PSXI-13 Effects of corn containing gene for high concentration of alpha amylase (Enogen Feed corn) on fermentative parameters, digestibility and methane in vitro

Abstract The objective of this study was to evaluate different corn hybrids, with (Enogen) or without high amylase concentration, on fermentative parameters, dry matter disappearance and in vitro gas production. The treatments evaluated were Tropical flint corn (TFC), Enogen flint corn (EFC) and Enogen dent corn (EDC). All corn was processed and had the same average particle size. The experiment was carried out using automatic gas pressure detection modules (ANKOM, RF). Rumen fluid was collected from two animals fitted with a rumen cannula and fed a diet containing 60% forage. The ruminal liquid was combined with buffer in a 1:4 ratio, respectively, and each bottle received 150 mL of this mixture plus 1.5g of DM corn sample. After 24 h of testing, the pH was measured in each bottle, samples were collected for analysis of short-chain fatty acids (SCFA), ammonia, gas samples for methane quantification and the final residue was taken to determine the DM disappearance. The data were analyzed using Proc Mixed from SAS (9.4), using the following contrasts: 1) TFC (without Enogen technology) vs. Enogen corn (EFC and EDC) and; 2) EFC vs. EDC. Corn with Enogen technology increased the proportion of propionate (TFC: 28.2; EFC: 29.8; EDC: 30.7 mM/100mM; P < 0.01), butyrate (TFC: 9.83; EFC: 10.8; EDC: 11.3 mM/100mM; P = 0.01), isovalerate (TFC: 1.48; EFC: 1.68; EDC: 1.61; P < 0.01) and valerate (TFC: 1.06; EFC: 1.23; EDC: 1.08 mM/100mM; P = 0.03) and decreased acetate (TFC: 58.7; EFC: 55.8; EDC: 54.6 mM/100mM; P < 0.01) and the acetate:propionate ratio (TFC: 2.09; EFC: 1.88; EDC: 1.79; P < 0.01), without affecting ruminal pH and total SCFA. The EDC reduced acetate (P < 0.01), valerate (P = 0.01) and ammonia (TFC: 0.58; EFC: 0.60; EDC: 0.40 mg/dL; P < 0.01) compared with EFC, without affecting the other fermentation variables. The Enogen technology increased the disappearance of DM (TFC: 75.6; EFC: 78.4; EDC: 82.4%; P < 0.01) and reduced the concentration of methane (TFC: 2.99 EFC: 2.09 EDC: 1.87%; P = 0.05) in relation to TFC. Furthermore, EDC corn increased the disappearance of DM (P < 0.01) without affecting gas and methane production when compared with EFC. In conclusion, Enogen technology optimizes the fermentation and DM disappearance, in addition to reducing the concentration of methane, and using the Enogen technology, dent corn is superior to flint corn.