Relationship Of Molecular Structure Of Processing Methods Cottonseed With Rumen Degradation And Small Intestine Digestion

The objective of this experiment was to explore the effects of dry heat(heating at 140 ℃,150 ℃ and 160 ℃ for 1 h),microwave(heating at 700 W for 1 min,2 min and 3 min)and γ irradiation(30 k Gy,45 k Gy and 60 k Gy)on the molecular structure spectral parameters of cottonseed and their relationship with nutritive value,ruminal degradability and digestive characteristics small intestine.Laboratory chemical analysis method,Cornell Net Carbohydrate-Net Protein System(CNCPS),nylon bag technology and a modified three-step in virtro method was used to evaluate the nutritive value of different processing method cottonseed.Investigate whether there is a correlation between molecular structure and nutritional value,with a view to using the obtained spectral information as a predictor for predicting the nutritional value of cottonseed,and to establish a regression equation.Experiment ?: Effects of processing methods on nutrition components and CNCPS components in cottonseedThe test results showed that:(1)Dry heat and microwave increased the content of dry matter(DM)and neutral detergent fiber(NDF)(P<0.05),and reduced the content of non-fibrous carbohydrates(NFC)(P<0.05);γ-irradiation had no significant effect on chemical composition of cottonseed(P>0.05).(2)Dry heat,microwave,and γ-irradiation significantly reduced the content of rapidly degraded carbohydrates(CA)(P<0.05),and had no significant effect on the contents of other CNCPS proteins and carbohydrate components(P>0.05).Experiment II: Effects of processing methods on rumen degradation parameters and small intestine digestibility of cottonseedThe test results showed that:(1)The effectf of dry heat,microwave,and γ-irradiation on rumen degradation kinetics parameters of dyr matter(DM)and crude protein(CP)and small intestinal digestibility of cottonseed(P<0.05).(2)As the heating temperature increased,the microwave time increased,and the radiation dose increased,the effective dry matter degradation rate(EDDM),effective protein degradation rate(EDCP)of cottonseed,small intestinal digestibility(Idg)of rumen non-degradable protein and total digestible protein(TDP)content gradually decreased,and small intestinal digestible protein(IDP)content gradually increased.Experiment III: Effects on protein molecular structure of cottonseed and its relationship with nutritional valueThe test results showed that:(1)Dry heat,microwave,and γ-irradiation significantly increased the amide I band peak height and peak area,amide II band peak height and peak area,α-helix peak height,and the ratio of α-helix to β-sheet peak height(P<0.05).The peak height ratio and peak area ratio of the I band to the II band and the β-sheet peak height had no significant effect(P>0.05);(2)There was a correlation between the molecular structure of cottonseed protein and its nutritional value;(3)In addition to the instantaneous degradation protein(PA)and the rumen degradable partial degradation rate(Kd),protein spectral parameters could be used effectively to estimate its nutritional value and establish a regression equation.The regression equations of crude protein(CP),neutral detergent insoluble crude protein(NDICP),soluble crude protein(SCP),non-protein nitrogen(NPN),rapid degradation protein(PB1),moderate degradation protein(PB2)and slow degradation protein(PB3)were highly fitted.Experiment IV: Effects on carbohydrates molecular structure of cottonseed and its relationship with nutritional valueThe test results showed that:(1)Except for the ratio of total carbohydrate peaks 2 and 3,dry heat,microwave,and γ-irradiation had significant effects on the spectral parameters of cottonseed carbohydrate molecular structure(P<0.05);(2)There was a correlation between the molecular structure of cottonseed carbohydrates and the nutritional value of carbohydrates;(3)In addition to fast-degrading carbohydrates(CA),rumen culture degradable parts(D),rumen culture non-degradable parts(U),and the use of carbohydrate spectral parameters could effectively estimate the nutritional value of carbohydrates.Neutral detergent fiber(NDF),acid detergent lignin(ADL),carbohydrate(CHO),reduced non-fiber carbohydrate(NFC),cellulose,hemicellulose and slow degradation carbohydrate(CB2)had good fitting degree.In summary,dry heat,microwave,and γ-irradiation had effects on rumen degradation parameters,small intestinal digestibility,and molecular structure of cottonseed DM and CP.There was a correlation between the molecular structure characteristics of cottonseed and its nutritional value,and the nutritional value of cottonseed could be estimated and simulated by using its molecular structure,and a regression equation could be established,which provided a theoretical basis for the analysis of nutritional value of feed by FTIR technology.