In order to eliminate infectious and parasitic conditions from the rabbit colony bred and used for antibody production for cancer research, a hysterectomy-derivation programme, based on hand-reared germ-free rabbits was carried out. The resulting SPF rabbits were held within a barrier system where the diet was sterilised by gamma irradiation. While all pathogens and parasites were successfully eliminated, problems of dietary origin had emerged. At first, young rabbits were affected by muscular dystrophy due to the partial loss of vitamin E during irradiation. This was eliminated by the addition of 100 mg alpha tocopherol per kilogram diet. With longer survival in disease-free status, older rabbits have developed soft tissue calcification due to vitamin D excess in the diet. This has ceased after the elimination of 3000 lU/kg vitamin D 3 supplementation, relying only on the presence of vitamin D within the ingredients. For this there was precedent in some of 33 surveyed world-wide used rabbit diet compositions. This, however, resulted in tooth enamel abnormalities and reproduction failures due to D-avitaminosis. 500 lU/kg vitamin D3-supplementation of the diet has redressed the balance and proved to be satisfactory for its correct supply of the colony for the ensuing years. However, corneal opacity cases occurred from time to time, which did not cease by doubling the vitamin A content of the diet on suspicion of its deficiency. Instead, aortic plaques found at necropsy and very high plasma cholesterol values revealed chronic, so far occult, vascular, ocular and parenchymal atheromatosis, affecting the whole colony. It was realised that the main protein source in the diet, 10% fishmeal, was the main cause, as by halving it in the diet, considerable, but not full improvement occurred. Its full replacement by grass-meal as the main protein source resulted in chronic diarrhoea of the whole colony. Eventually the provision of 5% wheat bran and 5% soybean meal in the diet as the main protein source, has fully eliminated atheromatosis for years to come, with the added bonus of an improvement in the quality, avidity and titre of sera produced from various antigens for cancer research, using with confidence only a single disease-free rabbit for each antigen.
|Number of pages||6|
|Journal||Magyar Allatorvosok Lapja|
|Publication status||Published - Nov 1 2011|
ASJC Scopus subject areas