Abstract:
Proc. Aust. Soc. Anim. Prod. 1996 Vol. 21 OBSERVATION OF DENTAL LESIONS CONSISTENT WITH FLUOROSIS IN SIX CATTLE HERDS IN THE NORTHERN HALF OF THE NORTHERN TERRITORY D. LA FONTAINEA, R.N. MACDONALDB and G.M. MURPHYC * Dept Primary Industry and Fisheries, PO Box 990, Darwin, N.T. 0801 * Dept Primary Industry and Fisheries, PO Box 1346, Katherine, N.T. 085 1 'Dept Primary Industries, Animal Research Institute, Yeerongpilly, Qld 4 105 Following concern in Queensland and northern Western Australia over the level of fluorine within fertiliser based phosphorus supplements, a small number of cattle were observed in the N.T. during 1992 93 with teeth symptoms suggestive of fluorosis (K. DeWitte, pers. comm.). To test whether these symptoms comprised a significant problem in affected herds, a survey of 5 properties known to have fed fertiliser grade Mono Ammonium Phosphate (MAP) in commercial or home made supplements was undertaken in June 1994. The mouths of approximately 80 commercial breeder cows were examined on each of the 5 properties surveyed (399 total). Each permanent incisor was allocated a damage score (1 - 5) following the descriptive method of Suttie and Faltin (1971) (where score 1 described a normal tooth and score 5 described a tooth with general mottling, hypoplasia, wear and erosion of enamel from dentine). All animals surveyed were aged according to the number of permanent incisors erupted, to account for normal erosion and decay. During the same month, 42 lower jaw samples from a separate station, selected to represent the range of previously observed tooth damage scores, were collected from the Katherine abattoir and analysed for fluorine content. There was no significant relationship found by regression analysis between tooth damage score and cow age (P>O.O5) over the entire sample (n=441), suggesting that there were factors other than normal erosion and decay involved in causing the observed tooth damage. Table 1. Observed tooth damage score on properties surveyed (399 cows) . Table 2. Level of fluorine in bone samples taken from the Katherine abattoir JUBB, T.F., ANNAND, T.E., MAIN, D.C. and MURPHY, G. M. (1993). Amt. Vet. J. 70: 379-83. SUTTIE, J.W. and FALTIN, E.C. (1971). Am. J. Vet. Rex 32: 217-22. 352
