|Knapp, Steven - Steve|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/10/1999
Publication Date: N/A
Technical Abstract: A long-term study was conducted to determine whether eroded cropland can be restored by grazing. Three blocks of six treatments including three sources of fertilizer nitrogen (NH4NO3, broiler litter, and clover N) and two grazing pressures were evaluated on eighteen, 0.7 ha Coastal bermudagrass pastures. The objective of this portion of the study was to determine if non-grazed cultivated land, expected to be free of parasites, could be maintained as parasite-free pastures by judious anthelmintic treatment of cattle prior to stocking each year from mid May to mid October. Anthelmintic treatment included pour-on ivermectin on day -21, albendazole on day -7 and injectable ivermectin 48 hr prior to stocking of the pastures, with the cattle remaining in drylot during the 48-hr period. There were no biologically important differences in nematode eggs per gram of feces (epg) among pasture fertilization and grazing pressure treatments. .Mean epg at the end of the first, second, third, fourth, and fifth season of grazing were 3.6, 0.4, 3.0, 2.1, and 1.9, respectively. Cultures of feces collected at the end of the fifth season revealed that Haemonchus (61%) and Cooperia spp. (31%) accounted for 92% of all larvae recovered being present on 17 of 18 paddocks. Other species recovered in smaller numbers included, Oesophagostomum radiatum (4%), Ostertagia ostertagi (3%), and Trichostrongylus spp. (1%). Thus, after five years of grazing during the warm season, there were no biologically important differences in epg, with all pastures remaining free of parasites.