Maternal Aggression... Can it be "bred out" of a line?

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artgecko
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Maternal Aggression... Can it be "bred out" of a line?

Post by artgecko » Thu May 19, 2016 10:34 pm

Hello all,
It's been a while since my last post. Roughly 8 months ago I had my first two litters. I used the same buck (Star) and two related females (Stella and Nova). These rats were to be the foundation of my breeding program and all came from the same breeder.

Nova showed pretty bad maternal aggression, including lunging and biting me pretty badly more than once. I kept back only the calmest acting of her pups, but even those showed nipping behavior when I would put my hands in the cage, so I elected not to use them for future breeding.

The other female, Stella, showed no aggression during breeding or rearing her pups. I kept back 4 females and 2 males from her litter. I chose 2 females to breed from (Myst and Smudge), the calmest and most outgoing, but I chose to breed them to their father as none of the bucks from that litter had as good of a temperament. Only one of the females took, which brings me to the subject of my post.

Myst, despite having a good temperament prior to giving birth showed nervousness once she had pups and has bitten me twice. I have found this highly disappointing and frustrating. I have asked around and found out that another breeder had MA issues with a doe she got from the same breeder and that the rats from her lines were "skittish" and hard to handle as a whole... I knew none of this when I chose to get lines from her. I had contacted her after the first doe (Nova) showed MA and she blamed it on me not "handling" the doe enough.. I have decided not to contact her for help again, as this is clearly a genetic issue.

My question for all of you, is, can I attempt to breed MA out of my lines and if so, what would be the best way to go about it? Stock is incredibly hard to come by in my area and it may be a year before I can source new lines to work with. If possible, I'd like to salvage this line, but I am just not sure about it.

At this point, I've been advised to not socialize the pups (only handle during cage cleaning) and thus, I will see their "true" temperament. I have been told that by doing this, I'll be able to select the calmest pups that show the least fear naturally and within a few generations, I will have pups that are (on average) calm and handlable. This will help improve the general temperament of my line, as they tend towards skittishness now, but I am not sure if this will help weed out MA as you can only tell temperament once the mother has the litter. It could also be carried by the buck, which further complicates things.

It is quite disheartening to find a female who you thought was a perfect pet turn on you like this. At this point, I am not placing any pups from litters that have shown MA out of fear that they will develop aggression in turn and I don't want to send pets out that might do that. I want to clean up my lines to be the best tempered possible it just seems like it might take a wee bit longer than I had thought. I would love any feedback from those that have dealt with MA that might be able to help me figure this out.

Thank you for your time and help!

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cyber ratty
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Re: Maternal Aggression... Can it be "bred out" of a line?

Post by cyber ratty » Fri May 20, 2016 8:32 am

I'm not sure it's necessarily possible to breed out an issue that could have already been fixed in a line. The best approach is to outcross.

We are relatively lucky in the UK that distance isn't really an issue so we're able to reach sources of good foundation rats or outcrosses and this sort of problem doesn't arise for established varieties, and with a new variety which has been sourced from outside of the fancy, then crossing with a well tempered line would help to improve things quite quickly.

I think it's shocking that the type of temperament issues you refer to are being spread between breeders, it will simply compound the situation. :(

If you are set on using these rats then my advice would be to make the journey, however long/difficult/expensive, to a reliable breeder who has a very good settled line. Adopt several rats and breed them as a side line in order to cross with your current rats. Keep the side line 'pure' to preserve them so you don't have to make the journey again for more, and mate as necessary to maximise temperament while keeping whatever you need from your current rats. After outcrossing using rats from the sideline, you could test what progress you've made by inbreeding.

Given the risk of maternal aggression, I would suggest removing the chance of there being a nurture influence by using a doe from the side line to foster any babies born to a mother in your chosen line.

artgecko
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Re: Maternal Aggression... Can it be "bred out" of a line?

Post by artgecko » Tue May 24, 2016 12:40 pm

Thank you so much for your advice!

