MANAGEMENT
PIH-116
pork industry handbook
PURDUE UNIVERSITY COOPERATIVE EXTENSION SERVICE • WEST LAFAYETTE, INDIANA
Handling Pigs
Authors:
Temple Grandin, Colorado State University
Collette Schultz-Kaster, Milan, Missouri
Reviewers:
Kenneth and Debra Ernst, Sidney, Ohio
Herman Mayes, University of Missouri
John McGlone, Texas Tech University
Steve Pohl, South Dakota State University
Introduction
Gentle handling and good husbandry practices will improve swine productivity. Reproductive performance tends to be high on farms where sows show little fear of humans, while on farms where sows are fearful of humans, reproductive performance is lower. Research shows that the performance of finishing pigs is positively affected by good stockmanship. Mistreated finishing pigs have lower weight gains.

In addition to daily handling, most growing pigs are “worked” at discrete stages of production. These include processing at birth (see PIH-18), castration, weaning, and moving to nursery, transportation, growing and finishing, and transporting to market. On some farms, the nursery and grower buildings are eliminated, and weaned piglets move directly into a wean to finish building. Sows (and forthe most part boars) are handled during breeding, artificial insemination, heat detection, pregnancy checking, vaccination, and farrowing/weaning (see PIH-1, PIH-8, and PIH-74).

Handling Pigs
Pigs are handled for specific reasons, such as medicating or redistributing into larger or different pens. Animals accustomed to frequent, close, gentle contact with handlers are less likely to experience a production setback by nonpainful procedures such as being weighed or being moved down an aisle. Painful procedures, or rough handling, can result in stress that negatively impacts production or handling. Thus, for maximum reproductive performance, the person who manages breeding animals should not perform painful procedures on the pigs.

People entering the finishing pens and walking the aisles once a week has no effect on weight gain, if the animals are handled gently. The pigs become accustomed to people in the pens and do not become excited. However, weight gains are
lower and stress hormone levels increase if a handler occasionally slaps or shocks the pigs with a prod. Even when the handlers are gentle most of the time, pigs probably become stressed when rough handlers enter their pen, because they fear a possible unpleasant experience. This is critical to remember when checking feeders and waterers.

Mixing and fighting. When pigs are mixed, they go through a period in which they establish social relationships. One or more pigs dominate and the others become subordinate. A socially stable pen is the desired environment, so each pig should have a stable social relationship with the other pigs.

Establishing social order requires that some, but not all, pigs fight. Some pigs submit without a fight. But, when pigs fight, they do not eat. Even the pigs that submit without fighting
Table 1. Relative pig performance setback because of mixing pigs and fighting.
Weight at mixing	Weight gain depression	Added days to market	Other problems1
8-40	None measurable	0	Wounds
40-80	7 days	0	Wounds
80-150	28 days	0	Wounds and Injury
Over 150	28 days	7 or more	Wounds and Injury
1 Source: McGlone, 1987
do not eat very much while the other pigs are fighting, thus reducing weight gain. Because newly weaned pigs do not eat much, fighting may not have a measurable negative effect on their performance. Older growing pigs, however, eat at a productive rate, and any disruption in feeding (such as pigs fighting) causes reduced weight gain. The older and heavier the

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