Parasitic management of the cord of destete in a natural field

II Alternate grazing with cattle in a crystalline basement area

Abstract

A total of three months old Corriedale lambs (mean), were exposed during the period December-June to two parasitary managements. The conventional weaning-dosification strategy in contaminated grazing was studied together with a weaning dosification strategy in safe grazings, obtained through previous alternative grazing with bovines above two years old. The same wide spectrum anthelmintic (OFZ) was used in both groups of lambs. A group of 45 lambs was used in both strategies as padock control, in order to detect possible interferences with the type of pastures, grazing area and/or watering places. Weight increase and evolution parameters were measured every 28 days and the elimination of eggs from feaces every 14 days. It was also established on a monthly basis for each group the relative parasitary composition of grastrointestinal nematodes. The use of safe pastures, obtained by alternate grazing, was successful in the obtention of low infestation rates up to at least four months polt-weaning of lambs. In comparison with the traditional strategy, it was possible to maximize the effect of the wide sprectrum drug. It was necessary to use 2.5 times less dosifications to obtain a similar weight evolution (<1 o/o). Alternate grazing did not have much influence on the composition of larvae challenges from safe grazings.