Conservação do farelo úmido de glúten de milho em diferentes estratégias de armazenamento

Abstract

Wet corn gluten feed (WCGF) is a byproduct of the wet milling of grains industry and, despite of potential use in animal diets, information about stock of the ingredient are scarce. Thus, were made two experiments to characterize the preservation of WCGF in different strategies of storage. In the first, aimed to evaluate physicochemical and microbiological aspects of WCGF according to time of ensilage. The coproduct was ensiled in experimental tubes of PVC and after one, three, seven, 14, 21, 28 and 42 days, physical, chemical and microbiological evaluation of the silage were made. Days of ensiling did not affect neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), mineral matter (MM), non-nitrogenous extract (NNE) e total digestive nutrients (TDN) percentages, beyond the count of colonies forming units (CFU) of clostridia. Equations of dry matter (DM), ether extract (EE), effluents losses and gas losses percentages and count of lactic bacteria had low coefficient of determination (r2≤0.6), with variation of 46.54 and 49.05%; 0.96 and 1.71%; 17.97 and 35,14 g kgNM-1; 1.90 and 5.68% and 5.0 and 6.9 log cfu g of silage-1, respectively. The pH (4.12926-0.00894days+0,00024126days2) and the counts of moulds and yeasts log cfu g de silage-1 (7.04228 0.09341days+0.00143days2) had their minor values, respectively, in 18.5 and 32.7 days, while the temperature (19,82657+0,11734dias 0,00502dias2) peaked in 11.7 days. The ensiling allows efficient chemical, microbiological and physical aspects conservation of the WCGF. In the second experiment, aimed to evaluate physicochemical and microbiological aspects of the WCGF in two methods of storage and inclusion of three additives. Were made silos and mounds with 100% of the by-product, 0.1% of sodium benzoate, bacterial inoculant and 10% of pelleted citrus pulp (PCP) evaluated at zero and 35 days. After variance analysis and means test, was observed that addition of PCP increased DM and ADF and even decreased CP, NDF in mounds and increased the count of clostridial at 35 days. The ensiling reduced 6.86% of DM and 17.76% of NNE. At 35 days, reduced 1.65% of the TDN, increased 12.18% of ADF and count of moulds and yeasts. Inclusion of sodium benzoate and bacterial inoculant inhibited fungal growth compared to control. As opposed to storage time, the sodium benzoate inhibited lactic bacteria growth. The interaction of the three variables affected temperature and pH, being lower at 35 days in the silages. Microbiological additive, sodium benzoate and ensiling favors the preserving of the wet corn gluten feed.