Mathematical models for adjustment of in vitro gas production at different incubation times and kinetics of corn silages

Abstract

In the present work, with whole plant silage corn at different stages of maturity, aimed to evaluate the mathematical models Exponential, France, Gompertz and Logistic to study the kinetics of gas production in vitro incubations for 24 and 48 hours. A semi-automated in vitro gas production technique was used during one, three, six, eight, ten, 12, 14, 16, 22, 24, 31, 36, 42 and 48 hours of incubation periods. Model adjustment was evaluated by means of mean square of error, mean bias, root mean square prediction error and residual error. The Gompertz mathematical model allowed the best adjustment to describe the gas production kinetics of maize silages, regardless of incubation period. The France model was not adequate to describe gas kinetics of incubation periods equal or lower than 48 hours. The in vitro gas production technique was efficient to detect differences in nutritional value of maize silages from different growth stages. Twenty four hours in vitro incubation periods do not mask treatment effects, whilst 48 hour periods are inadequate to measure silage digestibility.