Harvest delays in corn silage production often result in excessive dry matter (DM) content, impairing fermentation quality and increasing losses. Rehydration has been used in practice as an alternative to mitigate these effects. This study evaluated the effects of rehydration on physical and fermentation characteristics, microbial population, aerobic stability, and losses of high dry matter (DM) corn silages. Five harvests were performed at seven-day intervals, resulting in increasing DM contents (34.7%, 40.7%, 46.9%, 49.5%, and 54.2%). A portion of each high DM harvest was rehydrated to 35% DM before ensiling. Silages were ensiled in 20 L experimental silos for 90 days. Rehydration reduced pH and increased lactic acid concentration and lactic acid bacteria counts. Rehydrated silages showed fermentation characteristics closer to those observed in the control silage (34.7% DM), particularly regarding pH and lactic acid concentration. However, effluent losses increased significantly with rehydration, with the greatest losses observed in silage containing 54.2% DM. Water holding capacity and silage density exhibited variable responses across dry matter levels in non-rehydrated silages. Aerobic stability was improved by rehydration. Rehydration partially restored favorable fermentation conditions in high dry matter corn silage, although greater effluent losses were observed at the highest dry matter content evaluated.

This study aimed to evaluate commercially purified essential oil compounds to assess molecule-specific effects when applied as additives to rehydrated corn grain silage (RCGS). Dry ground corn grains were rehydrated to 350 g/kg moisture and packed (>1,000 kg/m3) in 5-L plastic buckets. Treatments were prepared as a factorial arrangement of two storage lenghts (30 and 60 d) × fifteen strategies (compound × application rate), being: control RCGS; carvacrol at 200, 600 and 1,000 mg/kg fresh matter (FM); cinnamaldehyde at [...] ABSTRACT This study aimed to evaluate commercially purified essential oil compounds to assess molecule-specific effects when applied as additives to rehydrated corn grain silage (RCGS). Dry ground corn grains were rehydrated to 350 g/kg moisture and packed (>1,000 kg/m3) in 5-L plastic buckets. Treatments were prepared as a factorial arrangement of two storage lenghts (30 and 60 d) × fifteen strategies (compound × application rate), being: control RCGS; carvacrol at 200, 600 and 1,000 mg/kg fresh matter (FM); cinnamaldehyde at

Tropical climates present environmental challenges to the stability of total mixed ration (TMR) in the feed bunk throughout the day. Increasing feeding frequency is a typical suggested strategy to compensate for TMR deterioration and to prevent refusal by animals. However, treatment with a propionic acid-based additive could stabilize the TMR enough to allow a reduction in daily feeding frequency. In the preliminary laboratory trial, the additive improved the aerobic stability of TMR, and the optimal dose of 2 mL/kg of fresh matter (FM) was selected for the Additive strategy in the subsequent animal performance trial. Twelve Holstein cows (mean ± standard deviation; 612 ± 158 kg of body weight, 27 ± 6.5 kg/d milk yield, 178 ± 60 days in milk, and 3.0 ± 0.5 of body condition score) were assigned to a switch-back design to evaluate the effect of two feeding management strategies: Control, with two daily feeding of a control TMR; and Additive, with cows receiving a single daily feeding of a TMR treated with the additive at 2 L/t FM. The TMR was composed of 446 g/kg of dry matter (DM) corn silage, 64.0 g/kg DM Tifton haylage, 211 g/kg DM rehydrated corn grain silage, 163 g/kg DM soybean meal, 92.5 g/kg DM citrus pulp, and 23.2 g/kg DM mineral-vitamin mix. Cows fed the Additive strategy significantly increased daily milk yield by 10.2% without changes in DM intake, although no difference was observed for the feed efficiency. Milk contents of total solids and fat were decreased for cows in the Additive strategy. An increase in somatic cell count was observed for cows in the Additive, which could be related to the faster first meal activity after milking than the cows in the Control strategy, rendering them more susceptible to teat contamination. Milk energy and milk urea nitrogen contents were not affected by treatments, although energy excretion through milk was greater for the cows in the Additive. The Additive strategy promoted a shift in the sorting behavior in favor of longer particles, increasing the time spent on rumination, and decreased the number of daily meals at the expense of larger meal size. Two contemporary trials were conducted to measure changes in the thermal and hygienic behavior of the experimental TMR offered in the animal performance trial, simulating aerobic exposure for a 24-h period in exclusive feed bunks installed in the free stall barn, without animal access. The Control TMR presented shorter aerobic stability for the middle and top layers in the feed bunk compared to the bottom layer, while the Additive TMR presented no differences across layers, suggesting a generalized microbial activity suppression independent of the protective effect of upper layers. The Additive TMR suppressed yeasts survival persistence and their activity. Our results suggest that treating TMR with the additive improves the maintenance of its hygienic and thermal profile in the feed bunk, which enables the strategy of a single daily feeding with significant benefits in animal performance.