The Quality Evaluation And The Microbial Contamination Analysis Of Bull Straw Frozen Semen In Productive Process

In recent years, due to frequent animal diseases, animal-derived raw materials in the production of animal husbandry have also been of great concern. Application of raw materials containing pathogenic microorganisms of animal origin will give animal production, and even the lives of human being enormous threat. In present, there are many limitations for prohibiting the application in the production of raw materials containing animal-derived ingredients. Application of no animal-derived ingredients of semen diluents can avoid the spread of pathogens in egg yolk, animal derived ingredients to avoid the risk of infectious diseases, thereby reducing microbial contamination. The microorganism content of the bull frozen semen and sperm activity, sperm survival time and conception rate had extremely close relationship. The test aimed to evaluate the quality of bull straw frozen semen after introduction of new production lines and new frozen semen dilution, dilution series of the freezing process in order to apply to the practical production, to understand microorganism contamination status and find out regularity for change of microorganism content, in order to better control the microorganism contamination in the process of producing frozen semen.The test for detecting and analyzing Holstein bull straw frozen semen, including the number of effective sperms per dose, frozening semen activity, abnormality rate, freezing aerobic bacterial counts, were used to evaluate the quality of straw frozen semen, in addition to analyze the microorganism contamination status in the process of producing frozen semen and bacterial colony. The results showed as followings.1. In the 100 samples from 10 Holstein bull, unqualified samples was 5, frozen semen qualified rate was 95%. Among them, the unqualified samples of effective sperms per dose was 2, with qualified rate of 98%; The unqualified samples of freezing semen activity was 0, with qualified rate of 100%; The unqualified samples of freezing bacterial counts was 1, with qualified rate of 99% ; The unqualified samples of abnormality rate was 2, with qualified rate of 98%. The average freezing activity was 0.38±0.04. The number of effective sperms per dose in the average number was 960.85±88.96 (million); the average abnormality rate was 10.87%±2.89%. The freezing aerobic bacterial counts were 17.67±85.55 per dose.2. The fresh semen the average colony density was 1500.08±528.05. After frozen semen, the bacterial colony of frozen density on average was 1.77±5.20, which significantly differ between the two. The average number of bacteria colonies of freezing semen was far less than that of fresh sperm. In all aspects of the frozen semen production, the semen is the essence of the original contamination.The prepared straw frozen semen had fine quality. The number of effective sperms per dose, frozening sperm activity, sperm abnormality rate and freezing bacterial counts meet national standard. The frozen semen dilution, dilution series of the freezing process was good for actual production.