The Assessment Of Availability Of Amino Acid In Undegradable Protein Of Protein Feeds

In this study, the protein and amino acids (AA) of different soybean meal (SBM) and repeseed meal (RSM) were analyzed. Then the degradability of protein and AA of SBM and RSM in rumen were evaluated by nylon bag method and the availability of AA of undegradable protein (UDP) was evaluated by Sibbald true metabolizable energy method (TME). The results were as follows:Experiment 1: SBMSBM were dry-heated and divided into three groups by different temperature. With the increasing of temperoture from 75 to 120 , the content of crude protein (CP) had little change, but protein solution (PS) decreased significantly (PO.01). Total amino acid and essential amino acid both changed little.Two yellow catties with cannulas were used for the measure of dry material (DM), CP and AA degradabilities of SBM in the rumen with nylon bag technology. The results showed: when heated at 75 , the degradability of DM (16h) decreased unsignificantly (P>0.05) and the degradability of CP decreased significantly (P<0.05); when heated at 120 , the egradabilites of DM and CP both decreased significantly (P<0.01). With the increasing of temperature, the average degradability of total amino acid and essential amino acid both decreased significantly (P<0.01) than original SBM.Avian adult cook was selected to study the availability of amino acid in UDP of SBM with TME method. The results indicated as follows: the average availabilitres of total amino acid and essential amino acid had not significant difference between the original SBM and SBM heated at 75 ; but the average availabilities of total amino acid and essential amino acid of SBM heated of 120 were higher than SBM heated at 75 (P<0.05) and extremely higher than original SBM (P,0.01).Experiment 2: RSMIn the group of RSM processed by prepress-extraction, the content of CP in double-low RSM was higher than normal RSM (P<0.05), and the content of total amino acid and essential amino acid were higher than normal RSM but not significant (P>0.05). In the group of double-low RSM. The content of CP in SBM processed byprepress-extraction was higher than other SBM (P<0.05); the content of essential amino acid and total amino acid in RSM processed by low temperature press was higher than other RSM; the content amino acid and total amino acid were higher and a little lower than prepress-extraction respectively.Nylon bag technology was used to measure the degradability of DM, CP and AA. The results showed as follows: in the group of RSM processed by prepress-extraction, the degradabilities of DM and CP of normal RSM were significantly higher (P<0.01) and higher than (P<0.05) that of double-low RSM respectively; in the group of double-low RSM, the degradabilities of DM and CP of RSM processed by cow temperature were significantly higher than other RSM (P<0.01), the average degradabilities of essential amino acid and total amino acid were significantly lower than double-low RSM (P<0.01), and in the group of double-low RSM, the average degrodabilities of essential amino acid and total amino acid of RSM processed by low temperature press were significantly higher than that of other RSM (P<0.01).TME method was used to study the availability of amino acid in UDP of RSM. The results indicated as follows: the average availabilities of total amino acid and essential amino acid of nomal RSM were higher than (P>0.05) and significant higher than (PO.05) double-low RSM respectively, and the difference of these availabilities between RSM processed by prepress-extraction and low temperature was significant (P>0.05). but these availabilities of RSM processed by screw press were significant lower than that of other RSM(P<0.01).The above results suggested that the treatment of dry-heat decreased the nutrient degradability in rumen, and the availability of amino acid in UDP was related to the process style and temperature. In addition, the TME method of poultry could reflect the availability of amino acid of UDP in reminant and can be operated conveniently.