In today's world with modern technology and genetic engineering we have been able to get very productive hybrid animals but still somewhere in the corner of my heart I feel whether it is humane to get a calf from a cow every year?
This is an age old discussion: should we kill and eat other animals (or in this case the very young) or should we try to live alongside with them? I eat meat and know a lot of people that are vegetarians (and tried to live a vegetarian life for a while, but failed). Interestingly enough it is a fact that eating a balanced diet (not too much meat and a fair share of vegetables) is indisputably good for you, yet very few people do it.
My simplistic conclusion is that we live in a society that provides a huge breath of choices and to a great extent what becomes available is directly related to what people are willing to pay for. If people didn't use tons of plastic bags every day when they went grocery shopping, there would be more environmentally friendly alternatives. For example I use tote bags when I go grocery shopping. It may be a hassle at the beginning, but like anything else once you get used to it there is nothing to it. And if you calculate the number of plastic bags you go through in a single year, that is a big pile of trash at the landfill.
Likewise you can't just tell people to stop eating something just because a group of people feel that it may not be moral (or humane). With a similar viewpoint I could argue that eating the eggs of chickens is also not humane since we are killing millions of future chickens. I would also argue that just because a calf may look cuter (or we are more aware of its existence) by no means makes it have more rights than any other animal that goes through as much, if not more. I do believe that at least in the US, by en large, animals used for food are treated in the most humane way possible, much better than it used to be. A great book on the subject is Upton Sinclair's The Jungle.
My two cents :)