Title: Effect of length of storage and chemical additives on the nutritive value and starch degradability of reconstituted corn grain silage
Abstract: The objective of this trial was to evaluate the nutritive value and ruminal in situ starch degradability of reconstituted corn grain silage (RCGS) treated with chemical additives stored for different lengths of time.Dry ground corn (177.2 kg) was rehydrated to 350 g/kg moisture and ensiled in 5-L plastic buckets sealed with plastic lids (mini-silo).The rehydrated grain was treated with polysorbate 80 (2 L/t) (POL), propionic acid 28% (2 L/t) (PRO), Mycoflake™ (2 L/t) (MYC) or nothing (CON).Mycoflake is a blend polysorbate 80 plus propionic acid.The effect of length of storage (15, 30, or 60 d) was also evaluated and combined in a factorial arrangement with the additives.Four replicates were used per treatment.Ammonia nitrogen increased from 15 d of storage from 30 and 60 d, 53.2 and 59.4%, respectively.There was an interaction between additive and storage length for ethanol content, at 60 d of storage all treatments had lower ethanol concentration than CON.A treatment vs. storage length interaction was observed for butyric acid content, at 30 and 60 d of storage, the untreated silages had higher butyric acid concentration than treated silages.Aerobic stability increased from 15 to 30 d, but was the same at 30 and 60 d.At 15 d of storage, the treatments PRO and MYC decreased the DM losses.The length of storage increased the ruminal in situ degradability of starch and dry matter (DM) and MYC increased in 3.6% the DM degradability at 12 h of incubation compared with POL.In conclusion, increasing the storage time of RCGS from 15 to 60 d improved starch and DM degradability, Mycoflake increased the availability of nutrients and POL can be a potential antimicrobial agent.