I need advice from the elders... Waste months or get a buck ASAP?

[Naelin]

Hello!
I started breeding meat rabbits 6 months ago, we are on our 3rd successful processed litter.
Unfortunately, we lost our wonderful buck to pasteurella, and his potential replacement as well. We just finished the "summer break" for the does and we're left with one little buck that is 12 weeks old and is not managing to get the job done yet, and we have our eyes on a tricolor satin rex buck that is just 7 weeks old and should come home around February.

I don't think our 12w buck will be able to perform for quite a while, he tried a couple of times with a doe that wasn't lifting fast enough and then stopped trying.
Unless we get a more mature buck asap, we're looking at 3-4 months lost without any production. I don't have a car and I live int he city, so that restricts our possibilities for picking animals. I saw a buck online that is 5 months old and is somewhat close to what I was looking for in the other rex (magpie harlequin, but not broken nor recessive brown).

If you were in my position, what would you do?
-Lose the months, wait for the 12w old buck to mature enough to give some litters and get the 7w old rex
-Get the magpie 5 month old buck to breed asap, get rid of homegrown 12w old, get tricolor rex while we keep producing with the magpie.
-Something else entirely

I'd appreciate your insight a lot, thanks in advance!

 

[tambayo]

How many does do you have, how are they related? How is the 12wk buck related and what breeding system are you working from?
Fresh genetics have their use, so depending on room and breeding system i'd look into getting what bucks you can. Your does are in many ways more important, they are the ones that need to raise the kits, bucks just do the fun part.

 

[Naelin]

How many does do you have, how are they related? How is the 12wk buck related and what breeding system are you working from?
Fresh genetics have their use, so depending on room and breeding system i'd look into getting what bucks you can. Your does are in many ways more important, they are the ones that need to raise the kits, bucks just do the fun part.

My two does are 100% unrelated to each other. One californian and one Fauve de Bourgogne from different breeders. They live in separate hutches, the buck lived in a pen with the growouts. I bred every three months.

The young buck is the son of the Fauve de Bourgogne doe, I also have a little doe from his same litter. We don't have a bunch of room for adults (4 hutches total, one is connected to the pen), but we can manage to lose either the buck or the doe from that litter (we just want to get one litter or two from either one)

I only have my eyes on a rex because we decided we prefer to breed multiple colours as I'm also keeping the pelts. Medium-term the californian is probably going away but we're keeping her for the moment.

 

[tambayo]

So if you get the 2 bucks you'll have 2 bloodlines you can keep seperate for now. The one doe with daughter you can keep and breed with the same buck, breed some rex carriers (recessive gene so needs one from both parents) with the cali if you want to replace her anyway longer term.
I´d take out the 12wk buck when you have a replacement (5mnth or 7 wk no matter) so you have 3 does, 2 of them proven and unrelated bucks for each line.

 

[Alaska Satin]

Hello!
I started breeding meat rabbits 6 months ago, we are on our 3rd successful processed litter.
Unfortunately, we lost our wonderful buck to pasteurella, and his potential replacement as well. We just finished the "summer break" for the does and we're left with one little buck that is 12 weeks old and is not managing to get the job done yet, and we have our eyes on a tricolor satin rex buck that is just 7 weeks old and should come home around February.

I don't think our 12w buck will be able to perform for quite a while, he tried a couple of times with a doe that wasn't lifting fast enough and then stopped trying.
Unless we get a more mature buck asap, we're looking at 3-4 months lost without any production. I don't have a car and I live int he city, so that restricts our possibilities for picking animals. I saw a buck online that is 5 months old and is somewhat close to what I was looking for in the other rex (magpie harlequin, but not broken nor recessive brown).

If you were in my position, what would you do?
-Lose the months, wait for the 12w old buck to mature enough to give some litters and get the 7w old rex
-Get the magpie 5 month old buck to breed asap, get rid of homegrown 12w old, get tricolor rex while we keep producing with the magpie.
-Something else entirely

I'd appreciate your insight a lot, thanks in advance!

Your 12-week-old might figure things out pretty quickly; if it was me, I'd let him keep trying every few days, but I'd also begin to arrange to buy the 5-month-old magpie buck if he has good meat type. If you're breeding for meat, make some rabbits. I've found that it's best to keep does in production, too, since if they are left unoccupied for too long they can get fat and/or otherwise less interested in breeding.

