Okay, going to make some comments... but understand that the information provided was not complete enough to make any real "diagnosis".
Not to be a "wise-azz" but have you raised bottle calves before? If you do not have much/any experience with them then please take what I say without offense. Sales/stockyards, are the very WORST place to buy baby calves. They get exposed to every germ there is and their immune systems have a hard time trying to just start to function so they get sick way too easy.
Yes, in my opinion you are feeding too much to start out with. Jerseys are smaller.....smaller stomachs, smaller capacity. I have raised hundreds over the years. 1 1/2 qts, or 3/4 bottle is plenty at a time. If on a cow they will only drink a pint to a qt at a time. They will drink even more frequently than a holstein just because they are normally fairly high energy and will just need less at a time but more frequently. They will drink as much as a holstein in a day but in much smaller quantities. Too much at a time is a recipe for scours for the first couple of weeks.
Plus you have no real idea what it had before you got it. Hopefully it had colostrum. You say it was a week old. But unless it came with a birth certificate, it could have been 1 day to 2 weeks.
Now for the milk replacer. I think you meant "dumor"? A typo I'm thinking. First off, I do not use medicated milk replacer because if you need to treat them for anything, it may take more or stronger stuff since they have a "low dose" of medication. I realize that the idea is to stop a problem before it starts.... especially from someplace like a sale barn.
But that is not the end of the world to use medicated.....HOWEVER.... is the milk replacer 100% ALL MILK, milk replacer... with NO SOY in it. All milk, can have milk, skim milk, whey etc. If not, that is the biggest problem there. Soy based milk replacers are cheaper than ALL MILK, milk replacers. However, soy protein is not easily digested by baby calves. They will not thrive on it and may actually "go backwards". If the calf has any issues, it can cause irritation to the gut tract and it is not readily absorbable.
My suggestion is first, determine the type of milk replacer. Then go to feeding 3 x a day with no more than 2-3 qts at a time. You want the calf to be a little "hungry", not so full like he just got done stuffing himself at the Thanksgiving table.
I don't know what to tell you about him not getting up. He may need a shot of "Bo-Se" which is a Vit E and Selenium combo to combat low selenium areas. Very common. That can affect the muscles, known as White Muscle disease. Easily treated. DO NOT feed him a bottle while he is lying down. It is too easy for the milk to literally "go down the wrong pipe" and wind up in it's lungs. It will drown him or cause him to get pneumonia.
This calf may need a couple of feedings of electrolytes just to get some "energy" in him. Vit B complex will help with stimulating his appetite. A multi vitamin might be of more benefit like "Multi-Min" , but that is from a vet.
How big is it? Maybe 40-50 lbs? You have to remember that smaller size for any treatments you need to give to him also.
I say him... is it a heifer or a bull? If a heifer, it is possible it is a twin to a bull so will have a 95% chance of being sterile.
If you are not real experienced with bottle babies, I would suggest either a friend that has experience, or talk to a vet. But then you are looking at some money that is really not well spent. Here jersey baby calves are bringing $1.00 to $10. Giveaway prices. It costs more to raise them than they will be worth. Sad but very true. You have to figure in the economics.
