Nutritional value of Tifton 85 grass haylage under different layers of polyethylene film and storage times

Abstract

Forage conservation processes are fundamentally aimed at maintaining the nutritional quality of forages so that they can overcome the low availability and quality of roughage feed in unfavorable times. The objective of this study was to examine the effect of the number of layers of polyethylene film and storage time on the nutritional value of haylage of Tifton 85 grass (Cynodon spp cv. Tifton 85). Four and six layers of milky white polyethylene film were used in the wrapping of silage bales with a capacity of 400 kg (100 and 150 μm in total thickness, respectively), for four different storage times (at baling and 30, 60, and 90 days). The experiment was laid out in a randomized-block design with four replicates, in a split-plot arrangement in time, in which the number of layers of polyethylene film that wrapped the haylage bales constituted the plots and the storage times the sub-plots. Neutral detergent insoluble protein (NDIP) levels were higher in the haylage wrapped with four layers of polyethylene film (35.8 g kg-1 CP). Storage time affected the neutral detergent fiber (NDF), acid detergent fiber (ADF), mineral matter (MM), NDIP, and lignin contents and in vitro dry matter digestibility (IVDMD). The ADF and lignin contents increased linearly, whereas IVDMD decreased linearly. Mineral matter showed a negative quadratic response. The NDIP and NDF contents exhibited a positive quadratic response. Storage time did not influence the dry matter (550.3 g kg-1), crude protein (102.3 g kg-1 DM), or acid detergent insoluble protein (28.9 g kg-1 CP) contents or in vitro NDF digestibility (582.1 g kg-1 DM). In conclusion, the number of layers of polyethylene film does not influence the nutritional value of Tifton 85 grass haylage. Storage for 90 days reduces the nutritional value of Tifton 85 grass haylage.