Garngang, I would give all the immune boosting of the treatment, and only of course treat the sick one (isolated) with any meds if you medicate.
As far as a mash, by that I usually mean a wet mash made of a probiotic, some water, honey (a taste), and then sometimes vitamins if I know the bird will eat all of the mash. If you're talking about boosting immunity to fight potential exposure to respiratory illness, then I'd go with the baby vitamins - the polyvisol. If you're talking about just slight respiratory immune boosting and for egg laying, etc then cod liver but you only want to use a tiny tiny bit of it and then only twice a week. I prefer to just spray it (from a hand held sprayer ) on to top of freshly poured food twice a week. I don't use it in drops, etc, because of potentially over doing it.
As far as a mash, by that I usually mean a wet mash made of a probiotic, some water, honey (a taste), and then sometimes vitamins if I know the bird will eat all of the mash. If you're talking about boosting immunity to fight potential exposure to respiratory illness, then I'd go with the baby vitamins - the polyvisol. If you're talking about just slight respiratory immune boosting and for egg laying, etc then cod liver but you only want to use a tiny tiny bit of it and then only twice a week. I prefer to just spray it (from a hand held sprayer ) on to top of freshly poured food twice a week. I don't use it in drops, etc, because of potentially over doing it.