If you've got two does, the magpie can possibly produce up to four litters while you wait for your first-pick tricolor to mature. If you're wanting an assortment of pelt colors, a magpie will bring not only harlequin but also chinchilla into your herd (and it's hard to say for sure that a rabbit doesn't carry chocolate or any other recessive allele, as those can hide for many generations). When the little tricolor matures, you can add the broken allele through him. Once the tri is mature and the magpie is proven, you may be able to sell the magpie since it sounds like there are not a lot of rabbits available in your area.

Because you started out with rabbits of different breeds, if it was me I wouldn't worry at all about inbreeding unless you see some problems in the kits (which will indicate that your stock is carrying some undesirable genetics that have little or nothing to do with inbreeding). I've been linebreeding for years; as long as you don't keep or breed rabbits with problems or that produce kits with problems, you should be fine for a long time. In fact, every time you bring new blood into your herd you also bring in the potential for new problems, which can be genetic, health or behavioral.

But what I would be cautious about is keeping any offspring from the buck that died of pasteurella. Strong immune systems are heritable, and as a rule I weed out offspring of animals that actually die from disease. Some of his offspring might be just fine, but it's something to think about. As @tambayo points out, your does are very important as they are the ones doing the raising of the bunnies, so if you have does with good mothering skills, I'd go out of my way to keep them. However, many breeders suggest that you pick the best buck you can find, since usually breeders use one buck with multiple does, which means his genetic material has a relatively larger affect on the future performance of your herd.

P.S. Your post heading seeking advice from "elders" made me smile. I started raising rabbits at the beginning of the fourth quarter of the last century... since we're now a full quarter of the way through the current century, I guess that makes me an elder.

 

[Naelin]

Your 12-week-old might figure things out pretty quickly; if it was me, I'd let him keep trying every few days, but I'd also begin to arrange to buy the 5-month-old magpie buck if he has good meat type. If you're breeding for meat, make some rabbits. I've found that it's best to keep does in production, too, since if they are left unoccupied for too long they can get fat and/or otherwise less interested in breeding.

If you've got two does, the magpie can possibly produce up to four litters while you wait for your first-pick tricolor to mature. If you're wanting an assortment of pelt colors, a magpie will bring not only harlequin but also chinchilla into your herd (and it's hard to say for sure that a rabbit doesn't carry chocolate or any other recessive allele, as those can hide for many generations). When the little tricolor matures, you can add the broken allele through him. Once the tri is mature and the magpie is proven, you may be able to sell the magpie since it sounds like there are not a lot of rabbits available in your area.

Because you started out with rabbits of different breeds, if it was me I wouldn't worry at all about inbreeding unless you see some problems in the kits (which will indicate that your stock is carrying some undesirable genetics that have little or nothing to do with inbreeding). I've been linebreeding for years; as long as you don't keep or breed rabbits with problems or that produce kits with problems, you should be fine for a long time. In fact, every time you bring new blood into your herd you also bring in the potential for new problems, which can be genetic, health or behavioral.

But what I would be cautious about is keeping any offspring from the buck that died of pasteurella. Strong immune systems are heritable, and as a rule I weed out offspring of animals that actually die from disease. Some of his offspring might be just fine, but it's something to think about. As @tambayo points out, your does are very important as they are the ones doing the raising of the bunnies, so if you have does with good mothering skills, I'd go out of my way to keep them. However, many breeders suggest that you pick the best buck you can find, since usually breeders use one buck with multiple does, which means his genetic material has a relatively larger affect on the future performance of your herd.

P.S. Your post heading seeking advice from "elders" made me smile. I started raising rabbits at the beginning of the fourth quarter of the last century... since we're now a full quarter of the way through the current century, I guess that makes me an elder.

Thanks a lot for your super detailed response, Alaska!
You put in writing a lot of what we were thinking about but couldn't decide. I got details that the magpie is a meat mutt, actually 12 months old and very much proven. It seems the owner had to sell her entire herd due to her baby's allergies.
We will definitely be keeping the magpie until the rex is proven as well and selling him afterwards. Hopefully we can pick up the magpie today.
My Cali is EsE and the Fauve is ee, so we have a lot to play with for the E locus

You make a very good point that I didn't consider about the buck with Pasteurella. He didn't actually die of it, he got it, got better and we tried giving him a chance but then he got it again plus a skin condition so we decided to cull him. Maybe he could have resisted it but it would have been a huge risk for our does. Two diseases in such a short time does raise an alarm about his offspring, though.

