blood samples, and pregnancy was confirmed by rectal
palpation at weaning. As MP from RUP with or without
propionate increased, a decrease (P = 0.03) was observed
in postpartum interval; however, differences in
pregnancy percentage (P = 0.54) were not influenced by
treatments. We hypothesized that additional AA from
RUP along with propionate would increase supply of
glucogenic precursors and, therefore, glucogenic potential
of the diet. Therefore, a postpartum glucose tolerance
test was conducted near the nadir of cow BW to
evaluate the rate of glucose clearance. Glucose tolerance
tests showed that RMP+- or RMP+P-supplemented
cows had greater (P = 0.03) rates of glucose clearance,
which might have influenced the observed abbreviation
of the postpartum interval. A glucose tolerance test
conducted at the end of supplemental treatments revealed
no differences in glucose clearance (P = 0.47)
among previously supplemented cows. These data suggest
that not only vegetative quality, duration of lactation,
and season of grazing, but also type of supplementation
may play a pivotal role in the young postpartum
beef cow’s ability to respond and incorporate nutrients
into insulin-sensitive tissues.