Study On Utilization Of Amino Acids And Protein Turnover In Inner Mongolian White Cashmere Goats

This paper mainly studied on absorption and utilization of amino acids, and protein turnover in Inner Mongolian White Cashmere (IMWC) goats by nutrients infusion technique, arterio-venous technique and isotope technique. Firstly, It were analyzed and evaluated that amino acid profiles in the muscle, cashmere and hair, and ruminal microbial protein in IMWC goats. Four target amino acid patterns were established according weight of the amino acid pattern between muscle and cashmere. It were also calculated that the amino acid flow in the duodenum and the digestibility of amino acids in the small intestine of IMWC goats fed basal diet in vivo. Then doses of amino acid infusion for different patterns were calculated according to the Amino Acid Dynamic Addition Model. Twelve amino acids mixture in same amount but with different profile of amino acids were introduodenally infused in order to make ultimately target pattern for absorbable amino acid in the small intestine. Digestion, metabolism and utilization of amino acids with different pattern were investigated by arterio- venous catheter technique and digestion trials, so as to find an ideal absorbable amino acid pattern. After this, three amino acid levels with the same ideal absorbable amino acid pattern were designed to investigated the effect of amino acid level on metabolism and utilization of amino acids, and determined the appropriate absorbable amino acid level with ideal pattern in IMWC goats fed the basal diet. It also investigated the effects of absorbable amino acid pattern and level in the small intestine on FSR of protein in the jejunum, liver, muscle and skin, and cashmere performance in IMWC goats. The results showed M85+C15 pattern was an ideal absorbable amino acid pattern for IMWC goats, which was suitable for cashmere producing. It was suggested that cashmere and meat performance could improved by regulating absorbable amino acid pattern and increasing absorbable amino acid level in the small intestine.Part 1Study on target pattern of absorbable amino acids and digestibility in the small intestine.Exp.1To establish of target pattern of absorbable amino acids in the small intestine of IMWC goats.Eight wethers of IMWC goats (25-30kg) with the same father were used to analyze and evaluate the profile of amino acids in the muscle, cashmere and hair, rumenal microbe protein. The results showed the amino acid profiles were different among muscle, cashmere and hair, and rumenal microbe protein. The amino acids in ruminal microbial protein were imbalance for meat and cashmere producing. So four target amino acid patterns were established according weight of the amino acid patterns between muscle and cashmere, which were M100, M90+C10, M80+C20 and M70+C30, so as to find an ideal absorbable amino acid pattern in the small intestine for cashmere producing. Exp.2 Study on amino acid flow and digestion in the small intestine of IMWC goats fed basal diet Twelve wethers of IMWC goats (25-30kg) with the same father, fitted with permanent cannulas in the rumen, at the proximal duodenum and terminal ileum were used to investigate amino acid flow and digestibility in different sites of the digestive tract of IMWC goats fed the basal diet. The results showed the average digestibility of amino acid in the small intestine was 76%. The flow of SAA (Met, Cys) in the duodenum was 20mmol/d, but the digestibility of Met was 60%, significantly lower than the other amino acids (P<0.01), as the imbalance of absorbable amino acids in the small intestine resulted in deficiency of His and Arg for the basal diet.Part 2Effect of absorbable amino acid pattern in the small intestine on digestion, absorption and metabolism of amino acids in IMWC goats.Exp.1 Effect of absorbable amino acid pattern in small intestine on digestion of AA in IMWC goats.Twelve wethers of IMWC goats (25-30kg) with the same father, fitted with permanent cannulas in the rumen, at the proximal duodenum and terminal ileum were used to investigate effect of absorbable amino acid pat...