Study of helmintic infection in Suffolk lambs: submited to two systens of finished

Abstract

It was conducted an experiment at Unidade de Pesquisa e Desenvolvimento, at Itapetininga, SP, Brazil, in order to evaluation the helmintic infection in Suffolk lambs finished in rotational grazing and in feedlot. Feces and blood samples were collected every 14 days of 39 lambs, from 45 days of age up to reach the slaughter weight age, for the individual determination of the eggs for gram of feces (EPG) counts, the larval cultures, the average packed cell volumes (VG) and the total plasmatic protein (TPP). Anthelmintic treatment was used when the individual counts was equal or higher to 500 EPG. By EPG counts was observed significant difference between the treatments (p ? 0.01), with the average values of 2,507 and 1,050 EPG counts found in the animals on grazing and confined, respectively. During the experimental period it was necessary, on the average, 2.6 and 3.8 anthelmintic treatments for the animals in feedlot and in rotational grazing, respectively. To VG there was no significant difference between the treatments, with the average values of 33 and 34% for animals in grazing and feedlot, respectively. There was significant difference (p ? 0.05) between two systems for total protein values, with 5.70 % for grazing animals and 5.53 % for feedlot animals. In the present experiment, the grazing animals presented higher EPG counts, probably due to the reinfection. This result, however, it did not interfere in the average values of the VG. The gastrointestinal nematodes found were Haemonchus, Trichostrongylus and Strongyloides.