Mr Casey said gone are the old wives tales many had attributed to causing bearings.
"Fat ewes fed too much grass is an old wives tale, but that just doesn't add up and neither does 'keep them skinny and you won't get bearing'."
He is sold on his blend of seaweed, selenium and iodine included with thistle control spray in April/June/July, although he has had success with applications as early as February.
"Selenium and iodine are critical at conception and birthing, so it's hardly surprising they have an effect on nearings too. I know all the experts, including vets have no hard and fast reasons for bearings and while my trials have been far from scientific, the results speak for themselves and I have at least one large sheep and beef station client extremely happy.
"We've heard of as many as 40 ewes per 1000 falling to the condition, while now we are finding under 4 per 1000. I can't believe farmers are not interested in rectifying the problem when it's as easy as spraying at thistle time," Mr Casey said.