Crampy or Progressive Posterior Paralysis in Mature Cattle

Abstract

Records from 12,387 dairy bulls of live breeds, and 448 beef bulls of four breeds, were studied to establish the frequency and age at occurrence of the crampy condition, and to determine if evidence of genetic influence existed. The 323 dairy and ten beef bulls which were affected represented all nine breeds. Chi-square analysis showed that the frequency of occurrence differed significantly (P < 0.01) among the dairy breeds. Death or last effective service of affected bulls occurred at a mean age of 10.02 ± 2.49 yr. Numerous familial relationships were demonstrated; differences in frequency of occurrence in sire groups, and in lines and line-crosses, were significant (P < 0.04 and P < 0.01, respectively). Thus, a genetic background of the condition was indicated strongly. Although multiple gene inheritance was not discounted, inheritance was suggested as a single recessive factor with incomplete penetrance. © 1961, American Dairy Science Association. All rights reserved.