Double-low rapeseed meal (RSM) is currently used as a protein ingredient in animal diets. Heat treatment of RSM at varying processing conditions removes the residual hexane and efficiently reduces the glucosinolate content. However, variations in heat processing temperatures and duration of heat treatment may result in Maillard reactions, resulting in the formation of sugar-amino acid complexes. Maillard reaction products result in reduced standardized ileal digestibility (SID) of amino acids (AA), with Lys being the most sensitive AA. However, there is limited information about how heating affects the concentration of digestible energy (DE) and metabolizable energy (ME). Therefore, the objective of this experiment was to test the hypothesis that both the degree of heating and the time that heat is applied will affect the concentration of DE and ME and the SID of AA in double-low RSM fed to growing pigs.

Liu, Y., M. Song, T. Maison, and H. H. Stein. 2014. Effects of protein concentration and heat treatment on concentration of digestible and metabolizable energy and on amino acid digestibility in four sources of canola meal fed to growing pigs. J. Anim. Sci. 92:4466-4477. Link to full text (.pdf)

Almeida, F. N., J. K. Htoo, J. Thomson, and H. H. Stein. 2014. Effects of heat treatment on the apparent and standardized ileal digestibility of amino acids in canola meal fed to growing pigs. Anim. Feed Sci. Technol. 187:44-52. Link to full text (.pdf)

Almeida, F. N. and H. H. Stein. 2013. Efeitos do melhoramento genético e técnicas de processamento na utilização do farelo de soja por suínos. "Americas: International Conference on Soybean Utilization", Oct 22-24, 2013, Bento Gonçalves, RS, Brazil. Link to full text (.pdf)

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

Almeida, F. N., J. K. Htoo, J. Thomson, and H. H. Stein. 2013. Amino acid digestibility in heat damaged distillers dried grains with solubles fed to pigs. J. Anim. Sci. 91(Suppl. 2):110 (Abstr.) Link to abstract (.pdf)

Sunflower meal and cottonseed meal can be used in place of soybean meal as protein sources for swine diets. The production of both involves heat treatment, to extract oil from sunflower seeds and cottonseeds and to reduce antinutritional factors. When heat is applied to feed ingredients in the presence of moisture, a series of chemical reactions known as the Maillard reaction may be initiated.  In the Maillard reaction, amino acids and reducing sugars combine to form indigestible compounds known as Amadori compounds. These amino acids are therefore not available to the pigs. Lysine is particularly susceptible to the Maillard reaction. It is important to know the extent of heat damage in feed ingredients so that diets may be formulated that supply the appropriate amounts of digestible amino acids to pigs.

Little information is available about the effects of heat processing on amino acid digestibility in sunflower meal and cottonseed meal. Furthermore, equations to predict the concentration of digestible amino acids in sunflower meal and cottonseed meal from the analyzed nutrient composition have not been reported. Two experiments were conducted to determine the standardized ileal digestibility (SID) of amino acids in sunflower meal and in cottonseed meal fed to growing pigs, and to test if regression equations could be developed to predict the concentration of SID lysine in sunflower meal and cottonseed meal.

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.