Effect of environmental enrichment devices on behavior of individually housed beef heifers.

In research settings, certain experimental designs may require cattle to be housed individually. Individual housing of cattle may make the animals more susceptible to boredom and result the development of undesirable behaviors. The objective of this trial was to investigate the effects of different environmental enrichment devices (EED) on the behavior and feed intake of heifers. Twenty mixed-breed single-sourced heifers were used in a completely random design. Heifers were housed individually (3.05 m × 3.66 m) with the ability to have physical contact with adjacent heifers. Heifers were randomly assigned to one of the four EED treatments, including a jolly ball (JLY), a broom head (SRCH), a 182 cm 5-knot rope (RP), or a Pas-a-Fier roller (RLR). Behavior was recorded using 8 h long daily instantaneous scan sampling in 30 min intervals over three periods: 7 d prior to EED addition (PR), 7 d with EED (EDP), and 7 d after removing EED (PST). Standing, laying, eating, drinking, and exploratory behaviors were evaluated. Exploratory behaviors included: interaction with water trough, feed bunk, water pipe, pen gate, pen wall, EED, grooming, or allogrooming. Rumination behavior was also recorded during each observation time. Time standing and standing bouts were greatest for RP (P < 0.05), while JLY and RLR spent the most time lying down (P < 0.05). All heifers spent the majority of observation times lying down, followed by solely standing (P < 0.05). Heifers on the RP treatment interacted the most with their EED, followed by SRCH (P < 0.001). Rumination increased during EDP compared to PR (P < 0.001). These results suggest that a RP suspended from the ceiling in the pen may be used most frequently by individually housed beef heifers.