The Effect of Soybean Meal Treated With Formaldehyde on Amount of Protected Protein in the Rumen and Absorption of Amino Acid From Small Intestines

Abstract

This study was conducted to determine the effects of soybean meal (SBM) treated with formaldehyde on rumen fermentation pattern, microbial protein synthesis, amount of by-pass protein, and amino acid absorption from small intestines. Four 1-year-old rams with ruminal, duodenal, and ileal cannulas were fed 800 g of dry clover plus a concentrate mixture containing 100 g of SBM treated with 0%, 0.3%. 0.6%, and 0.9% formaldehyde. The amount of crude protein passed through the duodenum was not affected by the formaldehyde treatment; however, the amount of microbial protein decreased in rams fed with SBM treated with both 0.3% and 0.6% formaldehyde (P < 0.05). Digestibility of acid detergent fibre (ADF) and neutral detergent fibre (NDF) in the duodenum and ileum did not differ by treatments. In the rams fed SBM treated with both 0.3% and 0.6% formaldehyde, absorbability of arginine, histicline, leucine, methionine, phenylalanine, and valine (essential amino acids), as well as alanine and aspartic acid (non-essential amino acids) significantly increased, whereas tyrosine absorbability notably decreased (P < 0.05). Formaldehyde treatment increased the absorbability of other essential amino acids (leucine and valine) and non-essential amino acids (serine and tyrosine) in the ileum (P < 0.05). Increasing the percentage of formaldehyde linearly increased total essential amino acid absorption in the duodenum (P < 0.05). In conclusion, 0.3% and 0.6% formaldehyde treatment enhanced the bioavailability of protein in SBM.