Effects of Pistacia atlantica gum essential oil on ruminal methanogen, protozoa, selected bacteria species and fermentation characteristics in

The objective of the current research was to investigate the effects of Pistacia atlantica subspecies Kurdica gum essential oil (PAKEO) on ruminal methanogen, protozoa, selected bacteria species, feed intake, and ruminal microbial fermentation in sheep. Six rumen-cannulated male Sanjabi sheep (average BW = 49 +/- 2.4 kg) were used in a crossover design with two periods and 2 treatments: control (CON, without additive) and PAKEO (1.2 ml/sheep/day of PAKEO). Voluntary feed intake and ruminal ammonia-N concentration were not affected, but ruminal pH decreased by PAKEO. Total VFA concentration (P = 0.06) and propionate molar proportion (P < 0.05) increased, but acetate molar proportion not affected in PAKEO treatment compared to the CON. Also, PAKEO supplementation decreased the acetate: propionate ratio (P = 0.05). Results showed that PAKEO supplementation increased (P < 0.01) the relative abundance of total bacteria and Ruminococcus flavefaciens, and decreased (P < 0.05) Fibrobacter succinogenes abundance, but not influenced Ruminococcus albus. The ruminal relative population of methanogens was dramatically decreased by PAKEO (P < 0.01). Protozoa population was not affected by the addition of PAKEO. Results suggest that PAKEO could have the potential as feed additives to change the rumen microbial population and subsequently improve the ruminal fermentation characteristics. The decrease in ruminal methanogens and enhanced production of the gluconeogenesis precursor, propionic acid, demonstrated that PAKEO could be used to improve ruminal fermentation.

Automated summary

The study investigated the effects of Pistacia atlantica subspecies Kurdica gum essential oil (PAKEO) on ruminal microbial population and fermentation in sheep. The results showed that PAKEO supplementation increased the abundance of total bacteria and Ruminococcus flavefaciens, decreased Fibrobacter succinogenes abundance, and dramatically decreased the population of methanogens. This suggests that PAKEO has the potential to improve ruminal fermentation.