A viable alternative to insecticides for fly control?

[Dead Rabbits]

https://www.spalding-labs.com/products/fly_control_products/cow_vac/default.aspx

Always wary of using insecticides on cows (or anything) could this be effectively used to reduce or eliminate fly spraying on dairy farms?

 

[Spear]

Can’t see it making a big difference except at milking time.
Remember hearing about mobile giant vacuums you drove up and down the feed fence that sucked in flies from 10-15 feet away. Forget which country it was but they collected literally tons of insects a day with them [emoji15]

 

[Mr Mackay]

Our cows would probably stampede through it and wreck the whole thing!!