The objective of this study was to determine the contribution of corn kernel enzymes, bacteria, fungi, and fermentation end-products (main acids and ethanol) to protein solubilization during fermentation of reconstituted corn grain silage. Flint corn kernels were ground (5-mm sieve), rehydrated to 32% of moisture, and treated with no additives (control), gamma irradiation (32 kGy), gamma irradiation + fermentation end-products (1% of lactic acid, 0.3% of acetic acid, and 0.7% of ethanol, as fed), and natamycin (1% as fed). Treated grains were ensiled in nylon-polyethylene bags and stored for 90 d. Protein solubilization was calculated for each treatment and the contributions of proteolytic sources were determined. Bacterial activity was the main contributor to proteolysis (60%) followed by corn kernel enzymes (30%), whereas fungi and fermentation end-products had only minor contributions (∼5% each).

The aim of this study was to compare strategies to prevent clostridium growth in sugarcane silages added with lime. In Experiment 1, treatments were (as fed basis): no additives (Control), 15 g lime kg−1 (L), 15 g lime kg−1 + 1.5 g sodium benzoate kg−1 (L+B), 15 g lime kg−1 + 0.7 g sodium nitrite kg−1 (L+N), 15 g lime kg−1 + Lactobacillus buchneri (5 × 105 cfu g−1) (L+LB) and 15 g lime kg−1 + Lactobacillus plantarum (5 × 105 cfu g−1) (L+LP). Plastic buckets (20 L) were used as experimental silos. Silage fermentative losses and aerobic stability were also evaluated. Lime treatment was not effective in decreasing dry matter (DM) losses compared with control silage (121 and 158 g kg−1, respectively). On the other hand, L+LB, L+B, L+LP and L+N treatments significantly decreased DM losses (70, 73, 87 and 98 g kg−1, respectively). The aerobic stability of silages L (172 h), L+B (155 h) and L+N (223 h) was substantially higher compared to those treated with L+LB (49 h), L+LP (48 h) and control (52 h). Control silages had low counts of clostridia (log 3.3 cfu g−1) whereas L and L+LB treated silages reached very high clostridium counts (log 6.7 and log 6.0 cfu g−1, respectively). The remaining treatments resulted in intermediate values. In Experiment 2, sugarcane treated with lime (15 g kg−1) received the following doses of sodium nitrite prior to ensiling: 0, 0.5, 1.0 and 1.5 g kg−1 as fed. Treatments did not affect clostridium counts but decreased butyric acid and 2,3‐butanediol. The silage with the highest nitrite dose decreased the butyric acid content substantially compared to other treatments but the final level (5.9 g kg−1 DM) was above the target value for well‐fermented silage. None of additives combined with lime were able to provide completely butyric acid free silages.

The techniques used to assess pH in silages vary greatly. The aim of this study was to evaluate the effects of water-to-sample ratio, extraction procedure, and standing time on pH determination. Silage samples (n = 20 for each silage) were chosen to represent diverse crops (corn, elephant grass, sugarcane, and forage peanut) to have a varied ensilability index and thus a wide range in final pH. Three water-to-sample ratios and 2 extraction procedures were used to measure pH at 0, 5, 10, 15, 30, 60, and 120 min of standing time. The ratios (undried silage to water) were 9:60, 25:100, and 30:270. The samples with the first 2 ratios were manually extracted, using a glass beaker and a glass stirring rod. The samples with the 30:270 ratio were extracted by using a stomacher blender for 4 min at 200 rpm. An electrode was used to perform pH readings. Dry matter (DM), water-soluble carbohydrates, and lactic acid concentrations were determined. The experimental design was completely randomized using a mixed repeated-measures model. Mean separation was performed using the Tukey test at P < 0.10 using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). The DM concentrations ranged from 24.5 to 40.2, 15.8 to 25.9, 26.9 to 30.6, and 17.8 to 21.4% for corn, elephant grass, sugarcane, and forage peanut silages, respectively. The lactic acid concentrations ranged from 2.9 to 10.1, 1.8 to 4.4, 0.7 to 11.4, and 0.3 to 1.4% of DM for corn, elephant grass, sugarcane, and forage peanut silages, respectively. The pH values measured by the 9:60 method were greater than other techniques at any standing times. The pH values from the 25:100 and 30:270 methods did not differ for elephant grass and forage peanut silages at any standing times. However, the 30:270 method had greater pH values for corn and sugarcane silages than the 25:100 technique at any standing times. The pH values measured by the 30:270 method did not vary for any of the silages according to standing time. Nevertheless, the pH values of the 25:100 method were greater from 0 to 10 min than for other standing times for all silages. Thus, for this method, there was pH stabilization from 15 min of standing time on. Overall, the 25:100 and 30:270 methods are recommended for assessment of silage pH. Fifteen minutes of standing time should be used for the 25:100 method but the pH reading can be performed immediately after mixing for the 30:270 technique.

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The aim of this study was to evaluate the feed quality of reconstituted corn grain silage (RCGS), treated with chemical additives and stored for 15, 30, or 60 d in 5-L plastic buckets. Dry ground corn was rehydrated to 350 g·kg−1 and treated with either polysorbate 80 (2 L·t−1) (POL), propionic acid 28% (2 L·t−1) (PRO), Mycoflake™ (2 L·t−1-blend polysorbate 80 and propionic acid) (MYC) or nothing (CON). The effect of the length of storage was combined in a factorial arrangement with the additives. Ammonia-N increased from d-15 of storage. A treatment × storage length interaction was observed for ethanol content at d-60 of storage, and all treatments had lower ethanol concentration than CON. There was an interaction for butyric acid content at d-30 and d-60 of storage; CON showed higher butyric acid concentration than treated silages. Aerobic stability increased from d-15 to d-30. At d-15 of storage, the PRO and MYC treatments decreased the DM losses. The length of storage increased the ruminal in situ degradability of starch, and DM and MYC increased the DM degradability in 3.6 percentage units at 12 h of incubation, compared with POL. In conclusion, increasing the length of storage of the RCGS from d-15 to d-60 improved the starch and DM degradability. Mycoflake increased the availability of nutrients, and the length of storage enhanced the aggregation of particles; further, polysorbate 80 (Tween 80) might be further studied as a potential antimicrobial agent in silages.

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