Off-quality lentils occasionally become available as animal feed. With 25 percent crude protein and approximately 40 percent starch, they are a very interesting, albeit scarcely known, ingredient, suitable for all monogastric species. Even when lentils are of low quality (low for human consumption) due to frost damage, discoloration, or seed damage, such problems do not affect their nutritive value as a feed ingredient.
Lentils contain approximately 7 percent non-protein nitrogen, which figures as protein in the "crude protein" measurement. To this end, it is often recommended that diets based on lentils be formulated on digestible and not total amino acids, but accurate values for amino acid digestibility in lentils were not available and had to be inferred from similar ingredients.
A recent study from Canada has looked into this issue and determined the net energy value in lentils. It was determined that the digestibility of lysine in lentils was 81 percent, which was found to be lower than normal soybean meal (93 percent), with similar trends in most amino acids. The exact values are shown in the following table, which should prove to be of immense value to feed formulators worldwide.
In terms of energy, lentils were found to contain 3,910 kcal digestible and 2,600 net energy per kg dry matter, compared with 4,450 and 2,630 kcal for soybean meal, respectively.