Effect of different varieties of pomegranate peels (Torsh Jangali Gorgan, malas Behshahr and Shirin kolbad) on dry matter digestibility, number of protozoa and methane production in vitro

Iran in addition to the emergence of pomegranate and its natural habitat, the number of varieties and is the largest producer of pomegranate in the world. Pomegranate peels comprising almost 26–30% of total fruit weight; in recent years the biological activity of pomegranate peel polyphenols has become a subject of interest among many researchers and consumers. Tannins effects on rumen methanogens and protozoa was proven, as well as the effect of that on gas production kinetic and rumen fermentation according to the type of vegetation is varies. Thus the objective of this study was to determine the chemical composition, polyphenolic components, in vitro apparently and truly degraded dry matter, methane production, the number of protozoa of three pomegranate peels (Torsh Jangali Gorgan, malas Behshahr and Shirin kolbad) varieties.
Varieties collected during harvested season (autumn) from different region of Golestan province and dried. The study was carried out in a completely randomized design with tree treatment and four replicates. After an initial gas test to evaluate 96 h gas production profiles of pomegranate peels, the time to half maximal gas production was calculated and a second incubation conducted with fermentation stopped at substrate specific half time (t ½) and 24 h for each substrate. True DM degradability was measured from incubated residues and combined with gas volume to estimate the partitioning factor (PF).
Highest CP in Shirin Kolbad and highest EE and ADF in Torsh Jangali Gorgan varieties were observed. Total Phenol composition in Torsh Jangali Gorgan variety with 8.91% and total tannin in malas Behshahr variety with 8.06% were high than Other varieties. Shirin kolbad pomegranate peel had greater in vitro apparently and truly degraded dry matter, microbial protein, and short chain fatty acids (respectively 0.347, 0.590 (mg), 500.79 (g/kg DM), and 0.9 (mmol) in 24 h incubation (P The results of this study showed that pomegranate peel is an important agro-based by-product that is produced in Iran and because of having phenolic components and tannins has antimicrobial activity against microorganisms that produced methane as well as protozoa, that, three varieties of this pomegranate peel can be used for modulating rumen fermentation and methane reduction.