A modeling approach for estimating seasonal dietary preferences of goats in a Mediterranean Quercus frainetto-Juniperus oxycedrus woodland

Goats are characterized as selective feeders due to their specific feeding behavior, thus the study of their seasonal preferences in a Mediterranean oak-juniper ecosystem is of great interest. The current research was conducted in an open oak forest in Megalo Dereio region, northeastern Greece which was grazed mainly by a flock of 650 local breed goats. Grazing behavior data as the number of bites per plant species were recorded using a direct observation method in late spring (May), middle of summer (July) and late autumn (November) of 2010 and 2011. Additionally, a modeling approach was followed in order to study the factors influencing the dietary preferences of goats. Inference – by adopting the Bayesian paradigm – was based on the best multinomial response logistic regression model, selected by the suitable model assessment criteria. According to the results, seasonal and yearly effects were both important in explaining the grazing behavior of goats, with season being the dominant factor. The model’s estimation accuracy was additionally assessed by the comparison of the calculated model-based dietary preferences with the corresponding observed values. The model could be a useful tool to estimate the seasonal changes of dietary preferences of grazing goats.