Salmonella in Animal Feeds: A Scoping Review

Abstract

The objective of this study was to describe the volume and nature of published literature on Salmonella in animal feeds using a formal scoping review methodology. A structured search followed by eligibility screening resulted in the identification of 547 relevant studies, encompassing studies conducted in the fields in which animal feeds are grown (15 studies), the manufacturing sector (106), during transportation (11), in the retail sector (15), and on-farm (226), with the sector not described for 204 studies. The most common study purposes were to estimate the prevalence of Salmonella in animal feeds (372 studies) and to identify serovars (195). The serovars that were found in animal feeds included serovars associated with human illness, with animal illness, and with serovars identified in food (livestock and poultry) intended for human consumption. There were 120 intervention studies and 83 studies conducted to evaluate potential risk factors. Within intervention and risk factor studies, there may be sufficient depth to warrant synthesis research in the areas of heat interventions, fermentation and ensiling, organic acids, season, and geographic region. Some deficiencies were identified in the completeness of reporting of key features in the relevant studies.

Keywords: Salmonella; evidence map; feed; feed environment; livestock; poultry; scoping review.

Figure 1

PRISMA 2020 flowchart showing the flow of citations and abstracts in a scoping review of Salmonella in animal feeds modified from (19).

Figure 2

Number of studies published per year by sector of feed production as identified in a scoping review of Salmonella in feeds (search included publications between January 1995 and October 2020).

Figure 3

Geographic distribution of 429 studies investigating Salmonella in animal feeds that reported the country where the study was conducted.