Evaluation of hepatic changes and weight gains in sheep grazing Kochia scoparia

Sixteen Western Whiteface ewes were divided into 2 groups to determine the effects of plant maturity on liver function and weight gains. They were allowed to graze a greater than 95% pure stand of Kochia scoparia for 72 or 55 d. Four additional sheep (controls) were placed on weedy Bermuda grass pasture with the same water supply as the kochia-fed sheep. Body weights were determined on June 5, 1996 and on removal from the kochia pasture. Blood samples were collected at approximately 7-d intervals for serum chemistry profiles. Kochia scoparia plant samples were also randomly collected at 5-6 w intervals, oven dried, identified by date of collection and stored for later nutrient, oxalate, nitrate and sulfate analysis. Liver biopsies were performed pre-, mid- and post-study to assess morphologic changes. An almost exclusive diet (> 95%) of Kochia scoparia resulted in minimal elevations in serum GGT, suggesting mild hepatocellular injury, but was not associated with overt hepatic lesions or clinical disease. Other serum chemistry measurements were within normal ranges. Unlike for other domestic animal species, Kochia scoparia may be a useful grazing forage for sheep, offering little risk of toxicosis.