inheritance of tibial hemimelia in galloway cattle
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Inheritance of tibial hemimelia in Galloway cattle1
By H. W. LEIPOLD, G. SAPERSTEIN, R. SWANSON, M. M. GUFFY and R. SCHALLES
Ms. received 10. 4. 1977
Tibial hemimelia, a congenital syndrome in Galloway calves, may include these defects : nonfusion of the Mullarian ducts in female calves, cryptorchidism in male calves, and in both sexes cranioschisis, meningocele, internal hydrocephalus, bilateral agenesis or shortening of the tibia, bilateral agenesis of the patella, and an open pelvic symphy- sis. Most commonly Galloway calves affected with tibial hemimelia are stillborn or die shortly after birth. The syndrome has been described in one calf of unspecified breed in Scotland (YOUNG 1951) and in Galloway calves in the United States (OJO et al. 1974). Tibial agenesis also occurs in man (CLARK 1975) dog (BAKER and LEWIS 1974), and goat (GIDDINGS 1977). In this paper we describe pathologic changes of tibial hemimelia and report results of a breeding trial.
Materials and methods
For the breeding trial, part of a long-term study of the nature, frequency, cause and effect of congenital defects of cattle (LEIPOLD et al. 1972), in 1973 we purchased from a rancher in Southeast Kansas eight open Galloway COWS (I,,, I,,, I,,, I,,, I,,, I,,, I,,, and I,,, fig. 1) that previously had given birth to affected calves and one Galloway bull (bull E, Fig. 1) known to have sired affected calves. The animals were trans- ported to Kansas State University and were placed on pasture and allowed to breed naturally. In addition, bull E was bred to a Chianina cow. All abnormal calves born during the breeding trial were radiographed. All abnormal calves and three dams (cows I,,, I,,, and I,, in Fig. 1) were necropsied and organs examined grossly and histologically. Ratios of normal to abnormal calves were tested.
During the breeding trial, 16 Galloway calves were born, ten calves were clinically normal and 6 calves were affected with tibial hemimelia. The Chianina cow bred to the Galloway bull (not included in Fig. 1) produced a clinically normal calf. All affected calves except one were stillborn, that one which lived only several days (Figs 2, 3 and 4). Of the affected calves four were females and one was a male, and the sex of one was not determined due to severe postmortem autolysis. Of the normal calves, six were females and four males.
Cont. Nos. 443-j, 222-j, and 528-j, respectively, Department of Pathology, Department of Surgery and Medicine, Department of Animal Science, Kansas Agricultural Experiment Station, Manhattan, Kansas, USA, 66506.
%. Tierzuchrg. Zuchtgsbiol. 94 (1977/78) 291-295 (0 1978 Verlag Paul Parcy, Hamburg und Berlin ISSN 004C3581/ASThbCodcn: ZTZBAS
294 H. W . Le$old, G. .Taperstein, R . Swanson, M . M. Guffy and R . Schalles
Gross, radiographic, and histologic lesions in affected calves (Table) were con- sistent with our previous report (OJO et al. 1974). Cow I, and cow I,, showed no lesions. Internal hydrocephalus caused by a prolapsed vermis, was present in cow I,.
Hemimelia is defined as agenesis of any part of the limb (as seen in adactyly, meromelia, or phocomelia) as opposed to amelia or absence of an entire limb. Agenesis of the tibial side of the lower limb has been reported in man as an autosomal dominant trait (CLARK 1975). Studies reported here and previously (OJO et al. 1974) revealed that expressivity on the tibial and femoral structures varies. In the slightest degree tibias were shorter than normal, and there was agenesis of the patella, and the distal joint surface of the femur carried only a single trochlea without subdivision into medial and lateral. Severely affected calves had bilateral agenesis of the tibia, and their femurs had one distal trochlea and the patella was absent. In addition, the skeleton of each calf had defects in the pelvic girdle and the cranium. The symphysis oft he pelvis remained open in all calves, including those having a short tibia. With one documented exception, all calves had cranioschisis ranging from an opening of .25 cm to 1.0 cm in diameter.
Other pleiotropic effects of the genes causing tibial hemimelia in Galloway calves included meningoceles (Table). The brains had moderate to marked internal hydroce- phalus. In addition, their reproductive systems and abdominal muscles had various changes. All calves with tibial hemimelia have ventral abdominal hernia. Defects of the reproductive system included cryptordichism in males and persistence of the Mullerian ducts in females.
The data suggested tibial hemimelia in Galloway calves is caused by recessive inheritance involving one locus. The expected phenotypic ratio would be: 4 affected and 12 normal calves. We observed 6 affected and 10 normal calves, that gave a chi- square value of 1.3 and a probability of 0.28 of having this amount or more deviation from the expected ratio. This probability supports the hypothesis of recessive inhe- ritance. Based on our breeding trial, we concluded that tibial hemimelia is a hereditary disease and that the mode of inheritance is simple autosomal recessive.
Three calves from one cow (1%) were affected. That cow had hydrocephalus typical of tibial hemimelia, however other signs were not present. Two other cows that had given birth to tibial hemimelia calves were normal upon necropsy. The remaining 5 cows and bull were not necropsied.
Other types of inheritance considered included dominance, incomplete dominance, sex-linked recessive and polygenic influence. If the