Little Buck that just isnt growing

[Lopsofloverabbitry]

One of my first timer Holland Lop does has a litter of 5, only 2 survived. So this little buck (whose name is Spruce) when he was born he fell out of his cage onto the concrete floor. He was there for about 20 min before we found him and gave him lots of TLC and he is perfectly fine now. 3 months later he is the most petite kit I have ever seen. He in with his brother in his cage (whose name is Aspen). Aspen is now about 4 times bigger than Spruce. It is a huge difference.
Spruce just doesnt seem to be growing!
Does anyone know of any special feed mixture I could give him?
He seems to be lacking something, but I'm not sure what. He is fed Sprout rabbit good, hay in the morning, and is turned out to graze during the day.
I was thinking of adding some alfalfa to his diet, add some grain to his food. Any advice?

 

[Zass]

Old fashioned oatmeal would be the first thing I'd consider feeding a kit that isn't growing well. Oats are easy on their digestive tract due to the high soluble fiber content.

 

[Dood]

If the size difference is that significant he was likely born with a congenital defect or suffered permanent damage when he fell out as a kit :shrug:

 

[Susie570]

Dwarf genes? :shrug:

 

[akane]

Is he not maintaining a good weight? You can add oatmeal or black oil sunflower seeds if he needs more flesh. If he's filling out and maintaining a healthy weight for his size then there probably isn't anything you can do to make him grow. Every now and then the really small breeds will have all the right modifier genes line up and make a rabbit at about half the size of the standard. I've had 2 Netherland bucks stop at 1lb and live healthy for years. 1 bred well and produced healthy kits. The other is having major issues getting anything bred and his 2 litters so far have not had any survivors but there is no visible health issue with him and the does contributed to problems with the litters. Sometimes I do just come across bucks that no doe wants to breed with.