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.”