Effect on Gilt Behavior and Postures when Selected for Residual Feed Intake Selection in Response to a Lipopolysaccharide Challenge

Abstract

<p>The objective of this study was to determine low and high-RFI gilt sickness behavior when challenged with lipopolysaccharide (LPS). This work was conducted with seven low residual feed intake gilts (RFI) and eight high RFI gilts (63±4 kg BW) from the 8th generation of the ISU Yorkshire RFI selection lines. Gilts were challenged intramuscularly with 30 µg/kg BW Escherichia coli O5:B55 LPS at 1000±1 hour. Gilts were video recorded one day before the LPS challenge (baseline) and on the treatment day (LPS challenge). Video was analyzed for lying, sitting, standing, eating and drinking using a 1-minute scan sample at two time points on the baseline and treatment days; 1) 1000 to 1200 hour and 2) 1700 to 1800 hour. There were no line by treatment interactions for behaviors and postures in response to the LPS challenge (P ≥ 0.32). There were no RFI selection line differences in behavioral and postural responses to the LPS challenge (P ≥ 0.45). Regardless of the RFI selection line, after the LPS challenge gilts laid more (P < 0.0001) and stood less (P < 0.0001). However, there were no differences observed in the percent of time engaged in sitting, eating and drinking (P ≥ 0.16). Regardless of the RFI selection line, gilts laid more (P = 0.0004) and stood and ate less (P < 0.0001) during the first (AM) compared to the second time point (PM). In conclusion, gilts from both RFI selection lines similarly expressed classical sickness behaviors and postures when challenged with LPS.</p>