Livingston SE, Staples CR, Renjifo A, Sullivan KE, Valdes EV. 2009. Evaluation of season of harvest and water addition on forage quality of willow (Salix caroliniana) processed for silage at Disney’s Animal Kingdom. In Ward A, Treiber K, Schmidt D, Coslik A, Maslanka M, Eds. Proceedings of the Eighth Conference on Zoo and Wildlife Nutrition, AZA Nutrition Advisory Group, Tulsa, OK.
The objective of this study was to evaluate two seasons of harvest and water addition at the time of ensiling on silage quality of Carolina willow (Salix caroliniana). If successful, willow silage could be used as a supplement during the winter months for some browse-consuming animals at Disney’s Animal Kingdom. The experiment consisted of two harvest seasons and two moisture concentrations for the willow in a two by two factorial design. Willow was harvested in April and August (beginning and middle of the Florida willow-growing season), chipped to reduce particle length, and packed into plastic-lined 208-liter drums for ensiling. At each harvest month, water was added to half of the willow just prior to packing in order to reduce dry matter content and potentially improve fermentation. After approximately 300 days of storage, samples were collected and analyzed for nutrients and fermentation characteristics. Approximately 80% of the sugar of the fresh willow (10% of dry matter (DM)) was used during fermentation. Willow harvested in the spring experienced a slightly less favorable fermentation based upon lower lactic acid concentrations (1.19 vs. 1.52% of silage DM), greater butyric acid concentrations (0.043 vs. 0.0% of silage DM), and elevated pH (4.97 vs. 4.48). This may have been due to greater concentrations of starch and lower concentrations of ash in willow harvested in the summer compared to that in the spring. Decreasing the DM concentration by 2 to 3% units by adding water at the time of ensiling resulted in lower concentrations of lactic acid (1.03 vs. 1.68% of silage DM) and greater concentrations of acetic acid (0.64 vs. 0.38% of silage DM). Adding water to willow prior to ensiling may improve silage quality when willow is harvested in the summer due to increased concentration of acid. The concentrations of lactic acid and acetic acid in willow silage were lower than that expected in corn or legume silages, although the lactic acid to acetic acid ratio fell within the range reported for corn silage. Carolina willow can be successfully ensiled. Its use as a potential dietary item during the winter months for those animals requiring browse in their diets remains to be determined.17_Livingstonsilage.pdf     167 KB