Study On The Preparation Of Ruminal Protected V_A Microcapsules And The Evaluation Of Its Coating Effects

This study consists of three parts as follows:Part 1. 3 kinds of coating material (Polyacrycic resin, Ethylcellulose and shell-lac) were selected to prepare ruminal protected VA by FLP-5 pelleting drier though spray-drying method.Part 2. Based on the result of part 1, the stability of protected VA with three coating materials was studied, at different ratios of concentrate to roughage by In vitro and In Sacco techniques, and determined the degradability of protected VA in the abomasum by In vitro technique.Part 3. A feeding experiment was carried out based on the results of part1 and part 2, to verify the stability of protected VA microcapsule in the rumen, and to evaluate the feasibility of coating processing procedure by the effect of different dietary protected VA levels on production performance and immunity enginery in lactating cows.The result shows as follows: 1. The degradabilities of non-protected VA at 24h are 19.73% and 60.54% at the ratios of concentrate to roughage 20:80 and 55:45, respectively. 2. The degradabilities of ruminal protected VA (Ethylcellulose coating) at 24h are 9.94% and 25.33% at the ratios of concentrate to roughage 20:80 and 55:45, respectively.3. The degradability of both non-protected VA and protected VA increase as the level of dietary concentrate improves and culture time prolongs.4. The release rate of ruminal protected VA in abomasum closes to 60%.5. The result shows that milk production, milk quality, VA content in milk and serum immunoglobulin increase as the improvement of ruminal protected VA levels; feeding experiment shows ruminal protected VA diets has better effects than non-protected VA in the same dietary VA level. 5. It is practical and practicable that VA could be protected with Ethylcellulose coating, and by FLP-5 pelleting drier though spray-drying method...