Plan Now For Breeding Program And Pre-Breeding Vaccinations
US - Spring is finally here. Many of our clients have been fighting the wet, muddy conditions as they are calving.
1 May 2007
2 minute read
Many producers have been complaining about low conception rates in their replacement beef heifers. The heifers are vaccinated pre-breeding with these common breeding vaccinations and are in good physical condition. These heifers are then AI bred and followed with a clean-up bull or merely turned out with a calving ease bull. The heifers cycle well and appear to be bred.
In late summer, the heifers are pregnancy tested and 20 percent to 30 percent of them are open. Strangely, there are few of these animals impregnated by the clean-up bull. The tracts appear to be normal and there appears to be no palpable reason the heifers are open.
This syndrome would be indicative of early embryonic abortions. The heifer becomes pregnant on first service and carries the pregnancy for several months. The embryo then dies and is sloughed from the uterus with no apparent clinical signs. This causes a heifer to not recycle during the time the clean-up bull is used. The resulting pregnancy rates of 60 percent to 70 percent on these heifers are devastating on the cost of raising replacements.
The common causes of breeding problems like this would include inadequate bulls, nutrition and trace mineral deficiencies, Trichomoniasis and of course, the old standby, bovine virus diarrhea (BVD). Through testing, we have been able to rule these causes out in most herds. This forces us to turn our attention to an emerging disease problem, Leptospirosis hardjo-bovis.
Most producers vaccinate for Lepto with a five-way product that includes Lepto hardjo, but it does not produce immunity for the sera of Lepto hardjo-bovis. The Lepto we remember was traditionally associated with late-term abortions (7-9 months) and weak calves. This new syndrome has been dubbed “reproductive wastage” because of the unnoticeable embryonic death and resorption.
Source: Tri State Neighbor
For more information on cattle disease, click here.
