@SarahBeeney
This is a very vast subject, so if you don't mind I'll answer the questions you've posed directly and if you have any more I can elaborate further.
"I've heard that Dairy farming is cruel because the calves are taken away from the mother straight away and then obviously the cows are milked relentlessly for our benefit."
I realise this isn't a question but it's a statement that I shall address. There is a hell of a lot of fear-mongering surrounding the dairy industry. As a result we see a lot of lies intermingled with aspects of the truth being spread as fact and used to criticise the industry, usually from people with an ulterior motive. I am not a dairy farmer myself so I have limited experience, but our neighbour is and I'm familiar with his practices. In my experience dairy calves are not taken from their mothers immediately. They stay with them for a few days where they suckle and get the necessary colostrum to help build their immune system. Dairy cows are separated from their calves earlier than any other cattle because yes, the milk is intended for human consumption. The issue with dairy cows is that once that colostrum has been consumed by the calf and her milk comes in she's immediately producing far too much milk for her calf to take. She becomes an immediate mastitis risk. Once separated, which is done in a calm and gentle manner, not like these foreign videos I see on social media perpetuated by the vegan agenda in our country (different topic so I won't go on a full tangent, but an interesting one to discuss nonetheless), the calf will go to live in a group with other calves (some start in calf hutches to allow their immunity to develop even more before being introduced to the group) and will be fed on fresh cows milk. The cow will go into the milking system where she will be milked, most commonly, twice a day to relieve the load and harvest the milk. Is the dairy industry for our benefit? Absolutely, all farming practices primarily benefit humans. Does this mean the animals must suffer and don't have a quality of life? Absolutely not. Dairy farmers are most definitely the most wealthy sector of all livestock farmers because, unlike all other livestock farmers, they have a regular monthly income. This means they usually have the financial means to provide the utmost care for their animals. The dairy industry has the most advanced technology to help promote the animals' welfare and comfort, including automatic cleaning devices so the cows always have a clean environment when inside, electronic brushes for the cows to rub on and play with to scratch itches, self-milking machines so the cow can choose when it wants to be milked and do it itself, and much, much more!
"We have switched to Organic milk but that obviously doesn't make any difference to this practice."
The only difference with organic dairy is that should any animals require antibiotic treatment the typical withdrawal period (the time it takes for the medication to leave the animal's system, during which the animal's product cannot be entered in the food chain) must be extended by three times. This is a little bit pointless since the withdrawal period is established by medical science so extending it does nothing extra other than waste perfectly good milk until the extended time limit is up. Also, organic animals are limited on what food they can consume, but only in the sense that their food was limited to certain types of pesticides when it was being grown.
"What's your opinion on the milking industry?"
I have varying opinions on different aspects of the milking industry. I don't think it's "evil" as it is often propagated to be. I absolutely acknowledge that there are bad eggs in the industry, and like all bad farmers I believe they have no right to be in the industry. I detest factory scale dairy farming because I believe that once it turns to that massive scale and is run by minimum wage workers overseen by someone in an office somewhere who calls the shots but never farms a day in their life then the respect for the animals goes out the window and that's when bad practices start to rear their ugly heads. The technology in the industry is astounding and much of it is developed for the well-being of the animals. While I'm in awe of much of the tech I do also worry that it's taking away that personal aspect from farming where the farmer knows his animals individually. If I could have it my way I think it would be best to go back to the old ways where milk was more valuable and so farmers didn't have to milk hundreds of cows to fund their business, they could milk smaller numbers and give more individual attention to their animals. We are already well past this point in the industry I think, and farms milking less than a hundred cows nowadays are few and far between. I just hope that the UK family based dairy farms are able to survive the evolution of the industry because if we devolve into a solely mass production factory farming industry like those in many other countries then dairy really will become scary. So my opinion is, value your milk, respect it's origins, and support your local farmers!