Persistent bovine penile frenulum
Keywords: frenulum, penis, bovine
A persistent frenulum of the penis found during a breeding soundness examination of a bull.
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The penile frenulum develops as the genitalia are masculinized during fetal development. It is thought to break down under the effect of androgens with the approach of puberty. Understandably therefore, its persistence has been linked to androgen deficiency or the expression of androgen stimulation. However literature searches reveal a lack of objective data in that regard.
In most cases, the frenulum does not persist beyond a year of age but is occasionally frenulums are found during routine breeding soundness exams in yearling bulls. This is a source of concern for bovine practitioners, unsure as to how the problem should approached. Some of this uncertainly arises because frenulums may break down spontaneously after bulls have failed breeding soundness evaluations. Also, the heritability of this condition is not known. A study on 1,200 yearling Angus bulls did not demonstrate that persistent frenulums were heritable. However, the authors acknowledged that the size of the study limited the value of that conclusion. In short, more research is required on this subject.
Perhaps obviously, bulls with persistent penile frenulums are unable to copulate normally.
In view of the value of some bulls and uncertainly surrounding the condition, some practitioners are inclined to transect the frenulum and dismiss it as an incidental finding.
In most cases, the frenulum does not persist beyond a year of age but is occasionally frenulums are found during routine breeding soundness exams in yearling bulls. This is a source of concern for bovine practitioners, unsure as to how the problem should approached. Some of this uncertainly arises because frenulums may break down spontaneously after bulls have failed breeding soundness evaluations. Also, the heritability of this condition is not known. A study on 1,200 yearling Angus bulls did not demonstrate that persistent frenulums were heritable. However, the authors acknowledged that the size of the study limited the value of that conclusion. In short, more research is required on this subject.
Perhaps obviously, bulls with persistent penile frenulums are unable to copulate normally.
In view of the value of some bulls and uncertainly surrounding the condition, some practitioners are inclined to transect the frenulum and dismiss it as an incidental finding.
Selected references:
Ashdown R. R. 1960. The adherence between the free end of the bovine penis and its sheath J Anat. 94 198–204.
Ashdown R. R. 1960. The adherence between the free end of the bovine penis and its sheath J Anat. 94 198–204.
Christmas, R.A. et al 2001. Genetic relationships among breeding soundness traits in yearling bulls. Cattlemen's Day, Kansas State University, Manhattan, KS, March 2, 2001
