Sewage solids as supplemental feed for ruminants grazing rangeland forage

TitleSewage solids as supplemental feed for ruminants grazing rangeland forage
Publication TypeConference Proceedings
Year of Publication1980
AuthorsSmith G.S., Kiesling H.E., Herbel C.H., Ray E.E., Trujillo P.A., Orcasberro R., Sivinski J.S
Conference NameTransactions of the American Nuclear Society
Date Published1980
Keywordsforage, rangeland, ruminants, sewage solids, supplemental feed
AbstractThe solids in raw sewage represent a vast resource of nutrients that are potentially returnable to agriculture where constraints of pathogens and toxic chemicals are not prohibitive. Gamma irradiation from waste radionuclides such as 137Cs appears to be feasible as a means of pathogen reduction in large-scale operations. Since 1975 New Mexico State University has evaluated dried, "radicized" solids from raw sewage (primary sludge) as a prospective supplemental feedstuff for ruminants (cattle, sheep) subsisting on poor-quality roughage feeds. Our published reports and unpublished data support the view that products derived from raw sewage could provide substantial nutritive value to ruminant animals without necessarily incurring intolerable risk to the animals or the human food chain, especially if such products are used only periodically in the maintenance of breeding herds and/or in the early "background" programs of young ruminants destined for slaughter much later. Objectives of experiments reported here were to demonstrate under practical conditions the benefits from an experimental feed supplement (containing 62% dried, irradiated sewage solids) for gestating-lactating beef cows grazing dormant forage on semidesert rangeland and to assess, under extreme conditions, the accumulation of heavy metals and/or refractory organic compounds (toxicants) in tissues of cattle fed sewage solids for almost 3 months.