Strangely, the difference between organic milk in Canada vs organic milk in the USA is something I actually have researched! I have a group of friends all around Canada and the US that were all pregnant and due the same month, we have been friends now for just over 17 years. When our babies were little, the topic of organic milk came up and the discussion was whether or not organic milk was worth it.
So, here are some differences.
Non-organic milk in Canada:
In Canada dairy farmers are not allowed to use growth hormones at all. While they are allowed to treat sick animals with antibiotics, they are not allowed to add it to feed. As well, any animal treated with antibiotics is milked but the milk is taken out of the supply chain and disposed of for the period of the treatment. After that period, the milk is tested and if any traces of antibiotics are found, it is disposed of.
Organic milk in Canada:
Same as above plus a few extra things. If an animal is treated with antibiotics more than once in a year, it is permanently removed from the organic milk supply. Also, cows that produce organic milk are fed organically grown feed and are given more access to outside grazing.
Non-organic milk in the USA:
Cows are allowed to be given growth hormones and if an animal is given antibiotics, that animal's milk is kept in the supply and is allowed to be sold.
Organic milk in the USA:
Animals are not allowed to be given growth hormones nor are they allowed to be given other hormones including reproductive ones. Any animal that needs to be treated with antibiotics is immediately taken out of the organic milk production. As well, animals that produce organic milk must be fed at least 30% of their diet on pastures. The rest of the feed must also be organic.
So, to sum up, most of what we sell as non-organic milk in Canada would be considered to be organic milk in the States with the exception of the feed. It's for that reason that I don't personally buy organic milk here but if we lived somewhere like the USA, I probably would.
FTR, I checked online and 4L or non-organic milk at my local grocery store is selling for $5.49 and organic milk from the same producer is selling for $9.49