Disclosed is a process for producing unsaturated aldehydes andor unsaturated acids from olefins or alkanes in a fixed bed shell-and-tube heat exchanger-type reactor by catalytic vapor phase oxidation. A control device generates a control signal for controlling the supply of feed to be consumed by an animal at a feed trough. A data interpreter 193 analyzes and converts to text data at least part of the data acquired by the data communication unit 191. Similarly, the second junction can be between a third section having a third predominant pressure loss characteristic and a fourth section having a fourth pressure loss characteristic.