Determination of temperature requirements of group-housed sows fed high fiber diets to reduce energy costs

Abstract. The shift in the pig industry from stalls towards group housing for gestating sows has led to a search for alternative management options that can address potential problems or take advantage of the potential benefits of housing sows in groups. It has been hypothesized that since sows housed in groups can interact with one another and perform thermoregulatory behavior (e.g., huddling), grouped sows can potentially tolerate temperatures below the lower critical temperature (LCT) reported for pigs. If so, this could result in lowered energy costs for heating and ventilation. Housing sows in groups can also lead to aggression among gestating sows and is aggravated by feed restriction during gestation. High fiber diets have been reported to increase satiety and reduce aggression among sows in addition to increasing heat production of sows. Hence, the addition of fiber to the diet could be a means of addressing behavioral issues associated with grouped-sows as well as contributing to the energy balance of sows under reduced barn temperature.

In this study, an operant mechanism was designed and developed that allowed the sows to manually control their environmental temperature. Two barn rooms were configured for group housing, with each room housing 28 gestating sows. One room was operated at a typical set-point temperature (16.5 °C) while an operant mechanism was installed in the other room, allowing the sows to control the temperature. Identical electronic feeders were installed in both rooms to monitor feed consumption. A diet with a high heat increment was fed to the sows. The barn experiment was carried out during winter season and results have shown that sows could tolerate temperature lower than the current set-point maintained in most gestation barns. Lower temperature set-points could result to considerable reduction in energy consumption for heating and ventilation. However, additional trials will be conducted in order to provide a more definitive conclusion on the impact of low temperature housing on sow performance and physiological response.