Glycerin/Glycerol Use by Poultry: The influence of source and level of inclusion of raw glycerin in the diet on growth performance, digestive traits, total tract apparent retention and apparent ileal digestibility of nutrients was studied in broilers from 1 to 21 days of age. The experiment was a 2 × 4 factorial with two sources of glycerin and four levels of inclusion (2.5, 5.0, 7.5, and 10%). The glycerin sources contained 87.5 or 81.6% glycerol. Study results indicated that the feed conversion utilization, and apparent ileal digestibility of dry matter and gross energy were significantly increased as the glycerin content of the diet increased while average daily gain was not affected. The researchers concluded that raw glycerin from the biodiesel industry can be used efficiently, up to 10% of the diet, as a source of energy for broilers from 1 to 21 days of age and that the energy content of well-processed raw glycerin depends primarily on its glycerol content.

Mandalawi, H.A., M.V. Kimiaeitalab, V. Obregon, D. Menoyo and G.G. Mateos. 2014. Influence of source and level of glycerin in the diet on growth performance, liver characteristics, and nutrient digestibility in broilers from hatching to 21 days of age. 93:2855-2863.

A laying hen study was conducted to determine the energy value of bi-distilled glycerin and the comparative performance of diets containing bi-distilled glycerin, linseed oil and/or soybean oil. The treatments consisted of the replacement of energy from soybean oil with graded levels of bi-distilled glycerin and/or linseed oil. Results indicated hen performance was not affected by the level or oil source (P > 0.05). Bi-distilled glycerin showed gross energy, AME, AMEn and energy coefficient of metabolizability of 4,217 kcal/kg, 3,362 kcal/kg, 3,505 kcal/kg, and 79.7%, respectively. The conclusions developed were the dietary energy from soybean oil in the layer’s diet can be replaced with energy from bi-distilled glycerin and/or energy coming from a mixture of 50% linseed oil and plus 50% bi-distilled glycerin.

Melo, T.S. and co-workers. 2014. Bi-distilled glycerin, linseed, and soybean oil in laying hen diets: Digestibility and performance. Poultry Sci. 93(E-Suppl. Poster 429, page 142.