Amino Acid Requirements Of New Strain Of Yellow-shin-silkie Chickens

New strain of Yellow-shin-silkie chickens was used in the experiments. Amino acid profiles of carcass, feather and maintain were established by comparative slaughtering test and nitrogen balance. Amino acid requirements during the growth period were determined by a factorial design.1. Establishment for amino acid profiles of carcass and feather in Yellow-shin- silkie chickensFour male and four female Yellow-shin-silkie chickens were selected to be killed by cervical dislocation at 0, 4, 8 and 12 week-age old, respectively. After carcass and feather were separated and treated respectively, crude protein and amino acid contents in carcass and feather were determined and various amino acid contents were expressed as the percentage of crude protein. The result indicated that sex had no effect on amino acid profile of carcass and feather protein (P>0.05). The rate of Glutamic acid (Glu),Arginine (Arg), Threonine (Thr), Proline (Pro), Leucine (Leu), Phenylalanine (Phe) in carcass protein showed significant difference for 0 day in comparison with others (P<0.05). There is no difference among 4, 8 and 12 week–age old (P>0.05). The rate of Arg, Glycine (Gly), Pro, Alanine (Ala), Valine (Val), Isoleucine (Ile), Leu, Phe, Histidine (His), Tyrosine (Tyr) and Tryptophan (Trp) in feather protein showed significant difference for 0 day in comparison with others (P<0.05). There was no difference among 4, 8 and 12 week-age old. In view of the above results, amino acid profiles of carcass and feather of broiler could be decided according to the mean of 4, 8 and 12 week-age old.2. The research of amino acid profile and requirements for maintenance in Yellow- shin-silkie chickensAdult Yellow-shin-silkie chickens weighing basically similar were used in the experiment. N-free diet and low nitrogen diet were fed in the nitrogen balance trials. N-free diet was used to estimate endogenous nitrogen excretion, low nitrogen diet was used to estimate creatinine excretion and skin integuments losses consist of feather and scurf. The results were as follows: Nitrogen retention and creatinine excretion were determined at 702.51 mg/day and 0.15mmol/day in low nitrogen diet birds. When fed an N-free diet, endogenous nitrogen excretion was 291.49 mg/day. The protein requirement for maintenance was calculated at 3668.40 mg/BW0.75 /d. Amino acid profiles of excretion and feather for N-free diet were regarded as amino acid composition of endogenous nitrogen and skin integuments nitrogen. Creatinine excretion was replaced by equivalent mol of Gly, Arg and methionine. Summed the endogenous amino acid excretion and losses of the skin integuments, amino acid profiles of requirement for maintenance were calculated.3. The research of amino acid requirement for growing period of Yellow- shin-silkie chickensA total of 200 day old Yellow-shin-silkie chickens were used in the feeding test and comparative slaughtering test, respectively. During the period, body weight and body composition were measured every two weeks. The amino acid requirements for growth of feathers and carcass were calculated according to the growth of feathers and carcass, and their amino acid profiles. Amino acid requirement for maintenance was calculated according to the average body weight of each growing period and amino acid profile for maintenance. The sum of amino acid requirements of carcass and feather and requirement for maintenance was the total amino acids requirement. Amino acid levels for diet in Yellow-shin-silkie chickens were calculated according to the general requirement and the average daily feed intake.