ACTIVE IMMUNIZATION AGAINST ESTRONE IN GOATS AND ITS EFFECTS ON OVARIAN HORMONES AND CYCLICITY

Cycling non-parous crossbred goats (Alpine x Beetal) in the age group of 1 1/2-2 years were immunized against estrone. 6. CMO. RSA conjugate during the non-breeding season to study the effects of estrone immuni zation on the levels of ovarian hormones and cyclicity. Blood samples were collected at regular intervals starting from - 4 day till day 138 of immunization. Estrus detection was done by parading a vasectomized buck. Goats immunized against estrone over a period of time showed ma ximum titres of antibody ranging between 1:1 000 and 1:5 500. Circulat ing estrogen and progesterone levels measured in immunized goats showe d a significant increase (P<0.01) over the levels before immunization. Levels of both the ovarian hormones showed an increase during the imm unization schedule and then persisted till the end of the experiment. Except for goat B which exhibited estrus once on day 30, none of the g oats showed any symptoms of heat during the process of immunization ev en though they passed through a breeding season. These results suggest ed that even though active immunization against estrone increases ovar ian hormone levels, persistent titres of antibody appear to neutralize the biological activity of estrogens thereby leading to disruption of the estrous cycle in the goats.