Integrated crop-livestock system as grassland contamination control method for gastrointestinal helminths of sheep

Abstract

Will be evaluated four Integrated Crop-Livestock Systems (ICLS) to verify if after a rest period of nine months the pasture will be decontaminated by infective larvae of gastrointestinal parasites of sheep. The systems will be: (1) Maize + palisadegrass + oats spread out manually; (2) Maize + palisadegrass + pigeon pea + oats spread out manually; (3) Maize + palisadegrass + oats on the line; (4) Maize + palisadegrass + pigeon pea + oats on the line. An experimental cycle (2015/2016) evaluation using 64 sheep (n = 16) Corriedale x Poll Dorset crossbred with an average of 90 days old and 25 kg body weight will be accomplished. The grazing animals will be rotated (12 paddocks per treatment) with three days of occupation and 33 days of rest. Will be assessed two grazing cycles (two cycles of oats), totaling 72 days of experiment. The animals will be collected at the end of the day in pen in a covered shed, and each group will be allocated on a pen and on this occasion will be supplemented with concentrated + silage from the same treatment. The pasture collected to verify contamination by infective larvae (L3) of gastrointestinal parasites will be evaluated every nine days, after the occupation for animals, at the pickets 1, 6 and 11 of each treatment. Will be compared two pasture collection methods for quantification and identification of infective larvae. The first is the 'W' method and the other the Square Method. Before the occupation of the lambs test in these paddocks, will be used 12 tracer lambs, free of helminth infection (n = 3), to verify if the rest period of nine months was enough to decontaminate the pasture. These animals will be slaughtered for recovery and quantification and identification of parasites present in the gastrointestinal tract (abomasum and small and large intestines). We hoped this project validate the ICLS as a method to decontaminate the pasture by gastrointestinal parasites of sheep.