Supplementation with probiotics and amino acids in the development of beef cattle: identity model study

SUMMARY The goal of this study was to analyze the weight gain of calves supplemented with probiotics and amino acids, through model identity analysis. There were utilized 64 catrated Canchin and Canchin x Nelore calves at 24 ± 1,8 months of age and initial average weight of 395,4 ± 10,5 Kg. The calves were kept on continuous grazing system in a Brachiária brizantha pasture. Four treatments were evaluated: witnesses (test); probiotic liquid (ProbL); probiotic liquid plus amino acids powder (ProbL+AAsPó); and probiotic liquid plus injectable amino acids, in a randomized experimental design with 16 animals by each treatment. The treatments, in turn, were compared trough identity model test, on R software. In order to represent the daily average weight gain over time, the logistic model with three parameters (L3p) was selected. The parameter’s estimates of the model were significant in every treatment, with high coefficient of determination (R2)and low root mean square error (RMSE). There was not significant difference between the models for the treatments, based on the identity model test. Therefore, there was no difference in weight gain by probiotics and/or amino acids utilization.