Effect of aflatoxin B1 on blood serum oestradiol-17β and progesterone concentrations during the luteal phase and the synchronized oestrus of goats

The effect of prolonged aflatoxin B-1 (AFB(1)) administration on blood serum oestradiol-17 beta and progesterone concentrations in goats during the luteal phase and the synchronized oestrus was investigated. Thirty-six Greek indigenous primiparous goats were used, during the oestrus period; 12 goats received, per os, 50 mu g (treated group T50) and 12 goats received 100 mu g (treated group T100) AFB(1)/day/head, respectively, for approximately 1.5 month, while 12 goats served as controls (C). On day 36 of the experiment, each goat was injected, i.m, 0.5 ml prostaglandin F-2 alpha (PGF(2 alpha)). Blood samples were collected from each goat twice a week, before PGF(2 alpha) injection, as well as every 4 hours from the onset to the end of the synchronized oestrus. Oestradiol-17 beta and progesterone concentrations in blood serum were determined using radioimmunoassay. During the whole luteal(s) phase(s), linear regression analysis revealed a significant negative dependence (P < 0.05) of oestradiol-17 beta and a significant positive dependence (P < 0.05) of progesterone over group (C = 0, T50 = 50, T100 = 100), in a dose dependent manner. During the synchronized oestrus, multiple linear regression analysis revealed a significant negative dependence (P < 0.05) of oestradiol-17 beta, as well as a significant positive dependence (P < 0.05) of progesterone over group (C = 0, T50 = 50, T100 = 100) and over time (hours, from the onset to the end of the synchronized oestrus). No significant differences were noticed among the three groups, regarding the body weight of the goats from the onset to the end of AFB(1) administration, the occurrence or the duration of the synchronized oestrus presented by the goats (P > 0.05). In conclusion, prolonged AFB(1) administration at doses of 100 or even of 50 mu g/day/head changes the hormonal pattern in blood during the luteal phase and the synchronized oestrus of goats, being in oestrus period.