I beg to differ. It does work well if you use it for at least 2 weeks (research shows 2 weeks for most worms, 6 weeks for cecal). It effectively kills the 3 most common worms for chickens...cecal, round, and I forgot the 3rd at the moment (on smart phone killing time while truck is serviced or I'd look that up)
It is not an herbal but real meds. However it does not require egg withdrawal and the wormer (Hygromycin B) is currently the only FDA approved wormer for egg layers. I sell my eggs so that is important for me as I prefer to stay on approved label use. Valbazen and Wazene are now off label use and thus technically "illegal" for hens used for eggs for human consumption.
Industry uses Hygromycin B with continuous feed but many small owners use it periodically. I find it effective to use for 2 weeks quarterly or semi annually for 2 to 3 weeks then herbals in between to keep worm load down (keeping very clean litter management as herbals do not kill the worms...just help the body immune system expel them.)
Edited to add capillary worms!
Lady of McCamley
Hygromycin B has been used as a poultry wormer for a long time. The problem with mixing wormers in feed or water is that birds wont eat or drink the mixtures, or they dont eat or drink enough of the mixture to be effective. Additionally most people are not proactive in preventing worms and are only reactive when they see worms in feces. It is then when birds are very ill due to the amount of worm feces excreted in the chickens digestive system. When this happens, sick birds will NOT eat nor drink anything. Soil conditions dictate how often and when one should worm their birds. Herbals may or may not work as preventatives, depending WHAT they are....I want to reiterate... that SOIL CONDITIONS are the deciding factor.
Wazine is also approved for use in chickens and it only gets rid of large roundworms and no other types of worms. The FDA has not directed that wazine be pulled from shelves. True, the label states "not for use in layers," or something to that effect, there is a 14 day slaughter withdrawal after using wazine. That is simply because there hasnt been studies to conduct egg withdrawal periods since eggs come from controlled commercial operations... the chickens are caged and their feet never touch the ground (to get worms.) Then at two years old, the chickens are hauled off to be processed. So, there is no need to worm these birds, it would be a waste of time and money for the manufacturers to conduct testing for backyard flock owners.
I understand why you want to stay legal regarding wormers since you sell eggs, and I agree.
For folks that consume their own eggs and not sell them; there are a myriad of "off label" wormers that can used, AND tests have been conducted in poultry for effectiveness in killing worms. Again, egg withdrawal periods arnt mentioned due to the fact that most eggs come from commercial operations and testing isnt needed. It boils down to cost effectiveness and profit.
When folks use wormers, common sense should prevail regarding egg withdrawal periods when none are recommended...giving time for the residues in eggs to dispel in case a person might have an adverse reaction to the wormer itself.
For folks that dont sell eggs; they have plenty of choices which wormer to choose.... whether or not they want to string out treatment times and have short egg withdrawal times(hygromycin B, flubenvet, levamisole) or short treatment times and have long egg withdrawl times (valbazen, safeguard, ivermectin, wazine.) Some wormers are better than others. I use valbazen and safeguard given ORALLY...that way I KNOW they've been properlty wormed. Whatever the wormer choice...the goal is the same...healthy egg producing hens.