My does are great mothers, though the cali's offspring are all very skittish. It's a shame we lost the buck as he had an excellent temperament and was also great with the growouts.

40-something years of bunny husbandry definitely makes you an elder in my books

 

[Alaska Satin]

Thanks a lot for your super detailed response, Alaska!
You put in writing a lot of what we were thinking about but couldn't decide. I got details that the magpie is a meat mutt, actually 12 months old and very much proven. It seems the owner had to sell her entire herd due to her baby's allergies.
We will definitely be keeping the magpie until the rex is proven as well and selling him afterwards. Hopefully we can pick up the magpie today.
My Cali is EsE and the Fauve is ee, so we have a lot to play with for the E locus

You make a very good point that I didn't consider about the buck with Pasteurella. He didn't actually die of it, he got it, got better and we tried giving him a chance but then he got it again plus a skin condition so we decided to cull him. Maybe he could have resisted it but it would have been a huge risk for our does. Two diseases in such a short time does raise an alarm about his offspring, though.

My does are great mothers, though the cali's offspring are all very skittish. It's a shame we lost the buck as he had an excellent temperament and was also great with the growouts.

40-something years of bunny husbandry definitely makes you an elder in my books

That's very interesting to hear your Cal is E(S)E. I have been talking to quite a few longtime breeders of Californians and Silver Fox that specifically include steel in their lines; they say it seems to darken and deepen the points and the undercolor. I'm playing around with it in my self black Satins right now and there seems to be something to it.

I feel like I should mention that I don't actually have 40 years of rabbit-raising behind me. I raised Satins, Californians, French Lops and Harlequins in the 1970s-80s in Southern California; I took time off while I was traveling around working as a wildlife biologist and moving every 6 months or so; within a few years of settling in Alaska in 2000, I got rabbits again and have raised numerous breeds here. So it's more like 25-30 years total. But I won't argue about the fact that I am getting old.

 

[Naelin]

That's very interesting to hear your Cal is E(S)E. I have been talking to quite a few longtime breeders of Californians and Silver Fox that specifically include steel in their lines; they say it seems to darken and deepen the points and the undercolor. I'm playing around with it in my self black Satins right now and there seems to be something to it.

I've read the same in a couple of places, but what I can tell you that doesn't work if they are agouti as well.
We thought she was a self with somewhat blurry points during the winter and only discovered the steel genes as it started to show up in some of her black babies.
Fast forward to the summer... the soles of her feet are entirely white, and her ears and nose are showing the steel super clearly! Her ears are almost copper with just tiny black tips. We didn't realise she was agouti until then.

You can see the copper in the ears even in this somewhat blurry photo from the start of summer (Isn't she cute, though?)

 

[Alaska Satin]

I've read the same in a couple of places, but what I can tell you that doesn't work if they are agouti as well.
We thought she was a self with somewhat blurry points during the winter and only discovered the steel genes as it started to show up in some of her black babies.
Fast forward to the summer... the soles of her feet are entirely white, and her ears and nose are showing the steel super clearly! Her ears are almost copper with just tiny black tips. We didn't realise she was agouti until then.

You can see the copper in the ears even in this somewhat blurry photo from the start of summer (Isn't she cute, though?)

Yes, steel messes up a good "black" when it gets paired with an agouti <A>. It only works to have steel in Cals and SFs because they are selfs.

Yep, steel babies will show up if you breed a steel-carrying Cal with an agouti (like your Fauve). But I'm not sure I see the agouti/steel in your doe. Whitish footpads (and even a whitish undertail) are fairly common in himalayans, especially those that are heterozygous for himi (<c(h)c>). And the color-sensitivity of the himi allele really affects the color/shape/depth of the points. During molt, or in the summer, some Cals look coppery, or light sepia-pointed. And in fact they are: the himalayan allele not only prevents pheomelanin production, but also interferes with eumelanin production so that black becomes sepia. Through selective breeding, breeders have intensified that sepia to where it's almost black again, but it still can be iffy depending on environmental conditions. I expect that's why they add the steel, to beef up the darkness of the points by deepening/extending the undercolor.

Because the hair on ears, feet and nose is shorter and less likely to show a ring pattern, the way to determine if she's actually a steel (instead of a self carrying the steel allele) is to look at that spot on her shoulder. If she's a self, the hair will be all one color (with paler undercolor). If she's steel (agouti), you should see a ring pattern in the fur. In a steel, the rings are pushed way up the shaft, but they'll be there. If you pull some single guard hairs, they will look like this:

 

[Naelin]

Well.
This whole genes thing likes to throw wrenches my way. It's a lot of fun, though.

