Differences in ingestive behavior between grazing goats and sheep at the bite scale.

This study aimed to clarify the differences in ingestive behavior between goats and sheep at the bite scale. Animals were allowed to graze a feeding station of bahiagrass (Paspalum notatum Flügge) with two sward heights (short and tall) to two levels of bite depletion (20 and 40 bites). Ingestive behavior variables, which represent the rate and mass of bites and chews, intake rate, bite dimensions, and bite placement characteristics, were quantified. The interspecies difference in ingestive behavior became obvious at the short sward. Goats reduced the inter-bite distance and maintained bite overlapping but took deeper bites than sheep at the short sward, resulting in slightly greater bite mass. These behavioral changes with efficient chewing may be helpful to maintain the intake rate at the short sward. Sheep maintained their inter-bite distance regardless of the sward height and decreased overlapping bites at the short sward. These behavioral characteristics in sheep in response to sward height may partly compensate for the decrease in the bite mass at the short sward, although it may not always maintain the intake rate. Thus, the present study suggests that goats and sheep implement different bite scale ingestive behaviors, including bite placement, when they eat short swards.