Nonlinear Mixed Models Applied to Ruminal Degradability Studies

This article presents an application of three classical models to studies ruminal degradation kinetics, namely Ørskov and McDonald’s model (1979); Van Milgen, Murphy Berger’s (1991), Richard’s proposed in France, Dijkstra, Dhanoa (1996). Our approach is focused on accounting for animal e ects given that measurements are repeated the same animal. The were studied under perspective nonlinear mixed-e (NLME) models. In this way, we intended accommodate problems response variance heterogeneity correlations between measures. To apply method, used data from experiment conducted a Latin square design assess dry matter degradability following silages: Elephant grass (Pennisetum purpureum Schumach.) silage treated with bacterial inoculant, enzyme-bacterial corn (Zea mays L.) silage. Samples incubation 0, 2, 6, 12 , 24, 48, 72 96 h. For these experimental data, Murphy, showed better performance than others. indicated inclusion important obtaining more accurate information can be considered NLME modeling. Furthermore, it was also possible perform easy-to-interpret analysis contrasts treatments by using Tukey’s test.