Evaluation of milk replacer supplemented with lysine and methionine in combination with glutamate and glutamine in dairy calves

This study aimed to evaluate performance, gut health and metabolic changes in dairy calves receiving milk replacer supplemented with lysine and methionine with 0.6% or 1% AminoGut (10% Glutamate and 10% Glutamine). Forty-five Holstein calves were blocked and distributed in the treatments: (1) Control: no supplementation; (2) Lys, Met, AminoGut 0.6%; (3) Lys, Met, AminoGut 1%. Animals were individually housed, with free access to water and concentrate. Milk replacer (6 L/d) was fed until the eighth week of life. Feed intake and faecal score were monitored daily. Calves were weighted and measured weekly. Blood samples were collected every other week to determine metabolites. Supplementation did not affect the performance nor the metabolism of calves. There was no effect of supplementation for faecal score. An age effect was observed for most of the variables, mainly as a response of starter intake and consequent shift from a pre to a functional ruminant metabolism. The supplementation of the milk replacer with lysine and methionine in association with 0.6% or 1% AminoGut had no effect on performance, gut health nor metabolism of dairy calves. More important than the fine adjustment of amino acid requirements is the adoption of practices to improve starter intake.