Search

The effect of spraying cattle hair with Delcid on the number of midges was studied. The attack of bloodsucking midges decreases the milk productivity of cattle. According to literature data, losses can range from 5.19 to 53.4%. In Russia, synthetic pyrethroids are widely used to protect livestock from midges. Among the drugs in this group, Delcid (4% emulsifiable deltamethrin concentrate) has proven itself effective. The present research aimed to study the effect of spraying cattle hair with Delcid on the number of midges on pastures and the milk productivity of cows. Studies were conducted in livestock farms in the south of the Tyumen region in 2003–2005 and 2008. Cows before pasture were sprayed with 0.001% (by active substance) Delcid water emulsion in medium volume (0.5 l per animal) using the universal horizontal single-pipe spraying booms installed at the pen gate and developed at the All-Russian Scientific Research Institute of Veterinary Entomology and Arachnology. Midges were counted using an entomological net with removable sacks. The entomological efficiency of treatments was assessed by comparing the number of midges at the test and control pastures. Losses in milk productivity were calculated based on the “Method for determining the harmfulness of insects of the ‘gnat’ type for cattle” developed by the authors of the present research. The research revealed that the loss of milk productivity of cows in the south of the Tyumen region can reach 9.88% in some years. Systematic spraying of the hair of grazing cattle with a 0.001% aqueous Delcid emulsion reduced the total number of midges on the pasture by a factor of 1.7-7 and, accordingly, shortened the period of their mass swarming. This allowed getting additional 0,231 l of milk per day or 1.45% from each cow, thus increasing the profitability of cattle breeding. [ABSTRACT FROM AUTHOR]