Submitted to: Southern Pasture and Forage Crop Improvement Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/24/2002
Publication Date: 4/24/2002
Citation: Kaplan, R.M., Stuedemann, J.A., Franzluebbers, A.J., Seman, D.H. 2002. The salem road study: restoration of degraded land with pasture: the concept of parasite-free pastures. Southern Pasture and Forage Crop Improvement Conference Proceedings. Interpretive Summary: .
Technical Abstract: The objective of this report was to determine if parasite-free pastures could be maintained by anthelmintic treatment of animals prior to placing them on pastures. Yearling Angus steers (Bos taurus) were managed in a put-and-take grazing system with three "tester" steers assigned to each paddock and "grazer" steers added or removed at 28-day intervals. From 1994-1998, steers grazed the paddocks for a 140-day period from mid-May until early October each year. Anthelmintic treatment included pour-on ivermectin on day -21, albendazole on day -7, and injectable ivermectin 48 hours prior to stocking of pastures, with the cattle remaining in drylot during the 48-hour period prior to being placed on the experimental paddocks. All steers received only one series of treatments during any given year. Rectal fecal samples for worm egg counts were obtained on day 0 and at 28-day intervals thereafter except in years one, four and five when egg counts were also performed on day -21. On all sampling days after day 0, samples were obtained only from tester animals. Over the 5-year period, the mean eggs per gram of feces (epg) gradually increased from 0 (following treatment) to a mean of 2.2 (range from 0.7 to 3.0) by the end of the grazing season (the last sampling date) in October. Although there were statistical treatment differences in epg among both the fertilization and forage mass treatments, the very low average epg (0.7 to 3.0) indicated that there were no biological differences. Although the epg were not zero, they were below threshold levels that would allow development of a parasite burden in cattle. Consequently, we can say that under the conditions of this experiment, pastures were maintained in a parasite-free condition for at least five years by simply therapeutically treating animals prior to placing them on the parasite-free pastures. The therapeutic treatment prevented transport of larvae to the pastures, thus preventing pasture contamination and reinfection.