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

Effects of exogenous protease addition on fermentation and nutritive value of rehydrated corn and sorghum grains silages

The study objective was to evaluate the effects of the addition of exogenous protease on the fermentation and nutritive value of rehydrated corn and sorghum grain silages during various storage periods. Treatments were applied using a 2 × 6 × 3 factorial combination, with 2 types of rehydrated grains (corn and sorghum), 6 doses of the enzyme (0, 0.3, 0.6, 0.9, 1.2, and 1.5%, based on natural matter) and 3 fermentation periods (0, 60, and 90 days) in a completely randomized design, with 4 replications. The protease aspergilopepsin I, of fungal origin, produced by Aspergillus niger, was used. The lactic acid concentration increased linearly as the enzyme dose increased in corn (CG) and sorghum (SG) grain silages, at 60 and 90 days of fermentation. There was an increase in the concentrations of ammonia nitrogen and soluble protein, as well as the in situ starch digestibility in rehydrated CG and SG silages, compared to the treatment without the addition of protease. The addition of 0.3% exogenous protease at the moment of CG ensiling and 0.5% in rehydrated SG increased the proteolytic activity during fermentation, providing an increase in in situ starch digestibility in a shorter storage time.

Effects of different moist orange pulp inclusions in the corn grain rehydration for silage production on chemical composition, fermentation, aerobic stability, microbiological profile, and losses

This study evaluated the effects of different moist orange pulp (MOP) inclusions in corn grain rehydration for silage production as a strategy to store and use MOP and whether these inclusions result in adequate fermentation and aerobic stability (AE) and acceptable losses. Ground corn grain and MOP were weighed separately and mixed to obtain MOP inclusions of 21%, 34%, or 42%. The control treatment was obtained with corn rehydrated with distilled water and MOP inclusion of 0%, with five laboratory silos (15-L buckets) per treatment. Acid detergent fiber, acid detergent insoluble protein, acid detergent lignin, lactic acid, acetic acid, and ethanol contents increased linearly with increasing MOP inclusion, whereas starch, in vitro dry matter (DM) digestibility and butyric acid contents and pH decreased linearly. NH₃ -N/TN content reduced quadratically and was minimal with 8.34 g/kg DM at 14% MOP inclusion. Total DM losses increased quadratically with maximal losses of 4.26% DM at 25% MOP inclusion. AE reduced by 2.8 h for each 1% increase in MOP inclusion. Rehydration of corn grain with MOP results in an adequate fermentation process. The inclusion of 34% MOP was the best because DM losses were lower and AE was not drastically reduced.

Effects of exogenous α-amylases, glucoamylases, and proteases on ruminal in vitro dry matter and starch digestibility, gas production, and volatile fatty acids of mature dent corn grain

Two separate experiments were carried out to evaluate the effects of incremental doses of 10 exogenous endo-acting α-amylase and exo-acting glucoamylase; 1LAT (bacterial α-amylase), 2AK, 3AC, 4Cs4, 5Trga, 6Afuga, 7Fvga, and 10Tg (fungal α-amylases, glucoamylases, and α-glucosidase), 8Star and 9Syn (fungal amylase-mixtures; experiment 1) and three exogenous proteases; 11P14L, 12P7L, and 13P30L (bacterial proteases; experiment 2) on in vitro dry matter digestibility (IVDMD) and in vitro starch digestibility (IVSD) of mature dent corn grain using a batch culture system. Incremental doses of the exogenous enzymes (0, 0.25, 0.50, 0.75, and 1.00 mg/g of dried substrate) were applied directly to the substrate (0.5 g of ground corn, 4 mm) in sextuplicate (experiment 1) or quadruplicate (experiment 2) within F57 filter bags, which were incubated at 39 °C in buffered rumen fluid for 7 h. Rumen fluid was collected 2-3 h after the morning feeding from three lactating dairy cows and pooled. Cows were consuming a midlactation total mixed ration (TMR; 1.60 Mcal/kg DM and 15.4%; net energy of lactation and crude protein, respectively). Three independent runs were carried out for each experiment. Data were analyzed as a randomized complete block design using run as the blocking factor. Dose was used as a fixed factor while run was considered a random factor. Linear, quadratic, and cubic orthogonal contrasts were also tested. In experiment 1, enzymes 2AK, 3AC, and 10Tg did not increase (P > 0.10) IVDMD and IVSD, whereas 0.25 mg of enzymes 1LAT, 5Trga, and 8Star increased (P < 0.01) IVDMD by 23%, 47%, and 62% and IVSD by 35%, 41%, and 58%, respectively, compared with the control. Enzymes 4Cs4, 6Afuga, 7Fvga, and 9Syn linearly increased IVDMD and IVSD (P < 0.01). Greatest increases in IVDMD (82.9%) and IVSD (85.9%) resulted with 1 mg of 6Afuga compared to control. In experiment 2, the lowest dose of exogenous proteases 11P14L and 12P7L increased (P < 0.01) IVDMD by 98% and 87% and IVSD by 57% and 64%, respectively, whereas the highest dose of 13P30L increased (P = 0.02) IVDMD by 44.8% and IVSD by 30%, relative to the control. In conclusion, IVSD and IVDMD were increased by one α-amylase, certain glucoamylases, and all proteases tested, with the glucoamylase 6Afuga in experiment 1 and the neutral protease 12P7L in experiment 2, increasing IVDMD and IVSD to the greater extents. Future in vivo studies are required to validate these findings before these enzyme additives can be recommended for improving the digestibility of mature dent corn grain.

