13 Summary
Ursula Schulze
Development of a web-based monitoring system for anomalies in cattle and first analysis of cases
The aim of this study was a detailed description of the phenotype of bovine congenital anomalies and to elucidate as far as possible underlying causes. For this a web-based system for the reporting of bovine congenital anomalies was established.
Development of a web-based monitoring system for anomalies in cattle.
A web-based system for the reporting of bovine malformations was developed at the Institute for Animal Breeding and Genetics. This system is accessible for all persons such as farmers and veterinarians. A brief description is provided for selected anomalies and supplemented with photographs of previous cases. A questionnaire was developed to record the origin of the animal and the type of malformation. The advantages of this system are its instant and far-ranging availability as well as the chance of establishing immediate personal contact with the researcher. As the reports were frequently made shortly after the births of the calves, a lot of cases could be submitted to further clinical, moleculargenetic and biochemical examinations.
From August 2004 until November 2005 altogether 109 reports were filed, with 46 registered by Rinderunion West, and 11 by clinics of the University of Veterinary Medicine Hannover and passed on to the Institute for Animal Breeding and Genetics.
A detailed examination of the deformed calves was carried out in 17 cases.
Malformations of the digestive system (19%), the head (18%), the spinal column (17%), and limbs (14%) were most frequently registered. A further extension of the present system with improved feedback of information to farmers and vets as well as topical information about anomalies would appear reasonable and promising, so as to improve and enlarge the system of reporting malformations.
13 Summary 134
Within the framework of this study the following cases were investigated:
Diprosopus
Diprosopus was diagnosed in six German Holstein calves born on different dairy farms. The degree of facial duplication varied from a partial doubling of the nostrils and upper jaw to complete duplication of the face with formation of two mouths, four eyes and four ears. A joint pedigree was ascertained for the calves with diprosopus.
Furthermore, a previously reported case of diprosopus could be traced back to the same ancestors of this pedigree. Consequently, we detected the first time a familial accumulation of diprosopus. Since the ancestors showed no signs of diprosopus and the frequency of diprosopus in German Holsteins is presumably low, an oligogenic inheritance is likely. Recessive genes or a combination of recessive and dominant genes may cause this anomaly.
Thorakopagus
A black and white German Holstein calf displayed a complex double malformation in shape of a thoracopagus parasiticus. By means of a molecular genetic investigation the genesis of the malformation from one zygote could be demonstrated. The pedigree of the affected animal showed neither inbreeding nor any other affected animal.
Cyclopia
A German Fleckvieh calf was diagnosed with cyclopia in shape of united eye sockets in one orbit. However, two fully developed eye balls were present while the nostril was not developed. The malformed calf was inbred on a bull used for artificial insemination (AI) with an inbreeding coefficient of 3.125%. Teratogenic plant alkaloids were unlikely to be responsible for the malformation of this calf.
Myoclonus
A female German Holstein calf was not able to stand up after birth. Sensory stimuli like auditory or tactile impulses induced myoclonic jerking of the whole body.
Afterwards it calmed down quickly. The signs observed correspond to the clinical findings of congenital myoclonus in poll Hereford calves. The present type of
13 Summary 135
congenital myoclonus in the calf examined is likely to be genetically determined, even if the point mutation in exon 2 of the glycin receptor, alpha 1 genes was not confirmed.
Ectopia cordis
A case of ectopia cordis pectoralis was diagnosed in a black and white coloured German Holstein calf. The heart and pericard were displaced through a fissure in the breastbone. The heart was connected with the thoracic cavity by its large vessels.
The liver was deformed and many organs showed passive hyperaemia. The calf was well developed and died under birth. The lungs were not ventilated. The malformed calf was inbred on a bull used for artificial insemination with an inbreeding coefficient of 3.125 %. The ectopia cordis probably resulted from the fissure of the breastbone.
Congenital defect of the keratinisation of the skin
Congenital dysfunction of the keratinisation of the epithelium with thymus atrophy was diagnosed in two female German Angus calves born on the same farm. The relationship coefficient between the two affected Angus calves was 34.38 %. The clinical findings were similar to ichthyosis congenita as the alterations of the skin were present at birth and the levels of zinc in the blood were not decreased. Contrary to previous findings in ichthyosis congenita thymus atrophy was already seen in both calves. On account of the close relationship between the two affected calves a genetic cause is likely for the present cases.Congenital defect of the skin
Congenital dysfunction of the epithelium with thymus atrophy was diagnosed in two German Angus calves born on the same farm. The relationship coefficient between the two affected Angus calves was 34.38 %. The clinical findings were similar to Ichthyosis congenita as the alterations of the skin were present at birth and the levels of zinc in the blood were not decreased. Contrary to previous findings in Ichthyosis congenita thymusatrophy was already seen in both calves. On account of the close relationship between the two affected calves a genetic cause is likely for the present cases.
13 Summary 136
Anophthalmia
In three German Holstein calves and one German Holstein-Limousin crossbred calf from different farms anophthalmia/microphthalmia was diagnosed. Additionally, three calves showed a ventricular septum defect and two animals anuria/brachyuria.
Further malformed calves closely related or not-related to these animals on the respective farms were not seen. BVD virus infection and lack or excess of vitamine A of the mothers could be ruled out. As for bovine anophthalmia/microphthalmia autosomal recessive inheritance is discussed, a genetic cause might also be likely in the present cases.
Aphakia associated with additional ocular malformations
Aphakia and further malformations of both eyes were diagnosed in a female German Holstein calf. Neither the clinical nor the pathological examination revealed any further malformations. A BVD infection could be excluded as cause for the ocular malformations observed. A deficiency or excess of vitamine A was unlikely because this would have also applied to all other calves born at the same time on the farm.
The inbreeding coefficient of the malformed calf was 3.168% indicating a hereditary problem.