Effect of ensiling time on fermentation profile and ruminal in vitro starch digestibility in rehydrated corn with or without varied concentrations of wet brewers grains

Abstract

The objective of this study was to evaluate the effect of rehydrating and ensiling dry ground corn (DGC) with varying concentrations of wet brewers grain (WBG) on fermentation profile and ruminal in vitro starch digestibility (ivSD; 7-h incubations on dried and 4-mm ground samples). Samples of DGC and WBG were weighed separately and mixed into 100% WBG (WBG); mixture of DGC and WBG targeting 60 (RC60), 65 (RC65), or 70% (RC70) of dry matter (DM); and DGC rehydrated with distilled water targeting for 70% of DM (REH). Samples were ensiled in vacuum-sealed bags and allowed to ferment for 0, 1, 3, 7, 14, and 28 d. The experiment consisted of 30 treatments (5 mixtures of DGC and WGB × 6 ensiling time points) and 120 mini-silos (4 silos per treatment). All samples were analyzed for fermentation profile and water-soluble carbohydrates. Except for WBG, samples from 0 and 28 d were analyzed for ivSD. Content of DM was greater for REH (70.0%), followed by RC70 (69.2%), RC65 (63.9%), RC60 (58.4%), and WBG (17.5%) on d 0, with a slight decrease (1 to 2 percentage units) observed for all treatments until 28 d. Measurements of pH were highest for REH (6.19) and lowest for WBG (4.68) on 0 d, but all other treatments were lower than WBG on 14 and 28 d (3.83 vs. 4.14, on average). Except for WBG, all treatments had a gradual increase in lactic acid concentration from 0 to 28 d. In contrast, butyric acid gradually increased from 0 (0.25%) to 28 d (2.16% of DM) in WBG but not the other treatments. Fermentation patterns were related to water-soluble carbohydrates concentration, which was greater for all treatments except WBG from 0 (1.41% on average vs. 0.38% of DM, respectively) to 28 d (0.37% on average vs. 0.19% of DM, respectively). Except for RC60, greater ivSD was observed for all treatments on 28 than 0 d, but magnitude of the difference was greater for REH and RC70 (14.5 percentage units on average). Rehydration and ensiling of DGC with WBG resulted in adequate fermentation and enhanced starch digestibility.

Silage of rehydrated corn grain

“…In experiments with reconstitution of dry sorghum grain at three moisture levels, Huck et al (1999) found pH values of 5.0, 4.4 and 4.05 for the DM contents of 75, 60 and 55%, respectively, which are very similar to those of the present study. However, Ferraretto et al (2018) found a slightly lower pH for silages of corn grain reconstituted with 30% moisture. The obtained pH data was 4.0 for silage with 28 days fermentation.…”

“…The decrease in the CP values can be possibly explained by the degradation of the protein compounds via the activity of microorganisms, which is also demonstrated by the increase in the NPN/TN contents as the water levels are increased. The values obtained in this experiment for CP are above the 8.71 and 8,9% of DM obtained for silage of corn grain with 35 and 30% of moisture at 64 and 30 days after ensiling, respectively (Morais et al, 2012;Ferraretto et al, 2018).…”

“…The adoption of this technique allows for elimination or considerably reduced development of fungi, (Reis et al, 2001), to improve the starch digestibility of corn (Ferraretto et al, 2018) and nutrients utilization by ruminants (McAllister et al, 1993). Moreover, to the small and medium and farmer, this technique allows to reduce production costs and losses caused by the attack of bugs and rodents, which is very common in grains deposited in warehouses.…”

Lactic Acid Bacteria as Microbial Silage Additives: Current Status and Future Outlook

“…For the trial with brewers' grain-based TMR, the main bacteria found in the stable silages were L. buchneri, but for the soybean curd-based TMR, the main LAB found were P. acidilactici and L. brevis [78], showing potential association of those bacteria to preserve TMR silages. A similar trial was performed by Ferraretto et al [79] to test how the process influenced luminal in vitro starch digestibility. They used dry ground corn to adjust the humidity level of wet brewers' grain and observed an increase in digestibility of the starch from the combined feed.…”

Effects of Sodium Formate and Calcium Propionate Additives on the Fermentation Quality and Microbial Community of Wet Brewers Grains after Short-Term Storage

“…Silage is a common processing method of high-moisture feed; however, most sugars are removed from WBG during the malting process leaving inadequate levels of the substrate (water-soluble carbohydrates, WSCs) for silage fermentation, which can result in silage failure [ 5 ]. Adding a substrate to WBG to enhance its DM and WSC concentrations is an option that can improve the fermentation effect of WBG.…”