Feno de gliricídia em substituição ao milho e farelo de algodão em dietas completas à base de silagem de palma

Abstract

The aim of this study was to evaluate the effects of including gliricidia hay as a substitute for corn and cottonseed cake in complete silage with small variety forage palm (Nopalea cochenillifera ), analyzing nutritional value, fermentation profile and losses, microbial population counts and aerobic stability. In total, 25 experimental mini-silos made from polyvinyl chloride tubes (10 x 33 cm) fitted with a Bunsen-type valve, with a density of 700kg/m³ were used in this study. The mini-silos were distributed in an experimental design with the aim of evaluating the inclusion of gliricidia hay in small palm silage at levels of 0, 5, 10, 15 and 20% based on natural matter (NM). The mini-silos were stored for 120 days until later evaluations of nutritional value, fermentation profile (pH, ammonia nitrogen content, organic acid content: acetic, propionic, butyric and ethanol), fermentation losses (gases, effluents and dry matter recovery), aerobic stability, and counts of microbial populations (lactic acid bacteria, molds and yeasts). The statistical analysis used PROC MIXED from SAS® (Statistical Analysis System). Polynomial orthogonal contrasts were used to obtain linear and quadratic responses to the level of inclusion of gliricidia hay and co-products at a 5% probability level to indicate significance. Increasing the inclusion of gliricidia hay generated a quadratic effect (P<0.05) for the results of CP, EE, RMS forage losses. And a linear effect (P<0.05) for the results of NDF, FDA, hemicellulose, MM acetic acid, pH, NFC, TC, maximum temperature, minimum temperature and effluent losses. There was no breakdown in aerobic stability during the 120-hour evaluation period. The inclusion of 20% gliricidia hay in the natural matter to replace corn and cottonseed meal is recommended for silage of small palm, and the addition of 3% minerals allowed the nutritional quality of the silage to be maintained for feeding ruminants.