The short answer ...

I was reading about a white buffalo, Miracle's Second Chance, which was born on a Wisconsin farm in 2006 and killed in a lightning strike a few months later. What are the odds that livestock will be struck by lightning? I wondered. I read this article, which doesn't answer the question. But it has this passage:
So how can a farmer tell if livestock have fallen victim to lightning? "They're dead," Fultz said.
OK, it's not a laughing matter. But I laughed. And to answer my original question, livestock have a greater chance of getting struck by lightning than humans do but no one really knows how many animals are hit in any given year.