Lemna Protein Concentrate (LPC) is derived from the leaves of duckweed, one of several rapidly-growing aquatic plants of the genus Lemna. LPC is produced by de-oiling and de-hydrating leaves and stems of the duckweed plant. Duckweed has a number of advantages as a protein source. It is relatively inexpensive to produce and requires less growing area and fewer inputs than other plant protein sources such as soybean products. In addition, LPC has a favorable amino acid profile for use in swine diets. No published data exist on the nutritional value of LPC as fed to pigs. Therefore, two experiments were conducted to determine the concentration of digestible and metabolizable energy and the digestibility of phosphorus in Lemna Protein Concentrate.

Almeida, F. N., J. K. Htoo, J. Thomson, and H. H. Stein. 2013. Effects of adjusting the standardized ileal digestibility (SID) amino acids in heat damaged soybean meal (SBM) or distillers dried grains with solubles (DDGS) in diets on performance of weanling pigs. J. Anim. Sci. 91(E-Suppl. 2):686 (Abstr.) Link to abstract

Animal protein sources such as fish meal and protein plasma are often used in diets fed to weanling pigs because the amino acids in these sources are highly digestible and because animal protein sources do not contain the anti-nutritional factors present in soybean meal. However, the cost of fish meal has increased in recent years and there is, therefore, a need for less expensive alternatives.

Chicken meal and and poultry by-product meal are protein ingredients that have a concentration of amino acids similar to that of fish meal. Poultry by-product meal is produced from the offal of carcasses of slaughtered poultry and includes feet, necks, undeveloped eggs, and intestines. Chicken meal is prepared from clean flesh and skin of chickens without or with bone derived from the whole carcass of poultry. The quality of chicken meal and poultry by-product meal depends on the quality of the rendered parts to produce them. Ultrapro is produced from enzymatically hydrolyzed porcine intestines, and AV-E Digest is produced by enzymatically hydrolyzing whole spent hens and extruded egg albumins. Insufficient data exist on the digestibility of crude protein and amino acids in these ingredients.  Therefore, an experiment was conducted to determine the digestibility of crude protein and amino acids in chicken meal, poultry by-product meal, Ultrapro, and AV-E Digest when fed to weanling pigs and to compare these values with values obtained for soybean meal.

Rojas, O. J. and H. H. Stein. 2012. Energy, phosphorus, and amino acid digestibility in Lemna protein concentrate, fish meal, and soybean meal fed to weanling pigs. J. Anim. Sci. 90(E-Suppl. 3):467 (Abstr.) Link to abstract (.pdf)

Soybean meal fed to pigs undergoes heat treatment to destroy trypsin inhibitors and other antinutritional factors that impair the digestion of protein and thus reduce performance. However, heat treatment can damage nutrients as well. In particular, the Maillard reaction reduces amino acid digestibility by combining amino acids with sugars to produce biologically unavailable compounds.

An experiment was conducted to determine the digestibility of amino acids in pigs fed soybean meal that had been heat treated in varying ways and for varying times. Conventional soybean meal was divided into four batches. One batch was not heated; one was autoclaved at 125°C for 15 minutes; one was autoclaved at 125°C for 30 minutes; and the last one was oven dried at 125°C for 30 minutes. Ten growing barrows were fed a total of five different diets. The experimental diets contained 40% each of the four different soybean meals being tested. An N-free diet was also formulated and fed to measure the basal endogenous loss of protein and amino acids.

González-Vega, J. C., B. G. Kim, J. K. Htoo, A. Lemme, and H. H. Stein. 2011. Amino acid digestibility in heated soybean meal fed to growing pigs. J. Anim. Sci. 89:3617-3625. Link to full text (.pdf)

Rojas, O. J. and H. H. Stein. 2011. Concentration of DE and ME in fermented soybean meal, conventional soybean meal, and fish meal fed to weanling pigs. J. Anim. Sci. 89(E-Suppl. 1):333 (Abstr.) Link to abstract (.pdf)

Sulabo, R. C., W. S. Ju, and H. H. Stein. 2011. Amino acid digestibility and energy content of copra expellers, palm kernel expellers, palm kernel meal, and soybean meal fed to growing pigs. J. Anim. Sci. 89(E-Suppl. 2):99 (Abstr.) Link to abstract (.pdf)

Baker, K. M., B. G. Kim., and H. H. Stein. 2010. Amino acid digestibility in conventional, high protein, or low oligosaccharide varieties of full-fat soybeans and in soybean meal by weanling pigs. Anim. Feed Sci. Technol. 162:66-73. Link to full text (.pdf)