CAJ | 학술논문

为了评定不同生育期虉草的营养价值，分析体外产气法和 CNCPS 法两种营养评价方法的相关性。采用体外产气法测定抽穗期、开花期、灌浆期、乳熟期4个生育期虉草的体外发酵产气量、发酵参数（a、b、c）、DM 消化率、NDF 和 ADF 降解率，用康奈尔净碳水化合物和蛋白质体系（cornell net carbohydrate and protein system，CNCPS）分析方法测定相应组分，评价其营养价值，并比较研究两种方法评价结果的相关性。结果表明，体外发酵至72 h 结束，累计总产气量和产气参数 a 以开花期最高（122．68和4．46 mL），显著高于各组（P ＜0．05），且从抽穗期、灌浆期、乳熟期有降低的趋势；抽穗期和开花期的 DM 消化率、NDF 和 ADF 降解率分别显著高于灌浆期和乳熟期（P ＜0．05）。随着虉草生育期的延长，CP 和 SOLP 呈递减趋势，即抽穗期和开花期显著高于灌浆期和乳熟期（P ＜0．05）；NDF、ADF 和 ADL 呈递增趋势，但 NDFIP、ADFIP 呈递减趋势。灌浆期和乳熟期的 CHO 含量显著高于抽穗期和开花期（P ＜0．05），而 CA 和 CNSC 含量则相反，且 CC 含量同样以灌浆期与乳熟期较高；蛋白质组分中，PA与 CA 及 CC 与 PC 组分呈现同样的趋势。虉草 CNSC、CA、CB1、CB2、PA、PB3组分含量与不同时间点产气量呈显著或极显著的相关性（P ＜0．05或 P ＜0．01）。因此，开花期虉草营养价值最高，其次为抽穗期、灌浆期和乳熟期，产气法和 CNCPS 评价牧草具有相关性，用体外产气量估测牧草 CNCPS 组分是可行的。
위료평정불동생육기역초적영양개치，분석체외산기법화 CNCPS 법량충영양평개방법적상관성。채용체외산기법측정추수기、개화기、관장기、유숙기4개생육기역초적체외발효산기량、발효삼수（a、b、c）、DM 소화솔、NDF 화 ADF 강해솔，용강내이정탄수화합물화단백질체계（cornell net carbohydrate and protein system，CNCPS）분석방법측정상응조분，평개기영양개치，병비교연구량충방법평개결과적상관성。결과표명，체외발효지72 h 결속，루계총산기량화산기삼수 a 이개화기최고（122．68화4．46 mL），현저고우각조（P ＜0．05），차종추수기、관장기、유숙기유강저적추세；추수기화개화기적 DM 소화솔、NDF 화 ADF 강해솔분별현저고우관장기화유숙기（P ＜0．05）。수착역초생육기적연장，CP 화 SOLP 정체감추세，즉추수기화개화기현저고우관장기화유숙기（P ＜0．05）；NDF、ADF 화 ADL 정체증추세，단 NDFIP、ADFIP 정체감추세。관장기화유숙기적 CHO 함량현저고우추수기화개화기（P ＜0．05），이 CA 화 CNSC 함량칙상반，차 CC 함량동양이관장기여유숙기교고；단백질조분중，PA여 CA 급 CC 여 PC 조분정현동양적추세。역초 CNSC、CA、CB1、CB2、PA、PB3조분함량여불동시간점산기량정현저혹겁현저적상관성（P ＜0．05혹 P ＜0．01）。인차，개화기역초영양개치최고，기차위추수기、관장기화유숙기，산기법화 CNCPS 평개목초구유상관성，용체외산기량고측목초 CNCPS 조분시가행적。
The objective of this study was to evaluate the nutritional value of reed canary grass at different growth stages using in vitro gas production and the Cornell net carbohydrate and protein system (CNCPS) methods,and to compare results from these two methods.The in vitro gas production method was used to de-termine gas production,fermentation parameters (a,b,c),dry matter (DM)digestibility,and the degrada-tion rates of neutral detergent fiber (NDF)and acid detergent fiber (ADF)at heading,flowering,seed filling and milk ripe growth stages of reed canary grass.CNCPS components were also determined for comparison of the two methods.The cumulative total gas production and the a value (122.68 and 4.46 mL)at the flowering stage were significantly higher than those at other stages,and they tended to decrease from the heading to milk ripe stages.Similarly,DM digestibility and degradation rates of NDF and ADF at the heading and flowering stages were significantly higher than those at the seed filling and milk ripe stages.As reed canary grass ma-tured,the crude protein (CP)and soluble protein (SOLP)contents tended to decrease,and were significantly lower at the seed filling and milk ripe stages than at the heading and flowering stages NDF,ADF and acid de-tergent lignin (ADL)components increased while the NDF insoluble protein (NDFIP)and ADF insoluble pro-tein (ADFIP)generally decreased.The carbohydrate (CHO)content at the filling and milk ripe stages was sig-nificantly higher than that at the heading and flowering stages,while sugar content in CHO (CA)and non-structural carbohydrate (CNSC)contents were higher at the heading and flowering stages.The unavailable fi-ber (CC)content was also higher at the milk ripe stage.The protein component,the non-protein nitrogen (PA),and the bound protein (PC)showed similar trends to those of CA and CC.The levels of CNSC,CA, starch+non-starch polysaccharide fractions (CB1 ),CB2 ,PA,and low degradability protein (PB3 )levels of reed canary grass were significantly or very significantly correlated with the gas production at different time points.Therefore,the nutritional value of reed canary grass was the highest at the flowering stage,followed by the heading stage,filling stage and milk ripe stage in that order.The results from the two evaluation meth-ods,in vitro gas production and the CNCPS method,were closely correlated,suggesting that it was feasible to estimate CNCPS components of forages using the in vitro gas production method.