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|Title:||The Role of Lysine and Sulfur Amino Acids in Canine Nutrition|
|Author(s):||Hirakawa, Diane Aiko Sue|
|Department / Program:||Animal Science|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Agriculture, Animal Culture and Nutrition|
|Abstract:||Growing Pointer puppies were used in experiments designed to delineate the dietary requirements for lysine and sulfur-containing amino acids (SAA). Rate of gain and feed conversion efficiency were maximized when SAA comprised 0.45% of the diet (109.8 mg SAA/100 kcal ME). The portion of the SAA requirement contributable by cystine was determined to be 50% on a weight basis (50% on a molar basis). Excess dietary cystine superimposed on a methionine-deficient diet manifested as an amino acid imbalance. This imbalance resulted in reduced voluntary feed intake, and hence, reduced growth. Skin lesions also developed on the paw/pad region. An additional study revealed that dietary inorganic sulfate was unable to spare a portion of the physiological need for cysteine in the growing puppy. In studies with lysine, growth performance was maximized when lysine constituted 0.70% of a crystalline amino acid diet or 0.80% of an intact-protein based diet consisting of a mixture of corn gluten meal, sesame meal and meat and bone meal. Bioavailability of lysine in this intact protein mixture was subsequently determined to be 90% based upon a chick bioassay. It was judged that 50% of the disparity in requirements between the intact-protein and crystalline amino acid diet was caused by lysine bioavailability factors and 50% by other factors.
Organic sulfur sources were also evaluated as urinary acidifying agents for Pointer puppies fed a corn-soy-meat and bone meal diet. Urinary excretion of taurine, inorganic sulfate and ammonia increased in puppies fed supplemental levels of methionine, hydroxy methionine free acid or cystine. Toxicity as evidenced by a depression in weight gain and feed efficiency was demonstrable at a 1% level of supplemental methionine. Acidification of urine was only achieved when methionine was present at growth-depressing levels.
In the course of this investigation, two experimental purified diets were developed and tested: a crystalline L-amino acid diet and a methionine-fortified casein diet. Both of these diets produced weight gains and efficiencies of energy, protein and dietary dry matter utilization as good or better than that achieved with a commercial chow diet.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1986.
|Date Available in IDEALS:||2014-12-15|