A strong start marks the arrival of Elisa Monte's dance company

Elisa Monte, the choreographer who supplied the Alvin Ailey American Dance company with two glossy new pieces last year, ''Pigs and Fishes,'' and ''Treading,'' is venturing onto the dance scene with her own company this year. So it was good to see how Elisa Monte and Dancers dished out these and other dances recently at the Jacob's Pillow Dance Festival.

''Pigs and Fishes,'' danced to music by Glenn Branca, looks like a workout. The dancers run through it full out, while searching capacities of their pelvic joints. They moved their hips back and forth in such deep, strenuous swings that there was no question of suggestiveness. They were primal gestures, and they looked like some primitive tribe being pursued over a rocky terrain as they scrambled about a jaggedly lit stage.

But there were also moments of daintiness when the dancers swung their hands in front of them in small arcs as if swinging baskets, their hips just swaying. Then they swayed into a turn and all would be in formation for a while.

The women, in pewter-colored tunics swathed low across the chests with hipbands below the hips, with arms and legs bare and often flailing or flexed, looked brawny. Two men in darker, tighter clothes, seemed to shadow them, doing the same pelvic dance, but passing up rolling on the floor. They looked both more orderly and less strong than the scrambling women.

''Pigs and Fishes'' is a dance of great, almost violent energy, and it is rare that women dancers embody this. They danced well, with convincing, but not threatening, strength.

Elisa Monte, especially, danced as if her life depended on it. Tiny compared with the other members of the company, she used her body to push the swing of jazz dance past its limits to great swoops of the pelvis and arms and chasm-bridging leaps with the legs. She looked as if she were passing the limits of her own body at times, springing like a catapult shot from her very limber hip joints. She covered more ground than dancers twice her size usually do.

''Pigs and Fishes'' is both a vigorous jazz dance and a bold exploration of space made by dancers pushing themselves beyond the bounce.

''Treading'' is performed to music by Steve Reich, - in this case music that repeats tones and rhythm until new patterns seem to appear in it. It was less striking on the Elisa Monte company than it was in the Ailey repertoire. Dancers in seamless leotards, looking as smooth as frogs, move slowly, climbing on each other and waving their arms gently as if they are undersea plants. Unfortunately , there are too many ''amphibian'' works in the world of modern dance, and most of them are insipid. When the Ailey company danced it, as a duet, it was with an underlying tension and energy and it wasn't just a display of elasticity.

The Elisa Monte company presented a duet with a chorus of three who crouched onstage like crabs ambling up to an underground forest. The tension and energy which made ''Pigs and Fishes'' so exciting was missing in Elisa Monte's own performance of ''Treading.'' This is too bad because that is what distinguishes Elisa Monte's work from so many bouncy but wan jazz-based works. Elisa Monte and Dancers can next be seen in Paris, Oct. 4-10, at the International Dance Festival.