Fubá de milho como aditivo na ensilagem de genótipos de capim-elefante [Cenchrus purpureus (Schumach.) Morrone] consorciados com cunhã (Clitoria ternatea l.)

Abstract

The research was conducted to evaluate the effect of cornmeal addition on gas and effluent losses, nutritional value and aerobic stability of silages of two elephant grass genotypes [Cenchrus purpureus (Schumach.) Morrone] intercropped with butterfly pea (Clitoria ternatea L.). The experiment was carried out under a completely randomized design, following a 2 x 2 factorial arrangement composed of two elephant grass genotypes (Taiwan A-146 2.37 and IRI-381), both intercropped with butterfly pea and harvested at 75 days of regrowth, with and without additive on four repetitions. The silages were made in experimental PVC silos, which remained closed for 60 days. Higher gas loss values (1.2% DM) occurred in the Taiwan A-146 genotype silages 2.37. Additive silages showed lower total loss of dry matter (DM) and higher with DM recovery, with values of 16.5% DM and 83.5%, respectively. The presence of the additive also promoted a higher concentration of soluble carbohydrates in remaining water (2.22 mg/g DM). Higher pH values (4.2) and lower ethanol concentration were observed in Taiwan A-146 2.37 silages. Although no difference of organic acids concentration was observed it is assumed that all silages had good fermentative profile, considering the lactic acid high concentration (103 g/Kg MS) and low concentration of butyric acid (0. 3 g/kg MS). Higher mineral matter content, lower organic matter content, and acid detergent insoluble fiber were observed in silages made from Taiwan A-146 2.37. The additive silages had higher DM contents (221 g/Kg DM), in vitro digestibility of dry matter, lower levels of fiber on neutral detergent (584 g/Kg DM), acid (357 g/Kg DM), cellulose (305 g/kg MS), and hemicellulose (229 g/kg MS). There was interaction (P < 0.05) genotype × additive for crude protein (CP), with the highest value for the Taiwan A-146 2.37 silage (116 g/Kg MS). All silages lost aerobic stability 45 hours after opening the silos. The addition of cornmeal did not result in an increase in lactic acid concentrations, but there was an improvement in the fermentative profile of the silages and low concentrations of butyric acid. Other fermentative parameters (pH and ammonia nitrogen) also indicated that there was no secondary fermentation in the silages. In general, no relevant differences were observed in the nutritional value in the silages of the evaluated genotypes. The presence of butterfly pea does not negatively influence the fermentation profile of elephant grass silages. The addition of 5% cornmeal promotes lower losses and greater recovery of dry matter and nutritive value of elephant grass silages.