Baytril is enrofloxacin, an antibiotic which happens to be known for causing cartilage problems in animals at rapid growth phase (ie growing quickly). It is a broad spectrum bacteriocidal antibiotic with good penetration in many areas. It is banned for use in food producing animals in Canada (except maybe as a turkey egg dip or something like that but I don't do birds) so I've never used it in cattle. I personally think it was a mistake to licence it for cattle in the US, but that's my opinion.
Micotil is tilmicosin, a long acting antibiotic which is given subcutaneously at the rate of 1.5cc/100lbs in cattle over about 200 lbs, 3cc/100lbs under about 200lbs. It is especially good at pneumonia, and is bacteriocidal and also gets mycoplasma. It is licenced for use in cattle and has widely known safety data in them. Don't use in other species--it can cause anaphalactic reactions and death.
If you want to know which is better, likely Nuflor (florfenicol) but you didn't ask...
Thanks for your quick response. I have heard of Nuflor, but have never tried it. What is it mainly used for? Normally I go through the scours with some of my calves with out too much trouble as long as I keep a close eye on them. But this year it seems to be more of a respiratory problem. They don't feel like sucking and therefore get weak in a hurry. I've had two now that one day they seemed fine and the next day they couldn't hardy stand up on there own. There back ends sway and then they fall down. I have been feeding them electrolytes and giving them baytril. The first one has mostly pulled out of it, but stills seems like he doesn't feel real good after a week. Got any suggestions? The second one went down yesterday and I am treating him the same way. I am worried that all the other ones are going to catch it. I moved all the cows with the babies to a different field to get out of the contaminated one. I would appreciate any help you could give me. Thanks!!