Abstract
Different beddings result in alterations in barn environments and are responsible for changes in heifer behaviors and welfare. In this experiment, twenty-four Holstein heifers were randomly divided into four pens with various beddings, including sawdust (SD), fermented manure and sawdust (FSD), fermented manure and straw (FST), and a fermented manure mixture (FMM) for 31 days. The water content and surface layer temperature of the beddings were measured. We studied the activity budget, diurnal rhythms, and locations in lying and elimination of these heifers by videoing them for three consecutive days in the early and late stages of the experiment. Compared with the three fermented beddings (FSD, FST, and FMM), the SD bedding had a higher surface layer temperature and lower water content (p < 0.05). The SD bedding resulted in significantly less time ruminating (p < 0.01) and more time walking (p < 0.01) for heifers. The heifers in the SD and FMM bedding spent less time lying (p < 0.01) and more time standing (p < 0.01). Heifers in SD and FSD beddings presented lower scores in surface cleanliness rating (p < 0.01). Heifer activities, including eating, drinking, elimination, and lying, showed clear circadian patterns in four groups. Elimination behavior had a significant positive correlation with drinking/eating (p < 0.01). Moreover, similar location distributions in lying and elimination of heifers in various bedding pens were observed. Heifers preferred to eliminate the near eating area and drinking area and keep lying out of the eating region (p < 0.01). These findings could provide a reference for the selection of bedding materials and bedding management in dairy farming.