The objective of this study was to determine the nutritional characteristics of silage mixtures of pineapple crown including dehydrated citrus pulp and hay, with increasing levels of urea. The experiment was conducted between May to September 2013 and the crowns were from Guapiles, Costa Rica. These were chopped to obtain an average particle size of 3 cm, and packaged in vacuum- sealed bags to which were added: urea (0, 0.5, 1.0, 1.5% w/w fresh basis), 2 high sources of dry matter: hay (H) of Transvala grass (Digitaria decumbens Stent, cv Transvala) and dehydrated citrus pulp (DCP), both at a level of inclusion (10% w/w fresh basis), and a single level of molasses (3% w/w) and bacterial inoculum by molasses fermentation with whey (1 l/t). Also a sample without additives was prepared as a control. Hay increased dry matter content and all fiber components, but reduced crude protein content, non fibrous carbohydrates, and total digestible nutrients.. When PCD was used, the fiber level was reduced which increased digestibility of ensiled mixture. The use of urea increased the CP content and reduced nitrogen linked to fiber by a dilution effect. It was estimated that, silage materials allow to obtain from 0.43 to 1.89 kg of milk/cow, whenconsuming 5 kg fresh matter (FM)/animal; 0.86 to 3.77 kg milk/cow when consuming 10 kg FM/animal; 1.29 to 5.66 kg milk/cow when consuming 15 kg FM/animal.

Keywords: forage preservation, ruminant nutrition, pineapple byproducts, pineapple additives, silage.