By Robert J. Van Saun
Earlier this year a field study was initiated to look into potential causes of stillborn calves in dairy and beef herds in Pennsylvania.
This project was funded by the Pennsylvania Department of Agriculture. The study was only a short-term (6 month) intended to be a pilot study to address this important topic. Although various contacts were made to solicit appropriate calf submission, only 9 calves have been collected. The submitted calves were from 6 different farms with 4 beef and 5 dairy calves. Although the number of submissions is too small to make any assessment, there are some interesting observations. None of the submitted cases had evidence of dystocia and none were excessively large in size for the breed.
Only one case had a positive microbiologic finding, but no lesions consistent with an active infection were found. One case had a significant ventricular septal defect that was presumed to be the underlying cause. All other cases had no diagnosis for the stillborn cause. In evaluating trace mineral and vitamin status it was found that all submitted cases had one or more deficiencies in copper, zinc and selenium. No case showed any indication of abnormal thyroid function based on tissue histopathologic evaluation.
This observation is consistent with previous findings of lower trace mineral content in fetuses that had aborted compared to abattoir collected fetuses. Additionally, all stillborn cases submitted had low to deficient liver vitamin A status based on defined fetal-derived reference concentrations. Two cases had low liver vitamin E status. Although no lesions were identified that could be associated with these nutritional issues, not all appropriate tissues (i.e., bone, nervous tissue) were evaluated. These trace minerals and vitamins are important components of many metabolic regulators and physical lesions identified in organs or tissue might not be present. These very preliminary findings suggest further research should focus on potential roles for nutritional mineral and vitamin deficiency in assessing diagnostic procedures for stillborn calves.
We still have an opportunity to collect an additional 15 to 20 calves as part of this project. If you have a client willing to submit a stillborn calf as part of this study, please contact the Penn State Veterinary Extension office (814-863-2160). The study will cover all diagnostic costs relative to the case. In submitting a case to the Penn State Animal Diagnostic Laboratory, please make sure the submission is identified as participating in the stillborn calf study. Any questions, please contact Carol Burns or Dr. Robert Van Saun.
Source:psu.edu