Study On The Changes Of CNCPS Components In The Native Grass Silage During Anaerobic Fermentation And Aerobic Exposure

In order to explore the change regulations of protein and carbohydrate components in the anaerobic fermentation stage and aerobic exposure stage,and make sure whether the native grass silage has a certain influence on the feeding conversion efficiency,the changes of CNCPS components in the native grass during anaerobic fermentation and aerobic exposure were studied.The native grass from Xilingol native grassland was used for silage preparation.Silage was prepared without?Control?or with lactic acid bacteria?LAB?by using a small-scale silage simulated fermentation system.The contents of carbohydrate and protein?Cornell Net Carbohydrate and Protein System,CNCPS?of native grass silage were analyzed after 5 d,15 d,20 d,30 d,60d of anaerobic fermentation,and after 2 d,5 d,10 d of aerobic exposure,respectively.The main results are summarized as follows:?1?The overall changes of the protein components in the native grass silage during anaerobic fermentation process showed that the content of non-protein nitrogen?PA,rapid degradation part?and neutral detergent soluble protein?PB₂,medium speed degradation partin the true protein?were increased,while the contents of true protein?PB₁,rapid degradation part?,acid washing soluble protein?PB₃,slow degradation part in the true protein?,acid washing and insoluble protein?PC,unavailable part?were decreased,the overall availability of protein is increased.?2?When the native grass silage was opened,the overall changes of the protein components during aerobic exposure showed that the contents of PA,PB₃ and PC were increased continuously,while the contents of PB₁ and PB₂ were decreased continuously with the increase of aerobic exposure time,so the efficiency of protein utilization is decreasing.?3?The changes of carbohydrate content in native grass silage were similar both in ensiling and aerobic exposure process.The contents of CHO?Total carbohydrate?,CC?Non available fiber?,CB₂?Available fiber?,CNSC?Non structural carbohydrate?,CB₁?Starch?and CA?Sugar?showed a declining trend in all silages.?4?The addition of lactic acid bacteria has a certain protective effect on inhibiting the degradation of protein and carbohydrate in the native grass silage,but compared with the control group,the effect is not particularly obvious.It can improve the efficient conversion and utilization of protein and carbohydrate in a certain period of time.?5?Through the correlation analysis of the nutrient composition and the fermentation quality of the CNCPS system,it is found that the feed conversion efficiency in the protein and carbohydrate components is negatively correlated with the DM and WSC in the conventional nutrition indicators,that is to say,the higher the DM and WSC,the stronger the protection of protein and carbohydrates.