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

Simple Summary

The objective of this study was to examine the effect of sodium formate and calcium propionate on the fermentation quality and microbial community of wet brewers grains (WBG) after short-term storage. Both additives improved the silage quality of WBG ensiled for 20 days to different extents. However, ensiled WBG treated with sodium formate had higher contents of dry matter, water-soluble carbohydrates, and neutral detergent fibers and better fermentation quality, rumen degradation, and microbial composition. The addition of sodium formate enhances the abundance of desirable Lactobacillus and reduces the abundance of undesirable microorganisms, including Clostridium. In summary, during short-term storage of high-moisture feed, sodium formate has a more beneficial preservation effect than an equivalent dose of calcium propionate.

Abstract

The objective of this research was to examine the effect of sodium formate (SF) and calcium propionate (CAP) on the fermentation characteristics and microbial community of wet brewers grains (WBG) after short-term storage. In the laboratory environment, fresh WBG was ensiled with (1) no additive (CON), (2) sodium formate (SF, 3 g/kg fresh weight), and (3) calcium propionate (CAP, 3 g/kg fresh weight) for 20 days. After opening, fermentation characteristics, chemical composition, rumen effective degradability, and the microbial community of ensiled WBG were analyzed. The addition of CAP had no effect on pH and lactic acid concentration and increased the concentrations of propionic acid; the SF group had the lowest pH and acetic acid, butyric acid, and ammonia nitrogen contents and the highest lactic acid concentration. After fermentation, the SF group had the highest contents of dry matter (DM), water-soluble carbohydrates (WSCs), and neutral detergent fiber (NDF). The contents of the three nutrients in the CAP group were significantly higher than those in the CON group. The addition of the two additives had little influence on the crude protein (CP) and acid detergent fiber (ADF) contents of the ensiled WBG. Two additives elevated in situ effective degradability of DM and NDF compared with the parameters detected in the CON group; WBG ensiled with SF had higher effective in situ CP degradability than that in the CON and CAP groups. The results of the principal component analysis indicate that the SF group and two other groups had notable differences in bacterial composition. The analysis of the genus level of the bacterial flora showed that the content of Lactobacillus in the SF group was significantly higher than that in the two other treatment groups, while the content of Clostridium was significantly lower than that in the two other treatment groups. Therefore, the addition of sodium formate can suppress the undesirable microorganisms, improve the fermentation qualities, and ensure that WBG is well preserved after 20 days of ensiling.

Rehydration of dry corn preserves the desirable bacterial community during ensiling

This study evaluated the rehydration approach of mature corn grains as an alternative for high-moisture corn grain silage production in distinct corn hybrids, storage period, cultivation locations and kernel maturity at plant harvest. High-moisture corn was used as a control. The dry matter content and pH of the silage were measured, and the bacterial community associated with corn grains pre- and post-ensiling was also assessed through 16S rRNA high-throughput sequencing. The decrease in pH value was directly linked to an ecological microbial succession of Enterobacteriales and Actinomycetales to Lactobacillales in the silage at 120 days after storage, either in rehydrated or high-moisture corn. These results were similar for both maize production locations and hybrids tested. Finally, the similarity between the ensiling processes including rehydrated corn and the high-moisture corn grain silages proves the reliability of the rehydration approach as an alternative for the maintenance of a successful bacterial community structure and composition capable of producing high-quality silages from dent and flint corn hybrids in tropical conditions.

Silage of rehydrated corn grain

ABSTRACT The objective with this study was to evaluate the effect of different levels of water inclusion on the chemical composition and fermentation profiles of reconstituted corn grain silage. The experiment was carried out in a factorial arrangement in a completely randomized design, with three replicates per treatment. Five treatments were evaluated with different levels of water inclusion (% of the natural matter): dry corn grain (control); 90% dry corn grain (DCG) and 10% water; 80% DCG and 20% water; 70% DGC and 30% water; and 60% DCG and 40% water, totaling 45 experimental silos. Inclusion of water in the silage of reconstituted corn grain promoted a reduction in the CP (%) and NDF (%) contents. However, the water increase elevated the NPN/TN contents and the amount of effluent, gas and dry matter (%) losses. The treatment with inclusion of 30% water in the natural matter leads to a better fermentation profile and fewer losses of effluent and dry matter, so it is recommended for ensiling dry ground corn grain.