Preparation Of Novel Quaternary Ammonium Salts Of Chitosan And Infection In The Reproduction Of Cattle

Chitosan has good compatibility activity and has been applied in many fields of science, but its application has been greatly hampered due to its low solubility. In order to expand the application of chitosan by improving its water solubility, antimicrobial resistance and physiological activity, and based on the activity of the amino groups on chitosan, the article has modified chitosan through quaternization. As a result, many chitosan derivates have been generated, which is proved to have much better solubility and antimicrobial activity than the original chitosan.With chitosan of two different molecular weight and different degree of deacetylation as raw materials, six kinds of novel quaternary chitosan have been prepared including iodide N, N, N-triethyl chitosan quaternary ammonium salt, iodide N, N-diethyl- N-chitosan quaternary ammonium salt, iodide N-butyl-N, N-diethyl- N-benzyl chitosan quaternary ammonium salt. Compared with the original chitosan, the solubility of the new prepared chitosan derivates has been improved obviously and the best solubility can be reached 20%. Besides, we have structure characterized of chitosan and its derivatives by the infrared, thermogravimetric (tg), X-ray diffraction, and identified that the quaternary ammonium groups has been connected on chitosan’s amino.Antibacterial test of chitosan and its quaternary ammonium salts have proved that chitosan has good inhibitory effect on Bacillus subtilis, and the lower the molecular weight, the better the inhibitory effect. Besides it is also found that chitosan quaternary ammonium salts with an average molecular weight of three thousand have good antibacterial activity against Staphylococcus aureus, Salmonella, E. coli of 0139 has E. coli 0157 E. coli K88, E. coli K99 and so on. The TC is the best of the derivatives series because of its obvious inhibitory effect. While only the BDC has antibacterial activity among those quaternary ammonium salts with the average molecular weight of one thousand. It is proved through the study of the antibacterial activity of the six strains that four kinds of chitosan quaternary ammonium salt mentined above have a broad-spectrum antimicrobial effect. With comprehensive consideration of solubility and antibacterial effects, we have used N, N-diethyl-N-benzyl chitosan of quaternary ammonium with the average molecular weight of one thousand, instead of antibiotics in in vitro treatment of bovine metritis. And it is found that therapeutic effect is more obvious when the concentration of N, N-diethyl-N-benzyl-chitosan of quaternary ammonium salt increases, and when the quaternary ammonium salt concentration is 1%, the therapeutic effect of metritis of the ten cows in the experiment is most obvious.It is concluded through the experimental study that N, N-diethyl-N-phenyl methyl quaternized chitosan with an average molecular weight of one thousand has broad-spectrum antibacterial effect and it could be expected to have better physiological effects if used in bovine granulosa cell culture than the antibiotics. But due to time constraints the test has failed to achieve the expected result, and the trial has yet to continue with a more in-depth study.Meanwhile, the article has an additional study on the effection of chitosan used as buffalo calves starter foodstuffs, by adding chitosan to the starter of the buffalo calves unweaned and weaned within two weeks. The test results have showed that chitosan can effectively promote the development of the rumen of buffalo calves, improve their non-dairy feed intake and make early weaning. What’s more the test has proved that chitosan can reduce weaning stress and the adverse effects of buffalo calves, which is essential for the production of adult buffalo.