Studies On Endocrinology Mechanism And Regulation Of Broodiness In Wanxi Goose

Wan Xi Goose is an excellent local strain in China, which is famous for its perfectgeese, superexcellent plume and forepart growth rate in the world. But above 95% of themhave broodiness habit, which inhibit its laying capability seriously and restrict Wan XiGoose industrialization ultimately. It is well known that the poultry reproductiveperformance is regulated not only by gene but also by its endocrine hormone level.Therefore neuroendocrinology method was applied to grope for mechanism of broodinessand low laying performance, exotic hormone or medicine was utilized on the onset of WanXi Goose broodiness to grope endocrine method of inhibiting broodiness behavior in thestudies, in order to supply reference to further reproductive performance studies on Wan XiGoose. Grown Wan Xi Geese were chosen to sampling blood in wing vein in period of laying,broodiness and restoration respectively. Time-resolved Fluorescence Immunoassay (TRFI)was utilized to test the peripheral serum content of PRL, E₂, P₄ and LH in the each periodof Wanxi geese reproductive cycle respectively.The results indicated that the PRL level inbroodiness period was remarkably higher than it in the restoration and production period, itfluctuated in the whole broodiness period and maintained steady in the restoration andproduction period. It suggested that PRL plays the most important role on the onset andmaintaining of broodiness. E₂ level fluctuated in the entire reproductive cycle, which ishigh in production period and low in restoration and broodiness period. Many peak valueswere detected in the whole cycle, of which the highest value is in the middle anaphase ofproduction period, and the inferior value in the prophase of production. These changeindicated that high E₂ promoted the follicular expelling and the egg forming. P4 and LHhad the similar change in the Wanxi Geese reproduction cycle, P₄ has high level in theproduction period and low level in the restoration and broodiness period. These changesmay be one of the pivotal factors of inducing low productivity of Wanxi geese. LHfluctuated in the whole cycle, which fluctuated in the anaphase of restoration cycleobviously and a remarkable peak value was tested at the onset of laying egg, while theserum content of LH in the prophase of production and the broodiness cycle is very low. Wanxi Geese in laying telophase were chosen to studies effective measures ofcontrolling broodiness behavior in Experiment two. The results showed, (1) Aftermuscle-injection LHRH-A3 at the dose of 15μg/kg, E₂, P₄ and FSH were fluctuated andPRL was ascending and maintaining a high level in the control group, while in the testedgroup P4 and FSH was ascending a little, E2 was descending, and PRL had no obviouschange in the tested period. Two geese stopped broodiness behavior ahead of time, but noobvious laying time in advance. We can conclude that LHRH-A3 had an inhibiting functionto broodiness. At the same time it suggested that LHRH-A3 is benefit for fowl LHRHdeficiency and LHRH-A3 can restrain fowl broodiness behavior and improve its laying rate.(2) Different dose of testosterone propionate was adopted to test its effect on Wanxi geesebroodiness behavior, and the dose of 1.00ml/goose had the best efficiency, 0.70ml/goosewas inferior and 0.40ml/goose was not good. And the tested hormone results showed thatthe dose of testosterone propionate has a direct relation with broodiness-ceasing efficiency,after injection the physiological endocrine state of Wanxi goose has a tendency to layingegg state, the peripheral serum content of E2 was ascending, the peripheral serum contentof P4 and PRL were descending, and the change of FSH was not significant. Testosteronepropionate can be used to inhibit onset-broodiness and enhance the laying rate. (3)Dopamine and 5-HT receptor antagonists cholorpromazine and cyprohepetadine wereutilized to terminate broodiness of Wanxi goose and modulate its behavior. Drugs wereorally administered 80mg/kg·d cholorpromazine or 8mg/kg·d cyprohepetadine starting onthe first day of broodiness for...