The most important thing is hay, not the color. Green hay is sometimes dyed because buyers prefer green hay. But yellow hay might have been left out in the sun longer, and that means it has formed more vitamin D.

What is important though is variety. You can buy different hays and mix them or feed them in rotation, just so the bun gets hay that has grown on various soils under various conditions, harvested at various points in time (there are differences between 1st, 2nd and 3rd/4th cut).

You can use Timothy, oat, orchard, meadow + any other hay horses can eat like Bermuda grass, fescue, brome. You should avoid legume hays for adult buns (alfalfa, clover) but all the grassy hays are good. It should always smell good and be dry. Some growers declare nutritional content, because to horse owners, that’s important. It’s not unusual nowadays for horses to be on a hay-only diet, and rabbits and horses have very similar digestive systems and nutritional needs (adjusted for body weight, obviously).

As for your other bun, White discharge sounds a bit worrying. But if no vet has wanted to put him on antibiotics, you could try and de-dust the hay he gets. You can pour it out on a tarpaulin or a bed sheet and collect everything but the dusty short pieces back into a bag. Hay for pets should always be dust-free, but there are still differences from batch to batch, and not necessarily depending on the price tag.

Some buns are more sensitive to dustiness than others. A bun can even be allergic to certain hays. BB herself has a bun that’s tested allergic to timothy.

Now that I’ve signed the adoption contract for my new buns, I’m fixing to start stocking up on the needed supplies, including – of course! – hay. I checked the stocks at the local Petsmart and Petco today, and timothy hay seems to be the overwhelming majority of what’s available, certainly in the largest quantities (Petsmart and Petco sell up to 5- and 6-pound bags, and Pet Supplies Plus sells timothy in 8-pound lots for $18). Orchard and oat hay are to be had, but in much smaller quantities; one of the major brands ((I can’t remember whether Kaytee or Oxbow) sells mixed timothy and orchard, but in relatively small-quantity bags. I think I’ll have to go to the feed stores for non-timothy hays; fortunately, Southern States and Tractor Supply Co. have stores in my town and I am pretty sure I remember seeing various types of hay the last time I was at Tractor Supply.

Interesting that you pointed out the similarities in rabbit and horse digestive systems (though I don’t believe horses eat cecotropes!) Has anyone ever successfully put one of their bunnies on a hay-only diet (with water to wash it down with)? Such a diet, I imagine, would have to include as many different types of rabbit-suitable hay as possible.

Lol, some horses do eat their own poo if they feel they are missing something in their diet. Or if they are bored. Or just weird.

Hay only diets only work for horses if you get your hay regularly analyzed and make sure it has everything a horse needs – and hay that has everything a horse needs is pretty rare and would cost a lot because it would have to be grown specifically for that purpose. It doesn’t exist around me and isn’t a diet I would recommend. Hay should be the main part of the diet though. It isn’t that hard to do 95% hay and then a ration balancer.

Anyway, I will stop talking about horses. I don’t think a hay only diet would be safe for rabbits either – it just wouldn’t cover everything they need unless a farmer went and grew it just for that purpose – and that would be a hard and expensive thing to do. Hay is important, but so are other veggies as variety. Or pellets to help with the nutrients, if you like. I feed a pellet free diet but I make sure I do a huge variety of veggies, mostly dark leafy greens.