Unsure about sexing kit

[Juci]

Someone told me it's usually easy to tell when they're 1-3 days old and then harder to tell until they're about 3 months.
It's been many years and we're just getting back into breeding.
If that's the case (that it's easier to tell at a couple days old) I was thinking about tattooing just a dot in the ear of all of the bucks (or does) to make it easier later.

I'm open to more experienced thoughts on that idea.

That sounds like a really good idea, I’d also like to see if anyone has input about that. I’m embarrassed to admit I’ve never seen a baby rabbit that young since my doe gave birth underground. I don’t have a colony but they get lots of time outside the cage and it was a whole thing.
I ended up pulling out the baby buns at 2 weeks old and that was the first time I held them. If it’s true it’s easier to tell at a few days old that would be great for planning ahead.

 

[ladysown]

they look like blood vessels cause that's what they are. thin capillaries basically. They are what help the vent to turn dark red/purple when the doe is up for breeding.