Effects of electron beam, NaOH and urea on chemical composition, phenolic compounds, in situ ruminal degradability and in vitro gas production kinetics of pistachio by-products

摘要

The current study evaluated the effects of electron beam (EB; 10, 20, 30 and 40 kGy), urea and NaOH treatments on chemical composition, phenolic compounds, in vitro gas production and i n?situ ruminal degradability of pistachio by-product (PB). The EB decreased ( p < 0.01) neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) contents of PB. Treating PB by NaOH and urea increased cell wall constitute of PB ( p < 0.01). Irradiation at doses of 30 and 40 kGy reduced tannin and increased total phenol content of PB ( p < 0.01). NaOH and urea treatments decreased tannins, total phenolics and condensed tannins of PB compared to control ( p < 0.01). In situ ruminal dry matter (DM) degradation data showed that irradiation increased ( p < 0.01) and, urea and NaOH decreased ( p < 0.01) rapidly fermentable fraction ( a ) of PB. NaOH decreased ( p < 0.01) fraction b and total degradable fraction ( a + b ) of PB. Irradiation and polyethylene-glycol increased rate of gas production ( k ), metabolizable energy (ME) and short chain fatty acid concentrations (SCFA), while, NaOH decreased gas production potential ( b ), ME and SCFA ( p < 0.01). Data showed that although NaOH was efficient in detannification of PB, however, it reduced gas production and in situ degradation of PB. Key Words: Pistachio by-product, Beam electron, Tannin, Gas production.