Livestock grazing behavior and inter- versus intraspecific disease risk via the fecal--oral route

Livestock herbivores are at risk of parasite/pathogen exposure from livestock and wild mammal feces during grazing. Livestock exposure to parasites/pathogens will be dependent on the behavioral contact processes between grazing livestock and host animal (both livestock and wild mammal) feces at the bite scale. Here we use 2 grazing experiments to determine the affect of feces from different species and in different defecation patterns on the grazing response of cattle. In experiment 1, there were 4 plots, each with 4 replicates of 5 patch treatments of different fecal contamination (240 g/m-super-2 of Eurasian badger feces, cattle feces, fallow deer feces, Eurasian rabbit feces, and noncontaminated control patches). In experiment 2, there were 3 treatment patterns of badger fecal contamination (one 1-m-super-2 circular patch contaminated with 960 g of badger feces; two 1-m-super-2 circular patches each contaminated with 480 g of badger feces; and four 1-m-super-2 circular patches each contaminated with 240 g of badger feces), divided into 2 plots per treatment. The cattle's grazing response was determined by measuring sward depletion at each of the treatment patches. In experiment 1, cattle-grazed control and rabbit fecal--contaminated patches the most, whereas badger-contaminated patches were grazed the least. In experiment 2, cattle grazed the treatment with the greatest number of fecal-contaminated patches the most. We conclude that cattle vary their grazing response to feces from different host species and to feces in different spatial patterns. Quantifying these behavioral responses to feces is a key step toward quantifying infection risk to herbivores via the fecal--oral route in grazing systems. Copyright 2009, Oxford University Press.