Data from: Early life access to hay does not affect later life oral behavior in feed restricted heifers

Dairy cattle are often raised in environments that lack natural feeding opportunities and perform abnormal repetitive behaviors (ARBs) as a result. Early life restriction can affect later life behavior. We evaluated whether access to hay in the milk-fed period would affect later-life behavior in heifers experiencing short-term feed restriction, and whether individuals were consistent in behavioral expression over time. We had 2 competing ideas about how this would unfold. First, being raised with hay, which reduced early life ARBs, could lead to fewer ARBs later in life. Alternatively, heifers that were raised without hay and performed more ARBs in early life may be more prepared for a later feed-restricted environment and could engage in fewer ARBs than those raised with hay. We studied 24 pair-housed Holstein heifers. As calves, they were fed milk and grain from 0-7 wk of age (Control) or given additional forage (Hay). Tongue rolling, tongue flicking, nonnutritive oral manipulation (NNOM) of pen fixtures, self-grooming, and drinking water were recorded for 12 h (08:00-20:00) during wk 4 and 6 of life using 1-0 sampling at 5-s intervals. At the start of weaning at d 50, all calves were fed TMR. At d 60, all calves were fully weaned, and socially housed by d 65-70. After this point, all individuals were raised the same way, according to farm protocol, in groups that included both treatments. At 12.4 ± 0.6 mo of age (mean ± SD), heifers were restricted to 50% of their ad-libitum TMR intake for 2 d as part of a short-term feed challenge. Using continuous video recording from 08:00-20:00 on the 2nd d of feed restriction, we scored time spent performing oral behaviors: the 5 previously scored as calves, and intersucking, allogrooming, drinking urine, and NNOM of rice hull bedding and feed bins, specifically. We found that early life access to hay did not affect behavior performed by feed-restricted heifers 1 yr later. Most heifers performed a wide variety of behaviors that appeared abnormal. All heifers performed tongue rolling and NNOM, and at higher levels then when they were calves, while tongue flicks and self-grooming were performed less by heifers. Individual performance of NNOM and tongue rolling were not related across age classes (r = 0.17, 0.11, respectively), but tongue flicks tended to be correlated (r = 0.37). Intersucking was recorded in 67% of heifers, despite not being able to suckle a conspecific or dam in early life. Oral behaviors were highly variable across heifers, particularly tongue rolling and intersucking. Outliers, or extreme performance of oral behaviors relative to the rest of the population, were present in many behaviors. Most outliers were expressed by unique heifers that were not extreme in other categories. Overall, feeding calves hay during the milk-fed period did not affect later life performance of oral behaviors. The considerable variability, inconsistency across ages, and excessive performance of some behaviors raises additional questions about how these develop in cattle across life stages, and what we label "abnormal."