The research, being conducted at the University of Illinois’
Dixon Springs Agricultural Center, involves two dozen bulls. In one study,
student interns sprayed the insecticide pyrethrum on the bulls when the animals
were feeding.

The study began in 2012, when the bulls were sprayed daily
and checked once weekly. The results have been encouraging, according to Frank
Ireland, who heads up the cattle program at the center.

“Last year we didn’t see any effects from those products in
bull fertility,” he said. “We saw no differences in sperm morphology. We saw no
differences in sperm motility, and no differences in hormone levels,
testosterone levels or scrotal circumferences.”

This year the bulls were again sprayed. In addition,
researchers sprayed facilities housing the animals. A similar study done at
Joplin, Mo., had indicated some detrimental effects.

“We wanted to see if adding those two methods of application
would have any detrimental effects,” Ireland said. “We added a premise spray
from Bayer Animal Health called Tempo. We sprayed the barns throughout the
summer. We sprayed the bulls daily when we fed them with a hand sprayer. We
collected blood samples, semen samples once weekly to see if it had any
effect.

“We’ve done the motilities on all these bulls. We’ve not
seen any detrimental effects again this year. We’re still analyzing hormone
levels, the morphology of the sperm cells. All indications are that there are no
detrimental effects.”

In a companion trial, researchers looked at behavior of
bulls being subjected to an electro-ejaculator for a semen sample on a weekly
basis. They looked for resistance from the bulls or changes in
disposition.

The interns used a scoring system that included willingness
to go through the chute system and how well the animals stood in the chutes
during the process. They also measured vocal reactions, such as bellowing, along
with exit speed leaving the chutes.

Ireland said he was pleasantly surprised with the
results.

“I would have almost bet you that some of these 2,600-pound
bulls coming through the chutes on a weekly basis would have gotten tired of it
and said, ‘I’m bigger than you are, and I don’t want to come through the chute
anymore,’” he said.

“But what we found out was that the bulls, if anything, got
a little better. They either stayed the same or they got a little more
acclimated to it. They were obviously not exhibiting any pain or they would have
resisted coming through the chute week after week. Maybe they’re like dairy
cows. They got used to the routine.”

Ireland and other staffers still are compiling results of
the two studies.