Date Full Report Received


Date Abstract Report Received



Primary Investigator:

The use of traditional gestation stalls is currently under public scrutiny due to restrictions on sow movement and social interaction. But before alternative housing is adopted, knowledge of its benefits and limitations is required. Free-access gestation stalls are designed to provide both the protection of a standard stall and the behavioral freedom of a group pen, however research on their implementation is limited. This purpose of this project was to examine the effects of alley width on physiology, behavior, and production of gestating sows in a free-access stall system. After the 1st month of gestation, 7 sows were placed in pens with 7 free-access stalls and a shared alley of 3’, 7’, or 10’ wide where they remained until moving to the farrowing facility. Health measures collected through gestation included back fat depth, body weight, body condition score, lameness scores, and lesion scores. Blood samples were collected monthly for cortisol concentrations and immune function. Farrow rate, days to next estrus, percentage of sows rebred, and cull rate of the sows were calculated. Litter data collected were total litter size, live litter size, and litter weight. The health and physiology measures showed very few differences between alley sizes. Sows in pens with 3’ alleys used the space less, had fewer and smaller social interactions, and were less active than sows with either 7’ or 10’alleys. There was no difference in aggression between sows in different alley sizes. Neither sow productivity measures nor litter size  differed between treatments. However sows from pens with 3’ alleys had heavier litters than sows with 10’ alleys. In conclusion, alley width had little effect on sow health, physiology, or productivity. In contrast, the smallest alley width of 3’ limited the sows’ expression of normal behavior. The “Freedom to Express Normal Behavior” is one of the Five Freedoms of animal welfare whose foundation was laid by the Brambell Committee in 1965 and is still considered fundamental to farm animal welfare (FAWC, 2011).

Corresponding author: Ed Pajor, University of Calgary: eapajor@ucalgary.ca