Effect of dietary black cumin seed (Nigella sativa) on performance, immune status, and serum metabolites of small ruminants: A meta-analysis

Abstract A growing number of publications are identified toward the use of black cumin seeds (Nigella sativa L) on small ruminant animals since many beneficial evidences have been reported in humans and animals. This study used a meta-analysis approach to quantify the effect of black cumin seeds (BCS) supplementation on the productive performance, nutrients utilization, and blood metabolites profile of small ruminant animals. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocols, a total of 23 studies were aggregated in a database and were analyzed using mixed model methodology classifying the studies as random effects and levels of BCS as fixed effects in the models. Results found that interaction between BCS levels and animal species tended to be significant whereas increasing dietary BCS levels linearly increased average daily gain (ADG) (p