There are many differences between meat and animal products produced from animals fed a grain diet as opposed to a grass diet. One of the most important differences is in the ratio of Omega fatty acids. The polyunsaturated fatty acids composition of all cell membranes is to a great extent dependent on dietary intake. Two of the essential fatty acids are the omega-6 and the omega-3 fatty acids. Not only are these fatty acids important to human health they are necessary in the right proportions. Outside of the recommended proportions can cause health problems – sometimes serious health problems.

The recommended ratio of omega-6 fatty acids to omega-3 fatty acids should be less than 4:1. Grain-fed beef can have ratios that exceed 20:1 ratio, whereas grass-fed beef has a ratio of around 3:1. Grass-fed products are rich in all the fats now proven to be health-enhancing, but low in the fats that have been linked to ill-health and disease.

This dangerous imbalance is also common in poultry and egg production as well.

North Dakota University research showed similar results for bison. The grass-fed bison had omega 6 to omega 3 ratios of 4:1, and the grain-fed bison had ratios of 21:1.

Organic milk has up to 71 percent more omega 3 than non-organic milk, according to a recent study by the University of Aberdeen.

Microbiological contamination of food is recognised as the main contributor to acute food-borne illness in humans. Organic animal production probably makes little difference to this, although the grass- and hay-fed cattle, required in many organic systems, seem less likely to produce the very toxic Escherichia coli O157:H7 strain than grain-fed cattle.