(South African J of Animal Science, 2000, 30, Supplement 1: 105-106

De Vries, M.

De Vries, M.A.

Elsenbroek, J.H.

Loock, A.H.

Neser, J.A.

Smith, H.J.C.

Van der Merwe, A.J.

Van der Vyver, F.H.

English

AJOL - African Journals Online

South African Journal of Animal Science 2000, 30(Supplement 1)© South African Society of Animal ScienceShort paper and poster abstracts: 38th Congress of the South African Society of Animal ScienceThe South African Journal of Animal Science is available online at http://www.sasas.co.za/Sajas.html105Enzootic geophagia of calves and lambs in Northern Cape and Northwest and thepossible role of chronic manganese poisoningJ.A. Neser1, M.A. De Vries2, M. De Vries2, A.J.Van der Merwe3, A.H. Loock3, H.J.C. Smith3, F.HVan der Vyver4 and J.H. Elsenbroek51Pathology Section, Onderstepoort Veterinary Institute, P/Bag X05, Onderstepoort, 01102State Veterinay Laboratory,   P/BagX36, Vryburg, 8600.3Institute for Soil, Climate and Water, P/Bag X70, Pretoria, 0001. 4Directorate of Animal Health, P/BagX369, Pretoria, 0001.5Council for Geoscience and Geological Survey,  P/Bag X112, Pretoria, 0001 South Africa.IntroductionGeophagia, or the deliberate ingestion of soil, has been classified as a form of pica. Geophagia can besymptomatic for deficiencies of elements such as P, Na, Mg, S, Cu, Co or Mn (Kreulen & Jager, 1984). Geophagiamay also be an instinctive behavioural response to gastro-intestinal disturbances (Kreulen 1985: Johns & Duquette1991; Reid 1992). In this communication a specific enzootic form of geophagia is reported which occurs in youngcalves and lambs on farms in the Barkley West,  Postmasburg and Vryburg districts of the Northern Cape- andNorthwest Provinces of the RSA.Materials and MethodsA questionnaire was distributed to landowners in the Vryburg and Kuruman districts to determine theincidence and geographical distribution of geophagia in cattle and sheep.  This was followed by an investigation.Clinical-, macroscopical- and histopathological examinations were carried out on affected calves and lambs. Theconcentration of Mn, Fe, Zn, Pb, Co and Cu in liver specimens was determined.  Feeding trials were conducted toinvestigate the appetite of 3 days-old- calves offered soil from affected and unaffected farms. A calf- and a lambwere dosed with manganese sulphate, euthanased to compare histopathological changes and the mineral compositionof the liver with livers from natural cases of enzootic geophagia and hepatitis.  Soil, edible plants as well as faecesand milk specimens from cows were analysed for Mn, Fe, Zn, Pb and Cu concentrations.Results and DiscussionThe problem apparently occurs only on a limited number of farms in the Vryburg, Postmasburg and BarkleyWest districts.  They are situated in an area known as the Ghaap Plateau, and have superficial outcrops ofmanganese-rich dolomitic or carboniferous rock of the Reivilo Formation (Astrup & Tsikos, 1998). The soil on theaffected farms contains numerous small round to ovoid black-grey Mn rich carboniferous concretions ca. 1-10 mm.in diameter. Suckling calves display an insatiable appetite for the Mn rich soil and sometimes lick iron poles. Theconsequence is severe constipation, dehydration and death within 7-10 days. The highest frequency occurs in calvesof 7 – 14 days of age.  Calves older than ca 2 months are rarely affected. Morbidity and mortality rates were difficultto estimate, since farmers could reduce the occurrence of geophagia by keeping the cows with young calves on deeplitter in pens, allowing cows limited grazing during the day time. Prophylactic injections of iron dextran preparationsshortly after birth showed some measure of success.  Macroscopical pathological changes consisted of moderate tosevere jaundice, marked enlargement and yellow discolouration of the liver, as well as the presence of variableamounts of dark brown to black soil, largely consisting of Mn-rich concretions, in the stomach and intestine.Histopathology revealed a chronic hepatitis, characterised by a marked proliferation of bile-duct epithelium. Liversfrom 23 calves and 1 lamb with soil in their digestive tracts or a history of geophagia, contained high concentrationsof Mn, ranging from 10-1800 mg/kg wet mass [(normal range 2-3 mg/kg) (Hurley & Keen 1986)]. Theconcentrations of the other minerals in the liver were inconclusive. Experimental calves offered Mn-rich soil from anaffected farm displayed marked geophagia with a strong appetite for this soil. They developed severe hepatitis, whilethe control calves, offered "normal" soil, also ingested small quantities of soil, but failed to develop severe geophagiaor any of the other complications associated with enzootic geophagia. None of the three calves which receivedprophylactic injections of iron dextran and vitamin B12 intramuscularly, developed geophagia or any othercomplications. A calf dosed with manganese sulphate developed identical histopathological lesions in the liver tothose of natural cases of enzootic geophagia.  