When silage is exposed to air on opening the silo, or after its removal from the silo, fermentation acids and other substrates are oxidized by aerobic bacteria, yeasts and moulds. The use of additives to increase aerobic stability is advisable (Wilkinson and Davies, 2012). Many of biological or chemical additives were tested when they were applied during the harvesting/chopping operation or during filling of the silo (Kleinschmit et al. 2005). The objective of our study was to assess the impact of the application on the top layer of maize silage of two chemical preservatives, commercially identified as Albit and Safesil, on the nutritive value and indicators of fermentation.