Regarding the Cali, she HAS bands, the fun part is that they are showing especially in the ears, which does not make much sense for me. I took some ear hairs from her the other day and could count 4 distinct bands of black and copper. The spot on the side is white up to the tip, similar to your second picture, so I understand this does confirm she's steel (agouti), right?



Regarding the magpie... I am unsure if he's a high-rufous magpie or an extremely diluted harlequin. He's brindled black and white at first sight, but he is actually quite creamy on some of the white areas, and his hindquarters are straight-up brownish. I can't find anything online about magpies having cream or blue and fawn harlequins being so dark.
I am pretty sure that he was the dad of a litter that contained a BW magpie, a harlequin, two tricolors and a red, and then another with 5 harlis and a red (Does seem to be a magpie and a tricolor or broken red).
Any clues here?

EDITED TO ADD: I just realised he's probably sable instead of chinchilla and found a post of @Alaska Satin explaining the same to someone with a similar bun

 

[Alaska Satin]

Well.
This whole genes thing likes to throw wrenches my way. It's a lot of fun, though.

Regarding the Cali, she HAS bands, the fun part is that they are showing especially in the ears, which does not make much sense for me. I took some ear hairs from her the other day and could count 4 distinct bands of black and copper. The spot on the side is white up to the tip, similar to your second picture, so I understand this does confirm she's steel (agouti), right?

Regarding the magpie... I am unsure if he's a high-rufous magpie or an extremely diluted harlequin. He's brindled black and white at first sight, but he is actually quite creamy on some of the white areas, and his hindquarters are straight-up brownish. I can't find anything online about magpies having cream or blue and fawn harlequins being so dark.
I am pretty sure that he was the dad of a litter that contained a BW magpie, a harlequin, two tricolors and a red, and then another with 5 harlis and a red (Doe seems to be tricolor or broken red).
Any clues here?

All very interesting...

Let's start with the buck. As far as I know, there is no such thing as a high-rufus magpie; a magpie doesn't have any rufus. The chinchilla or sable allele that creates a magpie blocks most or all production of pheomelanin, so a magpie should not have any yellow/orange/red fur. While occasionally a chinchilla will be "rusty" for a while, that usually molts out by the time the rabbit gets its adult coat. But your buck has distinctly tan patches, so I'd call him a low-rufus harlequin. I would not call him "diluted" because that has a specific genetic meaning. A dilute rabbit (having two recessive dilute alleles <dd>) has all of the colors diluted, but your buck has very black fur in some areas - his dark fur is not blue as it would be in a dilute. Pale orange can happen without any dilute alleles needed; it just lacks those rufus modifiers that intensify the color.

If he is the sire of the first litter pictured - which does appear to have a magpie kit in it, adorable, by the way - then that means he and/or the dam carried a chinchilla <c(chd)> or sable <c(chl)> allele that paired up with another <c(chd)>, <c(chl)>, himi <c(h)> or REW <c> from the other parent.

On to the Cal doe... I would not actually interpret those photos or descriptions as steel. While the steel guard hairs have a white "stem," (all the guard hairs of any color I've ever looked at have pale stems, though I have never seen dominant black <E(D)>), the underfur on a steel, or any agouti (not including non-extension colors like orange), is usually dark. Look at the clump of steel fur in my previous post and you can see the slate gray underfur.

Below are photos of steel (gold-tipped), chestnut, and chinchilla. It is sometimes a little (or a lot, especially on dilutes and depending on modifiers) faded at the very base of the fur, but you'll almost always have dark underfur on an agouti with normal extension or the steel allele (but not on non-extension colors).


However... there is a characteristic called "snowball" in which the rabbit has color only at the tips of the hair, with extensive white undercolor where there would normally be dark color. I've never found anything from anyone who really understands what's going on with this, though @judymac is trying to work it out, and has posted a number of times about it on this forum.

If you look at the photo of the steel hair posted previously, you will see three distinct bands above the white stem: dark, then a pale band, then a dark tip. That, rather than the white stem, is diagnostic of steel. I don't see any indication of banding on the hairs on your doe; they all look like they have solid tips to me.

