Prolonged The Liquid Preservation Time Of Boar Semen By Keeping PH Stable

With the development of the economy,thedemandfor meat is greatly improved in production and life,and more and more attention was focused on how to improve the yield and quality of meat owing to the conditions of transport,preservation conditions and effects of meat prices.Therefore,how to enhance the quality of animal husbandry becomes a pressing matter of the moment.One of the key factors is how to improve the utilization rate of good breeding.Hence,artificial insemination techniques,which were the deliberate introduction of sperm into a female’s body for the purpose of achieving pregnancy through in vivo fertilization by means other than sexual intercourse,were generated.As semen preservation technology is one of the core techniques of artificial insemination technology,the ingredients of semen extender were widelyresearched around the world owing tothe composition of semen extendergreatly affects the female pregnancy rate and litter size.The main aspects of these investigationswere focusedon energy saving,osmotic pressure,and other modified components of the solution,including antioxidants,chelating agents and plasma membrane protectant.The pH value of porcine ejected semen was just between 7.2 and 7.5.The pH value of the solution can be reduced to about 6.2 within 20 hours in the presence of glucose in the preservation solution.Although it is generally accepted that the low pH value could reduce sperm motility and metabolism level which is benefit to maintain the vitality of sperm preservation and operation process,the metabolism of acid could cause sperm acidosiswhich is harmful to long-term preservation of semen.Therefore,it is necessary to supply buffer material in storage solution.Previous studies have confirmed that the initial pH value of the preservation solution is very important for the maintenance and preservation of sperm motility.But there is no detailed report on the change of pH value in the process of preservation,so it is very important for the optimization of long-term liquid storage of boar semento detect pH value of the preservation solution regularly,and to establish PH nonlinear model depending on time.In this experiment,by using Androhep based solution,we first confirmed the initial pH value of the preservation of the best preservation effect for semen between 6.4~6.5,followed by the establishment of sperm-pH value changes with the nonlinear model of time,further validation of the relationship between the changes of pH value and sperm vitality,through the analysis of the data the correlation coefficient was r=0.954.Then stable pH value could effectively improve the sperm viability significantly improve semen preservation time by changing liquid.According to the buffer range,we use a newly buffer material 2-morpholine sulfonic acid(MES)whose buffer rangeis 5.7~6.7,whichhas the advantages of large buffer capacity,wide buffer range and nobiological toxicity.The modified buffer is called Andromes,which could significantly improve the storage time of sperm motility.We also compared the effects of three different buffers on the liquid storage of boar semen.Sperm motility parameters,plasma membrane integrity,acrosome integrity and mitochondrial activity were estimated,the results as follows:(1)During semen preservation the decrease of sperm motility was closely related to the decrease of pH value.(2)The initial pH value of the best preservation of boar semen was between 6.40~6.50,when the pH value was too high or too low,it resulted in the decrease of sperm motility,which was harmful to the preservation of semen.(3)Androptris preservation solution could improve the effect of pig semen preservation compared with Androphep and Andromes,(4)Stable pH value could effectively improve sperm preservation and in vitro fertilization.