Effect Of Active Immunization Against Inhibin On Reproduction Of Youth Dairy Goat

The inhibin active immunization method, agar diffusion technique and radioimmunoassay are used to predict the antibody titers and hormonal level on youth Xinong Saanen dairy goats in this experiment. The main content is as the following:Eight 1.5 years old and weigh close youth dairy goats are allocated to two groups raised in the NWSUAF Saanen Goat Growing Field. The immunized group (n=4) are treated with s.c. injections of human inhibin vaccine into four sites followed by two booster injection at 4-week intervals and the control group (n=4) are treated with an equal volume saline. After the two booster injection, estrous cycles are synchronized by i.m. injection of 0.1mg PG. Two further PG injections are given at 11-day intervals. The estrus time is recorded after each PG injection. All estrus goats are bred in natural mating method after the third PG injection.The results show that: all in immunized group produce antibodies, and the antibody titres rise with increased of the immunized time. There are high titres in immunized group after the second booster injection, reaching 1:64, 1:128, 1:64 and 1:64 respectively. FSH mean concentrations in 72 hour after the third PG injection are significantly higher (P< 0.05) in inhibin-immunized goats than in the controls. The immunized group FSH surge level come at 48 hour after PG injection, while the control group at 56 hour. The surge value in FSH is higher significantly (P < 0.05) than the control group. Plasma concentrations of LH did not differ significantly between inhibin-immunized and control goats (P > 0.05). In both groups, PG injection is followed by a preovulatory sure in LH coincident with the FSH surge. Plasma concentrations of P decrease after the third PG injection, and the P mean concentrations in 6 hour after PG injection are significantly higher(P< 0.05)in inhibin-immunized goats than in the controls, but the overall mean concentrations after PG injection are not significantly between the two group. Plasma concentrations of E2 rise after PG-induced luteolysis to reach a peak value which is significantly (P< 0.05) higher in immunized goats than in controls. The concentrations then fall and remain relatively low. The time of peak value come later in immunized group than the control group. The conception rate is 100% in both groups. Immunized-goats produce 9 kids while only 5 in the controls. A 55% increase in kidding rate is recorded for youth goats in immunized group. The kidding rate is higher significantly between the two groups.The results demonstrate that the active immunization against inhibin enhances the secretion of FSH, E2 and P on youth dairy goat in estrous period. Immunization against inhibin induces the estrous and enhances the kidding of youth dairy goat.