Supplemental Figure S1: Contour-enhanced funnel plots

Supplemental Figure S1. Contour-enhanced funnel plots created for A) colostral IgG concentration in heat-treated versus raw colostrum, B) viscosity of colostrum in heat-treated versus raw colostrum and C) serum IgG concentration in calves fed heat-treated colostrum versus calves fed raw colostrum for all studies included in each meta-analysis. The symmetrical distribution of trials included in the meta-analysis (grey dots) around the mean difference suggests no publication bias. When asymmetry was identified the trials perceived as missing (hollow dots) were filled by trim-and-fill. When studies that appear to be missing were in low statistical significance areas, asymmetry was likely due to publication bias (Palmer et al., 2008).