Grazing plants from affected farms had higher concentrations of Mnand a higher ratio of Mn to Fe than plants from unaffected areas.  Soil specimens collected from three affected farmscontained more Mn (7,8% vs. 0,39%) and less Fe (2,4% vs. 7,8%) than specimens collected at the control sites.South African Journal of Animal Science 2000, 30(Supplement 1)© South African Society of Animal ScienceShort paper and poster abstracts: 38th Congress of the South African Society of Animal ScienceThe South African Journal of Animal Science is available online at http://www.sasas.co.za/Sajas.html106Faecal samples from cows also had a higher Mn concentration compared to control levels, while the results of themilk analyses were inconclusive.   The initiating cause of the urge in the calves and lambs to consume soil is notclearly understood.. On the affected farms, calves temporarily abandoned while their dams are grazing, tend to startlicking the soil. It was demonstrated that geophagia did occur in new-born calves when soil was offered, but severegeophagia with hepatitis occurred only when Mn-rich soil from the enzootic area was offered. Manganese interfereswith Fe, Co and Zn absorption in the digestive tract ( Hurley & Keen 1987; Morris, 1987).  A deficiency of Co hasbeen associated with geophagia  (Kreulen & Jager 1984) and pica in cattle  (Valli & Parry 1994), while Zndeficiency has been implicated as a cause of geophagia in children (Hambidge, Casey & Krebs  1987).  In the presentstudy the parenteral treatment of calves with iron-dextran compounds and vitamin B12  at 1-2 days after birth and at14 days had a significant preventative effect on the occurrence of geophagia. The histopathological changes in theliver, which could be induced experimentally by dosing manganous sulphate, were indistinguishable from the lesionsobserved in natural cases of enzootic geophagia, and corresponded to the changes induced by the dosing and injectionof manganous sulphate and manganous chloride in rodents ( Findlay, 1924; Witzleben et al., 1968).ConclusionsIt is concluded, that although the cause of geophagia may not be completely understood, the characteristiclesions in the liver can be attributed to a subacute to chronic form of manganese poisoning.ReferencesAstrup, J. & Tsikos H., 1998. Mineral Resources of South Africa. Handbook of Geological Survey of South Africa,No. 16, 6th Edn, Council for Geoscience, Pretoria. pp.450-460Findlay, G.M. 1924. Br. J. Exper. Path. 5, 92 - 99Graham, T.W.,et.al., 1994. J. Vet. Diag. Investig. 6, 77-87.Hambidge, K.M. et al., 1987. Trace elements in human and animal nutrition, 5th  Edn. Academic Press Inc., SanDiego. Vol. 2: 50 – 51.Hurley, L.S. &  Keen, C.L., 1987. Trace elements in human and animal nutrition, 5th  Edn. Academic Press, Inc. SanDiego,.Vol. 1, 185-223.Johns,T. & Duquette, M., 1991. Am. Jl. Clin. Nutr. 53, 448-456.Reid, R.M., 1992. Med. Anthropol. 13, 337–351.Kreulen, D.A., 1985. Mammal Rev. 15, 107-123.Kreulen, D.A. & Jager, T., 1984. Herbivore Nutrition in the ropics and Subtropics. The Science Press, Craighall. pp204- 221.Morris, E.R., 1987. Trace elements in human and animal nutrition, 5th Edn. Academic Press, Inc. San Diego. Vol.1,79-142.Valli, V.E. & Parry B.W., 1993. Pathology of Domestic Animals, 4 th  Edn., Academic Press Inc., San Diego.  Vol.3, 72.Witzleben, C.L., et. al., 1968. Am. Jl. Path. 53, 409–423.

Enzootic geophagia of calves and lambs in Northern Cape and Northwest and the possible role of chronic manganese poisoning

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Enzootic geophagia of calves and lambs in Northern Cape and Northwest and the possible role of chronic manganese poisoning

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