Back to back postpartum breeding?

[Skittles46]

Alright, we have set up (very small for now) with a tote each for a 1:4, two 1:3,s and a 1:2 (smaller tote).

We will be building racks and expanding later on, maybe with that extra money Uncle Sam is sending us in May, or maybe sooner than that if we can find the money.

My question for now is what are the pros/cons to both breeding styles I've seen so far. In other words, is it better to keep the females separate for birthing or is it better to just leave smaller quantities of females with the males to give birth? I've seen it both ways (between youtube videos and in person).

I would assume that leaving the girls in with the males will generally result in back to back pregnancies, resulting in more litters, but does it equal out because she has to be retired sooner?

Just playing with ideas trying to get it figured out before we go big Thanks for any suggestions!

[Beardedragon]

Rats or mice?

With rats, its a no. They cannot handle the stress of back to back breeding, and the numbers in the litters will go down dramatically. It takes four months to get rodents up to breeding size, why spend all that time and then shorten their lives and get hardly any more out of it?

With mice, yes. They can handle a few back to back breeding, but after three or four they should be allowed a break. The littles can be smaller if you do this, and the life spand will go down by a few months.

Theres my .2, hopefully someone can come in with a little more info

[Skittles46]

Rats, for now, and thanks for the input Thats what we are leaning towards for right now, just looking for other views and opinions, the guy we got them from did back to back, and tried to tell us we were crazy for thinking about doing it any other way.

I know that mice and gerbils can handle more of a constant thing.

[littleindiangirl]

Here's a little insight into wild rat colonies.
Rats live in a series of under ground tunnels. In one colony when the population is very steady, no over crowding, and no empty chambers. Just enough rats for the tunnels and chambers.

The female rats are all breeding with one male. I don't remember the number of females per male, but this is very true. The females when pregnant will go to their OWN chamber and nurse their own litter. They only share nursing duties when the rat population is severly over crowded in that area.

Proof enough for me if wild rats prefer to nurse singly that they should always nurse singly. Female rats that have given birth go into heat about an hour after birth, and afterwards do not go into heat until after the pups are weaned.

Rats that were not raised from the same litter are more likely to commit infanticide, stealing pups from each other and higher stress.

If you would like to read a little more on communal nesting in wild rats, please visit this site. If your considering doing communal harem breeding, you should read the page thoroughly to understand exactly what the rats and their young are going through during this phase.

Also, if you've ever raised rats, you know how much weight the females lose after nursing... I don't see the need to put that stress on a female rat and shorten her life span to 1 year when in captivity they can live for up to 4 years. Hardly seems fair or humane.

ratbehavior.org

[amon]

The female rats are all breeding with one male. I don't remember the number of females per male, but this is very true. The females when pregnant will go to their OWN chamber and nurse their own litter. They only share nursing duties when the rat population is severly over crowded in that area.

Just curious, what happens to other adult males?

What happens when it gets crowded? Do they dig more rooms to live or separate into more colonies?

[frankykeno]

Over the years we've bred rats for feeders I've tried a few different "styles" to see what works best for me breeding for a relatively small snake collection (we currently feed 20+ snakes per week).

While removing females and single maternity enclosures may not be at all feasible in a large rat production, for me and our needs - it works just fine. There's a number of stickies in this section showing various tubs configuratons, racks, etc. for rodent breeding.

The way we do it is to put one male with 2 to 4 females until we see the females develop the distinct pear shape that indicates a successful mating. Then the male goes back to the breeder male enclosure to hang out with his buddies (do rats brag? LOL) and each female goes into her own maternity enclosure (10 gallon tanks). She stays there until her offspring is about 18 days old and then she and another female rat she gets along with are moved into a bigger tub to finish raising their litters together. This frees up my maternity tanks and gives the females a chance to socialize and co-raise their busy big pups until weaning.

The females after their litters are weaned or fed off, go back into a large female only enclosure where they rest, hang out with older retired female rats or young females being raised as future breeders. We give them a certain time off to rest and regroup dependent on the number of offspring they nursed (bigger litter, longer nursing time = more rest for the momma rat).

For us this works beautifully but it's certainly not the only way to manage a feeder/breeder colony. I do find with rest that my female rats seem to have a longer and more productive breeding life and aren't burning out too fast on me. A top producing female rat is a treasure to me and I don't want to overdo it so much I waste her good genetics and great mothering skills.

[littleindiangirl]

Just curious, what happens to other adult males?

What happens when it gets crowded? Do they dig more rooms to live or separate into more colonies?

From the link I provided http://www.ratbehavior.org/WildRats.htm

They each have their own nest chamber, but they may share the burrow and may raise their young together (called communal nesting). When the offspring are weaned, the young males disperse.

The organization of male rats and the rat mating system changes depending on the population density of the colony. At low densities, a male rat monopolizes a burrow of females. He defends a territory, keeping other males away from the burrow and the surrounding area, and he mates only with the females of his group. One male mating with multiple females is a polygynous mating system. At low densities, Norway rats are therefore territorial and polygynous.

At high densities, males can no longer defend a burrow against intruders. There are simply too many intruders. At high densities, the social system becomes despotic, with one male becoming socially dominant while others become socially subordinate. Males no longer defend female burrows. Instead, when a female comes into heat a group of males rushes her and mates with her sequentially, with little or no competition between themselves. Males may mate with multiple estrus females this way, and females mate with multiple males. This mating system is polygynandrous. At high densities, Norway rats are therefore despotic and polygynandrous.

Hope that helps.

[Skittles46]

I had read the site about the wild rats, but not necessarily that part of it, thanks. We were planning more on leaving 2 or 3 mothers together in a larger bin, rather then separate them, due to everybody saying they are such social animals. However, I'm a large proponent of going with what an animal naturally does as much as possible, even in captive settings.

There's a whole set of videos on youtube right now of a rat barn that at least partially separates the mothers off by themselves, so it is possible with a large scale set up as well, they're just basically in mouse racks not rat racks at that point.

Thanks again and keep any other thoughts coming!

[frankykeno]

I did try the communal birthing/raising deal just to see how it would work in our small rat colony (we generally keep around 75 to 100 rats at any given time). While it might work for others, I found far too much pinkie stealing going on between some females and lost an unacceptable number of newborn rats to this.

I've found that single birthing works quite nice for me. It not only gives the mother rat time with her babies without competition for food, etc. but I can also keep a closer eye on production, genetics, and so forth from that specific female. If I have a female for instanct that consisistently produces top litters and mothers them well, then I have the luxury of knowing exactly what babies carry her genetics and choosing from them for my future female breeders.

Once the pups are about 18 days old - big, busy, eyes open, etc. then I pop them into a communcal tub where they can race around with the other litter and the mothers can socialize and share the work till weaning.