Effects of Chitosan and Whole Raw Soybeans on Feeding Behavior and Heat Losses of Jersey Heifers

Abstract

This study aimed to determine the effects of chitosan, whole raw soybeans or their interaction on feeding behavior and heat losses through thermography assay of Jersey heifers fed high concentrate diets. Twelve Jersey heifers (age of 6±0.5 months and 139.50±25.56 kg of live weight, mean±SD) were randomly assigned to a replicated latin square design with 2 × 2 factorial treatment arrangement. The experimental period consisted of 14 days of adaptation to the diets, 6 days of sampling and 5 days of wash out. The diets were: control (CO), chitosan (CHI, inclusion of 20 g/kg dry matter (DM) of chitosan), whole raw soybeans (WS, 163.0 g/kg of WS on diet DM basis), and chitosan + whole raw soybeans (CHI+WS). Chitosan decreased DM and neutral detergent fiber (NDF) intake (0.79 and 0.31 kg/d, respectively), increased the eating time (31.88 min) and decreased the NDF content of regurgitate rumen bolus (57 g). Whole raw soybeans did not affect feeding behavior, except for a higher time in standing rest. The association of CHI and WS increased the time which animal ruminated stand. The diets did not influence superficial temperature of heifers. However, WS diet increased heat losses by radiation and convection. The highest values of heat losses were observed after 2 hours of feeding. The interaction of CHI and WS did not alter feeding behavior and heat losses. Feeding WS to heifers increased the total heat losses.