This is a beautiful and profoundly disturbing documentary. That it manages to be both at the same time is a paradox. I'll explain a bit more how.
Like the movie Manufactured Landscapes by Edward Burtynsky, "Our Daily Bread" takes a look at aspects of our world that are not always readily accessible or known to most citizens of western countries. With a steady decline of agricultural and industrial workers over the years, most of us have little idea of what it takes to produce what we consume. This is certainly true for our food, the topic of this movie. Again, like Manufactured Landscapes, this documentary is "only" a sequence of very well composed and lit shots, without interviews or voice over. This may disturb or annoy some. I find this to be an extremely effective approach, as it makes one confront more directly ones own feelings and in the end gives more impact to the images.
While the author certainly has an agenda, I don't think it's an extremist one. He does not try to denounce the difficulty of working in the meatpacking industry or attempt to portray what is happening to the animals that will be processed as particularly horrible. His aesthetics are cold and distant, even maybe "scientist". Everyone will need to make up one's mind. But the way he frames most of his shots using highly symmetrical or geometrical compositions certainly contributes to the creation of a eery feeling of "elsewhere". That's the artistic and thematic bias of the movie: to show us that what lands on our plates comes from places we don't know about and don't think about.
One important point to note is that we typically don't get to see the end processing of the food products. Most of the steps shown are very much upstream in the food processing chain: animals are slaughtered and cut into pieces, but you don't see how they're turned into hamburgers or ready made meals. Only a few salads are packaged into plastic bags the way you will see them in supermarkets. This is very much in line with my observation above that the author is interested mostly in the less familiar. But be forewarned that while this is not a documentary about "the crap that we eat", certain images are extremely powerful and may stay with you a long time. Having watched Baraka I had already seen little chicks on conveyor belts, but this is nothing compared to the efficient violence with which bigs are cut in two and eviscerated, or full frontal cow slaughtering. The movie ends with the meat packing plant being cleaned up. It may not be so easy for you to forget what you saw. This might even be a good thing.