Pregnancy diagnosis is a critical procedure for monitoring goat reproductive performance. In the present investigation, pregnancy-associated glycoprotein (PAC) profiles during pregnancy and first month postpartum, as well as progesterone (P-4) concentrations throughout pregnancy, were determined in native goats from the north-east of Brazil. A total of 30 goats (Moxoto, n = 19 and Caninde, n = 11) were used. Peripheral blood was collected on days 0 (Day 0 = AI), 11, 16, 18, 20, 24 and 30 after Al. Samples were subsequently collected every 2 weeks until day 145, and weekly during the first month postpartum. The levels of FAG and P-4 were determined by radioimmunoassay (RIA). The profiles of FAG were not different between the breeds throughout pregnancy. However, a significant effect of the week of pregnancy (p < 0.01) and the number of fetuses (p < 0.05) in FAG concentrations were found. Lower concentrations of FAG were observed during weeks 1 and 3, compared to the rest of the gestation. Thereafter, there was a significant (p < 0.05) increase in FAG concentrations from week 5 to 7 and a significant decrease (p < 0.05) in week 9. The FAG concentrations remained relatively constant until week 17, and finally decreased slowly until parturition. After parturition, FAG concentrations decreased rapidly, and continued to decrease until week 4. During pregnancy, mean P-4 concentrations had weekly variations among the animals (p < 0.01) and the period of pregnancy (p < 0.01), but P-4 was not affected by the breed or number of fetuses. These results indicate that FAG and P-4 concentrations were similar for Caninde and Moxoto goats and that, for both the breeds, the stage of pregnancy and the number of fetuses could influence FAG production. (C) 1999 Published by Elsevier Science B.V. All rights reserved.
