05). High proportion of denuded oocytes, partially denuded and, or degenerated were recovered compared to the other categories from animals fed with 2.4% of UDM (P>0.05). Two morphological types of cytoplasm were found in Saanen goats, with differ by color and aspect, on the other hand they were not affected by urea concentrations in the diet (P<0.05).