Peat is notorious for growing mold. 99.9% of the time it is purely cosmetic and nothing to worry about.

I thought peat didn't grow mold, I thought that was was one of the points of using it in soilless mixes, but I dunno. Anyway, water with chamomile tea that will take care of it. (1 part grocery store peroxide: 9 parts water, also works but chamomile works better)

IME, peat is often sterilized, encouraging its use as a seed starting medium. Garden manure or compost is not (even most of the commerical bagged stuff) and fungal organisms are part of the natural content. As username 5 indicates, most evidence of fungal activity in potting soils is cosmetic in nature and is perfectly harmless.

Mold can form even on soilless mixes, most likely due to very moist conditions, fertilizer/manure, poor air circulation. I would let the top of the soil dry out between waterings and since you are growing indoors, it's important to have a fan running for air circulation. Watering from below (have it wick up the water through the drainage holes) instead of watering from above should also help.

It sounds like your mold came from your peat/perlite/manure/fertilizer mixture  not your peat/perlite/soil mixture. Are you sure it is mold, or could it possibly be smaller perlite fragments, a calcium precipitate, or something from the manure? I use peat moss all the time and have never seen a white mold on it. The white mold I am familiar with is like wax. I use peat because it is the most algae-resistant media available to me. A green algae can form when exposed to intense light, but it usually takes a long time & is easily removed.
It could be your climate, however  mine is hot and dry. I have just not seen white mold on peat mixtures.

I said above that peat was notorious for growing mold so I felt I should explain.

White mold as well as the green algae stuff is what I see when seed starting under artificial lights. Happens every year.

The top of the soil gets the green algae and peat pots (I don't use them anymore) always get white mold on the outside.

I attibute this to the fact that seed starting occurs indoors where the molds have ample opportunity to develop, coolish temps in the basement at the seed starting time of year and the need to keep the growing medium consistently moist during germination.

In the case of this poster I suspect the mold is indeed due to the manure content. Either way, no big deal.

I hate to disagree with anyone especially since I can't be certain. It sounds like this might be grey mold or botyris which is a common problem with non sterile medium in too moist and too dark locations. If it is, the question is moot. The seedlings will fall over and die before reaching transplant size. Sandy

Thanks, username_5 for your explanation. It helps me know what I might expect if I grew indoors or in a cooler zone with this media.

I've seen mold develop a few days after adding bone meal to a soil mix. I just remix the soil, and use it, and haven't had a problem so far. I don't normally amend a seed-starting mix, so I can't say if it would contribute to damping off.

The mold which typically develops in peat based seed starting mix (for me anyway) is not anything that contributes to damping off. Both are fungi, but not the same thing. What develops for me isn't so much a mold as an algae.

Mold on media is natural. Mold in the soil is natural. Heck, I even add leaf mold and mushroom compost to my soil. Mold is not your enemy.

p.s. if it were botrytis, it would be on the living plant, not on the dead peat.