Yes! but we want to be absolutely upfront about this; they do not live on pasture alone.
Pigs and chickens are very different to other livestock grown for our consumption in that they cannot be productive and survive on a diet of just pasture. These animals are omnivores and that means they have similar dietary needs to you and me. That doesn't mean that they don't eat grass, they certainly do!
To expect poultry and pigs to live on grass alone would be like committing yourself to a diet of leafy greens. We need a balanced diet and so do the animals.
Cattle and sheep have a rumen, sort of like a very large tank that ferments pasture to convert it into a digestible food source. They are unique in this ability. Single stomached animals, such as humans, pigs and chickens are not capable of digesting these fibrous materials and need a balance of energy, protein and fats to live well.
Pasture is a part of a balanced diet in pastured egg, chicken and pork production and a very important one. The diet is supplemented with grains, pulses and sources of protein to ensure that all the animal's needs are met to remain healthy and productive.
Chickens especially will consume lots of bugs, grubs and insects in the paddock and in the soil, but, we need to remember that in the wild, chickens would not flock in such large numbers and be confined to one farm. They would range large areas of grassland and forest and be constantly on the move looking for food. In a farm environment it is not realistic to expect the chickens to get all their protein needs from the paddock so their feed has to be supplemented. The chickens don't have to worry about where their next feed comes from either!
John Dunn CEO of Egg Farmers Australia, has been quoted as saying "Hens don't eat grass, it causes compaction which leads to disease and death" in this recent news article entitled "Egg farmers hit back at what they call myths about their industry". Sadly though, it is not the first time that opponents of pastured egg and pork production have made these fool hardy claims.
If eating grass causes compaction [of the gizzard] leading to disease and death, and hens don't eat grass; how did the grass get into the gizzard in the first place?
We are not denying that gizzard compaction happens, it certainly does but for many reasons. The most common reason is that people new to the industry do not understand pasture species, their make up or their food value. Often they don't understand the digestive processes of chickens and how grazing needs to be managed.
This is what you may find in a healthy hen gizzard, pebbles and course grit that will be used in conjunction with the powerful muscular action of this organ, to grind food the bird eats.
There are reasons why the gizzard would not be able to carry out this function effectively and they all relate to poor management of the birds and pasture.
Nice, healthy gizzard of young birds demonstrating how the pasture has been ground up. You can see a mix of grass and grains.