What you are saying is ridiculous. God gave animals, eggs and dairy for us to eat. It is only with the eco modern mindset that says we shouldn't eat those things. Also, valbazen will probably work fine without the fat, there are no requirements to give the animals fat with it that I have found.
If you have abdominal swelling it could be any number of things besides parasites. And there is no real way to know if you are killing parasites unless you want to go through your fecal matter with a fine tooth comb, so to speak. Even then you may not find parasites that are there. The professionals miss them all the time.