Time is of the essence today, because all the Bair Ranch cows come into heat within a matter of days. Ansotegui synchronized their ovulation in advance with two injections of naturally occurring hormone-like compounds, including prostaglandin. Prostaglandin, which is metabolized almost instantly, revolutionized the industry by reducing breeding time from three weeks (a cow's natural cycle) to days. Pioneering research done by Ansotegui through MSU in the late '70s was instrumental in getting the drug approved. "We were using it before it was cleared," he says.

Linda Ansotegui, a topnotch ranch hand, sits elegantly astride her palomino mare, her blue eyes scanning the sodden, shooting star-dotted pasture in search of "hots" -- cows mounting each other. It's a sure sign that the cow being ridden is in standing estrous and will ovulate in 24 hours. Linda also looks for activated estrous detection patches, nifty new inventions that are stuck to the cows' rumps and turn neon colors when rubbed, like lottery tickets.

Ideally, about 80 percent of the cows Ansotegui's team inseminates will conceive. The rest may be bred by a "clean-up" bull, or sold. AI ensures a high conception rate and enables ranchers to manipulate herd genetics without having to purchase or maintain a stable of bulls, which can be costly and dangerous. (In fact, man-killing dairy bulls motivated the development of AI.) "You can use superior genetics," Ansotegui explains. "Your calf will weigh more at weaning time. He's gonna be more fertile, have a higher carcass quality, and better rates of gain. And he's gonna do it on less feed."

Seed bulls are rated on genetically determined characteristics, including feed efficiency, calving ease (how readily a sire's female offspring give birth), and even scrotal size -- a marker of fertility. Semen is a multimillion dollar business: Whereas one bull may naturally breed 20 cows a season, one harvested ejaculation, by electronic anal stimulation, may fill up to 100 straws, translating into tens of thousands of offspring. Straws range in price from $5 to thousands, and can be frozen indefinitely.

Although AI is an increasingly important part of modern ranching, the National Association of Animal Breeders estimates that only 10 percent of beef producers participate. AI can pay for itself, but it's time-consuming and best suited to ranches that keep replacement heifers to develop their herd. And ensuring conception this way requires an old-school approach: skilled manual labor.

Teaching those abilities is arguably what Ansotegui does and loves best. He has mentored generations of OECs -- overeducated cowboys -- ranchers, veterinarians and cowhands who have shaped the cattle industry worldwide. At MSU, Ansotegui taught hands-on, requiring his AI students to breed 50 cows using their dominant hand, then switch. "Ray can bring it down to the practical level," says rancher and former student Matt Pierson, "because he has real-world experience." Despite his retirement, Ansotegui still teaches, lecturing for feed companies and at AI schools, and doing private consultation. And, of course, he continues to AI. After all, he says, "It's a cowboy job that pays."

The rain has ceased. Linda Ansotegui carefully thaws semen and loads guns, her waist-length hair in a braid. Abruptly, she turns to the door and says, disgustedly, "You know when I say, 'Crap!' I mean it -- literally." She wipes splattered manure from her mouth. Everyone outside laughs. From inside the Shaggin' Wagon, Ray inquires wryly, "They gettin' enough salt in their diets?" Linda nods and laughs, "Yes, yes."