Minimum Space Allowance for Transportation of Swine by Road

Terry L. Whiting - MAFRI Steve Brandt - Steve’s Livestock Transport (Blumenort) Ltd.

Note: This article originally appeared in the Canadian Veterinary Journal (2002) 43:207-212. "This material is posted, and the values converted from SI to Imperial units, with permission from the Canadian Veterinary Medical Association."

Abstract

Space allowance for animals in transit is a consistent concern in many countries that are developing codes of practice and regulations to assure humane treatment of food producing animals. The minimum space allowance requirements for a broad size range of swine in transit has not been well described or scientifically substantiated. A maximal loading pressure recommendation for pigs weighing from 5 to 250 kg was derived by a consultative process involving the swine transportation industry, animal welfare groups, and literature review. The recommended maximal loading pressure under ideal conditions for swine loaded in groups can be described as a Hoerl Model y = (37.53)(0.9969)W(W0.5008), where y = loading pressure in kg body weight/m2 and W = average animal body weight in kilograms.

Figure 1 Minimum space allowance for swine in transit based on average individual body weight (imperial). The top thick line describes the maximal floor pressure in the trailer in pounds per square foot, left hand Y-axis. The bottom grey line is the minimum space per pig in square feet measured on the right Y-axis. A standard 102-inch wide possum belly (8.3-ft. internal width) carrying 250-pound pigs at 57 lbs/ft2 would be carrying 475 pounds per running foot of deck.

Figure 2 Minimum space for weaners and cull and under market weight swine based on average body weight (imperial). The top thick line describes the maximal floor pressure in the trailer in pounds per square foot, left hand Y-axis. The bottom grey line is the minimum space per pig in square feet measured on the right Y-axis. A standard 102-inch wide possum belly (8.3-ft. internal width) carrying 50-pound pigs at 33 lbs/ft2 would be carrying 275 pounds per running foot of deck.

We consider these recommendations of loading pressure to be usable maximums in purpose built equipment with no concurrent risk of heat stress in the pigs. Multi-deck aluminium punch-out trailers, designed for swine and used in western Canada, have large ventilation holes positioned to assure equal ventilation of all decks. Some "cattle" trailers produced by the same manufacturer have removable decks to allow for triple decking of swine and double decking of cattle. The pattern of ventilation ports in dual purpose cattle trailers are primarily placed to prevent cattle from getting their feet entrapped in the ports. This ventilation hole pattern may not allow equal ventilation of all decks when hauling swine.

At all weights thin pigs require more space than a well-finished pig of the same weight. Allow 25% more space per pig when temperature exceeds 75oF (25oC). Where possible avoid transporting pigs in hot humid weather.