Figure 3.

Temporal variations in gentamicin resistance among Salmonella and Escherichia coli isolates from farm to retail, from 2003 to 2015.

^a Significant (P ≤ 0.05) farm-level sampling stage difference; level decreased at pre-harvest.

^b Significant temporal difference (P ≤ 0.05), level decreased between 2003 and 2015. Temporal analysis result is unavailable in the Ontario abattoir data due to small sample size.

Grey-shaded areas indicate no surveillance activities.

GENinj — gentamicin injection at the hatchery; LSinj — lincomycin-spectinomycin injection at the hatchery.