Study On Semen Preservation And Propagation Techniques In Dairy Goat

Sperm preservation has broken the limits of artificial insemination (AI) techniques, suchas area, time and domestic species, it contributes to promote genetic progress in domesticanimals. The main method of long preservation of semen is cryopreservation, while sperm isso easily to suffer from the freezing damage under the low or ultra-low temperature, whichcould result in a decline in the fertilization ability(＜50%). Meanwhile, its sperm motilitydecreased so rapidly at short time with the liquid storage of dairy goat semen, which limits theapplication and expansion of AI. Therefore, semen preservation play an important rolepropagation technique improving.This present research is conducted to study the optimizedliquid storage and cropreservation of Xinong Saanen dairy goat semen and protocol of estrussynchronization for AI. Collecting the semen from Xinong Saanen dairy goat bucks,compared the sperm quality among four seasons; semen sample were collected from6healthy, age1-4bucks by artificial vagina, evaluating the effect of temperature, egg-yolk andexchanging the extender on the semen liqud storage, and futher study the effect of rhodiolapolysaccharides and different cryoprotectants added extender on goat semen cropreservation,screening the best frozen diluent formμLa; Selecting220healthy Xinong saanen dairy goat,dividing into three groups based on parity. Semen samples were diluented and transcervicalAI with0.2mL, The effect of estrus synchronization, pregnancy rate and lambing, hormoneconcentration were collected, and the plasma hormone concentration were measureed threetimes at CIDR withdraw, in heat anD22d after AI. The resμLt of this study indicate that:1. The sperm motility were78.8±2.91%,82.2±1.93%,83.8±1.64%and70.5±3.15%,from spring to winter, autumn is the best of all, significantly（P＜0.05）better than winter, andthere are no significant difference with spring and summer.2. Based on the diluent of Tris-glucose, the extender with egg yolk provide a betterenvironment to spermatozoa than those without egg yolk; The motility of semen with eggyolk diluted by Tris-fructose with extender replacement was up to30%after12days’ storage,which is better than those without extender replacement;3. Semen were diluted in Tris-egg yolk with glycerol (6%), ethylene glycerol (3%,6%),DMSO (3%,6%) or DMA (3%,6%) and frozen at-196℃,evaluating the effects of four penetrating cryoprotectants supplementation on semen quality and oxidative stress variablesin frozen-thawed dairy goat semen, through assessing the motility, acrosome integrity, plasmamembrane integrity, mitochondrial activity, GSH and MDA concentration.After thawing,Glycerol (6%) and ethylene glycerol (3%,6%) both can protect goat sperm against theharmfμL effects of freezing, ethylene glycerol3%offers greater protection as cryoprotectantsupplementation on goat semen.4. Rhodiola polysaccharide were added into freezing extender Ⅰa nd Ⅱbased on thediluted of Tris-egg yolk, the concentrations were4mg/L,8mg/L,12mg/L,16mg/L,20mg/Land control0mg/L. The motility, plasma membrane integrity, mitochondrial activity wereincreased significantly（P＜0.05）than control, the GSH and MDA were significantly（P＜0.05）better compared with control. Therefore, added rhodiola polysaccharide to the diluentcan significantly improve the quality and antioxidant of goat freezing spermatozoa.5. Project Ⅰ:14days CIDR (Vagina sponge release device) and300IU PMSG afterremoving the sponge, andⅡ:5ug LHRH-A3based project Ⅰw hen AI, and Ⅲ:50IU FSHbased projectⅠ when removing the sponge.The results show that oestrus of three projects are93.5%、95.5%、93.5%, the project Ⅰwith14days’ CIDR and300IU PMSG provide a betterpregancy rate of32.81%, lambing of176.2%.6. Serum E2and FSH remain low before CIDR withdrawal, rapidly rise in heat andreduce a little after21days of AI, on the contrary, P and LH keep a high level before CIDRwithdrawal, falling fast in heat and rise slightly after21days of AI. The three times hormoneconcentration, there are no difference between pregnancy and nonpregnancy.