Gastrointestinal Parasitism of Cattle on Fescue Pastures Fertilized with Broiler Litter

SUMMARY The relationship between the degree of internal parasitism in beef cattle and the use of broiler litter as pasture fertilizer was studied for 5 years. Two established tall fescue pastures were used each year. One pasture was fertilized with NH 4 NO 3 and served as a control. The 2nd pasture was fertilized quarterly with broiler litter ( bl ). Both pastures were stocked with approximately 2.5 cows and their calves/ha. Nematode eggs and coccidial oocysts from rectal fecal samples from 10 cows and from as many calves as possible from each group were counted every 6 weeks. Grass clippings from each pasture were used to enumerate and differentiate the infective larvae present. Two calves were slaughtered annually from each group at the end of the 3rd, 4th, and 5th years of the experiment for total worm recoveries. Statistically, average numbers of trichostrongyle eggs were significantly higher (P = < 0.01) each year from control calves than from calves grazing the litter-fertilized pastures. The control calves had an overall average of 238 eggs/g of feces and the bl calves, 120. Of the eggs from the control calves (87%) and of those from the bl calves (80%) were of the Cooperia-Ostertagia-Trichostrongylus complex. Statistically, egg counts were significantly higher (P = < 0.01) consistently from calves than from cows. The numbers of eggs passed by the 2 groups of cows were not significantly different. In general, more oocysts were found in control cows and calves than in bl cattle, although the difference was not significant. Eimeria bovis was consistently the most prevalent species of coccidia found. At necropsy, significantly more nematodes were recovered each year from the control calves (average 17,773) than from the bl calves (average 7,374); Cooperia oncophora was the most prevalent species recovered. The quantity of available forage was greater in the bl pasture than in the control pasture. This additional available forage probably accounted for the difference in parasitism from the 2 groups of cattle.