When hay or greenfeed is baled, it will go through a sweat period that can last three to seven days. The breaking of stems during baling releases moisture into the bale. Aerobic bacterial activity increases creating heat within the bale resulting in an increased bale temperature.
When bale temperatures exceed 35o C, the Maillard reaction starts to occur. This reaction binds available crude protein to plant fibre. This makes a portion of the protein unavailable to the animals. At temperatures increase over 40o C, protein tie up increases linearly.
Moulds form when temperatures exceed 45o C. Odors develop, which reduces the animal’s willingness to consume the hay. At 49o C, digestibility of fiber and sugars is impaired. At 65o C, bales can spontaneously catch fire.
To reduce these problems, leaving bales in the field without stacking is recommended. Individual bales in the open are exposed to the wind which decreases or removes heat and moisture that are trapped in the bale. Lower evening and overnight temperatures help cool the bales further.
Putting bales into rows, stacks, or under cover will cause more heat retention compared to individual bales. Leaving bales out in the open for at least 10 days is recommended. Monitor temperature and moisture at least every second day. Do not move or stack the bales until conditions stabilize and bales have cooled off.
If stacked bales start to smell sweet or like tobacco, this indicates the bales are heating and both dry matter yield and quality are being reduced. Dismantling the stack is recommended. If the stack is steaming, temperatures are much higher and spontaneous combustion is possible. Opening the stack exposes the hay to more oxygen increasing the risk of a fire. Discuss the situation with the local fire chief before taking the stack apart.
For additional information about storing hay during the hot temperatures, contact Barry at 403-741-6032 or bjyaremcio@gmail.com.
Comments