Effects of Curcuma longa dietary inclusion against Eimeria spp. in naturally-infected lambs

•First study of the anticoccidial and weight-gain effects of curcumin in sheep.•Oocyst shedding and pathogenic species analysed.•First study of oxidative stress response and cytokines involved in inflammation generation after ingestion of a dietary supplement.

Ovine coccidiosis caused by Eimeria spp. can negatively impact health and overall productive performance in sheep with mortalities up to 20% in lambs. It is characterized by high production of pro-inflammatory cytokines and oxidative stress that can damage intestinal tissue. Currently, only drugs are used for the treatment of ovine coccidiosis. Nevertheless, anticoccidial resistance and the concern of drug residues in edible tissues and milk have prompted the evaluation of alternatives to prevent and control this disease. Based on preliminary findings, the use of Curcuma longa dietary supplementation was evaluated in this trial. Twenty crossbred lambs naturally infected with Eimeria spp., aged 28-days-old with an average weight of 12 kg, were divided in five groups. Three groups were treated orally for 14 days with 50 mg/kg, 100 mg/kg, or 200 mg/kg of C. longa. A placebo-treated group and untreated controls were included in this trial, too. Stool samples were obtained every other day to determine anticoccidial efficacy. Also, animals were weighed on day 0 and 42. To evaluate the immunomodulatory activity of curcumin, a proinflammatory (IFN-γ) and an immunoregulatory (IL-10) cytokine were measured by ELISA. Lipid peroxidation and nitrite generation were determined by means of the serum malondialdehyde test and the Griess reaction, respectively. C. longa anticoccidial activity increased over time in treated groups and reached a 100% efficacy on day 42. Animals treated with 200 mg/kg of this plant gained twice the daily weight recorded for untreated groups. IL-10 levels were higher in supplemented animals, whereas lipid peroxidation and generation of nitrites were significantly lower. Results showed that curcumin administration may reduce oocyst output, weight-loss, inflammation and oxidative stress-related effects caused by Eimeria spp. infection in lambs.