Emprego de um novo dispositivo intravaginal para liberação sustentada de progesterona em programas de TETF em receptoras de embrião (Bos taurus taurus x Bos taurus indicus) / Use of a new intravaginal device for releasing progesterone-based ETFT program in embryo recipients (Bos taurus taurus x Bos taurus indicus)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

There are many factors for the successful of ET programs, and the recipients are the major factor on this biotechnique. Nowadays, the products available in the brazilian market for releasing progesterone are imported and made of silicone, a biocompatible polymer, but not biodegradable. Recently, intravaginal progesterone devices made of PHB, a biodegradable polymer made from bacteria fermentation of sugar cane, have been studied. The objective of this present study was to compare the efficiency in ET programs of a new intravaginal device on ovulation, conception and pregnancy rate, in croosbreed heifers and cows, with a device made of silicone Crestar®, currently available in the brazilian market. The experiment was done with help of Embryo-sys® Company, which was responsible for the recipients synchronizations and inovulations. The synchronizations and inovulations were done in three different places: Paranapanema-SP, Itapetininga-SP and Ouro Fino-MG. All the animals were kept in pasture of Brachiaria decumbens with mineral supplementation and ad libitum water. The body and ovary condition score, postpartum period and animal category were utilized for equal division of recipients (n=205), in two groups: control - auricular device (Crestar®) with 3mg of norgestomet (n=103) and treatment - intravaginal device (Progestar®) with 1.72g of progesterone (n=102). On day 0, all the animals received 2mg of estradiol benzoate (IM). On day 8, the devices were removed, 400UI of eCG and 500μg of PGF2α were injected (IM). After 24 hours, was injected 1mg of estradiol benzoate (IM), as ovulation inductor. The animals had the following results, respectively for control and treatment group: ovulation rate (OR) - 72.8% (n=103) vs 83.3% (n=102), conception rate (CR) - 47.9% (n=73) vs 42.7% (n=82) and pregnancy rate (PR) - 34.7% (n=101) vs 35.0% (n=100). In further analysis, postpartum cows were divided in two classes: PP1 (2 - 4 months, n=35) and PP2 (4 - 8 months, n=24). There was an interaction between PP and ovary condition (OC) on OR, in which animals in PP2 and cyclic showed better results (83.3%) than the animals not cyclic (50%). There was effect of PP on CR, and the values for PP1 and PP2 were 48.5% and 35.5%, respectively. There was also effect of PP on PR: cows in PP1 showed 45.7% of PR, while cows in PP2, 26.4%. This experiment showed that the new intravaginal device (Progestar®) had the same efficiency on ovulation, conception and pregnancy rate, in ET programs, in crossbreed heifers and cows, as the commercially available device Crestar®.

ASSUNTO(S)

progestar® phb crestar® phb tetf recipient synchronization sincronização receptora et progestar® crestar®

ACESSO AO ARTIGO

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