Oocyte and embryo quality from goats feed with urea on the diet

Conselho Nacional de Desenvolvimento Científico e Tecnológico 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 (P0.05), 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 (P0.05). 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 (P0,05). Onze cabras responderam à superovulação. O número de estruturas e de embriões não diferiu entre os animais dos tratamentos (P>0,05). O número e a percentagem de embriões viáveis e o número e a percentagem de embriões excelentes e bons também não foram influenciados pela adição de 2,4% de uréia na matéria seca. Os embriões coletados das cabras alimentadas com uréia apresentaram estádio de desenvolvimento mais avançado que aqueles provenientes de animais não alimentados com uréia. O status folicular antes da aplicação da primeira dose de FSH revelou que o número de folículos com diâmetro menor que 5 mm foram menores no grupo alimentado com uréia (P0,05), entretanto estas apresentaram maiores médias no tratamento com 2,4% de UMS. A relação estradiol/ progesterona foi menor no fluido folicular dos animais do tratamento com 2,4% de UMS (P0,05). A alimentação com dietas com 2,4% de uréia na matéria seca proporcionou maior recuperação de oócitos desnudos, parcialmente desnudos e ou degenerados em relação às fêmeas submetidas à alimentação sem uréia na dieta (P