Effect of dehydrated grapefruit peels on intestinal integrity and Eimeria invasion of caprine epithelial cells in vitro and anticoccidial activity in vivo

Anticoccidial drugs are among the preferred resources to control coccidiosis, but the need to have natural alternatives has prompted research into plant products that improve animal performance and might also reduce Eimeria oocyst shedding while avoiding problems of drug residues. Two studies were conducted to evaluate the effects of dehydrated grapefruit peels (GDP) on Eimeria infection and intestinal health. In the first study, an in vitro culture system was used to evaluate the integrity of caprine epithelial cells infected with Eimeria ninakohlyakimovae and incubated with GDP, as well as the infection rate and schizont development of parasites exposed to GDP. In the second study, the anticoccidial effect of the inclusion of 15% GDP1 or 30% GDP2 in the diet and toltrazuril was evaluated in goat kids naturally infected with Eimeria spp. Parameters assessed included the reduction in oocyst counts, weight gain, fecal consistency, intestinal integrity, and malondialdehyde and nitric oxide (NO) production. In vitro, GDP2 and TTZ not only increased transepithelial electric resistance (TEER) values in infected caprine epithelial cells, but also decreased the mean cell invasion rate of sporozoites of E. ninakohlyakimovae and reduced the number and size of schizonts/mm2 of the intestinal cells culture. In vivo, the GDP2 group showed higher mean daily weight gains, reduced fecal oocyst output and decreased oxidative stress in goat kids. These findings demonstrate the beneficial activities of GDP in the enhancement of growth performance and gut health, and the feasibility of using a 30% inclusion of GDP for the replacement of corn in goat production.