Potential of graded doses of neem (Azadirachta indica) seed oil on ruminal fermentation characteristics, degradability, and methane formation in vitro

Waleed Al-Marzooqi, Sobhy M. Sallam, Othman Alqaisi, Hani M. El-Zaiat*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Neem (Azadirachta indica) belongs to Meliaceae family, represented mainly by trees, and widely cultivated and adapted in many tropical regions. The objective of this study was to evaluate the effect of increasing doses of neem seed oil (NSO) on ruminal methane (CH4) formation, diet degradability, and fermentation characteristics after 24 h of in vitro incubation. Treatments were randomly designed to four doses of NSO supplemented to the basal diet (0, 20, 40, or 60 ml/kg DM). Increasing NSO dose resulted in a quadratic decrease (P < 0.05) in net gas (expressed as ml/g DM and ml/g TDOM) and CH4 (expressed as ml/g TDNDF) production, while CH4 (expressed as ml/g TDOM), acetate and propionate proportions decreased linearly confirming a dose-related effect. A quadratic increase in TDOM and linear increase (P = 0.023) in DNDF, NH3-N concentrations, and total protozoal counts were observed. However, a linear increase (P = 0.009) was found in the ruminal butyrate proportion and partitioning factor as dietary NSO supplementation increased. In conclusion, dietary NSO supplementation mediated some desirable fermentation patterns, reducing ruminal NH3-N concentration and CH4 production with some adverse effects on fiber degradability. However, practical research under long-term conditions is required for further investigation.

Original languageEnglish
Pages (from-to)993-999
Number of pages7
JournalAnnals of Animal Science
Issue number3
Publication statusPublished - Jul 1 2022


  • feed degradability
  • methanogenesis
  • neem seed oil
  • rumen fermentation

ASJC Scopus subject areas

  • Food Animals
  • Small Animals
  • Animal Science and Zoology

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