Unfortunately, I think issues like this are pretty common here... People put an emphasis on socializing pups vs. their natural temperament, so even if pups are from an anti-social line (skittish, aggressive, etc.) it is not noticeable due to them being tame until certain circumstances happen. When I posted on a local FB rat group about the issues I had with maternal aggression from the first litter, I was virtually tar-and-feathered about it, with most people claiming that I had not handled the mother enough and that I should have socialized her more. I don't think a single local breeder on the group admitted that it could be a genetic issue.

I also think that many breeders have a reputation and have many friends that will vouch for them and make over-exaggerated claims for how great their stock is.

I am in the process of finding someone to get new lines from, but it will take me a while as there are not many breeders here. There are literally no shows in my area of the country, so most people that do breed do not do it for showing purposes, so it is not as popular here as it is on the west coast of the US and in the far north east. I know of someone that is about 3 hours travel away from me and I may be able to get stock from her, but she will not be breeding again until winter.

I am hoping that my second keeper female will take when I attempt to breed her again and I am praying that she will not be aggressive. If that is the case, I will only hold back pups from her litter to breed from in the next generation. I am hopeful that if I can keep back many females and only breed from the pups produced by females that do not show aggression, that I will eventually be able to weed this out. The line has some other issues that I need to deal with as well, but any physical traits are being put on the back burner until I can get temperament fixed.

Thank you again for taking the time to read my post and for your great advice! I will update the thread when I have results to report.

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Re: Maternal Aggression... Can it be "bred out" of a line?

Post by Tenmashi » Thu May 26, 2016 7:32 am

Maternal agression doesn't have anything to do with how tame they are. Also naturally tame babies will still be more tame than their less-tame siblings after socialising, not socialising to see "the true temperament" is not necessary imo and useless when trying to select away from maternal agression.

I also think maternal agression doesn't have to be a problem, to breed it out or not bother is a personal choice. Pretty much all mother return to normal after rearing the litter, many already calm down when the babies start walking around.
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Re: Maternal Aggression... Can it be "bred out" of a line?

Post by cyber ratty » Thu May 26, 2016 2:28 pm

There's a big difference between a protective mother (which tends to be an individual thing), and one who has what I would term maternal aggression - I've not had issues with my rats, but I believe there are some rats who appear to pass down extreme aggression.

artgecko
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Re: Maternal Aggression... Can it be "bred out" of a line?

Post by artgecko » Thu May 26, 2016 9:20 pm

Thanks for your responses.

I know that some people tolerate maternal aggression, but I don't want to fear being badly bitten when I stick my hand in the tub.. I've had to resort to wearing welding gloves with these two litters and I'd rather not have to do that. I think MA is related, or can be, to general skittishness / aggressive behaviors as well. In the case of the first female, she was always more "bossy" than the others and would nip at my hands when they were in the cage. This was before she had pups. In the case of the second female, she was always a little skittish. Not nippy, but more timid than her sister.

I don't know how severe the MA of each of these females would be considered... I do know that both bit me multiple times drawing blood on all occasions. I have heard of females that will hold your finger, mouth you, etc. this was not that behavior.

The main breeder that I'm getting advice from advocates not handling the pups other than cage cleanings. She is a biologist and works with genetics and does field research. I also know of several feeder breeders that don't handle but do heavily cull and select for only non-aggressive and calm rats and all of them say that you can achieve calm non-aggressive rats without taming them within a few generations just from selection for good temperament. I know that socializing them will not change their natural temperament and I also have seen that even with socializing them, it is still obvious who the most severely nervous ones are (I saw this with the litter this mother is from. She had siblings that were still very skittish and non-social even with frequent handling). I'm trying to weed out the middle ground though..those that appear tame with frequent handling, but might naturally be more skittish. I think the taming can hide this, as it did with this female.

So far, I am starting to see 2-3 pups that are less fearful than the others and more willing to come up to me and calmer when picked up. I am going to watch these and if they continue to be this way, I will hold those back for my next generation. There are also 2-3 that are very skittish...squeak when picked up, struggle, etc..That leaves about half of the pups in the middle ground so far.

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