Effects of daily oral doses of L-arginine on coccidiosis infections in chickens

L-arginine is an essential amino acid for chickens, as well. as the substra te for biosynthesis of nitric oxide (NO), a bioregulatory free radical mole cule known to have antimicrobial activity. Biosynthesis of NO by induced ni tric oxide synthase (iNOS) can be stimulated during immunological response to infection. Therefore in chickens, production of NO as a response to an i nfection should be influenced by dietary levels of L-arginine. Two experime nts were carried out to determine whether oral dosing with L-arginine durin g coccidia infections could influence the associated pathology or the devel opment of the parasites. Neither single nor dual daily doses (500 mg/kg) of L-arginine reversed weight gain reduction, augmented plasma NO2- + NO3- le vels, or lessened lesion scores in chicks infected with Eimeria acervulina, Eimeria maxima, or Eimeria tenella. Although the oocyst shedding from E. m axima (Ix dose) or E. acervulina (2x dose) infections were not affected, th e oocyst shedding from E. tenella infections was significantly reduced by b oth dose regimens.