I think it depends entirely on the numbers of animals you are talking about producing that determines whether buying frozen or breeding your own that is cheapest.
I worked in two research labs for 8 months last year, managing their mouse colonies, until I had to leave those two jobs to begin my graduate studies. I also grew up breeding mice and rats for the snakes my dad & I kept. I have plenty of experience breeding rodents & I even know a lot of science geeky things about their reproduction. That being said, I have some questions for you:
1) How certain are you of their genders? If you are unfamiliar with mice, it can actually be pretty easy to missex them. Also, if you purchased them as weanlings, that is the point in time I personally think they can be most difficult to sex accurately. This can easily depend on what mouse strain you are dealing with, and factors such as coat color & coat type. Basically, if you don't actually have 1.4 groups (1 male to 4 females), it can easily throw off a lot of the social dynamics of mouse breeding.
2) Do the females seem to accept the male readily? If your gender ratio is right, sometimes you can still be defeated by social dynamics: if the females oust the male, he won’t ever have the chance to breed them. If they hate him bad enough, they may vasectomize him (I have seen this).
3) Do the females have any kind of fluffy bedding material? Try giving them half a paper towel to shred. For some mice, this can make all the difference in the world. Others plainly don’t care.
4) How old do you think these mice are? It sounds like they shouldn’t be too young anymore, but they could be too old to breed.
For your own questions:
1) Food. Feed a “lab block” or “lab chow” diet. If there are any feed stores (like for livestock) around you, they can probably get 50 lb bags for you. The colony I grew up keeping & the lab colonies I managed were all fed a Mazuri chow http://shop.mazuri.com/rodentdiets.aspx
2) Temperatures. Mice seem to do best at the temperatures we typically keep our homes. If they were to endure some extremes, I suspect they can do a lot better in cooler temperatures than in hot temperatures. Heat stress is known to negatively impact reproductive performance.
3) Odor. Males smell much more offensively than females. Your question about odor actually prompted my first question. Either way, rodents are stinky. The labs I worked in used corn cob bedding, changed every 2 weeks. In the colony I had growing up, I honestly do not remember how often we would change the bedding, but we typically used about 3 parts corn cob bedding to about 1 part cheap kitty litter (adjust that mix to your preference). For cages that were known to produce large litters, and therefore LOTS of waste & stink, we would also add in some baking soda.
4) Supplies for the reptile industry are incredibly different from what they were when I was growing up, so it is not impossible that someone makes & markets some very nice, sturdy rodent housing that is relatively cheap, but I don’t know who would. We housed the colony I grew up with in 5-gallon buckets (you can now buy these very easily in hardware/home improvement stores), with hardware cloth “lids.” Hardware cloth is essentially heavy-duty screen. Our bucket cages had feed chutes built into the side, and water bottles attached to the outside, with only the spigot coming into the bucket. The hole around the water access was further reinforced with hardware cloth to prevent the mice from chewing a way out around the waterer. The hardware cloth lids were just a sheet of the material, cut to be about an inch bigger than the bucket in all directions, and held in place with some small weights (I would advise against the weights – it’s very easy to drop one inside a bucket & kill a mouse, which we only did once in 6+ years of breeding them in this system, but an avoidable risk).
5) What are some imformative websites I can check out? I honestly only scanned over these quickly, but they look like they will steer you in the right direction. The first 2 are written from the standpoint of breeding mice for research. The last one basically takes the approach of breeding them as pets, but it has some very helpful pictures/illustrations.
· http://ko.cwru.edu/services/musfrming.html
· http://www.research.uci.edu/tmf/husbandry.htm
· http://research.unc.edu/dlam/mousebreeding.htm
· http://www.thefunmouse.com/info/breeding.cfm
6) Tips: (I’m writing all of these assuming that there is no missexing in your current colony)
· Trade the males between the tubs. If you're wrong, and your females actually are pregnant, they will be impacted by what is known as the "Bruce effect" – this is a pheromone interaction that has been studied in great detail in rodents. As best as I can explain it off the top of my head, picture one female, and two males, A & B. The female has been housed with and bred by male A. While she is pregnant, male A is taken away & replaced with male B. His pheromones will cause her to abort the litter she is carrying. That is, unless she is far enough along in gestation (I want to say the threshold is somewhere around day 17)… if she is past day 17 of gestation, she will still carry the litter to term, but male B will almost certainly kill them as soon as they are born. The reason for this (the “Bruce effect” as well as male B killing pups from male A): the female will again become fertile within 4 days, allowing male B to breed her and pass on his “superior” genes (he must have ousted male A, or male A was eaten, or something like that remember). I’m suggesting this as a potential way to upset the social dynamics which may be debunking your breeding efforts, and IF it causes a Bruce effect, it will still make your females cycle again sooner. Observe their behavior. Take note of whether the males make an attempt to breed or not.
· If trading the males doesn’t work, you could easily have a problem with both of your bucks, or with a lot of your does, and you don’t really have a way to know which is which. Therefore, if you trade your males between tubs, and still see nothing as far as pregnancy after 30 days, use those males for feeders, and get some new ones. Observe behavior.
· Sometimes, particularly with young males (and I’m not trying to be funny), too many females end up being too distracting. If you think this may be the problem, try a smaller number of females: 2 or even 1 per male until you see some results.
· AFTER following the above, you may need to consider replacing your does.
Let me know if you have any other questions :)