Monitoring of feedlot associated flies fly populations at Karan Beef feedlot

Abstract

Monitoring of feedlot associated flies fly populations at Karan Beef feedlot Flies associated with feedlots have important impacts, especially regarding economic impacts such as meat production, feed intake of cattle, the influence on production costs due to chemical fly control as well as environmental impacts due to possible bio-accumulation of insecticides and the development of insecticide resistance in insects. The painful irritation caused by haematophagous flies cause cattle to stomp their feet and bunching of cattle to avoid fly irritation. This avoidance behaviour has a negative effect on mass increase. Integrated fly management programs is the preferred solution to address these impacts. The first step in the development of an integrated fly management program is an investigation into the composition of the fly population in feedlots for the development of threshold levels for chemical control measures. This project reports on an initial determination of fly populations in a feedlot. The composition of fly populations was determined with different fly trap types in areas noted for severe irritation on cattle. Nzi passive tsetse type trap, green Chinese baited trap and 'redtop' baited traps were used. Collections were carried out from January 2012 to May 2012. The three most important fly species collected which cause the biggest feedlot problems were the stable fly (Stomoxys calcitrans), the house fly (Musca domestica) and a few horse fly species (Tabanidae). The Nzi trap was by far the most effective trap for the collection of the haematophagous flies. The Nzi trap was further used to determine the daily distribution of Stomoxys calcitrans and showed that most flies were collected between 11:00 and 15:00. Further research is carried out on the development of an integrated fly control program against nuisance flies in feedlots with the ultimate objective to decrease the economic and environmental impacts in feedlots and to increase profitability.