Researchers at Agriculture and Agri-Food Canada, the University of Guelph and F. Menard Inc. suggest that space allowance in the nursery barn affects tail-biting behavior, and that the length of the docked tail affects both tail-biting behavior and physiology of the animal.

In trials at a commercial farm, piglets were individually identified and tail docked in one of two treatment lengths: 0.5 in. (“short”) or 8 in. (“long”). The 960 pigs were weaned at an average of 18 days with a space allowance of either 1.6 sq. ft. (“crowded”) or 2.5 sq. ft. “not crowded”).

Overall, nursery mortality was 2.3%, with a low number of losses recorded for both not crowded and crowded pens. Short-tailed pigs in crowded pens had slightly higher losses at 2.7%, with the highest mortality rate seen in the long-tailed, crowded pigs at 3.47%.

Average daily gain in the nursery was highest in the not-crowded pens of pigs, regardless of tail length.

Tail-in-mouth and tail-biting behavior began to occur in the nursery, with more than 50% of pigs showing evidence of bitten tails when examined at 8 weeks of age.

The greatest numbers of tail-bitten pigs were observed in the “crowded” pens of pigs, regardless of tail length. However, pigs with long tails from either space allowance were seen to have the greatest degree of tail damage.

When nursery pigs were assessed for scratches on the body, the greatest degree of damage was seen on crowded pens of pigs with short tails.

At about 8 weeks of age, 880 pigs were moved to grow-finish pens of 10 pigs/pen with 8 sq. ft./pig.

Grow-finish losses have been 5%, with slightly greater losses from the long- vs. short-tail treatments (2.95% vs. 2.05%, respectively).

Grow-finish pens were classified as having tail biting occurring if about 10% of pigs recorded mild or worse signs of tail biting on the tail health assessment (Figure 1). Of the 44 pens of short-tailed pigs, two pens (4.55%) were classified as tail-bitten. Twenty-five of the long-tailed pens of pigs (56.8%) were classified as tail-bitten.

Researchers: Kristi Bovey and Stephanie Torrey, Agriculture and Agri-Food Canada and the University of Guelph; and Jorge Correa and Benoit Laplante, F. Menard Inc. For more information, contact Bovey by phone (519) 824-4120, ext. 58580 or e-mail