Defecation rates of white-tailed deer (Odocoileus virginianus) based on fiber content in feces

Resumen

Objective: To develop three models in order to estimate the defecation rate of
white-tailed deer (Odocoileus virginianus) according to the season of the year,
content of neutral detergent fiber (NDF), and acid detergent fiber (ADF) in feces.
Design / methodology / approach: Nine captive adult deer were assigned to
three levels of dietary fiber. Fecal groups (defecation rate) were counted, forage
consumption was estimated, and feces were analyzed for NDF and ADF content. A
randomized block design was used, where the effect of the treatments was blocked
by season, and a multiple regression analysis was used to define the prediction
models of the defecation rates.
Results: The rates were different for dietary fiber levels (p<0.0001), and for the
year season (p = 0.0007). For spring, the defecation rate model (DR) was DR = -4.84696 - [0.02159 (NDF)] + [0.58397 (ADF)]; for summer DR = -51.0272 +[0.26868 (NDF)] + [1.61121 (ADF)]; and for winter DR = 7.82939- [0.02667 (NDF)]+ [0.17309 (ADF)].
Limitations / implications: Defecation rate or fecal group counting is a useful tool
to estimate deer populations. Nevertheless, the definition of an adequate
defecation rate represents a hard task, since it depends on various factors such as
the environmental conditions, and the components of the diet the deer consumes.
Findings / conclusions: The defecation rate varies depending on the year season
and the fiber content in the diet.