A few weeks ago I got shown a message which suggested that ASDA added animal based preservatives to its milk which would render it unsuitable for Muslims.
At first I considered it a hoax and then I promptly forgot about it as the local shop is way more convenient to getting milk.
So I did a quick google of it all and came across this page. Conclusion: it is Halal.
But unlike previous events if disinformation, it also stated that ASDA had posted an unhelpful message in Social Media which had suggested this, but the actual producers of of the milk had confirmed that there were no animal based fat or other products added to the milk, along with a confirmation from ASDA of the same.