| seasonal occurrence of infective nematode larvae in california high sierra pastures grazed by cattle. | worm-free holstein calves were used to assess the seasonal variation in numbers of nematode infective larvae on herbage at 2 commercial cow-calf ranches in the sierra nevada mountains. both ranches used herefords as their basic breed. one ranch near sattley, california, is at an elevation of approximately 1,500 m above sea level, whereas the study area on the 2nd ranch near susanville is at an elevation of approximately 1,250 m above sea level. worm-free tracer calves were allowed to graze for a ... | 1984 | 24049905 |