ترکیب و قابلیت دسترسی حقیقی اسیدهای آمینه سه رقم سورگوم کم، متوسط و پر تانن در طیور

In order to assess and determine amino acids profile and their availability in different sorghum grain (SG) varieties, three SG varieties including low tannin (0.09% , LTS), medium tannin (0.19%, MTS) and high tannin (0.37%, HTS) were grown at the same location. The grains were analysed for their proximate analyses, tannin and amino acids. True amino acid availability (TAAA) was obtained by Sibbald’s method using ceacectomized single comb leghorn cockerels. The results showed that methionine and cystine were the first and the second limiting amino acids, respectively in LTS and MTS. But in HTS, lysine (0.166%) was the first and methionine (0.176%) was the second limiting amino acid. Methionine content was 0.114% , 0.182% and 0.176% for LTS, MTS and HTS, respectively. Although, crude protein was lower in HTS (10%) than the other SG, but histidine, methionine and isoleucine were higher for HTS in comparison to LTS and MTS. TAAA decreased when tannin content increased and all amino acids had a lower availability in HTS than LTS and MTS (P<0.05). Methionine in HTS and LTS and glutamic acid in MTS had the highest availability. The availability of proline was most affected by tannin, and its availability was 91.55% for LTS, 84.82% for MTS and 22.82% for HTS (P<0.05).