Chapter 11 - Overview of Typical Monitoring and Control Systems

Ventilation, heating and cooling

A properly designed monitoring and control system should be capable of maintaining preset environmental conditions in the building. Baffles are usually controlled by motor controllers, fans may be either on-off or variable speed, heaters require on-off control, and evaporative coolers may require water supply to be automatically turned on and off. Static pressure is usually controlled by regulation the air inlets on negative pressure houses or the air outlets on positive pressure houses.

Some air quality factors such as temperature are essential to monitor and control. Others such as ammonia or carbon dioxide may be expensive to monitor (although periodic sampling may be desirable), and they may be controlled indirectly. Relative humidity, although a very important parameter in terms of broiler performance, dust control, and growth of microorganisms, is typically not monitored or controlled in the U.S. where most poultry houses use curtains and dirt floors. In Western Europe where the houses are typically fully enclosed and often have concrete floors, monitoring and control is usually done with computer-based control systems which monitor and control temperature, humidity, static pressure, and lights. Management must control the benefits, risks and costs associated with maintaining good environmental conditions inside poultry buildings. Different building designs, geographical regions and poultry management practices determine the air quality factors that need to be considered and that are practical to deal with. Environmental control can be complicated at times by competing objectives. For example, it is desirable to heat a pullet house to 90°F and to provide fresh air. In cold weather, levels of ammonia and carbon dioxide might reach harmful levels if the control system does not provide a certain level of minimum ventilation.

Feeding

A feeding control system requires some way of knowing when to turn the feeders on and off. It is important for the same amount of feed to be available at all locations along the feeder and, especially with some systems, for the desired amount of feed to be presented to the broilers. Feed monitoring systems are available to measure the amount of feed consumed by broilers. This can be accomplished in a number of ways: with electronic load cells on the feed bins that record pre- and post-feeding weights, with an auger run-time monitor, or with a dump scale in which feed passes into a container that is balanced to a certain weight, and the monitoring system counts the number of times the container dumps the feed into the surge bin. This may be desirable, for example, to increase calcium levels for night time feedings.

Lighting

A monitoring and control system should provide scheduling of lights that is easy to use. It is especially important breeding facilities for precise lighting schedules to be followed. A system than can pre-program lighting schedules over the life of the flock is very useful for management. It is also important to provide the desired intensity of light. Dimmers are available in existing control programs, but it is more common for light intensity to be manually adjusted. Low light levels require light meters for calibration and checking the light dimmers and levels in the house.

Water

Water flow monitoring can be used to track how much water the broilers are consuming to quickly detect changes in flock behavior, or to spot problems with the water supply or distribution system (such as a leak in the water line). By interfacing with appropriate alarms, the monitoring system can report a 3:00 AM water leak to an appropriate farm employee, minimizing potential losses, wetting of litter or floors, and damage to equipment.