Powered gates are used in many livestock handling systems to move animals. The large CO2 stunning systems use a series of powered gates to move pigs. When these group handling systems are used correctly, electric prods can be eliminated. For all species, a powered gate must never knock animals over or drag them. Dragging an animal with a powered gate is a violation of Humane Slaughter regulations. Dragging of conscious animals is not permitted.

The best powered gate systems are not fully automatic. The animal handlers should be able to control the movement of the gates. Fully automated gate systems usually work poorly. The manufacturer will often tell people they can be made fully automatic. The best systems I have observed have fewer powered gates and the handlers are able to control forward movement of the gates. The manufacturer will sell people many more powered gates than they actually need.

The gates should provide “power steering” and human judgment is needed to quietly move animals forward. This is especially true when a powered push gate moves pigs along a long alley. Recently, I saw a really good, powered gate system leading into two large CO2 systems. It had manual gates leading in from the yards that required almost no effort to move. There was only one lift hoist powered gate that moved the pigs up a wide main drive alley. The animal handler controlled the forward movement of this gate. This system did have automated gates for moving pigs short distances into the CO2 machine. There were no powered gates to move pigs out of the stockyards.

Fully automated gate systems often overcrowd the pigs. This results in them getting turned around. When they are too tightly packed together, re-orienting them is difficult. This is especially a problem in a long drive alley leading up to the CO2 machine.

Speed matters

A common problem with lift hoist gates occurs when the entire gate assembly is lifted up and it moves quickly back over the top of an approaching group of pigs. The group of pigs that is moving forward in the alley may either stop or turn back. Normally, these gates move fast. At one plant, they discovered that moving the gate slowly over the back of the pigs does not scare them. When the gate was moving over the pigs, it moved slowly. It sped up when it got past a group of pigs. This particular plant also did a very good job of timing bunches of pigs and not overloading the main drive alley to the CO2 machine. The main alley was half empty. A common handling mistake is to jam the main alley full of animals. I have observed this handling problem in both cattle and pig systems. The most experienced handlers time bunches of animals so that the next group enters an area immediately after the group in front of it is moved forward. The drive alley will be half empty. Doing this requires a change in mindset. Having a half empty central drive alley will make handling both easier and calmer. In each system, the most efficient small bunch of animals has to be determined. Good handling will require more walking to bring up small bunches. For both cattle and pigs, this is especially important when a crowd pen is used to direct the animals into a single file chute.