What to feed to hatchlings

Ok so here goes, I was watching a video that had two guys a father and son, who were force feeding rattlesnake hatchlings. I noticed that there was a bottle of baby food on the table O, so I know they have Pinkie pushers and etc to help feed unwilling hatchlings, but what besides pinkies can you fed hatchlings, and I know there is normal rat and other warm blooded animals, but what else, is there a mixture that you can use, I mean you can use Ben-bac to help build up gut bacteria, but what else. O haven't been able to find anything online on these types of mixtures that are healthy, safe, and effective? Does anyone know for sure, any links or things in that manner that can give me an idea?

If they won't take solid they might take mush, if you know what I mean...

Some people will feed them "rodent puree" as a last resort with a (needleless) syringe.

besides rodent food i have no idea.

plain chicken baby food mixed with calcium and water

I was just curious, as i said Isaw the video and saw the baby food in the background, on the table they were using. I understand the puree thing I have used it several times over the 30 years i have been doing this, just curious about babyfood