Effects of added 30 mg fluoride/1 drinking water given to pregnant ewes and their lambs upon physiology and wool growth

Abstract

SUMMARYTwo groups of pregnant ewes were given either 1 (control) or 31 (treatment) mg fluoride/1 drinking water. Weekly blood samples were tested for serum fluoride, haematocrit, T3, T4, cortisol, calcium and magnesium. At parturition, serum fluoride was measured in both ewes and lambs. Later, parallel blood and milk samples were taken from ewes and measured for fluoride. Weekly blood samples from the lambs were measured for the same variables, as well as serum phosphate, body weight, bone fluoride and wool production. Serum fluoride in control ewes ranged from 0·6 to 1·9 μmol/1 and in treatment ewes from 8·7 to 35·4/ μmol/1. At birth, serum fluoride of control lambs averaged 0·50 ± 0·042 μmol/1 and of treatment lambs 1·72 ± 0·167 μmol/1. In milk from the control group mean fluoride concentration was 7·11 ± 0·403 μmol/1, and from the treatment group 22·0 ± 1·48 μmol/1. No differences in haematocrit T3, T4, cortisol, calcium or magnesium of ewes were apparent during pregnancy. At birth, body weight of the treatment group lambs was reduced, and T3, calcium and magnesium increased. At 3–4 weeks mean bone fluoride of lambs was higher in the treatment group (580 ± 117 mg/kg) than the control group (105 ± 26·9 mg/kg). After 7 weeks there was an upward trend in serum phosphate of treated lambs, and their wool production (clean fleece weight) at 17 weeks was reduced by 18%, primarily because of decreased staple length.

Effects of addition of fluorine in diets differing in protein content on urinary fluoride excretion, clinical chemistry and thyroid hormones in calves

“…The results of the present study were in conformity with previous reports (Suttie & Kolstad, 1977;Wheeler et al, 1985). Increase in the F levels was noted as the feeding period increased.…”

“…In contrast, Hillman et al (1979) observed elevated levels of serum Ca in hydrofluorotic sheep. Again, some other researchers reported no effect in serum Ca due to F exposure (Wheeler et al, 1985;Vashishth et al, 1998). Similarly, the present observation on serum inorganic P was in line with earlier findings (Mehrotra & Singh, 1989;Vashishth et al, 1998) although there are reports of the contrary (Wheeler et al, 1988;Wu et al, 1995;Chandra, 1997;Madan et al, 2009).…”

Ingestion of soil fluorine: Its impact on the fluorine metabolism and status of grazing young sheep

“…In cattle, a severe fluorosis is associated with blood F concentrations > 0.5 mg litre-1 (Shupe et al 1963). A study with sheep suggests that they are unlikely to be more affected by fluorosis by high F intakes than cattle (Wheeler et al 1985). Serum F concentrations ranging from 0.47-0.66 mg litre-1 for 12 weeks in ewes given high F intakes as NaF via drinking water (calculated 54-75 mg F kg-1 DM ), over gestation and lactation, did not cause any health problems (fluorosis) in the ewes or their lambs (Wheeler et al 1985).…”

“…A study with sheep suggests that they are unlikely to be more affected by fluorosis by high F intakes than cattle (Wheeler et al 1985). Serum F concentrations ranging from 0.47-0.66 mg litre-1 for 12 weeks in ewes given high F intakes as NaF via drinking water (calculated 54-75 mg F kg-1 DM ), over gestation and lactation, did not cause any health problems (fluorosis) in the ewes or their lambs (Wheeler et al 1985). At birth the lamb serum F concentrations (0.01 for no F intake versus 0.03 mg litre-1 for high F intake), milk F concentrations (0.13 versus 0.42 mg litre-1 ), and bone F concentrations (105 versus 580 mg kg -1 ) of the 4-to 5-week-old lambs were increased as a result of increasing the F intake by the ewe from an estimated 54-75 mg F kg-1 DM (Wheeler et al 1985).…”

“…Cronin et al (2000) identified that there is a paucity of data on both the rates of absorption and retention of F from soil ingested by grazing sheep. In contrast, the effect of increasing F intake as sodium fluoride (NaF) on the apparent absorption or availability of F in terms of changes in serum F concentrations, urinary F excretion, and changes in bone F concentrations have been well documented (Suttie et al 1972;Suttie & Kolstad 1977;Wheeler 1985). This paper reports on a sheep feeding study where the effect of increasing F intakes as NaF and soil F on the apparent absorption of F, apparent retention of F, and the changes in serum, soft tissue and bone F concentrations were determined.…”