| This experiments was conducted to evaluated the nutrition value of 2 kinds of worse slag class feed:distilled grain, corn distillers dried grains with solubles (corn DDGS),and 6 kinds of roughages:ryegrass, hemarthria compressa, sweet potato stem, straw silage corn, corn stover and ricestraw.These feeds were analyzed by feeds proximate analysis and the cornell net carbohydrate and protein system (CNCPS). Three healthy and similar weight xuanhan cattles fitted with permanent ruminal cannulas were used as test animals. The nylon-bag technique was used to evaluate the degradation characteristics of nutrient. The modified three-step in vitro method was used to evaluate small intestinal digestibility of rumen undegraded protein (RUP), the intestinal digestibility of rumen undegraded amino acids (RUP-AA) of the seresidue after ruminal exposure, obtain the intestinal digestible crude protein (IDCP) content, Correlations between the energy vaue, rumen effective digestibility, IDCP content and the carbohydrate and protein fraction of roughage feeds were established, the results show that:1. In the worse slag class feed, the content of CP, non-protein nitrogen (NPN), true protein and available fiber (CB2) in corn DDGS were significantly higher (P<0.05) than distilled grain, the content of sugar (CA), pectin (CB1), fermentable organic matter and available energy of distilled grain were significantly higher (P<0.05) than corn DDGS. In roughage feeds,the content of CP, NPN,soluble crude protein (SOLP), pectin (CBj) in ryegrass, hemarthria compressa, sweet potato stem were significantly higher (P<0.05) than straw silage corn, corn stover and rice straw, the content of CA, rapidly degraded protein (PB1) in ryegrass, sweet potato stem and straw silage corn were significantly higher (P<0.05) compared with other roughages, rice straw has the highest available fiber (CB2), corn stover had higher (P<0.05) levels of carbohydrate (CHO) and intermediately degraded protein (PB2). The fermentable organic matter and available energy of sweet potato stem and ryegrass was higher and followed by straw silage corn, hemarthria compressa, com stover and rice straw had the lower available energy than others (P<0.05)2. In the worse slag class feed,DM,OM,NDF and ADF effective degradability of corn DDGS was significantly higher than that of distilled grain,while CP effective degradability was significantly lower (P<0.05) than that of distilled grain,but the content of RDP and RUP was significantly higher than that of distilled grain.In roughage feeds,DM effective degradability of ryegrass and sweet potato stem was significantly higher than that of hemarthria compressa, straw silage corn, corn stover and rice straw (P<0.05). CP effective degradability and ADF effective degradability of ryegrass was significantly higher than that of sweet potato stem, hemarthria compressa, straw silage corn, corn stover and rice straw (P<0.05). NDF effective degradability of ryegrass was significantly higher than that of sweet potato stem, straw silage com, hemarthria compressa, corn stover and rice straw (P<0.05). The rumen degradable protein (RDP) of ryegrass was higher and followed by sweet potato stem, hemarthria compressa, straw silage corn,corn stover and rice straw (P<0.05) The undegradable dietary protein (RUP) of ryegrass was higher and followed by sweet potato stem, hemarthria compressa, corn stover, rice straw and straw silage corn (P<0.05).3. In the worse slag class feed, the small intestinal digestibility of RUP and IDCP content of corn DDGS was significantly higher(P<0.05)than that of distilled grain. In roughage feeds, small intestinal digestibility of RUP of hemarthria compressa, corn stover and rice straw were significantly higher than that of straw silage corn, ryegrass and sweet potato stem (P<0.05). IDCP content of ryegrass and sweet potato stem were significantly higher than those of the other roughages (P<0.05)4. The amino acid (AA) of the feeds with different kinds was dissimilar, and the potential that can provide for essential amino-acid (EAA) content was different, the AA composition of feeds has change after rumen degradation and small intestine digest.In the worse slag class feed, the content of EAA, small intestinal digestibility of undegradable EAA was significantly higher (P<0.05) than that of distilled grain. In addition, Lys and Met of RUP-AA were the first and second restrictive amino acid respectively through the comparison with ideal patterns. In roughage feeds, the content of EAA, effective degradability of the EAA and small intestinal digestibility of undegradable EAA in ryegrass, hemarthria compressa, sweet potato stem were higher (P<0.05) than other roughages. In addition, Met of RUP-AA were the first restrictive amino acid,and Phe、Val、Phe、Thr、Leu、Thr wer the second restrictive amino acid in straw silage corn, corn stover, sweet potato stem, hemarthria compressa, and ricestraw ryegrass,respectively.5. The available energy of the roughages were significant positive correlation with CB1 (P<0.05), the effective degradability of the nutrient highly significant positive correlation with PA and PB3(P<0.01), the effective degradability of the DM,OM and CP were significant positive correlation with CA,CB1,PB1, and were significant negative correlation with CB2 (P<0.05). The effective degradability of the NDF,ADF were significant positive correlation with CA, and were significant negative correlation with CC,PB2 (.P<0.05).The IDCP content were significant positive correlation with PA,PB1 and PB3 (P<0.05),and were significant negative correlation with PB2.Conclusions:In the worse slag class feed, the content and available of CHO in distilled grain was high, CP effective degradability, FOM and available energy was high. The content and available of protein in corn DDGS was high, the content of RDP, RUP, small intestinal digestibility of RUP and IDCP was high. In roughage feeds, corn stover had higher (P<0.05) levels of CHO and rice straw has the highest CB2, the content and available of ture protein in sweet potato stem was high, the content of CP, NPN, SOLP,FOM and available energy in ryegrass, hemarthria compressa, sweet potato stem were high, effective degradability, the content of RDP and RUP was high.Small intestinal digestibility of RUP of hemarthria compressa, corn stover and rice straw were high, IDCP content of ryegrass and sweet potato stem were high. It was found that the available energy, and the effective degradability and IDCP content of roughages can be predicted according to the CNCPS fraction. |
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