Base of a rabbit diet, just like any herbivore is roughage like hay, gras or even straw. I don't know what the advice is from the bag of pellets in the US, but here (NL) concentrates like pellets are a supplemental feed, not the mainstay of the diet. My standard feed ration is 10grams/1 kilo of rabbit and that ends up at about 15 grams/rabbit/day of rabbitpellet (dwarf rex and yes for meat, just one in the house so that works best for me). Now my roughage is also a pellet (due to chopped bedding and hay becoming a soggy mess when mixed with that) and the rest is what i gather from garden and hedgerows (willow, hazel, bramble, comfrey, climbing rose, bamboo). Litters and nursing does get twice a day feed and there i multiply the standard ration based on condition and number of kits (mom eats along with that, kits either get the extra via the milk or directly when they are a bit older). From 12 weeks on i cut back to once a day 15 grams/rabbit, because then they don't grow so fast anymore and feeding more both doesn't gain me more rabbit and it can make them fat.
Bucks are always on the standard ration, because although they need some protein for good semen and muscle (being a meat breed they have more musle i.e. meat on them), they don't need the calories.
Pellets for me are first a vitamin pil like feed, it is to expensive and to concentrated to feed plenty of. I use the X grams/kg method to determine how much they get and the other roughage handles the fibre and protein part, because hay alone (and esp. in heat/drought conditions) is to low in protein to put meat on a meatrabbit. I have a 16% graspellet, a 10% chopped hay pellet and a 17% alfalfa pellet to mix into whatever amounts i need per rabbit. Now i mix and match from both meatbreeders and petowners when it comes to feed ration ideas. Rabbitpellets here are considered a treat and a limited feed item due to making them fat. Other than that they attract pests like mice, so feed them no more then they'll eat quick (like in 15 minutes) or a small weighed amount (makes it easier to calculate how much you need and what the costs are). They will also be happy to see you and want to eat, so ones that don't need checking for health issues.
Feed as much hay as they'll eat in a day, and clean out the previous feedings hay when putting in new. Rabbits need to chew a lot to keep their front teeth at correct alignment and length, hay does a big part of that, some twigs to debark does the rest.
Simply put a rabbit is a prey animal, herbivore and lives in small dens for the day, while most active around sunrise and sunset. Safety (hiding place), clean water, stuf to chew safely! dry feet, room to stretch both lying down and sitting up is needed for happy and healthy bunny.
Pen/hutch/cage what have not, make certain it is easy for you to reach all parts of it, so depth maxes out at about 2 feet/60cm i.e. armslength. Enough height for rabbit to sit up also gives you enough room to move arm and small cleaning tool around inside. Bigger = cleaner rabbit as there is more room to split pen into toilet, sleep place and food area.