If you could pull a couple of single guard hairs from the doe's shoulder patch and take a close-up of them on a light or dark background (whichever shows the most detail), it would easier to draw a more confident conclusion about her. If there is no banding on the body hairs, I do not think you can conclude the doe is an agouti, steel or otherwise.

The ears look to me like pretty typical Californian summer/molt pattern. As I said, they can get pretty darn brassy. I don't know what to tell you about finding bands on the ear hair, other than it would be surprising to find as many bands as you're describing, especially on such short hair. (I'm not saying you're not seeing them, just that they are probably not due to being an agouti.) I don't know exactly how quickly the follicles react to temperature changes, but possibly temp swings during the hair growth could explain it. But I don't really know how you could get a ring pattern on the ears but not the body fur.

Here's an example of a fairly typical Californian during a very warm summer (my Cals often looked like this when I raised them in Southern California):


And here's another example of how the temperature sensitivity (and also, importantly, humidity-sensitivity) of the himi allele can affect the fur of himalayan-patterned rabbits. It was not particularly cold when this litter was born, but there were several weather changes that produced spikes of humidity. Even though most people would not guess it, because the fur really looks "ticked," as if it was a sable agouti, this is a himalayan Satin kit (the red eyes give it away):


He molted out to look like this:


Interesting side note: a long-time Cal breeder told me that frosty kits (which is what breeders call kits that look like the one above) do not tend to get "smutty," i.e. develop dark patches on the usable parts of the pelt, which is a DQ for showing Cals. I'm testing that hypothesis in my barn right now.

 

[Naelin]

I'm learning so much, thank you <3

Regarding Rudy (the buck) - I've been trying to figure things out and after looking at a bunch of pictures I think he might be seal magpie, with two chl genes, based on his black belly and the rusty tinge, and either otter or self since he has a very dark belly and no eye rings. eje as well based on the red kit.
That would leave at/a_ B_ c(chl)c(chl) D_ eje- But then I got some hair and realised the black bits are very much like the cali, all white with only black tips. I have no clue what that says about all this. I might be missing grey bands but I don't get how he could be agouti without the agouti marks nor steel to hide them.


Regarding Saturno (the cali), I managed to post all of those pictures before and forgot the one with the pulled shoulder hair
Here it is. As you said, it's all white with a black tip, but that might be just the hair growing again, as that patch was formed when she pulled a bunch of hair for a nest and is fading away as the months pass.

 

[Alaska Satin]

I'm learning so much, thank you <3

This is way fun, right?!

Regarding Rudy (the buck) - I've been trying to figure things out and after looking at a bunch of pictures I think he might be seal magpie, with two chl genes, based on his black belly and the rusty tinge,

From my experience, I would call his tan areas orange, not just rusty. I still don't think he's a magpie. There are some modifiers that can produce "brassiness" in chins, but your buck just looks orange to me.

Harlequin <e(j)> basically separates what would be rings of two different colors (in an agouti) onto different hairs instead of areas of a single hair. A seal does not have two colors to separate, it has only sepia (and white, which is no color, due to the suppression of yellow pigment). What appears to be two colors on a sable or seal is due to the effect called shading, which is due to the differing densities of the same amount of pigment granules arranged in longer versus shorter fur.

either otter or self since he has a very dark belly and no eye rings. eje as well based on the red kit.
That would leave at/a_ B_ c(chl)c(chl) D_ eje-

If Rudy is an agouti-based harlequin, <A_B_C_D_e(j)_> there will be no eye rings or other agouti marks. A dominant harlie allele disrupts that agouti pattern pretty thoroughly, separating the two fur colors as explained above and eliminating the "trim."

There is what's called a "harlequinized agouti," in which the agouti has a recessive harlequin allele <Ee(j)> rather than one in the dominant position <e(j)_>. There will be eye circles etc. though it looks like an agouti with weird patches, as the harlequin allele is only partially dominant relative to the normal extension allele. But your buck is not a harlequinized agouti.

If he was a otter-based harlequin <a(t)_B_C_D_e(j)_>, you would see what's called a torted otter, where the dark pigment was darkest on the extremities. But your buck's dark color is actually quite clean - I don't see any indication of torting.

If he was a self harlequin <aaB_C_D_e(j)e(j)> he would need to be homozygous for harlequin <e(j)e(j)> for the harlequinization to show. But since he has produced orange kits, you know he's <e(j)e>.

So, I think you can assume he's an agouti-based harlequin.

