To determine the effect of deworming fallborn
yearling heifers on reproductive parameters,
78 heifers were allotted to a either
Ivomec® or control treatments. The heifers
were dewormed in June and October when
they were approximately 7 and 11 months old,
respectively. Ivomec effectively lowered fecal
egg counts from treated heifers compared to
controls. In these heifers that were maintained
on a marginal plane of nutrition, deworming
not only improved weight gains but also hastened
onset of puberty and improved conception
rate during a 60-day breeding season.
The positive effect of Ivomec on these reproductive
characteristics could not be explained
by increased weight gain alone, because the
correlation between weight gain and puberty
was not significant.