Protocolos de superovulação em zebuínos com doses convencionais ou split

Abstract

This experiment aimed to evaluate and compare result of superovulation of zebu females, using a product based on FSH/LH protocol, and with a smaller number of applications and similar dose (split dose). Were performed 32 superovulations in16 Zebu females, aged 17-42 months, body condition score 2,5 to 4 (scale 1-5), arrangedin arandomized cross-over. That is, all females were superovulated twice, once with each protocol .Before the beginning of the protocol, all animals underwent a synchronization: D0-introduction of a progesterone implant and applying 2 mL of estradiol benzoate. The females of the conventional group received 250 IU of FSH/LH, outline application for four days and eight decreasing doses. So, the administration of FSH/LH in D4, D5, D6 and D7 was in the morning and afternoon, with their respective strengths: 50,0 IU; 37,5 IU; 25,0 IU and 12,5 IU; D7 was added in 2 mL of application of cloprostenol in the morning and removal the implant of progesterone 12 hours after. On D8 was applied 2 mL of a GnRH analogue and held to first AI 12 hours after, and the second AI 12 hours after the first. D15 was performed on the collection of embryos. Female of split group received 250 IU of FSH/LH. D4 was administered 62,5 IU FSH/ LH intramuscular and 125,0 IU subcutaneously in the morning. Twenty-four hours after 62,5 IU was administered subcutaneously in the morning and on D7 was removed progesterone implantand applied 2 ml of cloprostenol sodico. On D8 was applied 2 mL of GnRH and AIs were performed 12 hours and 24 hours after. On D15 the embryos was collected. Before beginning the superovulation (D0) in the first day of superovulation (D4) in the middle of the superovulation protocol (D6) and on the end of the protocol (D8) were counted numbers of follicles present <3mm, between 3 and 8mm >8 mm in diameter, with the aid of ultrasound. The two groups were equivalent in number of follicles measured from day 4-6. From day 8, significant differences (P<0,05) between the conventional group and split up to 3mm follicles (2,19 ±1,22 and 4,06±2,59, respectively) and follicles >8mm (9,06 ± 4,54and 5,50±4,59, respectively).The evaluation of the superovulatory response was doneby counting the number of corpora luteaineach ovaryat harvest (D15) embryos. All embryos were collected by nonsurgical method and classified according to Lindner&Wright(1983). The amount of CLs were 8,12±3,26 for the conventional group and 4,69± 3,46 for the split group (P <0,05) and total number of embryos were collected: 6,69± 3,05 e3,37± 2,50, respectively (P <0,05). Also significant differences (P<0,05) for the number of viable embryos: 5,25 ±2,29 (conventional group) and 2,37±1,78(split group). From these results, it is concluded that the protocol split with three applications of FSH/ LH showed no equivalence or superiority in production of CLs and in total embryos produced and viable, compared to the conventional protocol superovulation.

&#8195;