Why does the nutritional info (protein content) on skimmed milk sometimes differ by brand?

actually the COW can vary the protein herself and I suspect the different companies use different values in the "normal" range to figure their label.

the other option is that some companies add non fat powdered milk to the skim to keep it from being watery tasting and that would boost protein. (we make both and lable them differently)

One of the most statements you point out reminiscent of 'low fat' are there to deceive in the hopes that humans will fall for the trick and buy that company instead than one that doesn't say 'low fats'. One claiming to be low fats might just have reasonably less than that equal manufacturer had last week but could still be bigger in fat than other manufacturers. The one strategy to recognize is to compare the main parts between unique manufacturers and that includes reading labels cautiously. It relies how predominant these matters are to the individual as as to whether they'll take the situation to find out precisely what they are eating. I verify salt content material more than some thing. I devour chocolate which is excessive in fats and sugar so cannot see the point in checking for those constituents in objects which incorporate far less. It's as much as me to minimize my chocolate consumption if fats and sugar are my difficulty. Salt is a gigantic obstacle, inflicting excessive blood strain oedema and plenty of other health issues so (to me) that is fairly predominant.

they used different labs to make their labels. and it is all estimations of the average.

It is due to permeate.