We need a cattle and chicken baby boom. Maybe after Trump ends the war against them they'll be in the mood?

A lot of this is due to the big packers doing everything they can to squeeze out every penny from ranchers. There's been recent developments that ranchers have won (mainly lawsuits to prevent them from butchering and slaughtering their own cows) and there's even been new "rancher's unions" formed where thousands of ranchers have gotten together in different places to fund and build their own processing plants after winning these lawsuits.

So I'd imagine this is gonna reverse pretty soon. There's other factors as well. like dairy cows being on the rise (dairy cows make more money than beef cows by several multiples), so its not that there's less cows total, it's just that there's less dedicated meat cows. A lot of herds are trying to mix beef and dairy in order to make ends meat (pun intended), and the dairy cows are taking beef stock off the market temporarily until they're run through their lifecycle, at which point they'll be slaughtered and returned to the beef market.

TL:DR: Basically, a lot of ranches are moving from strictly beef to a mix of beef/dairy cows, so there's a lag in beef production until the dairy cows are run through their life cycle and are then slaughtered for beef.