Because the optimum space allowance required for weaned pigs during transport is unknown, Texas Tech University scientists sought to establish a first estimate of their space requirements based on measures of animal well-being.

A commercial livestock trailer was divided into compartments fitted for 100, 11.5-to-22-lb., weaned pigs at a space allowance of 0.5, 0.6 and 0.7 sq. ft./pig. Instruments recorded environmental conditions. Digital scans recorded the frequency of standing or lying behaviors of pigs every minute during the trip.

Prior to transport, blood samples were taken from four pigs per compartment for physiology and immune measures, and weight and lesion scores were recorded.

Pigs were then transported two hours to the wean-to-finish site using the same route for each of the four replications during winter.

At the finishing site, blood samples were again taken from the same experimental pigs.

Space allowance influenced the behavior of weaned pigs in the last 15 minutes of transport (Figure 1). Pigs transported at 0.6 sq. ft./pig spent less time standing than pigs transported at 0.5 and 0.7 sq. ft./pig.

Reduced standing behavior in pigs transported at 0.6 sq. ft./pig suggests that these pigs may have been in a more “relaxed” state during the last 15 minutes of transport, or became habituated to transport conditions sooner than pigs transported at 0.5 or 0.7 sq. ft./pig.

Researchers contend pigs appear to spend the majority of their time during transport active. However, pigs transported at 0.6 sq. ft./pig appear to spend more of their time resting than the other two treatment groups.

Cortisol concentrations and the neutrophil-to-lymphocyte ratio both increased during transport regardless of space allowance, trailer deck or gender (Table 1).

Increased cortisol concentrations and neutrophil-to-lymphocyte ratio in transported weaned pigs suggests these pigs experience stress, but the stress was not impacted by the space allowances tested.

Albumin concentrations were increased after transport, suggesting that these pigs were slightly dehydrated. Increased concentrations of create kinase and aspartate aminotransferase after transport suggest that these pigs were somewhat fatigued as a result of the two-hour transport. However, there was no effect of space allowance on any of these measures (Table 1).

No pigs died or were injured during the transport study. Body weight loss during transport did not differ among space allowances tested.

Researchers: M.A. Sutherland, N. Krebs, J.S. Smith and J.J. McGlone, all of the Pork Industry Institute, Texas Tech University. Contact Sutherland by phone (806) 742-2805 (ext. 253), fax (806) 742-4003 or e-mail mhairi.sutherland@ttu.edu.