Effect Of Dietary Cation-Antion Balance On Fiber Degradation In The Rumen,Nitrogen Metabolism And Performance Of Sheep Fed A Corn Stover Based Diet

Based on the nutritional engineering technology for high efficiently utilizing low quality roughages proposed by professor Lu De - xun( 1998), the effects of 4 levels dietary cation - antion balance (DCAB) on the rumen degradation of dietary fibre~. rumen parameters and some blood parameters ; on the performance and nitrogen metabolism in sheep fed a corn stover based diet were studied. Treatments consisting of 0, 10,20,40 meq/lOOg DM of DCAB were achived by adding different levels of NI-LCI and NaHCO3 to the 4 diets with similar level of other nutrient levels in four groups ,such as ME, CP, Ca and P. The objective of this thesis is to provide some technical basis for mineral nutritional manipulation in the nutrtional engineeris technology for high efficiently utilizing low qulity roughages.Trial 1. Effects of different dietary cation - anion balance on the digestion and degradation dynamics of fibreTwelve 2 years old Inner Mongolian fine wool wethers(Body weight, 29 ± 3.36kg) with permanent rumen and duodenum cannula , divided into 4 groups of 3 were used to study the effects of 4 levels DCAB on the digestion and rumen degradation of dietary fibre and on digestion of the dietary DM, ADF and NDF and passage at the different sites of the digestive tract of sheep. The results show as follows With the increase of DCAB, the rumen effective degradations of DM, NDF, ADF, HC and CEL of corn stover tended to increase(P<0.05); the digest passage rate(Kp) decreased (P<0.05); the digestion of dietary DM, NDF and ADF in the rumen was improved (P<0.05); ruminal microbial protein synthesis went up (P <0. 05) . Moreover, all of the results showed the peak value appeared at DCAB of 20 meq/ lOOg DM.The digestions of dietary DM, NDF and ADF (P<0.05) in the digestive tract of sheep was improved, but there was no peak value.Trial 2. Effects of different dietary cation - anion balance on the rumen parameters and some blood parameters.Inner Mongolian fine wool wethers of two years old with permanent ruminal and duoouI.denal cannulas, divided into 4 groups of 3 at randomly , were used to study the effects of 4 levels DCAB on ruminal parameters including pH, NH3 - N, VFA concentration and on some blood parameters such as blood sugar, PUN, Plasam Ca and P. The results showed with t~e increase of DCAB, ruminal pH increased Linearly(P<0.05), the ruminal NH3 - N signiiicantly reduced (P<0.05) .There was a peak value at DCAB is 20 meq/ 100gDM.As the products of rumen fermentation, VFAs was not effected significantly(P> 0.05), ruminal acetic acid molar proportion had no significant difference, too (P>0.05), but ruminal propionic acid and butyrate acid concentration were effected significantly(P<0.05)and ratio of acetic acid to propionic acid are effected significantly(P< 0.05) . Plasma Ca and P concentration droped off and there was significant difference(P< 0.05) among the differe treatment.PUN Concentration was effected significantly(P<0.05).There was no significant effect in blood sugar(P>0.05).Trial 3. Dietary cation - anion blance effects on performance and nitrogen balance in the sheepThe effects of dietary cation - anion blance on performance and nitrogen balance in sheep fed with a corn stover based diet were investgated . 12 Inner Mongolian fine wool wethers of two years old with permanent ruminal and duodenal cannulas, divided into 4 groups of 3 at randomly, were used in this trail.The results showed that with the DCAB inerease,DM intake tended to increase, but the different treatments have no significant difference(P> 0. 05) . Body gain , N retention and the utiliation of digestible N were increased with the DCAB increase and had significant difference , respectively(P<0. 05) .Moreover, there was a peak value of DCAB at 20 meq/100gDM.To summirate, according to the all results obtained in this study, the conclution was drawn that the optimal DCAB for sheep fed a corn stover based diet was 20 meq/100gDM.