Let me try to analyze this.
On an average, dairy cow in India is forced to give birth to around 4-5 calves in it's lifetime. So, in the absence of natural predators, life threatening diseases, or natural calamities such as drought, flood etc. it is obvious that their population will keep growing multi-fold. The only way to keep their number in check would be to implement a "2 calf policy". Yes, the same way we talk about human beings!
Ok, let's say 2 calf policy is implemented. Now, how much milk a dairy farm can extract from one cow? Obviously it is less than half of current quantity. This means, cow population should first be more than doubled before even implementing this policy i.e. if the drop in current milk production is not acceptable. In any case, the milk price will be at least twofold once this policy comes into effect. In other words, if current milk price is Rs.X then new price would be Rs.2.5X let's say.
Next, if cow is not sent to slaughter house, then it's lifespan becomes more than double (or much more than that). And during old age, it would demand far more healthcare expenses***. This would further increase the price of milk to double value let's say Rs.5X
Naturally, there will be 50% of male calves. So, if we want to keep them also alive, then it will further double the milk's price, to Rs.10X
Already we are seeing that the current milk prices are subsidized by around 90%. This is just tip of the iceberg... If we consider additional things such as ensuring enough grazing land for cattle, instead of confining them to sheds, the price will go even higher. Price that we pay is just one thing - have you every wondered about environmental impact of animal farming? Check it out...
This basic math and analysis itself makes it very clear that dairy is unsustainable industry. Today it is thriving only because of it's deep association with slaughter houses. Shelters for old cows & unwanted bulls are just small scale efforts to reduce the guilt and spread superficial feel-good factor among gullible human beings, and can never be implemented at large scale.
Think about it, and if you really care, go vegan! If you really want to use "milk", then go for plant based ones, they are better choices for your health, environment and for animals. Why not adopt such a win-win-win situation?
*** By the way, I am curious; many people claim that cows are our 'mothers' and deserve a great deal of respect. So, with the modern technology and all, how far they are ready to go in terms of cow's healthcare? Are they envisioning hospitals with ICU, organ transplant facilities etc.?! Hmm, that's an interesting thought, isn't it? Nope, I am not being sarcastic here, believe me; I am genuinely trying to understand psyche of those who claim cows to be equal to their mothers.