Twelve weanling kittens (6 male and 6 female) were given six purified l-amino acidbased diets for periods of 10 days each in accordance with a 6×6 balanced latin square design. Diets contained either 5.5, 7.0 or 15 g, of either the d-or l-isomer of methionine/kg of diet. Neither food intake nor body weight gains of kittens were significantly different between kittens fed d-and l-methionine diets. Nitrogen retention of female kittens and of male and female kittens combined was significantly greater when fed the l-as compared to the d-methionine diets. When dietary methionine was just under the requirement (7 g/kg diet), weight gain and nitrogen retention of the d methionine group as compared to l-methionine group, respectively was 80% and 73% whereas below and above the requirement, the weight gain and nitrogen retention of the d-methionine groups was 90-106% of that of the L-methionine groups. Total methionine and D-methionine concentrations in plasma were significantly higher after ingestion of the d-than l-methionine diets for combined sexes. Plasma of kittens ingesting the d-methionine diet had 20-30% of the methionine present as d-methionine. Plasma half/cystine and cystathionine were significantly lower for the female and combined sexes after ingestion of the d-as compared to the l-methionine diets. Male kittens also had significantly lower plasma cystathionine after ingesting the d-than thel-methionine diets. The weanling kitten utilizes d-methionine well for growth; but N retention and plasme amino acids indicate that the efficiency of utilization of d-methionine for tissue growth may be lower than that for l-methionine.
- D-amino acids
- Sulfur amino acids
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Nutrition and Dietetics