Influência da irrigação e diâmetro do folículo pré-ovulatório na taxa de prenhez em búfalas leiteiras.

Abstract

This study aimed to evaluate the influence of irrigation and preovulatory follicle diameter on pregnancy rate in dairy buffaloes submitted to fixed-time artificial insemination. A total of 151 multiparous dairy buffaloes with more than 30 days of partum were used, aged between 4 and 8. The D0 synchronization protocol, the buffaloes received an intravaginal device containing 1,0g of P4 (Primer®, Agener União Química), application of 2.0mg of BE (Fertilcare Sincronização®, MSD Saúde Animal) at 16:00h. On D9, also at 16:00, the device was removed 0.265 mg of closprostenol sodium (Ciosin®, MSD Saúde Animal) and 300 IU of eCG (Folligon®, Intervet International) were applied via im. On D11 at 4 pm, 0.1 mg of GnRH (Fertagyl®, Intervet International) was administered i.m. On D12, 16 hours after the application of GnRH (at 8:00 am), at the time of insemination, the animals were evaluated for follicle diameter and its degree of irrigation, by transrectal ultrasound using a two-dimensional Doppler ultrasound (Chison Eco Vet, Beijing, China) equipped with a multi-frequency microconvex transducer, in which two-dimensional and Color-Doppler evaluation were performed, and the images were later evaluated through a software, the blood flow and associated tissue to calculate the vascularization index. The overall pregnancy rate was 32.45% (49/151). Smaller area follicles (99.01±16.18amm) were correlated with pregnant females, while in non-pregnant females the area of follicles was greater (117±46.17bmm) (P<0.05), and the images were later evaluated through a software, the blood flow and associated tissue to calculate the vascularization index. The overall pregnancy rate was 32.45% (49/151). Smaller area follicles (99.01±16.18amm) were correlated with pregnant females, while in non-pregnant females the area of follicles was greater (117±46.17bmm) (P<0.05). The mean and standard deviation of the other variables studied are shown to be smaller in pregnant buffaloes, in relation to the means and standard deviation in non-pregnant buffaloes. However, we detach the percentage of vascular perfusion (visual vascularization) for pregnant (19.04±5.2% a) and non-pregnant (56.57±9.95% b) buffaloes (P<0.05), the other variables, such as Fol/width distance (mm), Fol/height distance (mm), Fol perimeter (mm) and wall area + Fol (mm) we did not obtain statistical difference (P>0.05). We can conclude that the color Doppler is the indicator instrument, of great precision to the deficiency of vascularization of the pre-ovulatory follicle, as well as, by the area of the largest follicles, which not always the largest area, is related to predicting fertilization.