The spatial ecology of free-ranging domestic pigs (Sus scrofa) in western Kenya

Abstract

BackgroundIn many parts of the developing world, pigs are kept under low-input systems where they roam freely to scavenge food. These systems allow poor farmers the opportunity to enter into livestock keeping without large capital investments. This, combined with a growing demand for pork, especially in urban areas, has led to an increase in the number of small-holder farmers keeping free range pigs as a commercial enterprise. Despite the benefits which pig production can bring to a household, keeping pigs under a free range system increases the risk of the pig acquiring diseases, either production-limiting or zoonotic in nature. This study used Global Positioning System (GPS) technology to track free range domestic pigs in rural western Kenya, in order to understand their movement patterns and interactions with elements of the peri-domestic environment.ResultsWe found that these pigs travel an average of 4,340 m in a 12 hr period and had a mean home range of 10,343 m2 (range 2,937–32,759 m2) within which the core utilisation distribution was found to be 964 m2 (range 246–3,289 m2) with pigs spending on average 47% of their time outside their homestead of origin.ConclusionThese are the first data available on the home range of domestic pigs kept under a free range system: the data show that pigs in these systems spend much of their time scavenging outside their homesteads, suggesting that these pigs may be exposed to infectious agents over a wide area. Control policies for diseases such as Taenia solium, Trypanosomiasis, Trichinellosis, Toxoplasmosis or African Swine Fever therefore require a community-wide focus and pig farmers require education on the inherent risks of keeping pigs under a free range system. The work presented here will enable future research to incorporate movement data into studies of disease transmission, for example for the understanding of transmission of African Swine Fever between individuals, or in relation to the life-cycle of parasites including Taenia solium.

Prevalence and risk factors for gastrointestinal parasites in small-scale pig enterprises in Central and Eastern Uganda

“…However, for resource-poor farmers, the traditional pig production system is attractive (Verhulst 1993; Phiri et al 2003) because it requires much less space (Delgado et al 2001) and little to no housing due to the pig’s natural scavenging behavior to utilize kitchen leftovers and agricultural waste (Lekule and Kyvsgaard 2003). On the other hand, this scavenging behavior exposes them to diseases such as African swine fever or zoonotic agents such as Taenia solium , which have been reported from Uganda (Phiri et al 2003; Thomas et al 2013; Atuhaire et al 2014; Kungu et al 2016). …”

Geospatial and age-related patterns of Taenia solium taeniasis in the rural health zone of Kimpese, Democratic Republic of Congo

“…Similar lack of spatial correlation was reported by Morales et al (2008) in Mexico and explained by the combination of roaming behavior of pigs that covered large distances (2-5 km) daily (Copado et al, 2004) and mobile patterns of human in the study area. A study conducted in Kenya, geographically closer to our study area, found that free ranging pigs traveled an average of 4,340 m in a 12 h period and spent on average 47% of their time outside their homestead of origin and on average only 1.3% of their time interacting with the latrine area in their homestead of origin (Thomas et al, 2013). In such situation, ingestion of infective T. solium eggs by a free-roaming pig could therefore occur anywhere far from the homestead of origin and in the immediate circle of any tapeworm carrier.…”

Assessing the Potential Role of Pigs in the Epidemiology of Ebola Virus in Uganda

“…Furthermore, domestic pigs are often left to roam free in Uganda (Ouma et al., ), so their habit range can extend beyond smallholder farm perimeters where they encroach on various habitats. Collared free‐ranging domestic pigs in western Kenya travelled an average of 4340 m in a 12 h period and had a mean home range of 10 343 m 2 (Thomas et al., ). In this study, free‐ranging domestic pigs travelled large distances, throughout the day and night, with almost half of the time spent outside their homestead, extending the geographic range and habitats these pigs scavenge and travel in.…”