Eficiência reprodutiva em vacas mestiças leiteiras em municípios do nordeste paraense

Abstract

Cows reared in semi-intensive production systems of two farms, one in the city of Irituia and another in Mother River in northeastern Pará. We analyzed reproductive records collected during September 2006 to March 2009. We analyzed 851 females, 106 (12,45%) heifers and 745 (87,55%) cows with a total of 1,356 gynecological exams. The overall pregnancy rate was presented 87,74% to 63,35% for heifers and cows. In 1356 examinations of the animals had 66,41%, 33,59% are pregnant and not pregnant. The pregnancy rate in relation to the type of reproduction was 50,66%, 41,30% and 77,27% for insemination artificial conventional (IA), AI time-fixed (IATF) and mating natural (MN), respectively, with an average of semen doses per pregnancy of 2,01. The genetic groups Guzerá 87,03%, 71,74% and Gir 70,54% Brown Swiss showed differences (p <0,01) pregnancy rate compared to Girolando with 62,15% to 61,91% Simmental and Holstein with 59,45%. The pregnancy rate found in the dry season showed a 75,77% difference (p <0,01) obtained for the less rainy season with 58,95%. The mean age at first service (IPC) and the first calving (IPP) were 29,6 ± 5,71 and 38,57 ± 5,71 months respectively, occurring differences (p <0,05) in the IPP grating the type of reproduction IATF and MN and rainiest season and less rainy. The period of service (PS) was 110,97 ± 70,87 days, difference (p <0,05) between the rainiest season and less rainy, and also influences (p <0,05) the variable year study, decreasing from 2006 to 2008 respectively. The pathologies found were 2,35% ovary hypoplastic, cervix winding 1,52% 1,76% abortion, endometritis 1,29%, 0,7% Cervix fibrotic, follicular cyst 0,70%, 0,12% Adherence Tubovárica , cyst luteal 0,12%, Pneumovagina 0,12% and 0,12% Vulva child.