| seasonal pattern of inhibition of ostertagia ostertagi in calves in northeast mississippi. | the composition of, and seasonal changes in, populations of gastrointestinal parasites of calves in northeast mississippi were determined for 10 months post-weaning. after weaning on 15 october, 20 mixed breed beef steers were grazed together on a 4 ha fescue/bermudagrass pasture. from november through august of the following year, two of the calves were removed each month for necropsy and counting of gastrointestinal nematodes. eight species of worms were found: haemonchus placei, ostertagia os ... | 1996 | 8983154 |