| As an important part of pig herd,the semen quality of breeding boars is closely related to the productivity level of pig farm.The semen quality of breeding boars reflects the reproductive performance of breeding boars.The purpose of this study was to analyze the potential effects of different factors in semen production,packaging and transportation on the storage of standard semen at room temperature,in order to save the production cost of breeding boar semen,and to expand the service range of fine boar semen through long-distance transportation of fine boar semen,improve the utilization rate of semen and economic benefits of breeding pig farms.To further provide relatively standard operation,scientific basis and data reference for small and medium-sized pig breeding farms or newly established pig breeding farms,and realize regional sharing of excellent boar semen.So far,there has been no systematic study on the factors affecting the storage effect of breeding boar semen at room temperature from the perspective of semen production,packaging and transportation.In this study,5 purebred Yorkshire pigs from the same batch were selected to evaluate the specific operation,key point control and key parameters of diluted sperm(detection density of 50 million/ m L)in the semen production process through CASA(Computer-aided sperm analysis)computer assisted sperm analysis system,and evaluate the quality of boar semen from the key parameters such as the number of coagulants,viability,motility and sperm motility of semen stored at room temperature for 0-7 days,so as to explore whether it affects the storage effect of boar semen at room temperature.The main results of this study are as follows:(1)The difference in the number of filter paper layers when filtering through the original semen,A(Collection cup made of French Casoudofu three-in-one collection filter bag),B(collection cup made of ordinary three-in-one collection bag with built-in filter paper superimposed one layer of York semen filter paper),C(Collection cup made of ordinary three-in-one collection bag with built-in filter paper superimposed on two layers of York semen filter paper),D(ordinary three-in-one collection bag with built-in filter paper superimposed on three layers of York semen filter paper)Paper sperm collection cup)and group E(three-in-one sperm collection cup made of internal filter paper bag with 4layers of York semen filter paper)were compared.The results showed that there were no significant differences in the indexes of semen viability,motility and sperm motility(P >0.05).However,the filtration effect of French Casu three-in-one collection bag or ordinary three-in-one built-in filter paper bag with 4 layers of semen filter paper on fine fine glue and inflammatory exudate is better than that of superimposed 1,2,3 layers of semen filter paper.(2)RC-4 mini temperature recorder was used to record the temperature changes of semen in EG group and CG group during the whole semen collection process,and the evaluation parameters of semen preservation effect at normal temperature were compared from 0 to 7 days.The results showed that the decreasing speed of the vitality of EG group was less than that of CG group.The results of heat preservation test showed significant difference(P<0.05),but the three velocity parameters and movement parameters had no significant difference(P>0.05).Sequencing of EG group and CG group spermatozoa by RNA-seq,after analysis and comparison,all differentially expressed genes in EG group of constant temperature semen collection cup experimental group were up-regulated,and the expression of differential genes was mainly expressed as genes encoding sperm cell membrane proteins and enzymes,and the biological processes mainly reflected in energy homeostasis and metabolic processes.It is speculated that this may be caused by taking insulation measures.(3)Semen was diluted in two different ways,one slow dilution to target density and one gradient dilution to target density(50 million cells/m L).The results showed that the two dilution methods caused different degrees of sperm agglutination,but there was no significant difference in the total number of aggregates,which can be ignored in practical production.The effect of gradient dilution on sperm motility was not significant(P>0.05).(4)The parameters of semen diluted by two kinds of diluent were detected by CASA computer assisted sperm analysis system,including sperm linear velocity(VSL),sperm curve velocity(VCL)and sperm path velocity(VAP).The results showed that during 1～7days of constant temperature preservation,the sperm motility velocity and trajectory fluctuation of the sperm diluted with Quan neng jian dilution powder were greater than that of the sperm diluted with Kasu dilution powder,and there was no significant difference in sperm motility(P > 0.05).The sperm motility decreased faster than that of the sperm diluted with Quan neng jian dilution powder.The three velocity parameters,average forward direction and lateral head displacement amplitude of Qn group were higher than those of Ka group.(5)Use Jingchuang RC-4 mini temperature recorder to record the temperature change in the transport box during the packaging and transportation of semen in A,B,C,D,E and other large boar stations.The results showed that there was no significant difference in the temperature control effect among the different containers at room temperature.The longest storage time was kept at ≤25°C in the container A when the temperature of the container A reached the minimum value,which was about 24 h.And the time for the temperature to decrease to the minimum temperature is the longest,and the comprehensive evaluation of the transportation effect is the best.To sum up,in the production of semen at actual boar breeding stations,a constant temperature semen collection cup made of ordinary three in one built-in filter paper collection bags and four layers of semen filter paper is used to collect semen,which can better filter semen and reduce the impact of external temperature changes during the semen collection process.During the semen dilution operation,controlling the temperature difference between semen and diluent(<1°C)and the speed of adding diluent,and selecting diluent powder with relatively good dilution effect,can minimize the loss of sperm during the semen dilution process and maximize the production value of excellent boar semen.In addition,during the transportation of semen,the temperature of the cold chain transport box for summer semen needs to be controlled within a reasonable range(transport box A);Reasonable insulation in winter and ensuring that the transportation temperature is not less than 12°C can effectively control the transportation damage of sperm caused by changes in external temperature during the transportation process.Ultimately,the quality of high-quality boar semen can be guaranteed when the semen reaches the buyer’s hands,expanding the service range of semen,and achieving the ultimate breeding and reproduction goals. |
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