Stanton PhD Thesis final_docx - Atrium - University of Guelph

were bedded with straw. While housed individually, calves had no physical access to other
calves, but had visual access to calves in pens directly across the alley.
The naturally ventilated barn used as the Novel Environment was located adjacent to the
Nursery barn and contained two experimental pens (3.7 m X 6 m), which were bedded with
straw. Treatment groups were housed separately and had visual, but no physical access to the
other treatment group. No other animals were housed in this barn.
4.2.3. Study Treatment
Calves were randomly assigned to one of two treatments, either traditional management
in which they were not mixed prior to movement to a novel environment (Traditional) or mixed
prior to movement to a novel environment (Pre-mixed). Eight calves were enrolled at a time with
4 calves in each treatment group. Enrolment occurred when 8 calves were completely weaned
from milk, at which time all calves were moved to experimental pens (Day -4) within the nursery
barn, which were identical in design to calves’ pre-enrolment housing. Calves were randomly
assigned to treatment and experimental pen using a random number generator. Treatment groups
were balanced for age and breed (Holstein or non-Holstein).
From day- 4 to day 0, all calves were individually housed in experimental pens, within
the nursery barn. On day 0, the partitions between 4 experimental pens were removed creating a
single pen (4.8 m x 1.8 m) which housed the Pre-mixed treatment group from Day 0 to Day 7.
Traditional calves were housed in individual experimental pens until day 7. On day 7, both
treatment groups were moved 40 meters to group pens within a naturally ventilated, novel barn.
All calves within a treatment group were housed in the same pen. Treatment groups were
randomly assigned to 1 of 2 pens for each replicate. Each pen measured 14 meters by 22 meters
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