Comparison Study On Evaluating Ntritent Values Of Feedsutffs By DVE/OEB, CNCPS And NRC

In this paper, Cornell Net Carbohydrate and Protein System for Cattle (CNCPS) was used to analysis the protein and the carbohydrate component of corn, High-oil corn, sorghum and feed-type sorghum, and then, putting the measurement to analyze the relations of the metabolize protein (MP), protein degradation balance (DPBNRC) based on the data from the NRC (2001) model, and the truly absorbed protein (DVE), protein degradation balance (DPBDVE) calculated according to the DVE/OEB system, aim to explore the nutritional value of each feed by using different methods.The CNCPS system principles and methods was Used to analysis the chemical composition in accordance with and then, compare the nutritional value of four grain feeds to dairy cows. The results showed that, there had no significant difference in PA, PB1, PB3content (P>0.05) of four grain feeds, The PB2content of the corn and high-oil corn was significantly higher than sorghum and Feed-type sorghum (P<0.05); the rapid and moderate degradation part (PA+PB1+PB2) of high-oil corn was the highest, followed by corn, forage sorghum and sorghum. And there had the same result about the degradatable carbohydrate components (CA+CB1+CB2) of four grain feeds to the ruminant.Rumen degradation characteristics of four grain feeds was conducted by means of Nylon Bag Technique with3Holstein cows, which were fitted with permanent rumen fistula to probe in situ rumen degradation kinetics variance of corn, high oil corn, sorghum and feed sorghum sample. Bag residues were used to measure the dry matter (DM), neutral detergent fiber (NDF) and crude protein (CP) and Starch (Starch) degradation rate, and the rumen degradation parameters of DM and CP. The results showed that the DM, NDF, CP and Starch degradation rate were higher as the extension of rumen degradation time. The DM and NDF degradation rate of feed-type sorghum at48h was higher significantly than the other three grain feeds (P<0.05); the CP and Starch degradation rate of the high-oil corn at48h was highest; The results of rumen Dry matter degradation dynamic parameters showed that the S fraction of the feed-type sorghum was the highest, the D fraction of high-oil corn is the highest, and the U fraction of corn was the highest in the four grain feeds. The sorghum had a highest value of the rumen undegraded dry matter (RUDM), and a lowest value of the degraded dry matter (EDDM) of sorghum in the four grain feeds. The feed-type sorghum had lowest a value of the rumen undegraded dry matter (RUDM), and a highest value of the degraded dry matter (EDDM) in the four grain feeds. The results of the rumen CP degradation dynamic parameters showed that there were no contrasting differences among the four grain feeds in the S fraction(P>0.05), The D fraction of corn was significantly lower than the other three feeds(P<0.05); The degradation rate (Kd) was the lowest in sorghum. The sorghum had a significantly higher rumen undegraded protein (RUP) than the other three feeds (P<0.05), and had a significantly lower rumen degraded protein (RDP) than the other three feeds (P<0.05).The protein relative analysis of the CNCPS, the DVE/OEB system and the NRC (2001) model: The prediction of nutrient supply to dairy cows from the feeds using the NRC (2001) model and the DVE/OEB system, The quantitative predictions were made in terms of (1) rumen undegraded and degraded feed protein (RUP and RDP),(2)truly absorbed undegraded protein(ARUP),(3)potential microbial protein synthesized in the rumen from rumen available protein (MCP)or,(4)from total digestible nutrient(TDN),(5)truly absorbed rumen synthesized microbial protein(AMCP),(6)truly absorbed rumen endogenous protein(ENDP),(7)the truly absorbed protein in the small intestine (MP and DVE), and (8)the protein degraded protein balance(DPBNRC and DPBOEB). The results showed that the high-oil corn had higher Digestible Nutrients, Energy contends calculated according to NRC (2001) model and the degraded protein balance calculated according to the DVE/OEB system (DPBOEB). The results of correlation analysis of four grain feeds showed that there had a moderate positive correlation between the MP and DVE values (r=0.4638), the DPBNRC and DPBOEB values had a weak positive correlation (r=0.1242). The MP and the PA, PB1, PC values based on the data of CNCPS had moderate positive correlations (PA:r=0.7139; PB1:r=0.5209; PC:r=0.7493), and there had a week negative correlation with PB2, PB3(PB2:r=-0.1969; PB3:r=-0.2520); The DPBNRC and the PA, PB1, PB2values calculated from CNCPS had a strong negative correlations (PA:r=-0.8493; PBI:r=-0.9410; PB2:r=-0.7973), and there had a moderate positive correlation with the PB3, PC values (PB3:r=0.5257; PC:r=0.4242). The DVE and the PA, PB1, PB3values calculated from CNCPS had a moderate positive correlations (PA:r=0.6135; PB1:r=0.5097; PB3:r=0.3044), and there had a weak negative correlation with PB2values (PB2:r=-0.0490), a weak positive correlation with PC values (PC:r=0.2514). The DPBOEB and PA, PB1, PB2values had a weak negative correlation (PA:r=-0.2404; PB1:r=-0.2520; PB2:r=-0.0911), and there had a moderate negative correlation between DPBOEB and PB3values (r=-0.4918), a weak positive correlation with PC values (r=0.2154), but there had no significant differences (P>0.05), and the correlation analysis between the DVE/OEB system and CNCPS system also had similar ending. This indicates that further refinement is needed for a modern protein evaluation and prediction system.