|Lay, Jr, Donald - Don|
|Cheng, Heng Wei|
Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 2/24/2006
Publication Date: 7/9/2006
Citation: Lay Jr, D.C., Marchant Forde, J.N., Mcmunn, K.A., Marchant Forde, R., Pajor, E.A., Cheng, H. 2006. Two alternative combinations of pig processing methods affect cortisol and behavior. Journal of Animal Science. 84(1):412. Interpretive Summary:
Technical Abstract: Pig processing procedures can cause distress to pigs. Alternatives exist for every procedure, thus our objective was to compare a combination of five different procedures. Least aversive procedures compared to the most aversive procedures were determined by previous research. Comparisons were made between processing pigs with the ‘most’ aversive methods (Most): teeth grinding, tail docking with a hot iron, oral administration of iron, ear clipping, and castration by tearing, as compared to the ‘Least’ aversive methods (Least): teeth clipping, tail docking with a cold iron, injection of iron, ear tag, and castration by cutting. Two control groups were included, one in which blood was sampled (Control) and another that served merely as a behavioral control, which was not blood sampled or processed but was handled. A total of 8 pigs from each of 10 litters were used - one male and one female pig per treatment. Body weights were recorded prior to bleeding, at 24 h, 1 wk and 2 wk relative to application of treatments and blood was collected at 0 h, .75 h, 4 h, 48 h, 1 wk, and 2 wk in order to measure plasma cortisol. Behavioral data were collected to record escape attempts, squeals, and grunts. Body weight did not differ between treatments (P > .10). Females did not differ in their plasma cortisol response to processing (P > .10). In contrast, male pigs in both the Most and Least treatments exhibited elevated plasma cortisol at .75 h after processing as compared to Control pigs (P < .0001). Pigs in the Least treatment performed more squeals as compared to the Most (P < .01) and the two control treatments (P < .001). Pigs in the Most treatment performed more squeals than in the two control treatments (P < .07). However, when adjusted for the amount of time required to perform the two treatments, no treatment differences were noted (P > .10). These data indicate that either method of castration causes pigs to have a robust stress response as measured by plasma cortisol. In addition, the time required to perform procedures contributes significantly to the stress experienced by the pigs. Future work to qualify measures of stress during these procedures may be beneficial.