How to build up chicks resistance to diseases from their day of hatching

[Sire12]

They're due to go into lockdown tomorrow could anyone confirm if the egg is a quitter

 

[TheKindaFarmGal]

Just leave it unless it smells or is leaking.

 

[Sire12]

Ok isn't it better to remove them if they are not fertile incase they explode during lockdown is what I read

 

[TheKindaFarmGal]

They'll smell or leak first.

 

[Sire12]

Ok so they hatched 2 days ago with the last hatching last night , in the end I have 2 brahma and 2 australorp chicks, 3 seem perfectly fine but one of the Aussies has what I think is splayed leg even though I put an anti slip mat in the bator at lockdown, I watched a video that showed how to use a bandaid to act as a brace so il see how it goes and upload a pic tomorrow to see if I'm doing it right, the other chicks arent bullying it so I didn't separate them

 

[Sire12]

The chick with the splayed leg seems to be very lethargic and I haven't seen it go for a meal or a drink yet, I've seen it hobbling about a little bit better now that it has the braces on but that's it, can anyone offer advice pls