In “Barnyard,” cows can be either male or female. Both genders have udders. The way you can tell a boy cow from a girl cow is that the girl cows have bows in their hair, like Ms. Pac-Man.

The film, a breezy animated lark written and directed by Steve Oedekerk, doesn’t mention what’s in those udders that both sexes have. For that matter, the film doesn’t acknowledge the existence of the udders at all. They are clearly visible, but there are no jokes or references to them. Milk is mentioned as something teenage cows drink as a form of rebellion — it’s apparently the cow version of beer — but again, not even an inference of where that milk comes from.

Surely I’m not the only one to find this strange. The movie purports to take place in a comic version of the real world, with its chief joke being that when the humans aren’t looking, the animals can stand on their hind legs and speak English. Yet a male cow is a decidedly non-real beast. Furthermore, there is no gender confusion among the other animals here. The roosters are all boys and the hens are all girls. Why are the cows so screwed up? Where is Gary Larson when you need him? I bet he could explain all this.

The animation is reminiscent of Larson’s “The Far Side,” actually, with pudgy, round-cornered characters who move as if in a medium-grade video game. The film is part of the current trend where cartoons are animated with computers rather than hand-drawn, yet don’t take full advantage of computer technology, either. They look cheap, in other words, despite being expensive.

On this sunny, animal-friendly farm run by a vegan farmer, Ben (voice of Sam Elliott) is the head animal in charge, and yes, he’s a cow. (Honestly, YOU listen to that gravelly Sam Elliott voice and look at those teats and tell me it’s not a little unsettling.) Ben is responsible and sober, completely dedicated to two things: preventing the farmer from knowing the animals’ secrets, and keeping the animals safe from harm. He stands watch on a hill every night, looking out for coyotes.

His son Otis (Kevin James), on the other hand, is an unreformed party animal who takes nothing seriously and spends his time cavorting with his mouse friend Pip (Jeffrey Garcia) and a trio of Jersey cows who, true to their heritage, act like Newark thugs. Otis has no interest in taking over his dad’s leadership responsibilities but finds himself thrust into it when Ben is incapacitated by a coyote attack.

The story is slight; I just told you almost the whole thing. Numerous scenes exist not to develop the plot or characters but merely to show the animals partying while the farmer’s away. Luckily, those sequences are generally zippy and chuckle-worthy, and if the film stuck to just telling its story, it would only be about 45 minutes long.

So, you know, it’s fine. It’s nothing special. It is free of grating and superfluous pop-culture references, which is nice; it’s also free of memorable lines, characters or situations, though. I’m recommending it because it’s harmless silliness that kids will enjoy and parents will smile at. Just be prepared to answer some tough questions afterward regarding the difference between boys and girls.

B- (1 hr., 30 min.; PG, some sly innuendo.)