Nutritional composition of white oat (Avena sativa L.) with different levels of dry matter for use in the diet of horses

Abstract

White oat (Avena sativa L.) is used for the production of forage and, since it has low fibre content and high mineral and protein content, it is indicated for the most demanding equine categories. Its storage during the dry season is possible, but the literature is not clear on the dry matter (DM) level to be kept. The goal of this study was to assess the nutritional make-up of oat with different DM concentrations aiming at finding out the best level for its conservation and use in equine diets. In a 0.72 hectare plot, oat was planted and harvested at day 50 of vegetation. In the field, the material was subjected to wilting so increasing DM levels (25, 30, 45, 65 and 90%) could be obtained by drying in a microwave oven. Samples were manually collected from different spots of the plot and then added with biologic inoculant Silobac® (Lactobacillus plantarum and Pediococcus pentosaceus). They were wrapped with five layers of white plastic film, except those with 90% DM, which underwent haymaking, and each sample weighed 700 g. The material produced was stored for 60 days and were then analyzed for DM, ash, Ca, P, CP, pH, N-NH3, NDF, ADF, CEL, lignin, and HCEL. The trial design was fully randomized with five treatments (25, 30, 45, 65 and 90% DM) and four repetitions and the averages were compared through Tukey's test (P<0.05). The ash concentration was lower in hay, while P, CP, N-NH3, and lignin levels did not vary among treatments. With the increase of DM, Ca, ADF, and CEL content decreased, while pH, NDF, and HCEL increased. For being used in equine diets, oat must be stored with 65-90% DM.