Here's an interesting detail. A self rabbit appears to be only one color, but the melanocytes actually still produce two colors in full-color <C> rabbits. A self black is actually an orange rabbit with the black pigment going all the way up the hair, effectively covering up the orange. That is why, when you apply the non-extension <ee>, which restricts the extension of that black pigment, you end up with a tort: an orange rabbit with some black left at the tips of the shorter fur. So, a self black rabbit that gets a double dose of harlequin does have two colors to be split onto different hairs! I think that's cool.

But then I got some hair and realised the black bits are very much like the cali, all white with only black tips. I have no clue what that says about all this. I might be missing grey bands but I don't get how he could be agouti without the agouti marks nor steel to hide them.

There is a very wide range of depth of color; even without "snowballing," some rabbits have poor depth of color and/or faded undercolor. And as mentioned above, an agouti-based harlequin will not have agouti marks at all.

Regarding Saturno (the cali), I managed to post all of those pictures before and forgot the one with the pulled shoulder hair
Here it is. As you said, it's all white with a black tip, but that might be just the hair growing again, as that patch was formed when she pulled a bunch of hair for a nest and is fading away as the months pass.

That's a great photo!

This does not look like an agouti - I see no bands at all. She appears to be self with either snowballing or just very poor depth of color. The very tip of the hair is slightly faded - which can happen on old fur - but it is not a different color.

The oldest part of the hair is the tip, so if it's still growing, the newest part is at the bottom, not the tip. She got that patch from pulling the fur out - she made a cold spot so it grew in dark! Now that it's not exposed and cold anymore, the fur may grow back completely white.

According to @reh, fur grows from the dark tip of the hair and continues its growth under that. There is a super informative series of posts on the molecular development of agouti bands here:
https://rabbittalk.com/threads/func...eceptors-and-pigment-types.37081/#post-359796
This is where I discovered that, in spite of some breed Standards of Perfection calling for "white-tipped hairs," there really isn't any such thing.

 

[Naelin]

This info is all so amazing. I can't thank you enough.

After re-doing all of my tables, I think this is what I have:
Rudy: Harlequin (low Rufus) - <A_B_Cchd_D_eje> (the "chd" is from the magpie kit, though it'd be 50/50 of it coming from the doe)
Saturno: Black Himalayan - <aaB_c(h)_D_EsE> (the E is not 100% confirmed, but she had a bunch of black steel kits with a red buck, and a couple of stillborns that had light grey skin and per my understanding could have only been chestnut)

I'm excited to see what comes out of this pair I should be able to confirm some of those question marks (And some of the ones from my other doe, the one from my profile picture) with their litters.

 

[Alaska Satin]

This info is all so amazing. I can't thank you enough.

After re-doing all of my tables, I think this is what I have:
Rudy: Harlequin (low Rufus) - <A_B_Cchd_D_eje> (the "chd" is from the magpie kit, though it'd be 50/50 of it coming from the doe)
Saturno: Black Himalayan - <aaB_c(h)_D_EsE> (the E is not 100% confirmed, but she had a bunch of black steel kits with a red buck, and a couple of stillborns that had light grey skin and per my understanding could have only been chestnut)

I'm excited to see what comes out of this pair I should be able to confirm some of those question marks (And some of the ones from my other doe, the one from my profile picture) with their litters.

Those sound like a pretty good working genotypes.

Regarding the kits with light gray skin - they were probably not chestnuts. Chestnuts are usually born looking black with white inner ears and belly. In fact, in my experience, agoutis are born looking the color of their ticking (chestnuts & chinchillas = black; opals & squirrels = blue; ambers = chocolate; and lynx= lilac), with the light agouti inner ears and belly. Within a few days, the body color starts to change as the fur grows in, and soon you see the evidence of the intermediate bands.

@judymac posted some good photos of newborn chestnuts here: https://rabbittalk.com/threads/is-this-a-chestnut.37160/#post-360569

When I see light gray kits I think immediately of sable. When my first sables were born, I thought they were just really lousy pale blues. Here is a newborn sable next to its himi sibling:

There is a photo series showing the changes sables go through in their early color development here: https://rabbittalk.com/threads/chinchilla-rex-at-last.36724/#post-355913

If the light gray kits were sables, the red sire would be <A_B_Cc(chl)_D_ee>. The Cal doe could not carry sable. Too bad those kits were stillborn. It will be very interesting to see your upcoming litters!