8153

• UCREFRP Catalog Number: 8153
• Author: Jacobs, e. L. W.
• Title: Editor
• USFW Year: Series
• USFW - Doc Type: 1989
• Copyright Material: YES

SELENIUM IN SELENIFEROUS ENVIRONMENTS 41
tus officinallis (L.) Pall.], grown on fly ash containing 5.3 mg Se/kg, was
formulated at 35% of a diet fed to hamsters (Mesocricetus auratus) and guinea
pigs (Cavia porcellus) for 90 d (Furr et al., 1975). Sheep and goats (Capra
hircus) were fed a pelleted diet containing seleniferous white sweet clover
(Melilotus alba Medik.) harvested from a fly ash disposal area. The sweet
clover contained 66 mg Se/kg, but as prepared contained only 15.5 mg Se/kg,
which was fed for 173 d. In yet another study, wheat grain containing 5.7
mg Se/kg, was fed to Japanese quail (Coturnix coturnix japonica). The wheat
had been grown on fly ash containing 21 mg Se/kg (Stoewsand et al., 1978).
Feed consumption and weight gains in each of these studies were not ad-
versely affected by the seleniferous diets. Although body tissues from animals
fed the seleniferous diets contained elevated levels of Se, outward signs of
selenosis were not evident.
SELENIUM IN MUNICIPAL SEWAGE SLUDGE
Municipal sewage sludge represents a major portion of the national solid-
waste disposal problem with an estimated 4.5 x 1010 kg produced in 1968
(Furr et al., 1976b). Furr et al. (1976c) measured the elemental concentra-
tions in sludges collected from 16 U.S. cities and reported that the spectrum
and concentration of heavy metals in the sludge was generally a function
of the industry in the area. Selenium concentrations in the 16 sludges ranged
from 1.7 to 8.7 mg Se/kg, with an average of 3.2 mg Se/kg.
The bioavailability of the Se (and other metals) becomes an important
factor in the disposal of sewage sludges. Aheat-treated, waste-activated sludge
from the city of Milwaukee, WI, has been marketed commercially as Milor-
ganite, asoil conditioner for application on lawns and gardens. The product
contains 1.8 mg Se/kg. Furr et al. (1976b) grew a variety of garden crops
in pots with soil containing 10% Milorganite by weight. At harvest, the edible
portions of these crops had significantly greater concentrations of Se than
for those plants grown on the control soil, but the increase may not have
been biologically significant.
Waste from feed lots, poultry houses, and municipal sewage treatment
plants have also been evaluated as a supplemental feed for livestock. The
manures tested by Capar et al. (1978) contained 0.5 to 0.7 mg Se/kg, whereas
the Denver municipal sludge contained 5.4 mg/kg total Se. Feeding the Den-
ver sludge as 0, 4, or 12% of diet to 340 kg steers provided diets containing
0.16, 0.35, or 0.72 mg Se/kg (Kienholz et al., 1979). The sludge provided
very little metabolizable energy, and animal weight gains were less compared
with control animals. There was a trend (P > 0.05) for increasing Se con-
centrations in liver; 1.3, 1.7, and 4.2 mg Se/kg (dry basis) for the three treat-
ments, respectively. Selenium concentrations in dried blood were 1.3 and 1.7
mg Se/kg in the basal and 12% diet, respectively (P < 0.05).
In another study (Boyer et al., 1981), steers were fed a basal or basal
diet containing 12% Fort Collins anaerobically digested sewage sludge. The
sludge contained 16 mg Se/kg but, after dilution with the rest of the ration,