Many producers of biofuels tend to think of co-products in terms of protein quantity – i.e., the percentage of crude protein. While “quantity” is an important number, it has greatest application for ruminants (animals like cattle and sheep). For non-ruminants (animals like pigs and chickens), the protein “quality” is much more important. So, what makes a “quality” protein? (1) amino acid profile, and (2) digestibility.
Amino Acid Profile: Dietary proteins are broken down into individual amino acids through digestion. There are about 20 dietary amino acids of which 10 are called “dietary essential” – that is, the animal’s body cannot convert or synthesize enough of these 10 in order to meet nutrient requirements; they must be consumed in the diet. Further, since most USA livestock diets are based on corn, one of these 10 essential amino acids is, generally, most limiting: lysine. Therefore, a feed ingredient which provides a good source of lysine is particularly valuable.
Digestibility: Due to the chemical nature of proteins, they are susceptible to a phenomenon known as “heat damage” – more commonly known as “browning”. The scientific name is “Maillard Reaction”. A good example of browning occurs when you sear a steak and get the brown “crust” from the grill. For a steak dinner, this is nice – it adds flavor. For feed co-products – especially distillers’ grains – this is undesirable because it reduces the digestibility of amino acids. The amino acid that is most susceptible to browning is lysine – which is the one amino acid already identified as most limiting for our typical USA livestock diets.
Bottom Line for Livestock Diets: If you have a less-than-desirable amino acid profile accompanied by low digestibility, the value of your co-product may be much less than a similar co-product with the same (or even less!) overall crude protein.
Besides formal training in chemistry, biochemistry and nutrition, bio-fuels production facilities should employ a consultant who has specialized training and experience in fermentation and bio-fuels production – along with practical ingredient evaluation and testing. Further, the consulting nutritionist should have “hands-on” experience in ration formulation – especially with non-ruminant diets and amino-acid-based dairy diets. Why? Because the down-stream feed customers are making these determinations and valuing your ingredients accordingly.
Lee Enterprises Consulting is the world’s premier bioeconomy consulting group, with over 100 highly qualified experts serving in all these areas. Take a look at our experts and the services we provide. Most of our experts are also available to advise and serve as expert witnesses in bioeconomy litigation matters. For the larger projects, we specialize in putting together full service, interdisciplinary teams with one point of contact. Call us at 1+ (501) 833-8511 or email us for more information.