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Title: Does the presence of a human effect the preference of enrichment items in young isolated pigs?

item DEBOER, SHELLY - Purdue University
item LUCAS, JEFFREY - Purdue University
item GARNER, JOSEPH - Purdue University
item Eicher, Susan
item Lay Jr, Donald
item Marchant, Jeremy

Submitted to: International Society of Applied Ethology
Publication Type: Abstract Only
Publication Acceptance Date: 4/13/2011
Publication Date: 7/9/2011
Citation: Deboer, S., Lucas, J., Garner, J.P., Eicher, S.D., Lay Jr, D.C., Marchant Forde, J.N. 2011. Does the presence of a human effect the preference of enrichment items in young isolated pigs?. International Society of Applied Ethology. Proceedings.

Interpretive Summary:

Technical Abstract: Pigs may be housed individually in both production and research settings. Being gregarious by nature, pigs kept in isolation may show behavioral and physiological signs of stress. The aim of our study was to determine the preference of individually-housed pigs, for social and non-social enrichments. Three enrichment items were chosen: a mat on part of a woven wire floor (MAT), a companion visible across the passageway (COM) and a mirror on one wall (MIR). Fourteen weaner pigs (Yorkshire × Landrace) were housed individually with continual access to a row of 4 adjacent pens (1.5 x 3.0 m), one enrichment per pen and one control (C) pen with no enrichment. The pens were balanced with equal access to feed and water. The animal was only able to access each enrichment while in that enrichment’s pen. Pigs were video recorded 14 hours a day over 7 days. The video was analyzed by scan sampling every 10 minutes to determine location, posture and behavior. Differences in the enrichment preference of the pigs were tested using a GLM model in JMP. Pigs spent significantly more time in the COM pen (0.65±0.068, p<0.05) compared to MAT (0.57±0.068), MIR (0.42±0.068) and C (0.32±0.068). However, based on perceived effects during data extraction, we then expanded our analysis to investigate preferences when a human was present in the room or absent. The pens were then combined into 2 categories: social pens (COM and MIR) and nonsocial pens (MAT and C). These data were analyzed using Proc Glimmix in SAS. The time spent in social or nonsocial pens was only significantly different from each other when a human was present in the room (p<0.0001), during which the social enrichment pens were greatly preferred. Within the social enrichments, the probability of the animal choosing either MIR or COM was not different. Our results confirm that preference studies are highly sensitive to the experimental conditions and the assumption that the most important preference is the one the animal spends most of its time with can be misleading. It appears that a mirror may be used by the animal for social support during periods of perceived stress, however further investigation is warranted.