Preservation of total mixed rations for dairy cows in bales wrapped with polyethylene stretch film – A commercial scale experiment

The objective of the current study was to determine the storage shelf life of wet and semi-dry total mixed rations (TMRs) baled silages under farm conditions. Large bales of wet and semi dry TMR at dry matter (DM) content of 500 and 650 g/kg, respectively, weighing 600–750 kg were prepared and stored outdoors up to five months during the hot spring and summer months in Israel. Ambient high temperatures were 25–28 °C in spring and 33–36 °C in summer. A high dry matter density of above 400 kg/m3 was obtained in the bales. During storage there was an intensive build up of lactic acid (>100 g/kg DM) and the pH values in both wet and dry TMRs decreased to around 4.3. Dry matter losses during storage were small, but neutral detergent fiber (aNDF) decreased by about 100 g/kg during storage. The nutritional parameters including in vitro DM digestibility were hardly changed during storage. Fresh wet and semi-dry TMRs were spoiled, whereas the stored TMRs were stable upon aerobic exposure. In conclusion, during storage of baled TMR wrapped with polyethylene stretch film, an ensiling process takes place, and it is possible to store such bales outdoors for at least up to 4.5 months with enhanced aerobic stability.