The Study Of Equilibrium Time At4℃, Glycerol And Antioxidants On Semen Cryopreservation

The boar sperm is sensitive to the cold stress, so it failed to meet the satisfactory effect after freezing and thawing. From the birth of cryobiology to the present, researchers are still working at the cryopreservation procedures and cryoprotectants.On the basis of previous studies, this trial studied the effect of the equilibrium time, concentration of glycerol and antioxidants on boar semen crtopreservation. After the freezing and thawing, the study used the methods of subjective assessment, propidium iodide (PI) and rhodamine123combining staining, osmotic swelling test (HOST) as well as isothiocyanate fluorescence-linked peanut agglutinin to evaluated the sperm viability, mitochondrial activity, plasma membrane integrity and acrosome integrity respectively. The results in this paper were as follows:1. The second4℃equilibration time was90min and the best glycerol concentration was3%. Under such conditions, the sperm viability, mitochondrial activity, acrosomal integrity and plasma membrane integrity were significantly higher than other groups (p<0.05)2. When added alonly, the suitable L-carnitine and trehalose concentration were0.07mg/ml and12mg/ml respectively, the boar semen obtained the the best cryoprotective effects (p<0.05). But when added L-carnitine and trehalose at the same time,0.05mg/ml L-carnitine and8.0mg/ml trehalose obtained the the best cryoprotective effects (p<0.05), the effect of sperm viability, mitochondrial activity, acrosome integrity and membrane integrity were significantly better than L-carnitine and trehalose added lonely.3. The sperm CAT and T-AOC activity were showed gradual downward trend in periods of fresh semen, after equilibrium and frozen-thawed. Combined adding0.05mg/ml L-carnitine with8.0mg/ml trehalose to the extender could significantly improve the CAT activity after freezing and thawing. The T-AOC was improved significantly after equilibration and frozen-thawed and the production of MDA was inhibited significantly (p<0.05).4. Combined adding0.05mg/ml L-carnitine with8.0mg/ml trehalose to the extender could protect the sperm chromatin from injurying, the number of sperm in Go state (nuclear integrity, DNA no damaged) significantly increased (p<0.05).