Laying Performance And Folliculogenesis Of Xupu Geese In Response To Dietary Protein And Exogenous GnRH Analogue

Because of the lower reproductivity compared to chicken and ducks,it is necessary to improve the reproductive performance of geese in geese breeding and feeding. Gonadotropin-releasing hormone(GnRH),the central initiator of the reproductive hormonal cascade,is secreted from hypothalami and stimulates the biosynthesis and secretion of LH and FSH from pituitary gonadotropes.Over 2000 analogues of GnRH have been developed and tested over the last 30 years.With its stabler nature and higher receptor affinity,the synthetic GnRH analogues(GnRH-a) have achieved widespread clinical use for the control of reproduction in animals.Due to the ususal injection administration results severe stress on animals,this investigation was designed to study(1) the optimal protein levels in diets of Xupu breeder geese during its laying period,(2) the effect of oral administration of GnRH-a(LHRH-A₃) on egg production,egg quality,egg incubation,reproductive endocrine and folliculogenesis of Xupu breeder geese.This would shed light on possibility that oral administration of GnRH-a with optimal might improve the reproductive performance in geese.1 Laying,egg quality and hatchability in response to protein levels of diets in Xupu Breeder GeeseObjective:to study the optimal protein level of brown rice based-diets of Xupu Breeder Geese during laying period.Methods:using singular factor design,after feeding 5 kinds of brown rice based-diets with 13.0%,14.5%,16.0%,17.5%and 19.0%,egg production,egg quality and hatchability,parameters of serum biochemistry and reproductive hormone in different treatments were measured and determined,respectively. Results:(1) With the significant regression of two factors of feed conversion efficiency between the rate of laying and egg production,the rate of laying and egg production increased significantly,while the feed conversion efficiency decreased significantly.(2) There were no differences in egg quality and fertilization rate among all treatments. However,the egg hatchability and percent of healthy gosling decreased significantly in 13.0%treatment.(3) Uric acid in serum of geese increased significantly in 19%treatment. (4) concentration of P₄ and E₂ increased significantly in 16.0%,17.5%and 19.0% treatment.Conclusion:the optimal protein level of brown rice based-diets of Xupu Breeder Geese is 16.0%.2 Laying,egg quality and hatchability in response to oral and injection administration of LHRH-A₃Objective:to study the possibility of oral administration of LHRH-A₃ in geese. Methods:Birds were injected 5,10 and 15μg/bird of LHRH-A₃ in treatmentâ… ,â…¡,â…¢, respectively.Meanwhile,the other birds were oral administrated with 0,5,10 and 15μg/bird of LHRH-A₃ in treatmentâ…£,â…¤,â…¥,â…¦,respectively,and the egg production,egg quality and hatchability of geese in all of the 7 treatments was measured during the whole experiment.Results:Compared to control treatment,feed conversion efficiency decreased significantly and the tendency of eggs production increased in oral and injection treatments.Moreover,the eggs production increased significantly in 10μg/bird treatment. (3) there were no differences in egg quality,fertilization rate,hatchability and percent of healthy gosling in response to oral administration of LHRH-A₃.However,percent of healthy gosling was decreased in treatment of injection administration(p＞0.05).Conclusion:Oral administration of LHRH-A₃(mixed with feed) was a kind of better treatments in geese feeding compared to injection and egg production of geese was the highest in 10μg treatment.3 Laying,egg quality,hatchability,reproductive incretion and folliculogenesis in response to oral administration of LHRH-A₃Objective:To investigate the regulative mechanism of oral administration of LHRH-A₃ on laying performance,egg quality,hatchability,reproductive incretion and folliculogenesis of breeding geese.Methods:A feeding trial was carried out and lasted for 60 d according to a singular factor design.Birds were oral administrated with 0,5,10,15 and 20μg/bird of LHRH-A₃ every day,respectively.At the end of the feeding trial,the egg production,egg quality,hatchability,parameters of serum biochemistry and blood routine, reproductive hormone,apoptosis of granulose cell and slaughter performance of geese in all treatments were measured.Results:(1) Compared to control treatment,the laying rate increased significantly(P＜0.05) in 10μg/bird and 15μg/bird treatments,however decreased in 20μg/bird treatment.Feed conversion efficiency decreased significantly (P＜0.05) as LHRH-A₃ increased from 0 to 15μg/bird but increased at 20μg/bird.(2) No significantly(P＞0.05) difference was observed in egg weight,egg quality,fertilization rate,the egg hatchability and percent of healthy gosling among all treatments.(3) There were no differences in parameters of serum biochemistry and blood routine in response to oral administration of LHRH-A₃.(4) The serum contents of P₄ and E₂ in 10μg/bird and 15μg/bird treatments were significantly(P＜0.05) higher than that in the control.However, the P₄ content decreased significantly(P＜0.05) in 20μg/bird treatment.No significant difference in PRL content was observed.(5) The rate of apoptosis of granulose cell in 20μg/bird treatment was significantly(P＞0.05) higher than that in other group.(6) The eviscerated weight and percentage of eviscerated yield showed no significant difference in all treatments.However,the ovary weight was highest(P＜0.05) in 15μg/bird treatment and lowest(P＜0.05) in 20μg/bird treatment.Conclusion:The secretion of P₄ and E₂ can be improved by oral administration of 10 and 15ug/bird LHRH-A₃(mixed with feed). Meanwhile,the folliculogenesis and ovary growth can be promoted by oral administration of 15ug/bird LHRH-A₃.However,oral administration of 20ug/bird LHRH-A₃ would increase the rate of apoptosis of granulose cell and inhibit the folliculogenesis and ovary growth.The optimal oral administration dosage of LHRH-A₃ was 10ug/bird.4 The regulation mechanism of LHRH-A₃ oral administration on laying period extensionObjective:To investigate the regulative mechanism of oral administration of LHRH-A₃ on laying performance,egg quality,hatchability,reproductive incretion of breeding geese during the late stage of egg production cycle.Methods:A feeding trial was carried out and lasted for 30 d according to a singular factor design.Birds during the late stage of egg production cycle were oral administrated with 0,10 and 15μg/bird of LHRH-A₃ every day,respectively.During the whole period of the feeding trial,the egg production,egg quality,hatchability,reproductive hormone and ovary weight of geese in all treatments were measured every week.Results:(1) Compared to control treatment,the laying rate in 15μg/bird treatment was significantly(P＜0.05) higher,and the reducing speed of laying rate was slower in 15μg/bird and 10μg/bird treatments.(2) No significantly(P＞0.05) difference was observed in average egg weight among all treatments.(3) The ovary weight was significantly(P＜0.05) higher in 10μg/bird and 15μg/bird LHRH-A₃ treatment than that in the control.(4) The serum contents of P₄ and E2 in 10μg/bird treatment were significantly(P＜0.05) higher than that in the control. However,the serum P₄ and PRL contents in 10μg/bird treatment was significantly (P＜0.05) lower than that\in the control.Conclusion:The ovary growth of breeding geese during the late stage of egg production cycle could be promoted and the secretion of P₄ and PRL could be inhibited by oral administration of 10 ug/bird LHRH-A₃.Thus,the laying rate could be promoted and the laying period could be extended.