Abstract
The relationship between fecal worm egg count in fecal grab samples and total gastrointestinal worms was examined in 25 young steers. Also examined was the possible diurnal variation in worm eggs shed in feces using 10 lactating cows housed in stalls equipped for total fecal collection. In the steers, a relationship was observed (r = 0.64, P < 0.01) between fecal grab sample egg count and total gastrointestinal female worm count transformed by common logarithm. In the lactating cows, there was no evidence of diurnal variation in fecal grab sample worm egg counts. Most of the variation in the total number of worm eggs shed in feces in a 24-h period was accounted for in the fecal grab samples. The fecal egg count was considered to provide information with sufficient precision in making decisions on programs for the diagnosis and treatment of gastrointestinal parasitism. Key words: Subclinical parasitism, dairy steers, lactating cows, fecal egg count