It only takes 1 cow, 1 to 2 years in a dairy, to produce 8000 to 16000 litres of milk.
Enough milk for a life-time.
So by converting a Lacto-Vegetarian to Vegan, you save 1 cow, 1 or 2 years in a dairy. And, at most, 1 or 2 calves.
But, when that Vegan fails, as most of them do, and then goes back to eating 1000 animals, as most of them do, you lose 1000 animals.
If vegans genuinely cared about animals then vegans would:
1: Campaign against organic food that has been grown in blood and bone, chicken dung from factory farms and sprayed with fish emulsion.
2: Stop eating and promoting and selling organic food.
3: Stop their anti-milk propaganda.