Grade: C-

When the farmer’s not looking, the animals will party and play, human-style. Gary Larson did more with this idea in a single “Far Side” panel than Steve Oedekerk and his army of animators can muster over eighty minutes in this tepid computer-generated kidflick. “Barnyard” is the latest in this summer’s series of mediocre animated movies that should have gone directly to DVD but instead have been released to theatres in the hope they’ll catch fire. But like “The Wild” and “The Ant Bully,” it’s likely to sink from view fairly fast.

Of course, a story–even if only of the most rudimentary sort–has to be added to the premise, and so we have a standard-issue one in which a rambunctious young cow named Otis (Kevin James), whose only inclination is to get into trouble with his buddies–Pip the Mouse (Jeff Garcia), Freddy the Ferret (Cam Clarke), and Pig the Pig (Tino Insania)–is compelled to learn responsibility when his (adoptive) father Ben (Sam O’Neill), who’s kept the other animals in line and offered them protection from predators, is killed by a pack of coyotes led by the evil Dag (David Koechner, who seems to be in every third movie released nowadays). Naturally there’s passel of other critters on tap, most importantly a wise old mule named Miles (Danny Glover) and a newcomer, a pregnant heifer called Daisy (Courteney Cox), who’s sweet on Otis despite the misgivings of her attitude-rich pal Bessy (Wanda Sykes).

There are a few amusing moments in “Barnyard.” One comes early on, when Ben wishes a happy birthday to a 13-year old dog and we see the ancient critter’s response. Another involves a series of interruptions to the main story provided by a neighbor couple, Mr. and Mrs. Beady. Maria Bamford’s Mrs. Beady–surely modeled after the nosey Mrs. Kravitz in the old “Bewitched” series–is an irritation, but her long-faced and long-suffering husband, voiced by Oedekerk himself, gets laughs in his few scenes. On the other hand, the other episodes involving humans–a bit involving the farmer, another with a goofy pizza delivery guy, and a third featuring a nasty teen-ager, are weak. And elsewhere the makers offer more volume and saccharine lessons about growing up than real fun. The voice talent works hard but can’t overcome the mediocrity of the material (Cox, as it happens, is especially bland); the songs that periodically intrude are mostly nondescript (although Elliott’s rendition of “I Won’t Back Down” has a gravelly charm); and though the backgrounds are colorful, the character animation isn’t much of an improvement over “Valiant.”

There will always be room for exceptional animated movies in theatres, of the conventional sort and computer-generated. But the lackluster box office performance that can be expected of such middling efforts as this will insure, over time, that the current glut will subside. Even young kids, it seems, can reach a point of having had enough, and even Hollywood studios will learn the financial lessons in due course.

In the meantime, just consign “Barnyard” to the cinematic compost heap.