- With many cow operations very limited in forage resources,
cattle managers will be looking for methods to make optimum use of the
hay that they do have available. Purdue University beef nutritionists evaluated
the effect of limiting access time to large round bales on cow performance
and hay intake. They conducted two trials using 32 pregnant, non-lactating
cows in each trial. Cows were allowed access to large round bales for 4,
8, 12, or 24 hours each day. Trial 1 involved large (about 1480 pounds)
mature beef cows getting access to moderate quality orchardgrass/alfalfa
hay. Cows were limited access by enclosing the large hay bales in a small
corral. The cows were turned into the pen for the predetermined amount
of time and then moved back out of the pen. It is necessary to have adequate
space available for the cows to all get to the hay when the time is restricted
greatly. Mature cows, when limited access to the orchardgrass/alfalfa mixture,
had reduced intake from 29.6 pounds of dry matter intake per day down to
18.6 pounds of dry matter intake per day (Figure 1.). However, weight change
was only slightly affected (see Figure 2.).
In trial 2, second calf heifers (about 1180 pounds) were fed mixed
grass hay. This trial also was conducted for 50 days. Again notice the
dramatic decrease in the amount of daily dry matter intake that was measured
(Figure 3.). Not surprisingly, the young cows were more adversely affected
by the reduction in hay intake (Figure 4.).
Cows can be limit fed large round bales of hay by limiting access
time to extend forage resources. "Ball park" estimates are about 7.5%,
20%, and 40% reduction in dry matter disappearance, respectively, for 12,
8, and 4 hour limited access compared to 24 hour access. These researchers
felt that restricted access time resulted in more efficient use of the
hay. Part of the increased efficiency is due to less hay wastage, and part
is due to increased digestibility of the forage. Limited access time will
cause decreased dry matter intake and could result in reduced weight gain,
especially in young cows. Strategic supplementation may be necessary to
maintain adequate body condition on cows with limited access to forage.
Source: Lemenager, et al. Purdue University 1998 Annual Report to NCR-87
Committee and personal communication.