Effects of pistachio by-product tannin extracts by different solvents on degradability of soybean meal protein in rumen

The objective of this study was to evaluate the effects of different doses of pistachio by-products (PBP) tannin extracts obtained by water, ethanol 70 % and methanol 80 % on the soybean meals protein protection from ruminal degradability. Soybean meal supplemented with 0.5 and 1 % tannins of different tannin extracts of PBP. Ruminal degradability and disappearance of dry matter and crude protein in untreated soybean meal (control) and soybean meal treated by tannin extracts (6 treatments) was determined in an in situ trial (three head of castrated Taleshi male calves) and post ruminal disappearance was measured in DaisyII incubator. Soybean meal supplementation with 1 % tannin from water extract, 0.5 and 1 % tannin from ethanol and methanol extracts decreased the ruminal protein disappearance (P<0.01) without any negative effect on total gastrointestinal disappearance of dry matter and crude protein. Also, the addition of all of tannin extracts to soybean meal reduced (P<0.01) the concentration of rapidly degradable proteins. In conclusion, the results showed that tannins of water, ethanol and methanol of PBP extracts could be effective on soybean meals protein's protection from ruminal degradability; however, the use of tannin from water extract of PBP can be more economical and practical.