The effect of ramped nursery housing on pig behavior during loading and unloading at marketing

Abstract

Transportation is an essential component of commercial swine production in the United States. Stressors experienced during the process of transportation, including loading and unloading, can result in poor welfare outcomes and economic losses. The primary objective of this study was to determine whether exposure to a ramp structure during the nursery period affected ease of loading and unloading at marketing. A secondary objective was to determine if nursery ramp provision affected nursery pig behavior and pig growth throughout the nursery and grow-finish phases. Five hundred forty weaned pigs (17 – 21 days of age) housed in 20 pens (each pen holding approximately 27 pigs) were assigned to one of two experimental treatments: 1) access to a ramp with platform within the pen during the nursery phase (RAMP) or 2) a standard pen with no access to a ramp with platform during the nursery phase (CONT). After 6 weeks, ramps were removed from RAMP pens and all pigs were raised under standard conditions until marketing. Nursery behavior (posture, eating, drinking, aggression) and growth performance during the nursery and grow-finish phases were evaluated. No differences in nursery behavior or growth performance were observed between treatments (P > 0.05). At marketing, pigs were loaded in groups of four pen mates onto a semi-trailer and unloaded in mixed treatment groups upon arrival at the processing facility. During loading, duration to ascend the ramp to the trailer was quantified, along with the number of trips displayed by any animals and handler electric prod usage. Pigs in the RAMP treatment required a shorter duration to ascend the ramp compared to the CONT pigs (P = 0.002). An electric prod was used more frequently with CONT pigs compared to RAMP pigs (P = 0.02). During unloading, the total duration it took for pigs to descend the ramp, as well as the number of turnarounds, trips, and backward movement descending the ramp were quantified. Rattle paddle usage by the handler and dead on arrivals were also recorded. Control pigs required a shorter duration to descend the ramp compared to the RAMP pigs (P = 0.04). Additionally, a greater number of RAMP pigs descended the ramp backwards compared to CONT pigs (P = 0.02). No other treatment differences were observed. In conclusion, exposing pigs to a ramp during the nursery phase improved ease of loading at marketing and had no effect on nursery behavior and growth performance throughout the nursery and grow-finish phases.