![]() |
|
|
Department of Animal Sciences, Purdue University, West Lafayette, Indiana 47907
Studies were conducted with chicks on the interrelationship between cystine and methionine in either crystalline amino acid or wheat-peanut meal diets containing suboptimal levels of these two amino acids. The crystalline amino acid basal diet contained 0.2% DL-methionine and 0.2% L-cystine whereas the wheat-peanut meal diet contained 0.2% methionine and 0.26% cystine. Marked improvements in weight gain and feed efficiency were observed when these diets were supplemented with 0.2 to 0.6% DL-methionine. When similar levels of L-cystine were added to the basal diets containing 0.2% methionine, chick growth was depressed. When the diets contained 0.4% methionine, the growth depressing effect of cystine was not observed. These results point to the existence of an antagonism of cystine on methionine utilization when the dietary level of methionine is suboptimal.
KEY WORDS: methionine cystine interrelations chicks
1 Journal paper No. 7203, Purdue University Agricultural Experiment Station.
Manuscript received 23 June 1978.
This article has been cited by other articles:
![]() |
R. N. Dilger and D. H. Baker Cyst(e)ine imbalance and its effect on methionine precursor utilization in chicks J Anim Sci, August 1, 2008; 86(8): 1832 - 1840. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. N. Dilger and D. H. Baker DL-Methionine Is as Efficacious as L-Methionine, but Modest L-Cystine Excesses Are Anorexigenic in Sulfur Amino Acid-Deficient Purified and Practical-Type Diets Fed to Chicks Poult. Sci., November 1, 2007; 86(11): 2367 - 2374. [Abstract] [Full Text] [PDF] |
||||