Study On CNCPS Protein Composition And Feeding Value Of Hay And Silage In Different Haze/Probiotic Period

Objective:The purpose of this study was to explore the changes of nutritional quality,fermentation quality,Cornell net carbohydrate and protein systems?CNCPS?and rumen degradation rate of alfalfa hay/silage at different cropping times and mowing stages,and to provide theoretical basis for the efficient utilization of alfalfa hay/silage resources.Methods:The experiment set 3 stubble times?First stubble,Second stubble,Third stubble?and 3 mowing stages?Budding stage,Early blooming,Full blooming?to make hay and silage respectively.To explore the nutritional quality of alfalfa hay and CNCPS protein components change law of the alfalfa silage fermentation process 0,3,9,15,30,45,60 d and 60 d after aerobic fermentation period of 1,3,5 d nutritional quality,fermentation quality change rule and CNCPS protein components,and alfalfa hay and silage fermentation in rumen?60 d?12,24,36,48,72 h the degradation of nutrients;The correlation between protein components and nutrition indexes was compared.Results:Under the factors of different stubble times and mowing stages,the nutritive quality,protein components of CNCPS and rumen degradation rate were analyzed to evaluate the advantages and disadvantages of alfalfa hay and silage,and the following results were obtained:?1?The dry matter?DM?,non-protein nitrogen?PA?and rapidly degraded protein?PB₁?content of alfalfa hay increased with the increase of stubble times and the delay of mowing period,while the content of acid washing fiber?ADF?and neutral washing fiber?NDF?in the third stubble was lower.Crude protein?CP?and soluble carbohydrates?WSC?,crude fat?EE?,crude Ash?Ash?,relative feeding value?RFV?and medium speed degradation of protein?PB₂?value of a downward trend,faults at the same time in the above index is significantly higher than the second crops are 1 and 3 crop stubble?P<0.05?,the same time of different mowing period budding period is significantly higher than the above indexes of early flowering and full bloom?P<0.05?.?2?During the alfalfa silage fermentation process,with the prolongation of fermentation time,the contents of nutrition indexes,fermentation indexes and CNCPS protein components in each treatment gradually decreased.The first crop with different cropping times had better nutritional quality,and the contents of CP,WSC,EE and Ash were significantly higher than those in other treatments?P<0.05?.With the increase of stubble times,the pH value of each treatment in different clipping stages of the same crop showed a"V"type change,and the content of lactic acid and acetic acid showed an inverted"V"type change.Ammonia-nitrogen?NH₃-N?and ammonia-nitrogen/total nitrogen?NH₃-N/TN?were positively correlated with the stubble times and the clipping stages.The contents of PA,PB₁ and slow degradation protein?PB₃?in the first crop of the same cutting period at different stubble times were significantly lower than those in other treatments?P<0.05?,and the contents of PB₂ and binding protein?PC?were significantly lower than those in other treatments?P<0.05?.?3?The content of nutrients in alfalfa silage during aerobic stabilization increased with the extension of cellar opening time.The content of ADF and NDF in the third cropping stage was the lowest.The CP content in the first cropping stage was still the highest.Prolonged aerobic exposure time can increase pH and NH₃-N content,and reduce lactic acid and acetic acid content,resulting in decreased silage quality.The contents of PA,PB₁,PB₃ and PC were the lowest at different cutting stages of the same crop,and the content of PB₂ was significantly higher than that at the beginning and flowering stages?P<0.05?.PA and PB₁ contents in the first crop were the lowest and PB₂ contents were the highest in the same mowing period of different stubble times.?4?The rumen degradation of alfalfa hay/silage was the same,and the dry matter degradation rate?DMD?was the highest in the first crop at the same cutting stage.The dry matter degradation rate?DMD?,acid washing fiber degradation rate?ADFD?,neutral washing fiber degradation rate?NDFD?and crude protein degradation rate?CPD?of the same crop at different cutting stages and bud stages were significantly higher than those at the initial and blooming stages?P<0.05?.?5?The fitting degree of rumen degradation indexes and protein components of alfalfa hay/silage reached71.80%⁹8.60%and R² reached 0.516⁰.975.Conclusion:According to the comprehensive value evaluation of alfalfa hay/silage in different stubble and mowing stages,it can be concluded that the nutritive quality of the first stubble in the same mowing stage of different stubble is better,and the nutritive value of the first stubble in different mowing stages is better.The earlier the cutting,the younger the alfalfa,the higher the nutritive quality,the better the palatability,the better the plant regeneration,and the better the nutritive quality of alfalfa hay and silage.The degradation of protein components can reflect the nutritional quality of alfalfa,especially the protein content.The correlation and regression models of nutrient index,fermentation index,rumen degradation rate and protein components of CNCPS showed that the contents of ADF,NDF and CP were highly correlated with protein components,and it was feasible to estimate rumen degradation rate of alfalfa hay/silage by using protein components of CNCPS.Therefore,controlling mowing time can improve alfalfa silage nutrition,fermentation quality and alfalfa utilization rate.