Some producers make their decision on the worm status of the animals based on the presence of  white “segments”.  These white segments are small portions of tapeworm and whilst very visible they are only an indication of the presence of one type of worm. (Cestode)

The jury is still undecided on the economic importance of tapeworm. Yes they look bad but it is no indicator of the real worm burden. (RoundWorms - Nematodes) Tapeworm are not renown for ripping out vast amount of nutrient but can cause issues of compaction in the small intestine if numbers are large.

There are many other worms (mainly roundworms) which  are much smaller and their eggs can only be seen under a microscope which have a much greater impact on the well-being of your livestock.

Another misconception is that the consistency of dung is a good indicator of worm burden - if it is firm the worm burden should be low and if  runny  worms may be the culprit . The correlation between the two is weak, so again testing is the only way to be sure.