Aspectos clínicos, parasitológicos e produtivos de ovinos mantidos em pastagem de capim-aruana irrigado e adubado com diferentes doses de nitrogênio

Abstract

This work aimed to evaluate clinical, parasitological and productive parameters of crossbred lambs under a rotational grazing system of Panicum maximum cv. Aruana grass fertilized with four doses of nitrogen (75, 275, 475 and 675 kg ha-1 year-1). Eighteen lambs were used per treatment, totaling 72 animals. The following parameters were evaluated: daily weight gain (DWG), total weight gain (TWG), stocking rate (SR), meat production, number of fecal eggs per gram (EPG) and coproculture. Deworming was accomplished according to conjunctiva color compared using the Famacha© card. DWG and TWG were greater (p < 0.05) in the animals under pasture fertilized with 75 kg ha-1 year-1. However, SR and EPG were greater (p < 0.05) in the animals kept in pastures with 675 kg ha-1 year-1. There were no significant differences among nitrogen levels for the different colors of ocular mucosa or the number of animals dewormed. A prevalence of 80.0 to 93.0% of Trichostrongylus sp. was found. The deworming based on the evaluation of conjunctiva color did not reduce EPG into desirable levels for any of fertilized doses of nitrogen. The nitrogen dose of 475 kg ha-1 year-1 in Aruana grass allowed greater productive performance per hectare.