Utilization of L-Cystine and L- and D-Methionine by Mink during the Period of Intensive Hair Growth

The study, conducted 42 years ago, examined how mink utilize sulfur-containing amino acids (SAA) during their intensive hair growth phase. It involved 40 pastel male mink kits divided into four groups of 10, each group receiving diets with SAA from natural ingredients and additional supplements of either L-methionine, D-methionine, or L-cystine over three weeks. The findings indicated that D-methionine was not effectively utilized by the mink, while L-methionine and L-cystine were slightly more effective than natural SAA, though not significantly so. L-methionine was as effective as L-cystine, suggesting efficient conversion by the mink. The study recommended reducing the previously suggested optimum SAA levels in mink diets by about 25% when using natural ingredients or supplementing with L-methionine or L-cystine.