IMHO, I think we way over think and do as far as diet is concerned. That being said, I do agree that H2O is the most important ingredient. Simply put, if they're not drinking, they not going to eat. 11-12% protien is most natural for cattle. If you need to use probius, use it to get the "BUGS" right then let the calves take care of themselves. Many times on this & other boards people talk about feeding 2 to 3% of body wt. to the cattle, which is half correct. If you go out & just give your calf that amount of feed to begin with, you are more than likely going to have a varity of problems. You must start out @ 1%, and very gradually increase to the maximum levels. The quickest that this realalisticly can be done is 28 days,. That is if you don't ever have to back off & start back up. You can usually tell that the people asking for help do not have a great amount of experience, so please be careful as to what you are telling them, as it could potentially have devistating effects on their projects. I think that we all need to remember that most of the products that are reccomended here are very highly advertised products for the show industry, and guess what, someone's making very good money off of them. I have said B4, please go to some feed dealer in your area of the country and explain to him/her what you are trying to do. There are very capable people in all parts of the country that are familiar with what ingredients are readily avaiable to you in your area. YES you can burn off hair with certain ingredients @ certain times of the year. Talk to them about that also. The B12 vit. shouldn't have to be followed up weekly if the calf is feeling well he/she will be able to get adjusted from a balanced diet. I'm not saying that you shouldn't give it once, possibly twice, but not weekly. Too many people are over thinking diet and are easily sold products because we/they are uninformed and don't go talk to someone that they feel comfortable with or trust to buy from. Buyer beware, snake oil salesmen still working.
P.S., It is way harder in my opinion to feed 1 calf than 20-30-100. Example; If you are feeding 2 & one doesn't eat 1 evening, you can bet that the next day the other calf has over eaten because he got both calves share the night B4., If you are feeding 20 and 1 calf doesn't eat in the evening, 19 others divide his portion and everyone goes on normally the next day. If you are feeding 1, you MUST be very in tune with his appetite. You will have a tendancy to want to push too hard too fast. Make sense to you. Sorry for the long post, but every time that this subject comes up, it scares me with some of the replies.