In situ ruminal degradation of sallow tree leaves using different mathematical models

Abstract

Objective. The objective of this study was to determine the in situ digestion parameters of sallow leaves (Salix Alba) as an alternative food, not commonly used in animal diets using mathematical models. Materials and methods. Four mathematical models were used to describe the ruminal disappearance of dry matter (DM) and crude protein (CP) of sallow leaves: non lagged exponential (Model I); lagged exponential (Model II); Gompertz (Model III), and generalized Mitscherlich (Model IV). Results. Results of DM and CP degradability characteristics showed that all the models fitted well (r2>0.98) to the disappearance data. There were minor differences between the models in terms of statistical evaluations. However, the models differed in the estimated parameters depending on the model’s nature and structure and the parameters included. Conclusions. Given that some models estimated negative values for the studied parameters, they were not biologically acceptable. For this reason, the only model I can be used for estimating the degradability of DM and CP of sallow leaves. In terms of effective degradability (ED) of DM, model III was not used in the calculations because of calculating negative values for part A. Sallow leaves constitute the largest possible proportion of the ruminal degradability fractions, and effective degradability can be used as a forage source in ruminant feeds.