Research Progress Report 294 Project 1295 March, 1967
Internal Parasite Fecal Counts, Control Methods, and Related Weight Changes in Beef Cattle at the Southern Indiana Forage Farm
L. L. Wilson, S. M. Gaafar, C. J. Callahan, C . J. Kaiser, R. A. Petersonand K. J. Drewry
Departments of Animal Sciences, Veterinary Clinics and Veterinary Microbiology, Pathology and Public Health

Introduction
The economic losses resulting from infestations of stomach worms and other internal parasites in cattle are relatively unknown. The three main types of stomach worms are Haemonchus placei (twisted wire or barber pole worm), Trichostrongylus axei (bankrupt worm), and Ostertagia ostertagi (medium stomach worm). These three types are collectively referred to as trischostrongyles. Coccidia, a protozoal parasite, and the Strongloides worm may also be the cause of large economic losses in some cases.

In any animal high infestations of internal parasites may lower weight gains and feed efficiency and depress the general health of the animal, which in turn lowers the animal's resistance to disease and other stresses.

Internal parasites represent a constant threat to efficiency in beef cattle and sheep operations. High infestations of these "robbers" can mean the difference between profit and loss with any feeder cattle or cow herd operation. This study was originated to study: (1) level of internal parasite infestation at different seasons of the year; (2) effectiveness of two anthelmintic drugs in reducing the lev-
el of internal parasites; and (3) changes in weight of animals after treatment with the different drugs when compared to untreated control animals.

The production of the Forage Farm beef cow herd has not been as high as desired for several years. It was thought that perhaps internal parasitism may have been a contributing factor to the relatively low calf weights observed.

Procedure
The animals used in this study included 100 mature cows, 41 first-calf heifers and 40 calves which were born in the spring of 1966.

On May 10, 1966 all of the animals were weighed, and fecal samples were collected. Condition scores, reflecting the degree of fleshiness, were also obtained. The May 10 weights and animal ages were used to randomly allot the cows and heifers to three experimental lots: (1) control -- no parasite treatment; (2) phenothiazine -- given at the rate of 62 1/2 grams for the cows and heifers and 12 1/2 grams per 100 pounds of liveweight for the calves; and (3) thiabendazole* -- given at the rate of 3 grams per 100 pounds of liveweight

* The thiabendazole was contributed by Merck and Co, Inc., Rahway, N.J.

PURDUE UNIVERSITY • Agricultural Experiment Station • Lafayette, Indiana